High accumulation rates, the lack of bioturbation, an abundance of distinct laminae (probably varves), and the preservation of both siliceous and calcareous microfossils, make the anoxic sediments of the Cariaco Basin optimal for use in constructing high-resolution records of paleoclimatic change. During the field program piston, gravity, and box core samples of these laminated sediments will be collected. AMS radiocarbon time control and multiple paleoenvironmental proxies will be used to focus on changes in trade wind strength and hydrologic balance over the western tropical North Atlantic region during the last glacial termination, the Holocene, and the Little Ice Age. Preliminary analysis of existing data suggests that this change was large and related to global climatic change. After testing the annual nature of the sediment laminae, calibration time series of proxy data from the sediment directly against observed hydrographic and climatic data will be made. Synoptic analysis and climate model experiments will be used to understand reconstructed patterns of low latitude variability in the context of global change and to test hypothesized causes of this variability.
