Despite several decades of research focusing on prehispanic human ecology, debate continues over the impact of climatic and anthropogenic landscape change on human populations in Mesoamerica. One problem in identifying the cause of this change is the lack of high-resolution paleo-environmental data from many regions. The southern Mexican highlands, in particular, have yielded few paleoenvironment data, yet have a rich and diverse cultural history. The sedimentary record from Laguna Minucúa, located within the Sierra Madre del Sur, Oaxaca, offers an exceptional opportunity to address human and environmental interactions in the region. Minucúa is a small (∼0.25 ha), currently shallow pond with no apparent inlets or outlets. We retrieved two sediment cores from the site (3.5 m and 5.6 m long). The cores are highly laminated. Core chronology was developed with paleomagnetic secular variation data and compared with couplet counts and limited radiometric measurements. These data indicate that the Minucúa record at least spans the last ∼4500 ± 100 years. We discuss preliminary results that assess long-term environmental change for the region through examination of geochemical and magnetic susceptibility data. In particular, we discuss in more detail a 500 year time slice which encompasses the period known as the “Classic Collapse.” The record indicates overall dry conditions but with two extended wet periods experienced between 1160 and 1120 cal yr BP and 1060–1000 cal yr BP We place our findings in the context of current archaeological and paleoclimatological research in Oaxaca.
Bibliographical noteFunding Information:
The research described herein was funded by the following grants: University of Colorado Innovative Grant Program (AAJ), University of Colorado Norton Fund (AAJ). We would also like to thank the Centro de Investigaciones y Estudios Superiores en Antropología Social and the people of the municipio of San Miguel el Grande. We would like to thank Raymond Mueller, Lucia Pou and Pepe Aguilar. Guerra received a LacCore Visiting Graduate Student Program scholarship to LacCore to process the cores (Funds for the LacCore Visiting Graduate Student Program are partially supported by the National Science Foundation - Instrumentation and Facilities Program as part of LacCore / CSDCO operational funding ( 1462297 , 1338322 )). Synchrotron beam work is based upon research conducted at the Cornell High Energy Synchrotron Source (CHESS) which is supported by the National Science Foundation and the National Institutes of Health / National Institute of General Medical Sciences under NSF award DMR-1332208. The contribution of Celestian was supported in part by the Natural History Museum of Los Angeles County Trelawney Endowment. We appreciate the constructive critical comments from two anonymous reviewers and from Dr. S. Starratt.
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- Classic period
- High-resolution climate record
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