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the Mid-Atlantic Ridge (Original)

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Carolyn Silver
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« Reply #90 on: July 30, 2008, 10:13:45 pm »

BigFatFurryTexan

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Rate Member   posted 02-16-2006 10:47 AM                       
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Carolyn, very interesting research.

Here is a story i recently read about, but haven't had time to research. If anyone has anything that they can add, please do:

When Columbis was going to sail to the west to try to reach india, he only stocked a few weeks worth of provisions. His intention was to stay over on a large island that was located just beyond the Straits of Gibralter. Many maps of his day referenced this island, and referred to it as something along the lines of Antillia. He was fairly dismayed that he didn't find the island where he was supposed to, and wrote of it in his journal. He referenced it and mentioned that he was concerned about the Mission that was built there by the Catholic church (where there are "Godless" people, there are Catholics there to torture them into believing the same as them).

He contined on and landed in the Antilles (which he erroneously assumed was Antillia) as his first arrival in the New World.

This was only 500 years ago, and would hardly fall in the category of pre-history.

Along a simlar line, there are literally dozens reports of sea captains finding strange islands in areas there are well known and charted. Apparently a volcanic pillar lends support to the air filled volcanic rock on top. Eventually, enough pressure and weight builds and causes the whole column to collapse, causing the new island to sink. This has been reported as recently as the 70's.

Like I said, i don't know if any of it is true, and would like to know if anyone else can add anything. What i would say about Carolyns posts is that anyone who would discount the assertions made therein based on current scientific "knowledge" is basing their assertions on the scientific equivalent of voodoo. We are still banging on stones and looking for the answers in the pigs entrails.

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Carolyn Silver
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« Reply #91 on: July 30, 2008, 10:15:05 pm »

Herr_Saltzman

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  posted 02-16-2006 11:47 AM                   
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quote:
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An Evaluation of the Geological Evidence Presented By ''Gateway to Atlantis'' for Terminal Pleistocene Catastrophe
by Paul Heinrich
The book "Gateway to Atlantis", Collins (2000a), proposed that Atlantis originally lay in Hispanola, specifically Cuba with "other islands" associated with it being the "...island chains of Bahamas and Caribbean...". A significant part of his arguments involved Atlantis having been destroyed by a cataclysmic comet impact "...sometime around 8600-8500 BC...". Collins (2000a) argued in Chapters 21 and 22 that this cataclysmic comet impact ravaged Eastern Coast of the United States and possibly created two large craters on the ocean floor of the western North Atlantic. He claimed that this impact resulted in the destruction of Atlantis.

Being interested in both Holocene and Quaternary impact structures, i.e. Heinrich (2003a, 2003b), I decided that it would be interesting to evaluate this hypothesis. Because the task involved in completely researching and evaluating the "evidence" provided in Chapters 21 and 22 was quite large, and given the wildly subjective nature of interpreting oral history (from which innumerable, contradictory interpretations can be made) I focused only on the "hard" geologic evidence. The hard evidence that Collins (2000a) offered for his hypothesis for a terminal Pleistocene cosmic catastrophe consisted mainly of the "Carolina Bays", two alleged North Atlantic "deep Sea impacts"; a handful of pollen sites, the "muck" deposits in Alaska, and a Mississippi River glacial meltwater pulse reported by Emiliani et al. (1975).

Carolina Bays

Interpretations of the age and origin of the Carolina Bays played a very important role in the arguments of Collins (2000a) for a terminal Pleistocene comet impact along the East Coast of the United States. The importance of the Carolina Bays in the arguments of Collins (2000a) can be seen in the review of a lecture that Andrew Collins presented in the "Mysteries of the Past" lecture series in the 2000 "Questing Conference". A web page that was part of his web site in May 2004, Collins (2000b), stated:

"Yet the destruction of Atlantis, and its `other islands', identified as the island chains of the Bahamas and Caribbean, would appear to have begun some 500 years earlier. Sometime around 8600-8500 BC there came out of the north-eastern sky a brilliant object - a comet perhaps 100,000 times greater than the one which detonated above the tundra forests of Tunguska, Siberia, in June 1908. It passed low overhead the United States before disintegrating into millions of tiny fragments like some unimaginable millennial firework. The air shock-waves caused by the detonation and impact of these tiny pieces of the comet nucleus peppered the coastal plain, causing an estimated 500,000 elliptical craters, ranging in size from just a few hundred metres to 11 kilometres in length. Known as the Carolina Bays they extend from New Jersey down to Florida and can be found in six separate states - the greatest concentration being in the Carolinas. Each blast was like a mini nuclear explosion which caused spruce forests to be laid flat in great fan-like patterns. Two larger fragments of the comet struck the Atlantic Ocean north of Puerto Rico and east of Florida. The immense tsunami waves created by this event would have drowned the Bahamas and Caribbean, all but destroying its primitive culture and wiping out megafauna such as the giant sloth. Those who did survive reached the American mainland carrying with them a memory of this great cataclysm."

First, I found that both Muck (1977) and Collins (2000a) present a completely inaccurate depiction of the distribution of Carolina Bays as shown in Figure 1. Compilation of the distribution of Carolina Bays, as mapped by primary sources, demonstrated that the oval distribution of Carolina Bays shown by Muck (1977) and Collins (2000a) are completely wrong. Instead of these oval distributions, the Carolina Bays lie within coast-wise belts within the Atlantic and Gulf of Mexico coastal plains. They are found from southern New Jersey, a large part of Delaware, and easternmost Maryland southwest along the Atlantic coast into southern Georgia and north central Florida (Kaczorowski 1977, May and Warne 1999). Additional Carolina Bays, locally called "Grady Ponds", are found in southeast corners of Alabama and Mississippi within the Gulf of Mexico coastal plain (Otvos 1967, May and Warne 1999) (Figure 1). Neither Muck (1977) nor Collins (2000a) provide any documented evidence to support the inland occurrence of Carolina Bays as mapped in their figures.

In his figure, Collins (2000a) conflated the distribution of Carolina Bays along the coast together with a hypothesized concentration of meteorites inland of the coast, which was first interpreted by Nininger (1939) as coming from the disintegration of the meteorite that created the Carolina Bays. As shown in Figure 1 of Prouty (1952), the area inland of the Atlantic coastal plain illustrated by Collins (2000a) as containing Carolina Bays actually consists of Nininger's (1939) hypothetical area of "abundant meteorites", which lacks any Carolina Bays. Furthermore, more recent and detailed compilation of meteorite locations (Figure 2) demonstrated this hypothesized region of concentrated meteorites does not exist. Recent mapping of the distribution of meteorites showed that the distribution of meteorites within the Southeastern United States is random, without any apparent concentrations, contrary to what Nininger (1939) hypothesized. In addition, the meteorites found within the area of the hypothesized concentration of meteorites consist of a diverse mixture of stoney, stoney-iron, and iron meteorites that all differ in composition from each other to a degree that it is impossible for them to have come from the same parent body. Overall, there is a lack of any evidence for an inland concentration of meteorites associated with the Carolina Bays. As a result, the inland part of the oval mapped by Collins (2000a) for the distribution of Carolina Bays is a completely imaginary feature. Similarly, the distribution of Carolina Bays by Muck (1977), as shown in Figure 1, is completely wrong.

Similarly, neither Muck (1977) nor Collins (2000a) presented any hard evidence of Carolina Bays being found in the offshore areas that their figures indicate as containing Carolina Bays. There is simply no evidence that Carolina Bays occur as shown in their figures within the submerged surface of the continental shelves along the Atlantic Coast. The southeast edges of the distribution ellipses, which lie seaward of the continental shelf, are certainly imaginary. Thus, the offshore and inland distribution of Carolina Bays is based upon imagination, rather than any real evidence. Because of its imaginary nature, the oval distribution of Carolina Bays offers absolutely no evidence of an impact origin. Furthermore, the distribution of Carolina Bays along the Gulf of Mexico and northwestward into New Jersey, which Collins (2000a) conveniently ignored, remains unexplained by the impact hypothesis.

Another major problem for Collins (2000a) in using the Carolina Bays as evidence for a comet impact about 10,500-10,600 BP (8,500-8.600 BC), is the age of these features as indicated by radiocarbon dating, Optically Stimulated Luminescence (OSL) dating, and palynology. When the data from these techniques is considered as a whole, it is quite clear that the assignment of a terminal Pleistocene age to the Carolina Bays by Collins (2000a) and other catastrophists is soundly refuted. Although he discussed this data, Collins (2000a) grossly misinterpreted them and completely ignored how they contradict his ideas.

In case of radiocarbon dates, Collins (2000a), using radiocarbon dates found in Savage (1982), acknowledged that radiocarbon dates ranging between "…c. 70,000 years and 6,000 years BP…" and "…between 18,460 and 8,355 BP." had been obtained from samples taken from the sediments filling Carolina Bays. In citing these dates, neither author seemed to have grasped a fundamental principle of geology that in order for the sediments filling a specific Carolina Bay to have accumulated within it, the Carolina Bay must have existed prior to the deposition of that sediment. If a Carolina Bay contains a layer of sediment that accumulated within it around 18,500 radiocarbon years BP that is clear and irrefutable evidence that this Carolina Bay is at least 18,500 (radiocarbon) years old.

Figure 3 illustrates a collection of radiocarbon dates yielded by samples collected from the sediments filling various Carolina Bays. Figure 3 clearly shows that there exists numerous radiocarbon dates, largely ignored by Collins (2000a), that predate the proposed timing of his terminal Pleistocene catastrophe by tens of thousands of years. These dates clearly show that the Carolina Bays are older than the terminal Pleistocene catastrophe proposed by Collins (2000a) by tens of thousands of years. Regardless of the existence of younger radiocarbon dates, the numerous radiocarbon dates older than 10,500-10,600 BP (8,500-8.600 BC) shown in Figure 3 are clear evidence that these landforms are older than proposed by Collins (2000a).

In interpreting the dates in Figure 3., a person needs to understand that the radiocarbon dates reported from Carolina Bays are minimum dates. They just represent periods of time during which conditions within and individual Carolina Bay was favorable for the preservation of organic matter. There were times when sediments accumulated within the Carolina Bays, but the organic matter was not preserved. There were times that the glacial sea level dropped to the point that many Carolina Bays dried out because of lowered ground water tables within coastal regions. During these times, older sediments within them was deflated by eolian processes and older organic matter destroyed by oxidization and weathering of the lake sediments. As a result, it is highly unlikely that organic matter dating to the exact origin of any Carolina Bay would have been preserved. Thus, the dates seen in Figure 3 are minimum dates and that the actual age of the Carolina Bays is, in fact, older than any of these dates indicate.

The Carolina Bays are so old that some samples of organic material from the sediments filling Carolina Bays have found to be older than the useful limits of radiocarbon dating. This is demonstrated by the several greater than dates illustrated in Figure 3. These radiocarbon dates, especially since they are minimum dates, clearly show that the Carolina Bays are tens of thousands of years older than 10,500-10,600 BP (8,500-8.600 BC) as argued by Collins (2000a).

In Chapter 22, "End of the Ice Age", Collins (2000a) made vague complains about the use of radiocarbon dates calibrated to calendar years. His complaint includes the obligatory, for many alternative archaeologists, and unsubstantiated comment that some sort of dark "academic bias" is somehow at work in how radiocarbon dates are calibrated / interpreted in their transformation into calendar years.

Because these and many finite radiocarbon dates demonstrate that the age of sediments filling the Carolina Bays are more than 2,000 years older then the age proposed by Collins (2000a), it is impossible for problems with the calibration of radiocarbon dates to explain why these dates completely contradict his ideas. The difference between calendar dates and radiocarbon dates is simply not enough to make many of the radiocarbon dates shown in Figure 3, either younger or contemporaneous with the 10,500-10,600 BP (8,500-8.600 BC) date for the formation of the Carolina Bays. Thus, the disputing of older radiocarbon dates on the basis of problems with radiocarbon calibration only demonstrates a fundamental ignorance of radiocarbon dating on the part of the people, who make such arguments.

Finally, Collins (2000a) failed to understand that the average, "10,500" years ago, of five radiocarbon dates given by Kaczorowski (1977) provided by Savage (1982) is a scientifically meaningless number. Individual dates from layers of sediment within a Carolina Bay specifically indicate the age of each of these layers and the oldest of these dates obviously provides only a minimum age of the Carolina Bay containing them. Averaging them together produces a date that is scientifically meaningless. Averaging these radiocarbon dates is like averaging the date when five randomly chosen states entered the United States of America (USA), and claiming that this average date is the date at which the USA was created. That Savage (1982) thought his average of radiocarbon had some sort of importance and Collins (2000a) accepted this average as having any scientific validity showed a fundamental ignorance of the part of all of them concerning how radiocarbon dates are interpreted. If anything, it appears to be a pseudo-scientific attempt by Savage (1982) to deliberately distort, in a favorable way, data that contradicted his interpretation of the origin of the Carolina Bays.
 
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Carolyn Silver
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« Reply #92 on: July 30, 2008, 10:15:23 pm »

In terms of Optically Stimulated Luminescence (OSL) dating of the Carolina Bays, Ivester et al. (2002) wrote about a Carolina Bay called "Flamingo Bay":

" In the upper Coastal Plain, dates from Flamingo Bay indicate the rim was active at 108.7 ± 10.9 ka BP and again at 40.3 ± 4.0 ka BP. The nearby Bay-40 had an actively forming sand rim at 77.9 ± 7.6 ka BP. Near the confluence of the Wateree and Congaree Rivers in the middle Coastal Plain, an eolian sand sheet was dated to 74.3 ± 7.1 ka BP."

About Carolina Bays in general, Ivester et al. (2004a) wrote:

"Luminescence and radiocarbon dating of inland dunes and Carolina bay rims indicate activity during multiple phases over the past 100,000 years. Some bays have evolved through phases of activity and inactivity over tens of thousands of years, as evidenced both by multiple rims along a single bay and by multiple ages within single rims."

and

" Both dunes and bays were active during the Wisconsin glaciation, with ages tending to fall between 15,000 and 40,000 years BP, and near the isotope stage 5/stage 4 boundary 70,000 to 80,000 years BP."

These OSL dates and others shown in Figure 3, which lack any problems with calibration, as in case of radiocarbon dating, substantiate the radiocarbon dating. In fact, they show that as indicated by some greater than radiocarbon dates, Carolina Bays are even much older than 50,000 years. In fact, it appears that the Carolina Bays are as much as ten times the age proposed by Collins (2000a). As in case of the radiocarbon dates, multiple periods of reworking and modification of the sand rims have reset the luminescence "clocks". As a result, many of the OSL dates represent not the actual age of the Carolina Bays, but rather document multiple periods of eolian and lacustrine modification of the rim of these bays over the last 70,000 to over 100,000 years (Ivester et al. 2004a, 1004b). Regardless, the OSL dating of the sandy rims of Carolina Bays further refute the contention by Collins (2000a) that these landforms are only 10,500-10,600 years old. Because OSL dates do not need to be calibrated in order to convert OSL years to calendar years, it is impossible to use the calibration issue, which Collins (2000a) used to discard out-of-hand radiocarbon dates inconveniently contradicting his ideas, to discredit the above OSL dates.

The sequence of pollen spectra recovered from cores taken from various Carolina Bays have long refuted the terminal Pleistocene age proposed by Collins (2000a) and other catastrophists for these landforms. For example, years before Collins (2000a) was published, Frey (1953, 1955) and Whitehead (1964, 1981) documented the presence of full glacial pollen zones within the sediments filling Carolina Bays. These thick sediments containing pollen characteristic of full glacial conditions filling a Carolina Bay could only have accumulated within in them if they had existed prior to the catastrophe, which Collins (2000a) claimed ended the Pleistocene. Had the Carolina Bays been formed by a catastrophic event, which abruptly ended the Pleistocene and devastated local floras, they would have been created too late for sediments containing pollen characteristic of full glacial environments to have accumulated in them. The radiocarbon dates reported by Frey (1953, 1955) and Whitehead (1964, 1981) for the Carolina Bays, which they studied demonstrated that the sediments containing full glacial pollen. Thus the Carolina Bays filled by these sediments predates the date proposed by Collins (2000a).

After Collins (2000a) was published, Brook et al. (2001) published a detailed analysis of pollen recovered from cores from Big Bay within central South Carolina that on the basis of radiocarbon dates and palynology soundly refuted a terminal Pleistocene age for the Carolina Bays. In cores from Big Bay, Brook et al. (2001) found well-defined zones consisting of distinct pollen assemblages indicative of the accumulation of sediments from Holocene interglacial epoch, through the Wisconsinan glacial epoch, back into Oxygen Isotope Stage 5, 75,000 to 134,000 years BP. Thus, Big Bay existed as far back as 75,000 years BP. This period of time was tens of thousands of years prior to the date of Carolina Bay formation argued by Collins (2000a) and Collins (2000b). Their pollen interpretations are supported by radiocarbon dates of organic material, which are illustrated in Figure 3, derived from dating organic material from the cores that Brook et al. (2001) studied.

From the above discussion it is clear that there exists an abundance of evidence, which clearly demonstrates that Carolina Bays are far to old by tens of thousands of years to had been created about 8500 - 8600 BC (10,500 - 10,600 BP) as proposed by Collins (2000a). It is revealing that a significant amount of this data was published well before Collins (2000a). He was either unaware of this data or choose to dismiss them out of hand because it contradicted his theories about the formation of the Carolina Bays.

In addition, Brooks et al. (1996, 2001), Grant et al. (1998), and Ivester et al. (2002, 2003, 2004b) have clearly demonstrated that the shape and size of the Carolina Bays have been repeatedly modified at various periods in time by lacustrine and eolian processes during the last 100,000 to 120,000 years. In the case of Big Bay, a Carolina Bay in South Carolina, Ivester et al. (2003) found, using OSL dating, that the dozen or more concentric sand rims within Big Bay were not created simultaneously as argued by Collins (2000a) and other catastrophists. Instead Ivester et al. (2003) found that these sand rims became progressively younger towards the center of the bay. The four OSL dates reported from selected rims by Ivester et al. (2003), i.e. 35,660±2600; 25,210±1900; 11,160±900; and 2,150±300 years BP, demonstrate that Big Bay has shrunk over the last 36,000 years by 1.6 miles (1 km). These rims were not found to be composed impact ejecta, but rather "are composed of both shoreface and eolian deposits" (Ivester et al. 2004a). As a result of the OSL dating of the rims of numerous Carolina Bays, Ivester et al (2004b) concluded:

"The optical dating results indicate that present-day bay morphology is not the result of a single event, catastrophic formation, but rather they have evolved through multiple phases of activity and inactivity over tens of thousands of years. This is evidenced both by multiple rims of differing ages along the same bay, and by multiple ages within single rims."

Thus it is quite clear that the current elliptical shape of the Carolina Bays reflects not their original shape, but rather the result of tens of thousands of years of modification by lacustrine and eolian processes. As a result it is impossible, and quite unscientific, to use either their current elliptical shape or orientation to infer the original process, which created the Carolina Bays as practiced by and Collins (2000a) and others. As noted above this long history of repeated modification also proves that they are far too old to have been formed when Collins (2000a) and other catastrophists argued they formed.

Another major problem with the arguments made by Collins (2000b) and Collins (2000a) for an impact origin of the Carolina Bays is that research, i.e. May and Warne (1999), provided a "suitable terrestrial mechanism" by which these depressions were produced. The paper by May and Warne (1999) contradicted the claim by Collins (2000a) that "geologists now feel that the Carolina Bays might also be the result of aerial detonations produced by a "disintegrating comet nucleus".

Finally, Collins (2000a) speculated that the Carolina Bays might have created by "shock waves" resulting from the "aerial detonation" of a "disintegrating comet nucleus". However, Collins (2000a) failed to explain, in terms of a detailed a physical model, how a "disintegrating comet nucleus" can producing "shock waves" capable of forming craters the size of the Carolina Bays. Lacking a detailed physical model, a main argument for such an origin was a comparison, which he falsely claimed to be "favorable", between "funneled-shaped depression" a few meters deep found at the Tunguska impact site to non-funnel-shaped and shallow Carolina Bays that are 100s of meters to kilometers wide. It is quite possible that the funnel-shaped depressions at the Tunguska impact site consisted of thermokarst developed in local permafrost as the result of the local stripping of vegetation by the blast and resulting warming of the ground within the area of the blast.
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Carolyn Silver
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« Reply #93 on: July 30, 2008, 10:15:51 pm »

Deep Sea Craters

In support of the impact origin of the Carolina Bays, Collins (2000a) repeatedly referred to two very large, alleged impact craters, which Muck (1977) illustrated as existing in the Atlantic Ocean. The locations and size of these craters are illustrated by Muck (1977) only with a crude sketch and by Collins (2000a) with a figured with an inconsistent scale. As a result, the location and size of these alleged craters shown in Figure 1 are approximate and limited by the lack of accuracy in both of the source illustrations. Despite this problem, it is quite clear that the craters proposed by Muck (1977) are both of enormous size, at least of 320 to 480 km (200 to 300 miles) in maximum length. Individually, these craters far exceed the size, as shown in Figure 1, the Chixulub Impact Crater, which is associated with the Cretaceous-Tertiary boundary and the global extinction of dinosaurs and other organisms.

Concerning these two alleged impact craters, Collins (2000a) stated:

"..to my knowledge no geologist or astronomer has ever embraced Otto Muck's claim regarding the origins of the two deep elliptical holes in the West Atlantic Basin. This surprises me, for their shape and north-west orientation hint clearly at an association with the Carolina Bay event."

Looking at maps and publications available to geologists or astronomers prior to the publication of Collins (2000a), there should not exist any surprise that neither conventional geologist nor astronomer had embraced Muck's "two deep elliptical holes in the West Atlantic Basin" as impact craters. First, the formation of craters with lengths as much as 200 to 300 km (120 to 180 miles) would certainly have created well-defined magnetic and gravity anomalies as discussed by Pilkington and Grieve (1992). As illustrated by the free air gravity maps of the North Atlantic by Rabinowitz and Young (1990), which was published over ten years before Collins (2000a), and later maps, such anomalies are completely absent from the areas mapped as craters by Muck (1977) and Collins (2000a). In fact, later maps show that the original magnetic striping created by sea-floor spreading is undisturbed in these areas.

Second, Tucholke (1986) published a map of depth to basement for the western North Atlantic Ocean 14 years before Collins (2000a). This map clearly showed the presence of well-defined fracture patterns of oceanic crust unmodified by impact processes within the location of the alleged impact craters of by Muck (1977) and Collins (2000a). Sea floor mapping by Muller and Roest (1992) furthered confirmed the lack of any disturbance of primary sea-floor fracture patterns in the areas mapped as impact craters by Muck (1977) and Collins (2000a). These fractures include a fracture large enough to have been mapped and formally named the "Nares Fracture Valley" by Tucholke (1986) that crosses one of the craters mapped by Collins (2000a) and Muck (1977). The undisturbed nature of local and regional sea floor fracture patterns completely disproves the existence of the two large craters proposed by Muck (1977) and Collins (2000a).

Finally, the "Bathymetry of the North Atlantic Ocean", Tucholke et al. (1986), which was available more than 14 years before Collins (2000a), showed that the two deep elliptical holes, which Muck (1977) speculated as being impact craters are cartographic artifacts. One of the two deep elliptical holes illustrated by Muck (1977) and Collins (2000a) is actually an irregular-shaped area in the North Atlantic called the "Nares Deep". This area lacks any distinct crater morphology. This deep elliptical hole of Muck (1977) is nothing more than a cartographic artifact created by the way in which mapmakers contoured the limited data available in 1977. Tucholke et al. (1986) also demonstrated that the second deep elliptical hole illustrated by Muck (1977) and Collins (2000a) is completely imaginary. It is nothing more than another cartographic artifact, which Muck (1977) identified as a crater, solely on its outline.

The creation of even one crater with a maximum diameter of 320 to 480 km (200 to 300 miles) would have blanketed the surrounding Atlantic Ocean over 800 km (490 miles) away from the rim with a thick layer of impact eject. However, none of numerous cores that have been taken from the western Atlantic Ocean have shown any evidence of this ejecta layer. Given the complete lack of any credible evidence, even including the two alleged "deep elliptical holes in the West Atlantic Basin" mapped by Muck (1977), it is not surprising that conventional geologists and astronomers ignored these alleged impact craters as proposed by Muck (1977). At this point, the available data can only be interpreted as indicating that both of these alleged impact craters existed only in the imagination of Muck (1977).

Near the end of Chapter 21, Collins (2000a) commented that the formation of these impact craters "would have made quite a mess of any low-lying island landmasses located the North Atlantic Ocean". What Collins (2000a) overlooked is that the creation of even one crater with a maximum diameter of 320 to 480 km (200 to 300 miles) on land would have resulted in global extinction level event on the scale experienced at the Cretaceous-Tertiary, even Permian-Triassic boundaries. On land, a hypothetical impactor with a similar composition to a stoney meteorite, would have been a 25 to 30 km (15 to 24 miles) size asteroid. This asteroid would have been larger in size than the 17.5 km (10.6 mile) in diameter asteroid that created the Chixulub Impact Crater. The formation of a similar size crater in the deep sea would have required a larger asteroid or comet.

The impact of even a single 25 km diameter asteroid or equivalent size comet would not have simply "made quite a mess" of low-lying islands such as Cuba and Hispanola. Such an impact, and more so in case of two of them, would have obliterated anything and anyone on these islands and adjacent parts of North and South America. As determined from Marcus et al. (2004) and Collins et al. (2004), the formation of the closest crater would have created thermal radiation capable of igniting clothing; newspaper, wooden buildings, and grass and causing third degree burns over the body of people standing in the open in Cuba and Hispanola. In addition, the same impact would have subjected within both Cuba and Hispanola to an earthquake of 10.7 magnitude on the Richter Scale; an air blast with a velocity of 335 to 552 meters per second (750 to 1235 miles per hour); and a blanket of ejecta ranging in thickness from 4 to 15 meters (13 to 50 ft) thick. Just about every building, bridge, or structure would have been leveled long before 200 m high (660 ft) tsunamis obliterated everything on the surface of these islands and along a significant portion of the shorelines of the northern Atlantic Ocean. Despite massive destruction that the impacts proposed by Muck (1977) would have caused, evidence of such massive destruction having occurred within Cuba, Hispanola, and along the shores of the Atlantic Ocean and Gulf of Mexico during Late Pleistocene is completely absent. It is simply impossible for the cataclysmic asteroid or comet impacts needed to have created the impact craters illustrated by Muck (1977) have occurred and not left a shred of recognizable evidence of an extinction level event greater than the one that wiped out the dinosaurs.

In fairness, Collins (2000c) did recognize that the impacts proposed by Muck (1977) would have resulted in catastrophic tsunamis when he stated:

The latest theories regarding their formation feature the fragmentation of a comet into literally millions of pieces which impacted a wide area, including a large part of the Atlantic Ocean off the United States, sometime between 8500 and 9000 BC. Such an event would have caused super-tsunami waves that would have engulfed the low-lying regions of the Bahamas and Caribbean killing everything in their path."

However, neither Collins (2000a) nor Collins (2000c) provided a single shred of hard physical evidence of this "super-tsunamis", which would have been far worse then the tsunamis generated by the Chixulub Impact, having "engulfed" the low-lying regions of the eastern seaboard of North America, the Bahamas, and Caribbean. It is physically impossible for the "super-tsunamis" to have occurred as proposed and not have left behind a single shred of recognizable evidence. Collins (2000a) is both deluding himself and fooling his readers when he claimed these tsunamis would have "receded to leave the landscape hardly altered". For example, in cores of coastal lakes from which pollen records extending into the Pleistocene have been recovered, should be evidence of either of the deposits or environmental devastation which such "super-tsunamis" would have left behind as happened with the early Holocene Storrega tsunamis. In addition, such "super-tsunamis" would have reshaped the sandy coastal plains to the point of largely obliterating older, pre-existing landforms such as the Carolina Bays, beach ridges, and fluvial terraces. In the above quote, Collins (2000c) proposed "super-tsunamis" that were powerful enough to devastate and destroy an entire civilization, but by some unexplained magic failed to leave behind any physical evidence of having occurred.

Finally, while discussing these alleged craters, Collins (2000a) speculated that Barringer (Meteor) Crater in Coconino county, Arizona as either related to his hypothetical impact event that created the Carolina Bays or having been formed about 20,000 years ago. Sutton (1984, 1985), published 15 to 16 years before Collins (2000a), had already soundly refuted the inference by Collins (2000a) that Native Americans could have witnessed the meteorite impact that created Barringer (Meteor) Crater. Sutton (1984, 1985) dated Barringer Crater using Thermoluminescence (TL) dating techniques on impact breccia superheated at the moment of impact as having been formed between 47,000 to 52,800 years ago. Thus Barringer Crater was neither witnessed by Native Americans nor was associated with any terminal Pleistocene impact event. Given that TL dating does not suffer the problems of radiocarbon dating and does not need to be calibrated, the calibration of such dates is a nonexistent issue.
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« Reply #94 on: July 30, 2008, 10:16:17 pm »

Hibben's Glacial Muck of Alaska

At the end of Chapter 21, "Cosmic Pinball", Collins (2000a) quotes from "Lost American", Hibben (1946), about the "glacial muck" of Alaska to support and dramatize his interpretation of the catastrophic origin of the Carolina Bays. The quote, like much of Hibben (1946), talked dramatically of torn and twisted remains of bison, mammoths, other animals, and trees being piled together in the "glacial muck" of Alaska and of: "The evidences of violence there are as obvious as in the horror camps of Germany."

The so-called glacial "muck" of Alaska is a favorite, to the point of being cliché, piece of evidence for terminal Pleistocene catastrophism, including Deloria (1997), Hapgood (1970), Velikovsky (1955), and Allan and Delair (1995). In addition to Hibben (1946), many catastrophists often cite Rainey (1940) and Hibben (1942), which contain similar descriptions of "glacial muck" within Alaska as evidence of their catastrophic scenarios. For example Allan and Delair (1995) stated:

"In Alaska, for example, thick frozen deposits of volcanic ash, silts, sands, boulders, lenticles and ribbons of unmelted ice, and countless relics of late Pleistocene animals and plants lie jumbled together in no discernible order. This amazing deposit, usually referred to as 'muck', has been described by Dr Rainey as containing: '... enormous numbers of frozen bones of extinct animals, such as mammoth, mastodon, super bison and horse, as well as brush, stumps, moss and freshwater molluscs (281)'."

In the half century between when Hibben (1946) was published and the publication of Collins (2000a) dozens of papers and monographs have been published about the Quaternary deposits, which Hibben (1942, 1946) and Rainey (1940) designated as "muck". When examining this research, i.e. Pewe (1955, 1975a, 1975b, 1989); Westgate et al. (1990); and Guthrie (1990), a person finds that the so-called "glacial muck" as described by Hibben (1942, 1946) and Rainey (1940) exists only in their and various catastrophists' imaginations. These Quaternary deposits simply do not consist of "thick frozen deposits of volcanic ash, silts, sands, boulders, lenticles and ribbons of unmelted ice, and countless relics of late Pleistocene animals and plants lie jumbled together in no discernible order" as described by Collins (2000c) and Velikovsky (1955) and other catastrophists.

Instead, as described in numerous publications, i.e. Pewe (1955, 1975a, 1975b, 1989), Westgate et al. (1990), and Guthrie (1990), which published and distributed to libraries long before Collins (2000a), a person finds an ordered, layer-cake sequence of strata. Figures 20 and 29 of Pewe (1975), Figure 4 of Pewe et al. (1997), and the measured section of Westgate et al. (1990) show that the so-called "glacial muck" of the Alaska area consists of seven well-defined geologic layers. These layers in total are only 10 to 20 m (33 to 66 ft) thick at the thickest. Layers such as the Ready Bullion Formation, Engineer Loess, Goldstream Formation, Gold Hill Loess, and the Fairbanks Loess, consist either of silt that is either wind-blown silt called "loess" or colluvium moved down-hill by slopewash or solifluction. Other layers, i.e. the Dawson Cut and Eva Formations, contain buried, in situ forests that are rooted in "fossil" soils. The basal strata consist of stream gravels, i.e. the Tanana Formation, Fox Gravel, and Cripple Gravel. The contacts between these geologic layers are persistent, observable contacts that are often associated with forest beds, ice-wedge casts, and buried soils that demonstrate that periods of thousands to tens of thousands years occurred between the accumulation of individual layers. The loesses also contain numerous buried soils, paleosols, which formed during long periods of time during which no accumulation of loess occurred. Thus, the strata comprising the "glacial muck" of Collins (2000a) formed not during a single catastrophic event, but accumulated episodically over a period of two to three million years. The youngest of the loess layers actually postdates his proposed terminal Pleistocene catastrophe being only 7,000 to 8,000 years old (Pewe 1955, 1975a, 1975b, 1989, Pewe et al. 1997, Westgate et al. 1990, Muhs et al. 2003).

In addition, Rainey (1940) and Hibbens (1942, 1946) were wrong in their descriptions of plant and animal fossils occurring randomly together throughout the strata they called "glacial muck". For example, the presence of subfossil trees within these deposits is typically limited to one of three in situ buried forests. As shown in Pewe (1975a:figure 29), these buried forests occur at the top of the Fox Gravel, the Gold Hill Loess, and the Goldstream Loess. Each of these forest beds consist of the in situ stumps of mature trees rooted in buried soils developed in the top of each of these units (Pewe 1975a, 1975b, 1989). The youngest forest bed dates to the last interglacial, about 125,000 years ago as documented by Pewe et al. (1997). It and the strata beneath it are far too old to be related to any terminal Pleistocene catastrophe. The oldest forest bed, the Dawson Cut Forest Bed, has been found to be almost 2 million years old by Westgate et al. (2003). Therefore both forest beds are far too old to be related to the terminal Pleistocene catastrophe proposed by Collins (2000a). These trees consist of the in situ trunk and fallen trunks of forests buried in place by colluvial deposits or solifluction lobes. Finally, a careful reading of Pewe (1975a) and Guthrie (1990) would demonstrate that the claims by Rainey (1940) and Hibben (1942, 1946) about the abundance of fossil bones and how they are distributed are grossly exaggerated and quite inaccurate.

The so-called "muck”, which Rainey (1940) and Hibben (1942, 1946) described consists largely of the deposits of thermokarst, landslides, and debris and mudflows created by the melting of the permafrost and the slumping of oversteepened slopes. These deposits consist of relatively thin, discontinuous surficial layers blanketing the well-stratified loess, slopewash, alluvial, and colluvial deposits that actually contain the mummified remains of mammoths and other mammals (Pewe 1975a). Similar beds are sometimes found within the Quaternary units, but they are far too thin, discontinuous, scattered, and rare to have been created by a single event. These beds represent the deposits of prehistoric debris and mudflows and the periodic development of thermokarst during the accumulation of these deposits.

The numerous papers and books published about the Quaternary deposits of Alaska in 54 years between when Hibben (1946) and Collins (2000a) demonstrate that the dramatic descriptions a person can read in Hibbens (1946) are unsupported by any hard evidence. The research discussed above has demonstrated that these descriptions consisted entirely of the "geopoetry" of the type seen in disaster movies such as "Volcano", "10.5" and the "Day After Tomorrow". Although the comments of Hibben (1946), which are quoted by Collins (2000a) are as entertaining as seeing lava flow down Whilshire Boulevard and New York being fast frozen by catastrophic climate change, they have proved to be as scientifically bankrupt as the events depicted in such movies.

Even in the few years since Collins (2000a) was published, papers and books, demonstrating the scientifically bankrupt nature of both the physical descriptions and interpretations of Hibben (1942, 1946) concerning Alaskan sediments, which alternative archaeologists and catastrophists typically lump together as "muck", continued to be published. The most notable of these is a collections of papers, i.e. Berger (2003), Matheus et al. (2003), Matthews et al. (2003), Rutter et al. (2003), Westgate et al. (2003), which appeared in the July 2003 issue, vol. 60, no. 1, of Quaternary Research and Muhs et al. (2003). These papers further document that these deposits are the result, not of a single catastrophic event, but were rather created by the interaction of the gradual and periodic accumulation of loess, periodic development of soils, and their periodic modification by colluviation and solifluction. These papers contain numerous radiocarbon, Optically Stimulated Luminescence, and other dates, demonstrating that the so-called "Alaskan muck" periodically accumulated over a period of hundreds of thousands of years to over three million years in places.

Finally, Collins' (2000a) comments about "Alaskan muck" completely lack any extended discussion of the papers, i.e. Pewe (1955, 1975a, 1975b, 1989), Pewe et al. (1997), Westgate et al. (1990), and Guthrie (1990), published about the loess and other Quaternary deposits, which Hibbens (1942, 1946) included in his "muck". Despite these papers being readily available in the scientific literature and the significant evidence they contain regarding the origin of so-called "Alaskan muck, and having been published years before Collins (2000a), he made no mention of them. At the least, Collins (2000a) failed miserably in his research by completely overlooking over a half century of research, which have totally refuted the catastrophic interpretations made by Hibben (1942, 1946).

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« Reply #95 on: July 30, 2008, 10:16:51 pm »

Mississippi Meltwater Events

In Chapter 22, "End of the Ice Age", Collins (2000a) argued that research by Emiliani et al. (1975) and Emiliani (1976) provided evidence that linked the "termination of the glacial age and inundation of low-lying regions of the Bahamas and Caribbean, with, quite literally, the drowning of Atlantis". Collins (2000a) noted that Emiliani et al. (1975) identified a period of meltwater outpouring down the Mississippi River, which they interpreted to be a period of rapid ice melting and sea-level rise dated at 11,600 radiocarbon years BP. Despite being dated at 11,600 radiocarbon years BP by Emiliani et al. (1975), Collins (2000a) argued that this period of vastly increased flow of meltwater down the Mississippi River corresponded to his proposed catastrophic impact and planetary catastrophe at 10,500-10,600 BP (8,500-8.600 BC). They argued that this period of "progressive outpouring of ice meltwater" into the Gulf of Mexico represented a period of time 200 to 300 years after his proposed catastrophic impact during which the "sudden emergence of a warmer climate" caused ice sheets to melt, and sea levels to abruptly rise. He argued that it was these rising sea levels that abruptly drown low-lying coastal areas and "whole island land masses" in the Bahamas and Caribbean.

As shown in Figure 4, research conducted in the last 29 years, since Emiliani et al. (1975) was published, has rendered all of Collins (2000a) arguments moot. Unfortunately, this later research, as summarized by Aharon (2003), has shown that the DeSoto Canyon core studied by Emiliani et al. (1975) accumulated too slowly and was too bioturbated and too far from the Mississippi River to preserved an accurate record of Mississippi River meltwater pulses and spikes. The extremely poor preservation of the paleoenvironmental record by the sediments of this core resulted in Emiliani et al. (1975) grossly misinterpreting the number, chronology, and significance of meltwater pulses and events that occurred along the Mississippi River. As a result, the arguments of Collins (2000a) are based on interpretations of Emiliani et al. (1975), which has been fatally distorted by the extremely poor recording and preservation of the meltwater signature within the core from which the data came.

As shown in Figure 4, it is now known that the first of five significant outpourings, pulses, of glacial meltwater came down the Mississippi River between 14,000 and 16,000 radiocarbon years BP. During this period, it is quite clear that this was the first and only time that the meltwater came directly from the front of the Laurentide Ice Sheet. This is indicated by the presence of a high proportion of fine quartz found in sediments, which accumulated during this interval (Brown and Kennett 1998, Aharon 2003). The meltwater was derived from the melting of the Laurentide Ice Sheet as it retreated as the result of climatic warming. Because this meltwater pulse and associated retreat of the Laurentide Ice Sheet and climatic warming occurred 3,400 to 5,400 years later before Collins (2000a) claimed that his catastrophic impact occurred, it is obviously impossible that this hypothetical catastrophe was responsible in any way for either starting or causing them.

After a pause in the gulfward flood of meltwater down the Mississippi, three shorter pulses of meltward, separated by shorter pauses in meltwater flow occurred down the Mississippi River. 4, These meltwater pulses occurred at 13,200 to 13,600; 12,500 to 12,900; and 11,200 to 11,250 radiocarbon years BP (Figure 4) (Aharon 2003). Unlike the previous meltwater pulse, the sediments being brought down the Mississippi River and deposited in the Gulf of Mexico indicate that these meltwater pulses are not coming directly from the ice sheet. Rather, the sediments show that the water is coming from large proglacial lakes, which have developed in front of the Laurentide Ice Sheet as it has retreated northward (Brown and Kennett 1998). Because of these proglacial lakes, the pauses in meltwater flow down the Mississippi River are not related to climatic change. Rather they are the result of switching between drainages of the St. Lawrence, Hudson, and Mississippi rivers as different proglacial lake outlets were blocked and unblocked by shifting ice lobes, erosion, and isostatic uplift (Licciardi et al. 1999). After about 14,000 radiocarbon years BP because of the proglacial lakes and their shifting outlets, the rate at which the ice sheet is melting ceases to be the main factor in determining the amount of meltwater coming down the Mississippi River (Brown and Kennett 1998, Aharon 2003). Therefore, it is impossible after about 14,000 radiocarbon years BP for either Emiliani et al. (1975) or Collins (2000a) to make any inferences about climatic change simply based upon whether or not meltwater was flowing down the Mississippi River. The simplistic connection between climate change and Mississippi meltwater floods made by Collins (2000a) had been refuted even before he published it.

Between 10,000 to 11,200 radiocarbon years BP, there was a cessation of meltwater flow down the Mississippi River during a period called the "Cessation Event" (Figure 4) (Leventer et al. 1982, Flower and Kennett 1990, Marchitto and Wei 1995, Aharon 2003). In a complete refutation of the arguments of Collins (2000a), there is no flow of meltwater down the Mississippi River either at or 200 to 300 years after his alleged cosmic catastrophe. Melting at the margin of the ice sheet still generated huge amounts of glacial meltwater. However, instead of flowing down the Mississippi River and into the Gulf of Mexico, it emptied out of proglacial lakes in front of the Laurentide ice sheet into the North Atlantic via the St. Lawrence River. Therefore, climate was not a significant factor determining the lack of meltwater flowing down the Mississippi River. Thus, the latest research shows that the meltwater evidence used by Collins (2000a) used to link the "termination of the glacial age and inundation of low-lying regions of the Bahamas and Caribbean, with, quite literally, the drowning of Atlantis" exists only in his imagination.

It is not until 10,000 radiocarbon years BP, 400 to 500 years after the alleged cosmic impact, that a final pulse of meltwater flow down the Mississippi River started. This final pulse of final meltwater flooding occurred not because of pure climatic change and associated rapid melting of the Luarentide ice sheet as Collins (2000a) interpreted Emiliani et al. (1975). Rather, it occurred because isostatic rebound opened outlets of proglacial lakes draining into the Mississippi River. For the next 1,000 years, until 8,900 radiocarbon years BP, meltwater flooded down the Mississippi River into the Gulf of Mexico. At that time, the edge of the Laurentide ice sheet retreated far enough north that meltwater could empty into either the St. Lawrence or Hudson rivers or, by 8,200 radiocarbon years BP, Arctic Ocean (Licciardi et al. 1999).

As illustrated in Figure 4, Poole and Wright (1999) have delineated the occurrence of Holocene freshwater pulses from the Mississippi River. These pulses are clearly not of glacial origin. Likely they represent period of large-scale and frequent annual floods within the Mississippi Alluvial Valley. Although not as dramatic as comet and meteorite impacts, these periods of increased flooding within the Mississippi River Valley might have had catastrophic effects on the Native Americans occupying it at the times they occurred.

Finally, the timing of the global catastrophe of Collins (2000a) also failed to match any of the global meltwater events that have been found and dated in Fairbanks (1989, 1990), Clark et al. (1996, 2004), and other published papers (Figure 4). His global catastrophe occurs some 6,400 to 6,500 years after a period of rapid sea level rise and meltwater pulse, which started about 17,000 radiocarbon years BP (Clark et al. 2004). This meltwater pulse likely represents the first major period of ice sheet melting the start of the transition between glacial and post-glacial climates thousands of years before the cosmic catastrophe proposed by Collins (2000a). A second period of rapid sea level rise and meltwater pulse, called "mwp-1A", started about 12,200 radiocarbon years BP and ended about 11,700 radiocarbon years BP. Thus, it started about 1,600 to 1,700 years before and ended 1,100 to 1,200 years before his cosmic catastrophe. Given impacts of any sort, no matter how large, can not cause climatic change before they hit, it is impossible to use either of these meltwater events and the start of the climatic transition between the glacial and post-glacial climates as evidence of such an event. The last major global meltwater pulse, called "mwp-1B", occurred from 7,000 to 10,000 radiocarbon years BP and peaked at 9,500 radiocarbon years BP (Fairbridge 1989, 1990). This makes it too young to be associated with the cosmic catastrophe proposed by Collins (2000a).
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« Reply #96 on: July 30, 2008, 10:17:09 pm »

Pollen

In Chapter 22, Collins (2000a) interpreted the analyses of prehistoric pollen by Wright et al. (1963) and Ogden et al. (1967) as documenting a rapid period of climate change which was unusual and unique enough that it can only be explained by major comet or meteorite impact occurring at the "end of glaciation . In case of Kirchner Marsh, Minnesota discussed by Wright et al (1963), the formation of the kettle hole containing Kirshner Marsh during the retreat of the Laurentide Ice Sheet is clear evidence of the active, ongoing transition from glacial to post-glacial climate having started long before 13,270 radiocarbon years BP. This is over 2,000 years before a period of rapid climate change after 10,300 radiocarbon years BP, which is misrepresented by Collins (2000a) as being the entire period of change from glacial to post-glacial climate. After the formation of the kettle hole by deglaciation the continuation of active change from glacial to post-glacial climate is seen in the change from Spruce-Cyperaceae pollen zone, through the Spruce-ash, Spruce-Artemisia, Birch-alder, and Pine pollen zones and finally to Elm-oak pollen zone sometime after 10,230 radiocarbon years BP. In the case of Ogden et al. (1967), he concluded from the examination of numerous radiocarbon-dated Midwest pollen profiles that the spruce decline occurred about 10,000 radiocarbon years BP. This date is some 600 years after Collins (2000a) proposed his catastrophic impact occurred. It is clear from looking at the pollen data from the sites discussed in Ogden et al. (1976) that the transition from glacial to post-glacial climate started thousands of years before either the alleged catastrophic impacts and the period of abrupt climate change discussed by Ogden (1967). Examining these reference cited by Collins (2000a) it is quite clear that the period of abrupt, regional climate change after 10,300 radiocarbon years does not represent the entire transition from glacial to post-glacial climate as Collins (2000a) falsely claimed in Chapter 22. Instead, it is a brief period of rapid climate change that occurred about 5,700 years after the transition from glacial to post-glacial climate started. This distinction is important, because is quite impossible for the climate change that ended the last ice age to have started in response to his proposed catastrophic impact thousands of years before it happened.

In his discussion of Wright et al. (1963) and Ogden et al. (1967), Collins (2000a) falsely assumed that this single period of rapid climate warming was unique for the Pleistocene. Apparently he was unaware that throughout the last 125,000 years conventional geologists and paleoclimatologists have discovered numerous periods of rapid, hemispheric-wide, climatic change which are comparable to those he used as evidence of a cosmic catastrophe. Called "Dansgaard (Oeschger) events", 24 of these periods have occurred during the last glacial period, of which 16 of these occurred between 25,000 to 60,000 years ago. During a Dansgaard (Oeschger) event, which irregularly occurred approximately every 1500-2000a years, temperature increase by up to 8-10° centigrade over the period of a few decades (Broecker et al. 1985, Dansgaard et al. 1993, Stocker 1998). Thus, the rapid period of climatic warming used by Collins (2000a) is not unique as he claimed it to be. In fact, it is just one of many warming events, which have occurred throughout the last 125,000 years. It and other similar magnitude warming events are simply far too common to be credibly explained by extremely rare catastrophic processes such as meteorite or comet impacts.

As illustrated in Figure 4, Jacobson et al. (1987) demonstrated that the period of rapid climatic warming discussed by Wright et al. (1963) and Ogden et al. (1967) was not unique even for the period of climatic transition from glacial to post-glacial climates. Jacobson et al. (1987) found not one period of rapid, synchronous climate warming as claimed by Collins (2000a), but actually three periods of rapid, synchronous climatic warming having occurred during the transition from glacial to post-glacial climates (Figure 4). In this study, Jacobson et al. (1987) did a detailed analysis of the pollen records from 18 sites, characterized by continuous core, very closely spaced samples and numerous radiocarbon dates, covering southeastern and northeastern North America. He found that during the deglaciation of North America abrupt changes in vegetation, reflecting rapid, and synchronous changes in climate, occurred about 10,000, 12,300, and 13,500 radiocarbon years BP. Although noticeable in northeastern North America, the periods of synchronous climate change at 12,300 and 13,500 radiocarbon years BP were most pronounce in southeastern North America. In contrast, although noticeable in southeastern North America, the period of synchronous climate change at 10,000 radiocarbon years BP was most pronounce in northeastern North America. The number and frequency of these periods of climatic warming and the complete lack of any evidence, i.e. craters and ejecta, for a meteorite or comet impact associated with them discredit meteorite or comet impacts as a practical explanation for them. In contrast there are numerous climatic models that can explain these periods of climatic warming to varying degrees. In this case, either a meteorite or comet impact is simple-minded explanation for an event caused by the complex interaction of several processes. Broecker et al. 1988, Broecker 1998, Dansgaard et al. 1998, Stocker (1998), Alley et al. (2003), Sima et al. (2004), and many, many other published papers have discussed these processes and their interaction in great detail.

The timing of the periods of rapid and synchronous climatic warming delineated by Jacobson et al. (1987) also pose a significant problem for Collins (2000a). As determined by Jacobson et al. (1987) none of these periods, as in the case of the Mississippi River meltwater pulses and global meltwater events, are synchronous with the 10,500-10,600 BP (8,500-8.600 BC) date proposed by Collins (2000a) for his catastrophic impact. The two oldest periods predate the time of his proposed comet impact, respectively, by 2,900 to 3,000 and 1,700 to 1,800 years. They both show that the transition from glacial to post-glacial climate, including periods of rapid and synchronous change, was already taking place before the comet impact proposed by Collins (2000a) even occurred. The last period of rapid and synchronous climatic change occurred 400 to 500 years after his alleged impact. In the case of this period climatic change, it does not make any scientific sense why the effects a catastrophic impact, larger in size than the impact that wiped out the dinosaurs as illustrated by Collins (2000a), should take hundreds of years to occur.
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« Reply #97 on: July 30, 2008, 10:17:29 pm »

Other Climatic Data

Collins (2000a) cited Broecker et al. (1960) as evidence of abrupt climate change about 11,000 radiocarbon years BP. However, Broecker et al. (1960) fails to provide any evidence for his cosmic catastrophic. Eleven thousand radiocarbon years BP has been demonstrated to a very significant period of abrupt climatic cooling, which was the start of the "Younger Dryas" (Broecker et al. 1988, Broecker 1998, Flower and Kennett 1990, Sima et al. 2004). Although it was one the most significant periods of abrupt climate change during the last deglaciation, it fails to provide any evidence for a global catastrophe envisioned by Collins (2000a) as it occured 500 to 600 years before the proposed date for this global catastrophe and it was a period of rapid climatic cooling, not warming as he proposed. It occurs at the wrong time and represents climatic change in the wrong direction to be part of his proposed cosmic catastrophe. That Collins (2000a) confused the start of the Younger Dryas, a period of abrupt climatic cooling with its end, a period of abrupt climatic warming, 1,000 years later, in his discussions demonstrated a remarkable lack of knowledge of the timing of Pleistocene events on the part of Collins (2000a). This mistake is like arguing that the Battle of Hastings in 1066 and the London Blitz in World War II were contemporaneous and claiming that they are part of the same event.

Conclusions

In a detailed examination of the geologic evidence offered by Collins (2000a) for a catastrophic meteorite or comet impact about 10,500-10,600 BP (8,500-8.600 BC), I found that none of the observations or data provide convincing evidence for such an event. In the case of the Carolina Bays, there is overwhelming evidence that these features formed tens of thousands of years before 10,500-10,600 BP. Thus it is impossible that these features could have been formed at the time proposed by Collins (2000a). Also there exists a lack of any credible evidence indicating that some sort of impact related process produced them given that their morphology has been modified by tens of thousands of years of lacustrine and eolian processes. The deep sea craters cited by Collins (2000a) as evidence lack any convincing evidence of either their formation or existence to the point of being imaginary features. Similarly, the catastrophic interpretations of the so-called Alaskan muck by Hibben (1942, 1946) represent antiquated and obsolete research that has been complete refuted by research published in the decades since his papers and book were published. What is now known about the character and chronology of Mississippi River and global meltwater pulses contradicts Collins (2000a) interpretations to the point of refuting them. In fact the timing of meltwater pulses show that the transition from glacial to post-glacial climates started thousands of years before the date of his proposed impact and impossible to have been the result of it. Although rapid periods of synchronous warming have occurred during the transition from glacial to post-glacial climates, they were common features of paleoclimate during the last 125,000 years. They were far too common to be explained by invoking relatively rare large-magnitude comet or meteorite impact. The timing of these events is inconsistent with a meteorite or comet impact about 10,500-10,600 BP. Furthermore, as does the data on meltwater pulses, palynologic and other paleoclimatic evidence clearly demonstrates that the transition from glacial to post-glacial climates started thousands of years before 10,500-10,600 BP. In summary, none of the examined geologic evidence provided any evidence for the cosmic catastrophe provided postulated by Collins (2000a). When the latest research was examined, it directly contradicts his ideas concerning a terminal Pleistocene catastrophic impact.
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« Reply #98 on: July 30, 2008, 10:19:13 pm »

Herr_Saltzman

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  posted 02-16-2006 11:50 AM                   
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quote:
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Plate tectonics (from the Greek word for "one who constructs and destroys", τεκτων, tekton) is a theory of geology developed to explain the phenomenon of continental drift and is currently the theory accepted by the vast majority of scientists working in this area. In the theory of plate tectonics the outermost part of the Earth's interior is made up of two layers: the outer lithosphere and the inner asthenosphere.

The lithosphere essentially "floats" on the asthenosphere and is broken-up into ten major plates: African, Antarctic, Australian, Eurasian, North American, South American, Pacific, Cocos, Nazca, and the Indian plates. These plates (and the more numerous minor plates) move in relation to one another at one of three types of plate boundaries: convergent (or destructive, two plates push against one another), divergent (or constructive, two plates move away from each other), and transform (two plates slide past one another). Earthquakes, volcanic activity, mountain-building, and oceanic trench formation occur along plate boundaries (most notably around the Pacific Ring of Fire).

Plate tectonic theory arose out of two separate geological observations: continental drift, noticed in the early 20th century, and seafloor spreading, noticed in the 1960s. The theory itself was developed during the late 1960s and has since almost universally been accepted by scientists and has revolutionized the earth sciences (akin in its unifying and explanatory power for diverse geological phenomena as the development of the periodic table was for chemistry, the discovery of the genetic code for genetics, evolution in biology, and the theory of relativity in physics).
The tectonic plates of the world were mapped in the second half of the 20th century.This image shows the direction in which the plates are moving. Click the image to see a larger version.
Enlarge
The tectonic plates of the world were mapped in the second half of the 20th century.This image shows the direction in which the plates are moving. Click the image to see a larger version.
Contents
[hide]

* 1 Key principles
* 2 Types of plate boundaries
o 2.1 Transform (conservative) boundaries
o 2.2 Divergent (constructive) boundaries
o 2.3 Convergent (destructive) boundaries
* 3 Sources of plate motion
o 3.1 Friction
o 3.2 Gravity
* 4 Major plates
* 5 History and impact
o 5.1 Continental drift
o 5.2 Floating continents
o 5.3 Plate tectonic theory
+ 5.3.1 Explanation of magnetic striping
+ 5.3.2 Subduction discovered
+ 5.3.3 Mapping with earthquakes
o 5.4 Geological paradigm shift
* 6 Plate tectonics on Other Planets
* 7 See also
* 8 Metaphoric uses
* 9 References
* 10 External links

[edit]

Key principles

The division of the Earth's interior into lithospheric and asthenospheric components is based on their mechanical differences. The lithosphere is cooler and more rigid, whilst the asthenosphere is hotter and mechanically weaker. This division should not be confused with the chemical subdivision of the Earth into (from innermost to outermost) core, mantle, and crust. The key principle of plate tectonics is that the lithosphere exists as separate and distinct tectonic plates, which "float" on the fluid-like asthenosphere. The relative fluidity of the asthenosphere allows the tectonic plates to undergo motion in different directions.

One plate meets another along a plate boundary, and plate boundaries are commonly associated with geological events such as earthquakes and the creation of topographic features like mountains, volcanoes and oceanic trenches. The majority of the world's active volcanoes occur along plate boundaries, with the Pacific Plate's Ring of Fire being most active and famous. These boundaries are discussed in further detail below.

Tectonic plates are comprised of two types of lithosphere: continental and oceanic lithospheres; for example, the African Plate includes the continent and parts of the floor of the Atlantic and Indian Oceans. The distinction is based on the density of constituent materials; oceanic lithospheres are denser than continental ones due to their greater mafic mineral content. As a result, the oceanic lithospheres generally lie below sea level (for example the entire Pacific Plate, which carries no continent), while the continental ones project above sea level (see isostasy for explanation of this principle).
[edit]

Types of plate boundaries
Three types of plate boundary.
Enlarge
Three types of plate boundary.

There are three types of plate boundaries, characterised by the way the plates move relative to each other. They are associated with different types of surface phenomena. The different types of plate boundaries are:

1. Transform boundaries occur where plates slide, or perhaps more accurately grind, past each other along transform faults. The relative motion of the two plates is either sinistral (left side toward the observer) or dextral (right side toward the observer).
2. Divergent boundaries occur where two plates slide apart from each other.
3. Convergent boundaries (or active margins) occur where two plates slide towards each other commonly forming either a subduction zone (if one plate moves underneath the other) or an orogenic belt (if the two simply collide and compress).

Plate boundary zones occur in more complex situations where three or more plates meet and exhibit a mixture of the above three boundary types.
[edit]

Transform (conservative) boundaries

The left- or right-lateral motion of one plate against another along transform faults can cause highly visible surface effects. Because of friction, the plates cannot simply glide past each other. Rather, stress builds up in both plates and when it reaches a level that exceeds the slipping-point of rocks on either side of the transform-faults the accumulated potential energy is released as strain, or motion along the fault. The massive amounts of energy that are released are the cause of earthquakes, a common phenomenon along transform boundaries.

A good example of this type of plate boundary is the San Andreas Fault complex, which is found in the western coast of North America and is one part of a highly complex system of faults in this area. At this location, the Pacific and North American plates move relative to each other such that the Pacific plate is moving north with respect to North America.
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Divergent (constructive) boundaries

At divergent boundaries, two plates move apart from each other and the space that this creates is filled with new crustal material sourced from molten magma that forms below. The origin of new divergent boundaries at triple junctions is sometimes thought to be associated with the phenomenon known as hotspots. Here, exceedingly large convective cells bring very large quantities of hot asthenospheric material near the surface and the kinetic energy is thought to be sufficient to break apart the lithosphere. The hot spot which may have initiated the Mid-Atlantic Ridge system currently underlies Iceland which is widening at a rate of a few centimetres per century.

Divergent boundaries are typified in the oceanic lithosphere by the rifts of the oceanic ridge system, including the Mid-Atlantic Ridge, and in the continental lithosphere by rift valleys such as the famous East African Great Rift Valley. Divergent boundaries can create massive fault zones in the oceanic ridge system. Spreading is generally not uniform, so where spreading rates of adjacent ridge blocks are different massive transform faults occur. These are the fracture zones, many bearing names, that are a major source of submarine earthquakes. A sea floor map will show a rather strange pattern of blocky structures that are separated by linear features perpendicular to the ridge axis. If one views the sea floor between the fracture zones as conveyor belts carrying the ridge on each side of the rift away from the spreading center the action becomes clear. Crest depths of the old ridges, parallel to the current spreading center, will be older and deeper (due to thermal contraction and subsidence).

It is at mid-ocean ridges that one of the key pieces of evidence forcing acceptance of the sea-floor spreading hypothesis was found. Airborne geomagnetic surveys showed a strange pattern of symmetrical magnetic reversals on opposite sides of ridge centres. The pattern was far too regular to be coincidental as the widths of the opposing bands were too closely matched. Scientists had been studying polar reversals and the link was made. The magnetic banding directly corresponds with the Earth's polar reversals. This was confirmed by measuring the ages of the rocks within each band. The banding furnishes a map in time and space of both spreading rate and polar reversals.
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Convergent (destructive) boundaries

The nature of a convergent boundary depends on the type of lithosphere in the plates that are colliding. Where a dense oceanic plate collides with a less-dense continental plate, the oceanic plate is typically thrust underneath, forming a subduction zone. At the surface, the topographic expression is commonly an oceanic trench on the ocean side and a mountain range on the continental side. An example of a continental-oceanic subduction zone is the area along the western coast of South America where the oceanic Nazca Plate is being subducted beneath the continental South American Plate. As the subducting plate descends, its temperature rises driving off volatiles (most importantly water). As this water rises into the mantle of the overriding plate, it lowers its melting temperature, resulting in the formation of magma with large amounts of dissolved gases. This can erupt to the surface, forming long chains of volcanoes inland from the continental shelf and parallel to it. The continental spine of South America is dense with this type of volcano. In North America the Cascade mountain range, extending north from California's Sierra Nevada, is also of this type. Such volcanoes are characterized by alternating periods of quiet and episodic eruptions that start with explosive gas expulsion with fine particles of glassy volcanic ash and spongy cinders, followed by a rebuilding phase with hot magma. The entire Pacific ocean boundary is surrounded by long stretches of volcanoes and is known collectively as The Ring of Fire.

Where two continental plates collide the plates either crumple and compress or one plate burrows under or (potentially) overrides the other. Either action will create extensive mountain ranges. The most dramatic effect seen is where the northern margins of the Indian subcontinental plate is being thrust under a portion of the Eurasian plate, lifting it and creating the Himalaya.

When two oceanic plates converge they form an island arc as one oceanic plate is subducted below the other. Good examples of this type of plate convergence would be Japan and the Aleutian Islands in Alaska.

Oceanic / Continental


Continental / Continental


Oceanic / Oceanic
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Sources of plate motion

As noted above, the plates are able to move because of the relative weakness of the asthenosphere. Dissipation of heat from the mantle is acknowledged to be the source of energy driving plate tectonics. Somehow, this energy must be converted into force in order for the plates to move. There are essentially two forces that could be driving plate motion: friction and gravity. These are further subdivided below.
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Friction

Mantle drag
Convection currents in the mantle are transmitted through the asthenosphere; motion is driven by friction between the asthenosphere and the lithosphere.
Trench suction
Local convection currents exert a downward frictional pull on plates in subduction zones at ocean trenches.

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Gravity

Ridge-push
Plate motion is driven by the higher elevation of plates at mid-ocean ridges. Essentially stuff slides downhill. The higher elevation is caused by the relatively low density of hot material upwelling in the mantle. The real motion producing force is the upwelling and the energy source that runs it. This is a misnomer as nothing is pushing and tensional features are dominant along ridges. Also, it is difficult to explain continental break-up with this.
Slab-pull
Plate motion is driven by the weight of cold, dense plates sinking into the mantle at trenches.

There is considerable evidence that convection is occurring in the mantle at some scale. The upwelling of material at mid-ocean ridges is almost certainly part of this convection. Some early models of plate tectonics envisioned the plates riding on top of convection cells like conveyor belts. However, most scientists working today believe that the asthenosphere is not strong enough to directly cause motion by friction. Slab pull is widely believed to be the strongest force directly operating on plates. Recent models indicate that trench suction plays an important role as well. The over-all driving force and its energy source are still debatable subjects of on-going research.

Lunar drag
In a study published in the January-February 2006 issue of the Geological Society of America's journal Bulletin, a team of Italian and U.S. scientists argue that the westward motion of the world's tectonic plates is due to the tidal attraction of the moon. As the Earth spins eastward beneath the moon, they say, the moon's gravity ever so slightly holds the Earth's surface layer back. This "lunar drag" causes the crust to slip slowly westward. [1]

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Major plates
Plate tectonics map

The main plates are

* African Plate, covering Africa
* Antarctic Plate, covering Antarctica
* Australian Plate, covering Australia (fused with Indian Plate between 50 and 55 million years ago)
* Eurasian Plate covering Eurasia
* North American Plate covering North America and north-east Siberia
* South American Plate covering South America
* Pacific Plate, covering the Pacific Ocean

Notable minor plates include the Indian Plate and the Arabian Plate.

The movement of plates has caused the formation and breakup of continents over time, including occasional formation of a supercontinent that contains most or all of the continents. The supercontinent Rodinia is thought to have formed about 1000 million years ago and to have embodied most or all of Earth's continents, and broken up into eight continents around 600 million years ago. The eight continents later re-assembled into another supercontinent called Pangaea; Pangea eventually broke up into Laurasia (which became North America and Eurasia) and Gondwana (which became the remaining continents).

Related article

* List of tectonic plates

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History and impact
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Continental drift

For more details on this topic, see Continental drift.

Continental drift was one of many ideas about tectonics proposed in the late 19th and early 20th centuries. The theory has been superseded by and the concepts and data have been incorporated within plate tectonics.

By 1915 Alfred Wegener was making serious arguments for the idea with the first edition of The Origin of Continents and Oceans. In that book he noted how the east coast of South America and the west coast of Africa looked as if they were once attached. Wegener wasn't the first to note this (Francis Bacon, Benjamin Franklin and Snider-Pellegrini preceded him), but he was the first to marshal significant fossil and paleo-topographical and climatological evidence to support this simple observation. However, his ideas were not taken seriously by many geologists, who pointed out that there was no apparent mechanism for continental drift. Specifically they did not see how continental rock could plow through the much denser rock that makes up oceanic crust.

In the early 1940s, Maurice Ewing seismically tested the Atlantic edge of the North American continental shelf, and found a granitic layer dropped down to the basaltic ocean floor. If the continent had been torn from Europe and was plowing through the ocean bottom, the edge of the continental shelf should have marked the end of granitic rocks. Later studies aboard the Atlantis found that ocean bottom was not smooth, which suggested it was much stronger than if continents could push it aside.

Beginning in the 1950s, scientists, using magnetic instruments (magnetometers) adapted from airborne devices developed during World War II to detect submarines, began recognizing odd magnetic variations across the ocean floor. This finding, though unexpected, was not entirely surprising because it was known that basalt -- the iron-rich, volcanic rock making up the ocean floor-- contains a strongly magnetic mineral (magnetite) and can locally distort compass readings. This distortion was recognized by Icelandic mariners as early as the late 18th century. More important, because the presence of magnetite gives the basalt measurable magnetic properties, these newly discovered magnetic variations provided another means to study the deep ocean floor. When newly formed rock cools, such magnetic materials recorded the Earth's magnetic field at the time.

As more and more of the seafloor was mapped during the 1950s, the magnetic variations turned out not to be random or isolated occurrences, but instead revealed recognizable patterns. When these magnetic patterns were mapped over a wide region, the ocean floor showed a zebra-like pattern. Alternating stripes of magnetically different rock were laid out in rows on either side of the mid-ocean ridge: one stripe with normal polarity and the adjoining stripe with reversed polarity. The overall pattern, defined by these alternating bands of normally and reversely polarized rock, became known as magnetic striping.

When the rock strata of the tips of separate continents are very similar it suggests that these rocks were formed in the same way implying that they were joined initially. For instance, some parts of Scotland contain rocks very similar to those found in eastern North America. Furthermore, the Caledonian Mountains of Europe and parts of the Appalachian Mountains of North America are very similar in structure and lithology.
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Floating continents

The prevailing concept was that there were static shells of strata under the continents. It was early observed that although granite existed on continents, seafloor seemed to be composed of denser basalt. It was apparent that a layer of basalt underlies continental rocks.

However, based upon abnormalities in plumb line deflection by the Andes in Peru, Pierre Bouguer deduced that less-dense mountains must have a downward projection into the denser layer underneath. The concept that mountains had "roots" was confirmed by George B. Airy a hundred years later during study of Himalayan gravitation, and seismic studies detected corresponding density variations.

By the mid-1950s the question remained unresolved of whether mountain roots were clenched in surrounding basalt or were floating like an iceberg.
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Plate tectonic theory

Significant progress was made in the 1960s, and was prompted by a number of discoveries, most notably the Mid-Atlantic ridge. The most notable was the 1962 publication of a paper by American geologist Harry Hess (Robert S. Dietz published the same idea one year earlier in Nature. However, priority belongs to Hess, since he distributed an unpublished manuscript of his 1962 article already in 1960). Hess suggested that instead of continents moving through oceanic crust (as was suggested by continental drift) that an ocean basin and its adjoining continent moved together on the same crustal unit, or plate. In the same year, Robert R. Coats of the U.S. Geological Survey described the main features of island arc subduction in the Aleutian Islands. His paper, though little-noted (and even ridiculed) at the time, has since been called "seminal" and "prescient". In 1967, Jason Morgan proposed that the Earth's surface consists of 12 rigid plates that move relative to each other. Two months later, in 1968, Xavier Le Pichon published a complete model based on 6 major plates with their relative motions.
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Explanation of magnetic striping
Seafloor magnetic striping.
Enlarge
Seafloor magnetic striping.

The discovery of magnetic striping and the stripes being symmetrical around the crests of the mid-ocean ridges suggested a relationship. In 1961, scientists began to theorise that mid-ocean ridges mark structurally weak zones where the ocean floor was being ripped in two lengthwise along the ridge crest. New magma from deep within the Earth rises easily through these weak zones and eventually erupts along the crest of the ridges to create new oceanic crust. This process, later called seafloor spreading, operating over many millions of years has built the 50,000 km-long system of mid-ocean ridges. This hypothesis was supported by several lines of evidence:

1. at or near the crest of the ridge, the rocks are very young, and they become progressively older away from the ridge crest;
2. the youngest rocks at the ridge crest always have present-day (normal) polarity;
3. stripes of rock parallel to the ridge crest alternated in magnetic polarity (normal-reversed-normal, etc.), suggesting that the Earth's magnetic field has flip-flopped many times.

By explaining both the zebralike magnetic striping and the construction of the mid-ocean ridge system, the seafloor spreading hypothesis quickly gained converts and represented another major advance in the development of the plate-tectonics theory. Furthermore, the oceanic crust now came to be appreciated as a natural "tape recording" of the history of the reversals in the Earth's magnetic field.
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Subduction discovered

A profound consequence of seafloor spreading is that new crust was, and is now, being continually created along the oceanic ridges. This idea found great favor with some scientists who claimed that the shifting of the continents can be simply explained by a large increase in size of the Earth since its formation. However, this so-called "expanding Earth" hypothesis was unsatisfactory because its supporters could offer no convincing geologic mechanism to produce such a huge, sudden expansion. Most geologists believe that the Earth has changed little, if at all, in size since its formation 4.6 billion years ago, raising a key question: how can new crust be continuously added along the oceanic ridges without increasing the size of the Earth?

This question particularly intrigued Harry Hess, a Princeton University geologist and a Naval Reserve Rear Admiral, and Robert S. Dietz, a scientist with the U.S. Coast and Geodetic Survey who first coined the term seafloor spreading. Dietz and Hess were among the small handful who really understood the broad implications of sea floor spreading. If the Earth's crust was expanding along the oceanic ridges, Hess reasoned, it must be shrinking elsewhere. He suggested that new oceanic crust continuously spread away from the ridges in a conveyor belt-like motion. Many millions of years later, the oceanic crust eventually descends into the oceanic trenches -- very deep, narrow canyons along the rim of the Pacific Ocean basin. According to Hess, the Atlantic Ocean was expanding while the Pacific Ocean was shrinking. As old oceanic crust was consumed in the trenches, new magma rose and erupted along the spreading ridges to form new crust. In effect, the ocean basins were perpetually being "recycled," with the creation of new crust and the destruction of old oceanic lithosphere occurring simultaneously. Thus, Hess' ideas neatly explained why the Earth does not get bigger with sea floor spreading, why there is so little sediment accumulation on the ocean floor, and why oceanic rocks are much younger than continental rocks.
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Mapping with earthquakes

During the 20th century, improvements in seismic instrumentation and greater use of earthquake-recording instruments (seismographs) worldwide enabled scientists to learn that earthquakes tend to be concentrated in certain areas, most notably along the oceanic trenches and spreading ridges. By the late 1920s, seismologists were beginning to identify several prominent earthquake zones parallel to the trenches that typically were inclined 40-60° from the horizontal and extended several hundred kilometers into the Earth. These zones later became known as Wadati-Benioff zones, or simply Benioff zones, in honor of the seismologists who first recognized them, Kiyoo Wadati of Japan and Hugo Benioff of the United States. The study of global seismicity greatly advanced in the 1960s with the establishment of the Worldwide Standardized Seismograph Network (WWSSN) to monitor the compliance of the 1963 treaty banning above-ground testing of nuclear weapons. The much-improved data from the WWSSN instruments allowed seismologists to map precisely the zones of earthquake concentration worldwide.
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Geological paradigm shift

The acceptance of the theories of continental drift and sea floor spreading (the two key elements of plate tectonics) can be compared to the Copernican revolution in astronomy (see Nicolaus Copernicus). Within a matter of only several years geophysics and geology in particular were revolutionized. The parallel is striking: just as pre-Copernican astronomy was highly descriptive but still unable to provide explanations for the motions of celestial objects, pre-tectonic plate geological theories described what was observed but struggled to provide any fundamental mechanisms. The problem lay in the question "How?". Before acceptance of plate tectonics, geology in particular was trapped in a "pre-Copernican" box.

However, by comparison to astronomy the geological revolution was much more sudden. What had been rejected for decades by any respectable scientific journal was eagerly accepted within a few short years in the 1960s and 1970s. Any geological description before this had been highly descriptive. All the rocks were described and assorted reasons, sometimes in excruciating detail, were given for why they were where they are. The descriptions are still valid. The reasons, however, today sound much like pre-Copernican astronomy.

One simply has to read the pre-plate descriptions of why the Alps or Himalaya exist to see the difference. In an attempt to answer "how" questions like "How can rocks that are clearly marine in origin exist thousands of meters above sea-level in the Dolomites?", or "How did the convex and concave margins of the Alpine chain form?", any true insight was hidden by complexity that boiled down to technical jargon without much fundamental insight as to the underlying mechanics.

With plate tectonics answers quickly fell into place or a path to the answer became clear. Collisions of converging plates had the force to lift sea floor into thin atmospheres. The cause of marine trenches oddly placed just off island arcs or continents and their associated volcanoes became clear when the processes of subduction at converging plates were understood.

Mysteries were no longer mysteries. Forests of complex and obtuse answers were swept away. Why were there striking parallels in the geology of parts of Africa and South America? Why did Africa and South America look strangely like two pieces that should fit to anyone having done a jigsaw puzzle? Look at some pre-tectonics explanations for complexity. For simplicity and one that explained a great deal more look at plate tectonics. A great rift, similar to the Great Rift Valley in northeastern Africa, had split apart a single continent, eventually forming the Atlantic Ocean, and the forces were still at work in the Mid-Atlantic Ridge.

We have inherited some of the old terminology, but the underlying concept is as radical and simple as "The Earth moves" was in astronomy.
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Cheers, and Good Mental Health,
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« Reply #99 on: July 30, 2008, 10:35:47 pm »

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Hardy har, har.
You are SOOOO funny, Pagan.
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« Reply #100 on: July 30, 2008, 10:38:29 pm »

Plate tectonics -- a failed revolution

Plates in motion?

According to the classical model of plate tectonics, lithospheric plates move over a relatively plastic layer of partly molten rock known as the asthenosphere (or low-velocity zone). The lithosphere, which comprises the earth's crust and uppermost mantle, is said to average about 70 km thick beneath oceans and to be 100 to 250 km thick beneath continents. A powerful challenge to this model is posed by seismic tomography, which produces three-dimensional images of the earth's interior. It shows that the oldest parts of the continents have deep roots extending to depths of 400 to 600 km, and that the asthenosphere is essentially absent beneath them. Seismic research shows that even under the oceans there is no continuous asthenosphere, only disconnected asthenospheric lenses.
    The crust and uppermost mantle have a highly complex, irregular structure; they are divided by faults into a mosaic of separate, jostling blocks of different shapes and sizes, and of varying internal structure and strength. N.I. Pavlenkova concludes: 'This means that the movement of lithospheric plates over long distances, as single rigid bodies, is hardly possible. Moreover, if we take into account the absence of the asthenosphere as a single continuous zone, then this movement seems utterly impossible' [1]. Although the concept of thin lithospheric plates moving thousands of kilometers over a global asthenosphere is untenable, most geological textbooks continue to propagate this simplistic model, and fail to give the slightest indication that it faces any problems.


Figure 1. Seismotomographic cross-section showing velocity structure across the North American craton and North Atlantic Ocean. High-velocity (colder) lithosphere, shown in dark tones, underlies the Canadian shield to depths of 250 to 500 km. (Reprinted with permission from Grand [2]. Copyright by the American Geophysical Union.)

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« Reply #101 on: July 30, 2008, 10:40:45 pm »

The driving force of plate movements was initially claimed to be mantle-deep convection currents welling up beneath midocean ridges, with downwelling occurring beneath ocean trenches. Plate tectonicists expected seismotomography to provide clear evidence of a well-organized convection-cell pattern, but it has actually provided strong evidence against the existence of large, plate-propelling convection cells in the mantle. The favored plate-driving mechanisms at present are 'ridge-push' and 'slab-pull', but their adequacy is very much in doubt.
Thirteen major plates are currently recognized, ranging in size from about 400 by 2500 km to 10,000 by 10,000 km, together with a proliferating number of microplates (over 100 so far). Plate boundaries are identified and defined mainly on the basis of earthquake and volcanic activity. The close correspondence between plate edges and belts of earthquakes and volcanoes is therefore to be expected and can hardly be regarded as one of the 'successes' of plate tectonics! A major problem is that several 'plate boundaries' are purely theoretical and appear to be nonexistent, including the northwest Pacific boundary of the Pacific, North American, and Eurasian plates, the southern boundary of the Philippine plate, part of the southern boundary of the Pacific plate, and most of the northern and southern boundaries of the South American plate.

http://ourworld.compuserve.com/homepages/dp5/sunken.htm#pl
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« Reply #102 on: July 30, 2008, 10:42:37 pm »

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Continental drift

Geological field mapping provides evidence for horizontal crustal movements of up to several hundred kilometers. Plate tectonics, however, claims that continents have moved up to 7000 km or more since the alleged breakup of Pangaea. Satellite measurements of crustal movements have been hailed by some geologists as having proved plate tectonics. Such measurements provide a guide to crustal strains, but do not provide evidence for plate motions of the kind predicted by plate tectonics unless the relative motions predicted among all plates are observed. However, many of the results have shown no definite pattern, and have been confusing and contradictory, giving rise to a variety of ad-hoc hypotheses. For instance, distances from the Central South American Andes to Japan or Hawaii are more or less constant, whereas plate tectonics predicts significant separation. The practise of extrapolating present crustal movements tens or hundreds of millions of years into the past or future is clearly a hazardous exercise.
A 'compelling' piece of evidence that all the continents were once united in one large landmass is said to be the fact that they can be fitted together like pieces of a jigsaw puzzle. However, although many reconstructions have been attempted, none are entirely acceptable. In the Bullard et al. computer-generated fit, for example, there are a number of glaring omissions. The whole of Central America and much of southern Mexico -- a region of some 2,100,000 km² -- has been left out because it overlaps South America. The entire West Indian archipelago has also been omitted. In fact, much of the Caribbean is underlain by ancient continental crust, and the total area involved, 300,000 km², overlaps Africa. The Cape Verde Islands-Senegal basin, too, is underlain by ancient continental crust, creating an additional overlap of 800,000 km². Several major submarine structures that appear to be of continental origin are also ignored, including the Faeroe-Iceland-Greenland Ridge, Jan Mayen Ridge, Walvis Ridge, Rio Grande Rise, and the Falkland Plateau.


Figure 2. The Bullard fit. Overlaps and gaps between continents are shown in black. (Reprinted with permission from Bullard et al. [3]. Copyright by The Royal Society.)

Like the Bullard fit, the Smith & Hallam reconstruction of the Gondwanaland continents tries to fit the continents along the 500-fathom (1-km) depth contour on the continental shelves. The South Orkneys and South Georgia are omitted, as is Kerguelen Island in the Indian Ocean, and there is a large gap west of Australia. Fitting India against Australia, as in other fits, leaves a corresponding gap in the western Indian Ocean. Dietz & Holden based their fit on the 2-km depth contour, but they still have to omit the Florida-Bahamas platform, ignoring the evidence that it predates the alleged commencement of drift. In many regions the boundary between continental and oceanic crust appears to occur beneath oceanic depths of 2-4 km or more, and in some places the ocean-continent transition zone is several hundred kilometers wide. This means that any reconstructions based on arbitrarily selected depth contours are flawed. Given the liberties that drifters have had to take to obtain the desired continental matches, their computer-generated fits may well be a case of 'garbage in, garbage out'.
The curvature of continental contours is often so similar that many shorelines can be fitted together quite well even though they can never have been in juxtaposition. For instance, eastern Australia fits well with eastern North America, and there are also remarkable geological and paleontological similarities, probably due to the similar tectonic backgrounds of the two regions. The geological resemblances of opposing Atlantic coastlines may be due to the areas having belonged to the same tectonic belt, but the differences -- which are rarely mentioned -- are sufficient to show that the areas were situated in distant parts of the belt. H.P. Blavatsky regarded the similarities in the geological structure, fossils, and marine life of the opposite coasts of the Atlantic in certain periods as evidence that 'there has been, in distant pre-historic ages, a continent which extended from the coast of Venezuela, across the Atlantic Ocean, to the Canarese Islands and North Africa, and from Newfoundland nearly to the coast of France' [4].
One of the main props of continental drift is paleomagnetism -- the study of the magnetism of ancient rocks and sediments. For each continent a 'polar wander path' can be constructed, and these are interpreted to mean that the continents have moved vast distances over the earth's surface. However, paleomagnetism is very unreliable and frequently produces inconsistent and contradictory results. For instance, paleomagnetic data imply that during the mid-Cretaceous Azerbaijan and Japan were in the same place! When individual paleomagnetic pole positions, rather than averaged curves, are plotted on world maps, the scatter is huge, often wider than the Atlantic.
One of the basic assumptions of paleomagnetism is that rocks retain the magnetization they acquire at the time they formed. In reality, rock magnetism is subject to modification by later magnetism, weathering, metamorphism, tectonic deformation, and chemical changes. Horizontal and vertical rotations of crustal blocks further complicate the picture. Another questionable assumption is that over long periods of time the geomagnetic field approximates a simple dipole (N-S) field oriented along the earth's rotation axis. If, in the past, there were stable magnetic anomalies of the same intensity as the present-day East Asian anomaly (or slightly more intensive), this would render the geocentric axial dipole hypothesis invalid.
The opening of the Atlantic Ocean allegedly began in the Cretaceous by the rifting apart of the Eurasian and American plates. However, on the other side of the globe, northeastern Eurasia is joined to North America by the Bering-Chukotsk shelf, which is underlain by Precambrian continental crust that is continuous and unbroken from Alaska to Siberia. Geologically these regions constitute a single unit, and it is unrealistic to suppose that they were formerly divided by an ocean several thousand kilometers wide, which closed to compensate for the opening of the Atlantic. If a suture is absent there, one ought to be found in Eurasia or North America, but no such suture appears to exist. Similarly, geology indicates that there has been a direct tectonic connection between Europe and Africa across the zones of Gibraltar and Rif on the one hand, and Calabria and Sicily on the other, at least since the end of the Paleozoic, contradicting plate-tectonic claims of significant displacement between Europe and Africa during this period.
India supposedly detached itself from Antarctica sometime during the Mesozoic, and then drifted northeastward up to 9000 km, over a period of up to 200 million years, until it finally collided with Asia in the mid-Tertiary, pushing up the Himalayas and the Tibetan Plateau. That Asia happened to have an indentation of approximately the correct shape and size and in exactly the right place for India to 'dock' into would amount to a remarkable coincidence. There is, however, overwhelming geological and paleontological evidence that India has been an integral part of Asia since Precambrian time. If the long journey of India had actually happened, it would have been an isolated island-continent for millions of years -- sufficient time to have evolved a highly distinct endemic fauna. However, the Mesozoic and Tertiary faunas show no such endemism, but indicate instead that India lay very close to Asia throughout this period, and not to Australia and Antarctica. It would appear that the supposed 'flight of India' is no more than a flight of fancy!
It is often claimed that plate-tectonic reassemblies of the continents can help to explain climatic changes and the distribution of plants and animals in the past. However, detailed studies have shown that shifting the continents succeeds at best in explaining local or regional climatic features for a particular period, and invariably fails to explain the global climate for the same period. A.A. Meyerhoff et al. showed in a detailed study that most major biogeographical boundaries, based on floral and faunal distributions, do not coincide with the partly computer-generated plate boundaries postulated by plate tectonics. The authors comment: 'What is puzzling is that such major inconsistencies between plate tectonic postulates and field data, involving as they do boundaries that extend for thousands of kilometers, are permitted to stand unnoticed, unacknowledged, and unstudied.' Before their study was published by the Geological Society of America, a group of earth-science graduates was invited to study the manuscript. They became deeply disturbed by what they read, and commented: 'If this global study of biodiversity through time is correct, and it is very convincingly presented, then a lot of what we are being taught about plate tectonics should more aptly be called "Globaloney" ' [5].
It is unscientific to select a few faunal identities and ignore the vastly greater number of faunal dissimilarities from different continents which were supposedly once joined [6]. The known distributions of fossil organisms are more consistent with an earth model like that of today than with continental-drift models. Some of the paleontological evidence appears to require the alternate emergence and submergence of land dispersal routes only after the supposed breakup of Pangaea. For example, mammal distribution indicates that there were no direct physical connections between Europe and North America during Late Cretaceous and Paleocene times, but suggests a temporary connection with Europe during the Eocene. A few drifters have recognized the need for intermittent land bridges after the supposed separation of the continents. Various oceanic ridges, rises, and plateaus could have served as land bridges, as many are known to have been partly above water at various times in the past. There is growing evidence that these land bridges formed part of larger former landmasses in the present oceans (see below).
The present distribution of land and water is characterized by a number of notable regularities. First, the continents tend to be triangular, with their pointed ends to the south. Second, the northern polar ocean is almost entirely ringed by land, from which three continents project southward, while the continental landmass at the south pole is surrounded by water, with three oceans projecting northward. Third, the oceans and continents are arranged antipodally -- i.e. if there is land in one area of the globe, there tends to be water in the corresponding area on the opposite side of the globe.
The Arctic Ocean is precisely antipodal to Antarctica; North America is exactly antipodal to the Indian Ocean; Europe and Africa are antipodal to the central area of the Pacific Ocean; Australia is antipodal to the North Atlantic; and the South Atlantic corresponds -- though less exactly -- to the eastern half of Asia.* Only 7% of the earth's surface does not obey the antipodal rule. If the continents had slowly drifted thousands of kilometers to their present positions, the antipodal arrangement of land and water would have to be regarded as purely coincidental. The antipodal arrangement of land and seas reflects the tetrahedral plan of the earth. If one corner of the tetrahedron is placed in Antarctica, at the south pole, the other three lie in three vast blocks of very ancient, Archean rocks in the northern hemisphere: the Canadian shield, the Scandinavian shield, and the Siberian shield, and the three edges correspond to the three roughly meridional lines running through the three pairs of continents: North and South America, Europe and Africa, Asia and Australia.**


*Rupert Sheldrake likens the earth to a developing organism, and says that the existence of an ocean at the north pole and a continent at the south pole may be the culmination of a morphogenetic process: 'Such a morphological polarization of a spherical body is very familiar in the realm of biology; for example, in the formation of poles in fertilized eggs' (The Rebirth of Nature, Bantam, 1991, p. 161).
**J.W. Gregory suggested that in the Upper Paleozoic the tetrahedron was the other way up, with one corner at the north pole. Instead of a continuous southern ocean-belt separating triangular points of land, there was then a southern land-belt, supported by three great equidistant cornerstones: the Archean blocks of South America, South Africa, and Australia.


http://ourworld.compuserve.com/homepages/dp5/sunken.htm#pl
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Carolyn Silver
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« Reply #103 on: July 30, 2008, 10:42:56 pm »

Carolyn Silver

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   posted 02-16-2006 10:04 PM                       
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quote:
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Originally posted by Tom Hebert1:
Hi Carolyn,

I think you've done a great job with all of this research! Why can't people see the light? Must be a case of myopia.  Sad
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Hi Tom, thanks!
In answer to your question, I noticed that in order for people to try and get others to accept their own CRAPPY theories on Atlantis, they have to try their hardest to get other people not to accept not only the most popular ones, but the most basic ones as well, namely that Atlantis was an ISLAND in the Atlantic, like Plato says!!!
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« Reply #104 on: July 30, 2008, 10:46:37 pm »

Herr_Saltzman

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  posted 02-16-2006 10:10 PM                   
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quote:
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Mid-Atlantic Ridge
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Image:Mid-atlantic_ridge_map.png

Courtesy USGS

The Mid-Atlantic Ridge is a mostly underwater mountain range of the Atlantic Ocean that runs from 87░N (about 333 km South of the North Pole) to subantarctic Bouvet Island, where it turns into Atlantic-Indian-Ridge and continues further East through Crozet Plateau to the Southwest Indian Ridge, while in the West it is followed by Scotia Ridge. It is part of the mid-oceanic ridge. The highest peaks of this mountain range extend above the water mark, to form islands. Near the Equator, the Mid-Atlantic Ridge is dissected into the North Atlantic Ridge and the South Atlantic Ridge by the Romanche Trench, a narrow submarine trench with a maximum depth of 7 758 m, one of the deepest locations of the Atlantic Ocean. The portion of the ridge north of Iceland is in fact part of the Arctic Ocean. The islands are, from North to South, with their respective highest peaks, elevations in m, and location:

Northern Hemisphere (North Atlantic Ridge):

1. Jan Mayen (Beerenberg, 2277 m, at 71░06'N, 08░12'W), in the Arctic Ocean
2. Iceland (Hvannadalshn˙kur in the Vatnaj÷kull, 2119 m, at 64░01'N, 16░41'W)
3. Azores (Ponta do Pico or Pico Alto, on Pico Island, 2351 m, at 38░28'0"N, 28░24'0"W)
4. Saint Peter and Paul Rocks (Southwest Rock, 22.5 m, at 00░55'08"N, 29░20'35"W)

Southern Hemisphere (South Atlantic Ridge):

1. Ascension Island (The Peak, Green Mountain, 859 m, at 07░59'S, 14░25'W)
2. Tristan da Cunha (Queen Mary's Peak, 2062 m, at 37░05'S, 12░17'W)
3. Gough Island (Edinburgh Peak, 909 m, at 40░20'S, 10░00'W)
4. Bouvet Island (Olavtoppen, 780 m, at 54░24'S, 03░21'E)

These mountain ranges are where tectonic plates pull apart, this pulling motion creates cracks in the ocean floor called rift zones. As the plates pull apart, magma rises to fill in the spaces. Heat from the magma causes the crust on either side of the rifts to expand, forming the ridges. The ridge was discovered by Bruce Heezen and Marie Tharp in the 1950s. The discovery of this ridge led to the theory of seafloor spreading and general acceptance of Wegener's theory of continental drift. According to plate tectonics, this ridge runs along a divergent boundary.

This ridge is an oceanic rift that separates the North American Plate from the Eurasian Plate in the North Atlantic, and the South American Plate from the African Plate in the South Atlantic. The ridge actually sits on top of the mid-Atlantic rise which is a progressive bulge that also runs the length of the Atlantic Ocean with the ridge resting on the highest point of this linear bulge. This bulge is thought to be caused by upward convective forces in the asthenosphere pushing the oceanic crust and lithosphere.

This divergent boundary first formed in the Triassic period when a series of three-armed grabens coalesced on the supercontinent Pangaea to form the Ridge. Usually only two arms of any given three-armed graben become part of a divergent plate boundary. The failed arms are called aulacogens and the aulacogens of the Mid-Atlantic Ridge eventually became many of the large river valleys seen along the Americas, and Africa (including the Mississippi River, Amazon River and Niger River).



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Cheers, and Good Mental Health,
Herr Saltzman

http://forums.atlantisrising.com/ubb/ultimatebb.php?ubb=get_topic;f=1;t=001530;p=10

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