In:
GeoArabia, GeoScienceWorld, Vol. 14, No. 2 ( 2009-04-01), p. 101-140
Abstract:
Four reference sections through the calcareous-siliciclastic rocks of the Lower Cretaceous Kurnub Group and the Amman and Muwaqqar formations of the Upper Cretaceous to Paleogene Belqa Group in Jordan document the various processes of accumulation and alteration of organic matter (OM). Sections at Jerash, Sultani, Wadi Isal, and in the Kharazeh area were investigated by means of sedimentary petrography/mineralogy, organic petrography, and organic chemistry, and correlated with equivalent deposits in Syria and Egypt. The impacts of oxidation potential (Eh), acidity/basicity (pH) and temperature variations during the post-depositional alteration of these organic concentrations were assessed using x-y plots. Syngenetic Aptian-Albian coaly and organic-rich amber beds near Jerash developed in a tide-dominated delta under marginally alkaline conditions and were altered under slightly acidic conditions at temperatures of less than 100°C. Environmental analysis focused on Maastrichtian-Paleocene (?), oil shales in the Sultani area that were deposited in a small restricted basin on the continental shelf of the Neo-Tethys Ocean. Abnormally high contents of vanadium (V), phosphorus (P), zinc (Zn), and uranium (U) gave rise to yellow uranium ore minerals, phosphates and zinc sulfides and so bridge the gap between OM concentrations and those of uranium. The western part of the Arabian Peninsula is known for its uraniferous phosphorites and U-bearing calcretes. Reducing conditions during deposition of syngenetic OM in the oil shales may have shifted, in places, toward more oxidizing conditions in the course of post-depositional alteration at temperatures well below 200°C. Epigenetic fault-related concentration of OM was responsible for the Wadi Isal Aptian-Albian tar sand deposit and the oil seepage system in calcareous wall rocks of the Kharazeh Fault. The alteration of the tar sands (fluvial sandstones) is designated a high-sulfidation type (introduced aluminum sulfate minerals), whereas the oil seepage in Campanian shallow-marine carbonates is a low-sulfidation type (removal of aluminum sulfate minerals). Both alteration patterns may have implications for structure-bound base- and precious-metal deposits whose emplacement involves hydrocarbons as a carrier of metals in the mineralizing fluids. The Jordanian oil shales, tar sands, and uranium mineralization are possible sources of energy. Recent economic deals on the recovery and use of oil shales and uranium in Jordan are reviewed.
Type of Medium:
Online Resource
ISSN:
1025-6059
DOI:
10.2113/geoarabia1402101
Language:
English
Publisher:
GeoScienceWorld
Publication Date:
2009
detail.hit.zdb_id:
2961690-6
SSG:
13
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