GEOCHEMISTRY OF JORDANIAN AND ISRAELI OIL SHALES
Mr. Tsevi Minster
Geological Survey of Israel
Tuesday, June 17, 3:30 p.m.
Ben Bandy Conference Room
Center for Applied Energy Research
Carbonate rocks enriched in organic material, generally termed 'oil shales', are widespread in Israel; there are indications that they can be found in the subsurface in 10-15% of the area. They especially characterize the part of the section formed by the Mishash and Ghareb formations of the Mount Scopus Group (Campanian to Maastrichtian).
The Section of the Oil Shale Member (lower member of the Ghareb Formation) was studied in detail. Variations in organic matter content in time and space were found to be useful tools for stratigraphic and paleogeographic purposes. Spatial variations of the proposed depo-centers may hint at some tectonic events.
Based on calcareous nanoplankton zonation it is suggested to divide the Oil Shale Member into lower and upper sub-units. The lower unit represents the >10% TOC grade of the oil shales. Those sub-units differ in their geochemistry; significant geochemical parameters defining the subunits are the SiO2/Al2O3 and P2O5/Al2O3 ratios and the Mn and Mo contents.
The studied sequence is characterized by relatively high sulphur contents and depletion in iron. Both C/S ratios and DOP values indicate that the higher dysoxic conditions in the sequence prevailed in the lower sub-unit of the Oil Shale Member; the underlying Mishash Fm sequence and the overlying upper sub-unit represent less extreme anoxic events.
A great similarity is found between the oil shales of Israel and Jordan. Some results of the present study may be reflected in a revised look at the configuration of some Jordanian oil shale fields. A positive correlation between free silica content and higher organic matter content is suggested for the oil shale basins of Lajjun and Es-Sultani.