9313828 Johnson This Americas Program award will support a research collaboration between Prof. Markes E, Johnson of the Department of Geology of Williams College and Prof. Jorge Ledesma Vazquez of the Universidad Autonoma de Baja California (UABC) in Baja California, Mexico. The purpose of the collaboration is to study various relationships among geological formations located in a series of small sedimentary basins at the base of the Concepcion Peninsula in Baja California. A previous reconnaissance survey revealed the unexpected presence of widespread bedded cherts in these basins and preliminary thin sections expose microfossils of dinoflagelates. The researchers intend to test the theory that some of the geological formations represent periods of local tectonic uplift, while others, including limestones and cherts, represent episodes of marine incursion related to rising sea level. The collaboration will involve undergraduate students from Williams College and from UABC, thus providing them with an early research experience. ***