INITIAL XRF RESULTS FROM THE LAKE MALAWI SEDIMENTARY RECORD

Preliminary results from XRF core scanning of Lake Malawi sediments provide remarkable insights into climate change in East Africa over the past 1000 years. We will highlight the following: use of XRF results for refining chronologies based on varve-counting; identification of chemical fingerprints for “marker beds” that have been used for stratigraphic linkages among cores; high-resolution evaluation of seasonal, decadal, and centennial-scale variation in deposition of biogenic and terrigenous material. For example, there appear to be clear signals of climate shifts to drier, windier conditions at the time of the Little Ice Age. We will present lower resolution reconnaissance studies of earlier periods, showing how the processes that we observe on annual timeframes are related to change on millennial timescales.