Sedimentologic and Tectonic Patterns in Dead Sea Rift and Their Application to Hydrocarbon Exploration
Yoram Eshet, E. I. Robbins
The Dead Sea rift was produced primarily by sinistral strike-slip movement that offset many prominent geologic features along its 600-km length, from the Red Sea to the Lebanon Mountains. Unique structural patterns such as pull-apart basins arranged en echelon show that east-west extension and compression also occurred.
The sedimentologic history includes deposits of Miocene lacustrine and continental clastic sediments, Pliocene lagoonal evaporites from a marine tongue, and Pleistocene peat in the north with various clastic and chemical sediments derived from narrow, closed lakes in the south. The southern sediments were penetrated by the rising Sedom salt diapir.
Recent sedimentologic features include alluvial fans along the rift margins that are being dissected during the winter by runoff. At the eastern rift margin, sands are being offset by active faults. The Dead Sea, a remnant of an earlier lake, is halite saturated and is precipitating carbonates, sulfates, and halite.
Tar sands and asphalt seeps in marginal outcrops, oil and gas shows in cores, and the huge Sedom salt body have attracted hydrocarbon exploration to the Dead Sea area. Hydrocarbons may originate from (1) Senonian oil shales that occur both east and west of the rift, or (2) older (Permian-Triassic?) reservoirs that have undergone hydrologic changes brought on by rift-valley formation. An exploration model is being tested to evaluate the possibility of oil being generated by deep circulation of heavy, organic matter-rich brines along fault boundaries.
AAPG Search and Discovery Article #91043©1986 AAPG Annual Convention, Atlanta, Georgia, June 15-18, 1986.