FLEXER, A., Tel Aviv University, Tel Aviv, Israel, A. HONIGSTEIN, Geological Survey of Israel, Jerusalem, Israel, S. LIPSON, Institute of Petroleum and Energy, Tel Aviv, Israel, A. ROSENFELD, Geological Survey of Israel, Jerusalem, Israel, and E. TARNENBAUM, Consultant, Tel Aviv, Israel
ABSTRACT: Cretaceous Source Rock Sedimentation and its Relation to Transgressive Peaks and Geodynamic events for the Central Tethys
The reconstruction of the Mesozoic continents shows a wide triangle-shaped Tethys (or Neotethys) between Africa and Eurasia. The Arabian Craton comprised the central part of its southern margins.
The Cretaceous period started with extension, volcanism, continued by accelerated divergence during Aptian to Turonian and terminated by convergence and folding. The sea level stand, after a major fall at the commencement, is characterized by a steady stepwise rise with some minor retreats.
The global oceanic anoxic events correspond to large-extent transgressions and associated with organic rich sedimentation. The accelerated building up of mid-oceanic ridges is possibly connected to a mantle plume, active around 120-80 Ma. Sea level rise and sea floor spreading is felt mainly at these times in the passive southern margins of the central Tethys. The Senonian compressive tectonic regime transforms them into active margins (destruction of oceanic crust, obduction and thrusting); sea level highstands control dysoxic sedimentation.
Dysoxic sediments were observed in the Gevaram shales (Tithonian to Hauterivian). Talme Yafe marls (Late Aptian to Albian), Daliyya Formation (latest Cenomanian to Turonian) and the Mount Scopus Group (Santonian to Maastrichtian). The organic matter in the Gevaram shales is mixed marine and terrestrial (2.6% TOC) and in the Daliyya marls mostly marine (2.5% TOC). Both units have source rock possibilities and yield petroleum upon appropriate burial. The Senonian bituminous rocks (oil shales) are rich in marine organic matter (20% TOC) and are excellent source rocks in the Dead Sea area.
AAPG Search and Discovery Article #90988©1993 AAPG/SVG International Congress and Exhibition, Caracas, Venezuela, March 14-17, 1993.