RECONSTRUCTING WATER LEVELS USING CAVE SEDIMENTS, TO EVALUATE ACCESS POINTS TO THE SUBTERRANEAN PIT OF HOYO NEGRO

A pit named “Hoyo Negro” was discovered in the underwater caves of the Yucatan Peninsula; Mexico. It contained numerous Pleistocene fossils including the remains of a young PaleoIndian woman. There are numerous surficial access points to Hoyo Negro, which vary in size and age. The two closest access points are “Cenote Ich Balam” followed by “Cenote Oasis”. The formation age of Ich Balam was unknown due to its small stature. To determine if this cenote existed and provided ingress to Hoyo Negro during the time of bone deposition, the paleoenvironmental evolution of Ich Balam and Cenote Oasis were investigated. Measurements of the cave topography from the Cenote Oasis to Hoyo Negro including, floor and ceiling measurements, were documented. Additionally, nine sediment cores were taken directly in, and around the cenote breakdown piles. Radiocarbon dating, identification and abundances of foraminifera, thecamoebians and ostracods were determined for each core. Microfossil assemblages, along with sedimentary markers, indicated that Ich Balam was present and accessible no later than 8170 Cal BP, and during this time, Hoyo Negro was isolated from the surface. This information has implications for the anthropogenic use of Hoyo Negro, and will provide important information on the taphonomic history of the skeletal material.