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The Great Maya Droughts: A GK-12 Activity Utilizing ODP Core 1002D Jeri C. Rodgers NSF GK-12 Fellow, University of Texas Institute for Geophysics James Cano Earl Warren High School, San Antonio Texas Kathy Ellins University of Texas Institute for Geophysics Our Villain: Chac: God of Rain “The Long- Lipped God” Purpose of the Activity • Targets 11th-12th graders in GMO (Geology, Meteorology and Oceanography) courses, as well as IPC (Integrated Physical and Chemistry) • Teaches concepts which will help students attain GMO TEKS (Texas Essential Knowledge and Skills) objectives • Utilizes current technology, which is unusual in present lessons available to secondary teachers • Relates geophysical studies to an interesting historical mystery • Acquaints students with Excel techniques • Teaches world history, culture, geography, and mythology Outline of Presentation • Introduce the Maya area, history, and mystery of Maya city abandonment • Introduce the Cariaco Basin Ocean Drilling Project and the assumptions made in using Core 1002D Ti data as a proxy for rainfall • Introduce Lake Chichancanab core data as a CaC03/S proxy for rainfall •Maya history and area Maya Civilization: 2,000 BC to 950 AD Pre-Classic Period: 800 BC until 250 AD •Two collapses: 280 AD and 380 AD Classic Period from 250 AD to 950 AD •Major population decline between 67-93% of population lost and cities abandoned Post-Classic Period from 950 AD to 1500s Hodell, noaa website Left: Yucatan Peninsula showing Maya Lowlands and points of interest. Right: Temple 1 at Tikal, the funerary pyramid of Hasaw Chan K’awil Hodell, noaa website Climate regions of the Maya region: SA = Semiarid, AW = Tropical Savanna, AM = Tropical Monsoon, AF = Tropical Rainforest The Cariaco Basin Jaimes, 2003 Preliminary Data for the Activity • Core 1002D-H taken by JOIDES Resolution 1995-1996 within the Cariaco Basin • The basin is a silled, anoxic, pull-apart basin, which allows for deposition of undisturbed laminated sediments • Workers measured concentration of titanium (Ti) vs. depth for 30 cm section of laminated sediment, with calibrations of laminations based upon C14 dates ODP database Assumptions in Using Cariaco Basin Core 1002 Data • Rainfall amounts were comparable in the Yucatan Peninsula and the Cariaco Basin • Laminated core could be used as “tree rings” to measure climate and date those measurements • The concentration of titanium (Ti) in sediment layers can serve as a proxy for rainfall amounts in the sedimentary layers Correspondence of Yucatan and Cariaco Basin with Respect to the ITCZ Haug et al., 2003 Anoxic basins allow preservation of laminations because there is no bioturbation Why Ti? • Titanium (Ti) occurs in ilmenite and rutile – both forms of TiFeO3 • They are common in detrital sediment • Their weight means that they are washed off the continent in relationship to river energy • They are non-reactive in water and sediments • Note: The Asian tsunami of 2004 washed up enough ilmenite in Thailand that they are considering mining it for titanium! Figure 7. Muruwai Beach, North Island, New Zealand (11 January 2005.) Photograph by James Shook <http://en.wikipedia.org/wiki/Image:Muriwai_Beach_02.jpg>, accessed September 15, 2008. The black sand is a mixture of iron, titanium, vanadium and other materials volcanic in origin. Excel spread sheet with data used for the activity. All charts are plotted from this data summary. Hodell, noaa website Lake Chichancanab Correlative study by Hodell et al. (Nature, 1995) using %CaCO3 vs. %S as a rainfall proxy Products of this GK-12 Assignment • Maya Activity • Power point with history and mythology of the Maya • ASLO Oral Presentation (February 2005) • GSA-SC Workshop (April, 2005) chaired by Joel Stevens Whatever Happened To….? Chak He was replaced by: Tlaloc – Toltec God of Rain Acknowledgements and References • • • • • • • • Dr. Paul Mann and Marcy Davis of UTIG ODP Researchers for providing core photos GK-12 Workshop participants Haug, Gerald H., Detlaf Gunther, Larry C. Peterson, Daniel M. Sigman, Konrad A. Hughen, Geat Aeschlimann (2003) Climate and the collapse of Maya Civilization. Nature 299:1731-1735. Hodell, David A., Jason H. Curtis, and Mark Brenner (1995) Possible role of climate in the collapse of Classic Maya civilization. Nature 375:391-394. Jaimes, Martha A. (2003) Paleogene to Recent tectonic and paleogeographic evolution of the Cariaco Basin, Venezuela David Hodell provided slides for educational use through http://www.ngdc.noaa.gov/paleo/slides/slideset/12/12_196_cslide.html Data for ODP core obtained via ftp://ftp.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/haug2001/cariaco _ti.txt