A record of titanium content of undisturbed river sediments transported to the southern Caribbean Sea has been analyzed by Haug et al. (2003) to resolve climatic events during the collapse of the Mayan civilization. They conclude that the demise of this civilization in the lowlands of the Yucatan Peninsula of Mexico occurred at the time of a hundred-year drought punctuated by shorter but multi-year droughts at approximately 810, 860, and 910 AD. Rapid population expansion during a climatically favorable period from about 550 to 750 AD left the civilization operating at the limits of the environmental carrying capacity. This left the Mayan society highly vulnerable to subsequent multi-year droughts and led to its collapse.
Reference
Haug, G. H., D. Gunther, L. C. Peterson, D. M. Sigman, K. A.Hughen, B. Aeschlimann, 2003: Climate and the collapse of Mayan civilization. Science, 299, 1731-1735.