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Surface and subsurface oil shale (OS) rocks in Jordan have potential economic value for the country and still unutilized. This research paper focuses on central and southern OS deposits in Jordan. Brief characterization of four OS deposits is presented. Size distribution test and elemental analysis were performed. Shale oil was extracted via three solvation methods: Soxhlet extraction, extraction via mixing and stirring, and lastly super-critical fluid extraction. Major shale oil fractions were obtained from extract fractionation on chromatographic column. The nuclear magnetic resonance spectroscopy technique was used to study qualitatively the fractional composition of OS extract. Results show that all studied OS deposits have quite similar trend in their particle size distribution and their elemental composition. These OS deposits are found to be varying in their solvation behavior, fractional yield, and shale oil composition. Highest yield is obtained from polar solvents. The OS extraction via solvation processes is promising under certain extraction conditions such as super-critical conditions. The solvation variability of Jordanian OS indicates that different extraction techniques suit different OS deposits. Such variability should be considered in any future extraction options.

The Sultani oil shale (OS) deposit is considered as a major fossil fuel source in Jordan. Applying various petrographic and geochemical techniques, this paper aims to study the Sultani OS geochemical and organic petrographic features. Results show that Sultani OS is a bituminous limestone consisting of very fine-grained matrix with rippled micro-laminated texture and muddy material of cryptocrystalline micrite. The rock is rich in Cretaceous microfossil shells filled in organic matter (OM). The fillingOMis bitumen of the migrabitumen type. TheOMcontent reaches up to 17 wt.% with high oil-yielding capacity (up to 12 wt.%). High TOC values suggest that the Sultani OS has a very good source rock potential. Organic petrography shows lowOMmaturity level and reveals two varieties of vitrinite, namely primary and oxidized vitrinite. The latter is derived from terrestrial plant tissues. Additionally, liptinite macerals including alginite and to a lesser extent cutinite, also participate. Various diagenetic features such as pyrite replacement and bitumen thermal alteration have been recorded. Results suggest that Sultani OS is a marinite formed under marine conditions with limited contribution of terrestrialOMinput.

Quartz geodes are spectacularly displayed at Ras En Naqab where hundreds of geodes have weathered from their host chalky limestone and sandstone beds and scattered on slope surfaces. Geodes of different sizes, shapes and fillings appear in four horizons of the shallow marine sediments of the Upper Cretaceous Wadi Umm Ghudran Formation in South Jordan. They are characterised by a wide areal extent, but limited stratigraphic distribution, and as such, they represent a distinctive stratigraphic marker horizon. Ghudran geodes are mostly milky white in colour, botryoidally and crystalline in shape and range in diameter from 3 to 30 cm or more. It is believed that the formation of geodes took place in cavities, after complete dissolution of pre-existing fossils, which left no trace of their internal microstructures but only faint appearance of external moulds. Chalcedony and microcrystalline quartz occur as cavity linings and in some samples as cavity filling. The structure of the silica geodes begins with chalcedony in its outer rim followed, internally, by microcrystalline quartz and ends with prismatic quartz crystals in the central part. Spot analysis indicates that the geodes composed totally of Si and O with traces of Al (0.05 %). The silica-rich solutions that formed the geodes were possibly derived from the weathering of the overlying Amman Silicified Limestone Formation and the infiltration of chemical products by the action of groundwater. Investigations showed that the crystallization went slowly under equilibrium conditions and formed from the same silica source.

This work discusses status of the geologic and economic potentials of minerals and industrial rocks in Jordan. The major mineral resources are presented in details and the paper is designed to cover the lack of published data in this field. Geologically, the structural framework of Jordan is controlled largely by Arabian Nubian Shield in the south, block—faulted areas in the east, upwarping in north and east, and Wadi Araba-Dead Sea Transform Fault in the western part. The geologic environments include Precambrian crystalline basement (Late Proterozoic) of Arabian Nubian Shield (ANS) that is composed of igneous and metamorphic rocks at south-western part. Paleozoic rocks at southern and southeastern part consist of clastic minerals which are dominated by sandstone, whereas Mesozoic sedimentary rocks are widespread throughout southwestern, northern to southeastern parts of the country. They mainly consist of major industrial rocks and minerals such as phosphate, oil shale, limestone, dolomite, chalk, marble, gypsum, diatomite and tripoli. Cenozoic Era is composed of sedimentary and volcanic rocks in different parts of Jordan. There are more than twenty nonmetallic minerals and four main metallic deposits within the various geologic environments. This paper summarizes their distribution, chemical and mineralogical characteristics, in addition to their production statistics.

The effect of mineral matter content on the activation energy of oil shale pyrolysis has been studied. Kerogen was isolated from raw oil shale by sequential HCl and HCl/HF digestion. Oil shale and kerogen samples were pyrolyzed in a Thermogravimetric Analyzer at different heating rates (1, 3, 5, 10, 30, and 50 °C/min) up to a temperature of 1000 °C. Total mass loss of all oil shale samples remained almost constant irrespective of the heating rate employed, whereas it decreased with the increase of heating rate for kerogen (74.5 to 71.4%). From the pyrolysis profile activation energy (Ea) was found to vary between 70 and 83 kJ/mol for oil shale, while 82–112 kJ/mol has been determined for isolated kerogen. An increase of both Ea and pre-exponential factor was observed with an increasing heating rate. It is concluded that the mineral matter in oil shale enhances catalytic cracking as is evident from the reduced Ea values of oil shale compared with those for kerogen.

Phosphorite concretions are recorded for the first time within the lower part of the Umm Rijam Chert Limestone Formation (Eocene) in the Ma'an area, southern Jordan. The phosphorite concretions are typically hosted and encountered as individual layer in moderately lithified sediments of marl, chalk and chalky marl. The phosphorite concretions are present in thin layer (10–30 cm thick). They are localized on a hardground surface that formed as a result of cementation of soft ground by bioclastic materials. Light grey and brownish to black colors are encountered with isometric, ellipsoid, elongated, subangular to subrounded phosphorite concretions (up to 6 cm in length). Most of the phosphorite concretions preserve bioturbation structures; they also include fecal pellets of various sizes. The main biogenic components are fragments of macrofossils (bivalves) and microfossils (planktonic foraminifera) in different proportions. Petrographic examinations reveal that the phosphorite concretions are composed of cryptocrystalline apatite that characteristically appears in cross-polarized light almost as isotropic phosphate and minor anisotropic phosphate. Apatite and calcite are the main mineral constituents of the phosphorite concretions identified by XRD. The apatite is identified as francolite (carbonate-flour-apatite). Chemical analyses of the phosphorite concretions using X-ray florescence indicate that the P2O5 content ranges from 18.8 to 31.19%, whereas SEM–EDS analyses indicate that the phosphorus proportion is around 14% by volume. It could be argued that the phosphorite concretions were transported after being reworked, or were derived from carbonate and chalk pebbles that were later phosphatized and subjected to erosion, forming residual lag deposit along the hardground surface.

Degradation and subsequent calcitization of phosphate grains from the upper part of the Late Cretaceous Amman Formation at southeast Irbid in northern part of Jordan have been petrographically verified. A number of calcitization patterns were observed. The variety in calcitization patterns reflects the replacing nature of calcite. Filamentous schizophytes are assisted, through borings, in early degradation of bone fragments into phosphomicrite fillings and dark envelopes (haloes) around grains. Calcitization process is more likely attributed to the availability of calcite, restriction of apatite formation, nature and composition of phosphate grains, varying pH of sediment and pore-fluids and physico-chemical conditions of the depositional site. Diagenetic replacement of phosphate grains by calcite as a result of calcitization process resulted in poorer grade of phosphate deposits where the P2O5 is less than 15.2%.