ALBERT

Description: We studied Holocene sediments from the northeastern Arabian Sea near Pakistan, which were obtained from the same location in 1993 and 1998, to determine the composition and origin of laminated sediments for this 5 year time interval. Methods included geochemical, sedimentological and palaeontological analyses. We then compared our results with meteorological records, and satellite and sediment trap data. We suggest that short-term (few days) heavy rainfall periods in the hinterland and at the coast lead finally to flood events causing the deposition of light-coloured layers as event deposits on the continental slope. These layers are characterized by low percentages of biogenic compounds (i.e. organic matter, coccoliths and diatoms) and interpreted to have been deposited mainly during the winter season, when heavy rainfall can be expected. The thickness of the light layers seems to be related to the intensity of precipitation during a single flood event. In the 1997-1998 El Nino year, which was characterized by the strongest anomalies for the last 20 years, the thickest layer was deposited. The dark layers accumulate over the remaining larger part of the year and are characterized by an elevated input of biogenic material (marine organic matter, skeletal opal, foraminifera and coccoliths).