GSA Annual Meeting in Denver, Colorado, USA - 2016

Paper No. 124-4
Presentation Time: 2:40 PM


BEACH, Timothy1, DONN, Leila1, LUZZADDER-BEACH, Sheryl2, KRAUSE, Samantha M.3 and DOYLE, Colin2, (1)Geography and Environment, UT Austin, 305 E. 23rd Street, Austin, TX 78712, (2)Geography and the Environment, University of Texas at Austin, CLA Bldg. Rm. 3.306, A3100, 305 E. 23rd Street, Austin, TX 78712, (3)University of Texas at Austin, Austin, TX 78712,

This paper synthesizes and presents new geoarchaeological and paleoecological records of the Neundorf alluvial fan and wetland field complex based on two excavations of alluvial fans, three wetland field complexes, and a new pollen and charcoal record. The area lies in transition from a normal fault escarpment to a sequence of wetlands altered by the ancient Maya from 3000 to 1000 years ago. The escarpment has remnant tropical forest but deforestation of the wetlands occurred from 1958 to the 1970s. We present chronological and stratigraphic evidence of paleosols, sedimentation, and field formation in these fans and wetland fields and canals. Our methods include AMS dating, typical soil analyses, magnetic susceptibility, XRF/XRD, and new isotopic and elemental geochemistry of sediment sequences and water chemistry. This landscape aggraded by 2 m over a stable Holocene paleosol starting about 2600 years ago in the Maya Preclassic period when ancient Maya land uses intensified. Ancient Maya farmers built wetland field and canals after this time, which lasted until 1000 years ago in the Maya Terminal and Post Classic. Next, the paper compares these new data and interpretations with a 2016 LiDAR survey to interpret the extent of these systems as well as other wetland field systems based on two decades of soil geomorphology, water chemistry, and archaeological study. We will thus compare multiple scales of geoarchaeology and multiple drivers of landscape formation over the Late Holocene in this Neotropical fluviokarst lowland.