Source rock potential of the phosphorite-bituminous chalk-marl sequence in Jordan

The phosphorite and the overlying 'oil shale' succession in central and eastern Jordan has been studied for its organic matter composition, maturation, hydrocarbon potential and sedimentological implications. Pristine phosphorite was authigenically precipitated from interstitial solutions in ventilated environments. Later they were reworked and winnowed to produced the granular phosphorites possibly as wave or storm sand bodies. The oil shale was deposited in the same basins where restricted water circulation and subsequent hypersalinity led to more reducing conditions and better organic matter preservation. Both facies represent a high bio-productivity regime associated with paleo-upwelling on the shallow, southern epicontinental shelf of the Tethys Ocean. The organic matter is dominantly amorphous and the extractable part is high. Kerogen is Type II-S to Type III. All maturity parameters investigated proved it to be immature (e.g. R-0 < 0.3%). However, the high NSO content of the phosphatic and associated oil shale lithologies may explain the occurrence of in situ sulphur-rich asphalts and heavy oils at shallow depths in the Azraq Basin and the Dead Sea area. (c) 2005 Elsevier Ltd. All rights reserved.