Beschreibung
cited from: Stein, M., Z. Ben-Avraham, S. Goldstein, A. Agnon, D. Ariztegui, A. Brauer, G. Haug, E. Ito and Y. Yasuda (2011). "Deep Drilling at the Dead Sea." Sci. Dril. 11: 46-47.
At the lowest point on Earth, the Dead Sea, a unique scientific project, the Dead Sea Deep Drilling Project (DSDDP), is being conducted to establish a late Quaternary paleoenvironmental, tectonic, and seismological archive. Scientific groups from Germany, Israel, Japan, Jordan, Norway, Palestine, Switzerland, and the U.S.A. gathered for the first time on 21 November 2010 to perform scientific drilling at the floor of the deep basin of the Dead Sea. With current lake level of 423 m below sea level and water depth of 300 m, coring started at 723 m below mean sea level. During the first three weeks of drilling ~460 meters of sediment cores were recovered. As expected from shallow piston cores and on-land deposits from the lake level highstands, the cores are composed of alternating intervals of marly units and salts. The sedimentary intervals represent several glacial and interglacial cycles spanning an estimated interval of ~200,000 years. Two coarse-grained sections imply almost complete dry-out phases of the Paleo-Dead Sea, meaning that twice the lake surface was several hundred meters below present day sea level. Drilling is being conducted with the Large Lake Drilling Facility (see front cover of this issue) of DOSECC (Drilling Observation and Sampling of the Earth´s Continental Crust, Inc.). The upper 30 meters were cored by using a hydraulic piston coring system that is capable of penetrating several salt layers with high core recovery, while the deeper section was retrieved with the extended-nose bit coring tools.