Paleomagnetic and geochemical record from cores from the Sea of Marmara, Turkey: Age constraints and implications of sapropelic deposition on early diagenesis

Abstract

Abstract We present results of a multi-proxy analysis of two sediment cores from the Marmara Sea. The cores were analyzed using paleomagnetic and geochemical measurements. Two sapropels are documented in the last 11 kyr and are recorded in several locations across the Marmara Sea. These two sapropels have contrasting magnetic properties. The magnetic record is affected by intense early diagenesis; the most recent upper sapropelic layer has low remanence and susceptibility values. A record of paleomagnetic inclinations could still be isolated above the diagenesis front and is compared with secular variation models. The lower sapropel is identified in the deep part of the oldest studied core (Klg07) and has distinct magnetic properties characterized by high remanence and susceptibility values. Using the magnetic properties it is possible to constrain bottom water ventilation and reconnection episodes between the Marmara Sea and the Black Sea following the sea level rise during the last glacial to inter-glacial transition.