Abstract
Lacustrine sediments from a section of a core extracted from the central part of the former Lake Chalco were analysed for diatom content. Radiocarbon dates and tephra correlations bracket the period under study between 34 and 15 ka BP. According to the diatom stratigraphy, Chalco was an alkaline-saline lake during the interval 34–31.5 ka BP. After 31.5 ka BP, it went through a shallower and more concentrated phase until ca . 23.5 ka BP. At ca . 23.5 ka BP, a major environmental change took place during which Lake Chalco was transformed from an saline-alkaline pond into a freshwater lake. Previous archaeological work at Tlapaocya indicates that humans entered the Basin slightly after this environmental change, by ca . 22 ka BP. At 19 ka BP, another reduction in water level occurred with the onset of a period of quick fluctuations between slightly acidic and neutral water. These variations were probably associated with intensified volcanic activity that affected the area between 19 and 15 ka BP.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
