MEDITERRANEAN QUATERNARY SAPROPELS, AN IMMEDIATE RESPONSE OF THE AFRICAN MONSOON TO VARIATION OF

• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 1984
• Subjects: Ice Sheet
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.570.623; http://eesc.ldeo.columbia.edu/courses/w4937/Readings/Rossignol_Strick.1985.pdf

Rossignol-Strick, M., 1985. Mediterranean Quaternary sapropels, an immediate response of the African monsoon to variation of insolation. Palaeogeogr., Palaeoclimatol., Palaeoecol., 49: 237--263. In the subsurface of the East Mediterranean Sea, eleven discrete basin-wide, organic-rich, black sapropels were deposited uring the last 465 000 years. They are dated by oxygen isotopic chronostratigraphy. The too.st recent sapropel has been shown to be the consequence of heavy Nile River summer floods due to increased monsoonal summer precipitation over Ethiopia, and not of Scandinavian ice-sheet meltwater influx into the East Mediterranean Sea as was previously believed. While most sapropels were deposited uring interglacials, two thick sapropels formed during glacial periods, as shown by their position in the oxygen isotopic stratigraphy and by their pollen record in core RC9-181. The new evidence presented here is that the sapropel sequence in this core, including the two glacial sapropels, correlates on a one-to-one basis with the highest values of an index of insolation on top of the al~mosphere. The concept of this index derives from an analysis of the African monsoon process. The index variation is computed for the last 465 000 years from the caloric northern summer insolation in the tropical atitudes, con-trolled by variations of the Earth's orbital parameters. It is conjectured that this index might be linked through the climate system to the monsoonal precipitation which in Africa produces the Nile River sUmmer flood: