Message #214086

[Courtney Caine]

 Because the land is not suitable for agriculture, the foundations of structures have been largely preserved.

The site encompasses about 5 square kilometers (about 1,200 acres). Using rugged computers and specialized GPS receivers, the team has carefully mapped about a fifth of the site, recording more than 1,300 features, including house mounds, room blocks, buildings, small temples, plazas and agricultural terraces.

Such detailed mapping "is quite revolutionary because it gives us a chance to see what the economic picture was, and the social differentiation," said archaeologist Barbara Stark of Arizona State University, who was not involved in the research. "It's hard to describe how important that is for our understanding of these societies."

Most of the site dates from AD 1000 to about 1350, when it began to shrink as the population moved elsewhere. By 1500, it was largely abandoned.

Most of the rest of the empire disappeared soon after. Smallpox and other diseases that were spread to the Aztecs by the Spanish were transmitted to the Purépecha as well, killing 80% to 90% of the population. By the time the Spanish attacked the Purépecha, there was hardly anyone left to resist.

thomas.maugh@

latimes.com

Copyright © 2010, The Los Angeles Times

http://www.latimes.com/news/nationworld/nation/la-sci-mexico13-2010apr13,0,1360313.story