Atlantis Online
August 09, 2022, 03:47:33 am
Welcome, Guest. Please login or register.

Login with username, password and session length
News: USA showered by a watery comet ~11,000 years ago, ending the Golden Age of man in America
  Home Help Arcade Gallery Links Staff List Calendar Login Register  

Plate Tectonics Versus Earth Crust Displacement???

Pages: [1]   Go Down
Author Topic: Plate Tectonics Versus Earth Crust Displacement???  (Read 1047 times)
Carolyn Silver
Superhero Member
Posts: 4611

« on: September 27, 2009, 04:49:42 am »

    * Problems:
          o No adequate explanation for what caused geosynclines to develop and then deform. Airy isostasy (observed topography due to crustal root) was mechanism invoked.
                + Airy Isostasy -
                      # Layer below crust acts as fluid in the long term.
                      # Where crust is thick (mountains), it sinks into the fluid layer until bouyancy provides support. Where crust is thin (oceans), fluid wells up underneath.
                      # Why? - Stress Balance (fig. 2.29 in K&V):
                      # Thinning of crust by erosion or thickening by deposition, leads to adjustment in the form of uplift or subsidence due to removal or addition of loads, respectively.
          o No explanation for ophiolites in mountain belts (allow geosyncline formation in deep water? not just on continental shelves?)
          o No explanation of large amounts of shortening observed in Alps (down-sucking of European platform beneath Alpine geosyncline?)

Isostasy is undoubtedly an important driving mechanism for deformation on the Earth today, but it is not the only one.
Report Spam   Logged

Pages: [1]   Go Up
Jump to:  

Powered by EzPortal
Bookmark this site! | Upgrade This Forum
SMF For Free - Create your own Forum
Powered by SMF | SMF © 2016, Simple Machines
Privacy Policy