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Oil Shale
ISSN 1736-7492 (Electronic)
ISSN 0208-189X (Print)
Impact Factor (2022): 1.9
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In the authors’ recent papers on oil shale chemical composition and geochemical variability, as well natural gamma radiation, the sig­nificantly variable layered lithological structure of the up to 90 m thick oil shale (OS) unit of the Muwaqqar Chalk-Marl Formation (MCM), Central Jordan, was described in detail for the first time. In this work, the original results of detailed comparative petrographic and mineralogical studies of the unit and its separate layers are presented.
   The studied drill cores represent an area about 73 km2 out of the large Attarat Um Ghudran (AUG, Attarat) deposit Maastrichtian in age. Oil shale with primary depositional structure and texture dominates. Laterally, layers, beds and interbeds of uniform composition and conditions of accumulation continue over the exploration area. Significant layering-dependent variations of chemical and mineral composition in the vertical succession of the oil shale unit occur. Petrographically, the dominating thick finely laminated uni­form siliceous-carbonate mudstone (MS) oil shale intercalates with variable intervals of grain-bearing oil shale, in which interbeds of proper mudstone alternate with laminae, lenses and thin interbeds of wackestone (WS). The dominating biogenic compounds are: (i) calcite as < 5 mμ micrite forming the groundmass mudstone, and both micrite of the matrix and > 5 mμ to 1 mm grains – skeletal particles (shells and their broken fragments) in wackestone, (ii) silica as < 5 mμ particles belonging to the groundmass of mudstone and wackestone matrix, (iii) organic matter (kerogen) in the mud­stone and matrix of wackestone, (iv) phosphate skeletal fragments in certain interbeds of wackestone and very fine apatite in groundmass. The clay minerals are the only possible terrigenous admixture in certain intervals. In accordance with the negative correlation between CaO and SiO2 the layers of the dominant calcite or silica (quartz, tridymite, cristobalite) occur, whereas in MgO-rich barren interlayers dolomite may prevail and in certain P2O5-enriched beds/interbeds apatite or in Al2O3-enriched layers clay minerals occur. In the vertical succession of the oil shale unit, also quantitative proportions of principal mineral and organic (kerogen) com­ponents vary a lot. Distinct thin interlayers of carbonates with low organic matter (OM) and silica contents reflect temporary breaks and imminent recoveries of oil shale accumulation. The data serve for a further assessment and commercial development of oil shale deposits.


 1.       Puura, V., Soesoo, A., Voolma, M., Hade, S., Aosaar, H. Chemical composition of the mineral matter of the Attarat Um Ghudran oil shale, Central Jordan. Oil Shale, 2016, 33(1), 1830.

2.       Voolma, M., Soesoo, A., Puura, V., Hade, S., Aosaar, H. Assessing the geo­chemical variability of oil shale in the Attarat Um Ghudran deposit, Jordan. Est. J. Earth Sci., 2016, 65(2), 6174.

3.       Plado, J., Ots, S., Puura, V., Aosaar, H. Interpretation of gamma-ray logs of the stratified oil shale seam in the Attarat Um Ghudran deposit, Central Jordan. Oil Shale, 2016,33(4), 340356.

4.       Hutton, A. C. Petrographic classification of oil shales. Int. J. Coal Geol., 1987, 8(3), 203–231.

5.       DeWolfe, J. C., Horne, E., Morgan, C. A. Geology and Geochemistry of the Al Lajjun Oil Shale Deposit, Central Jordan. AAPG Conference and Exhibition, Calgary, Alberta, Canada, September 12–15, 2010.

6.       Abed, A. M., Amiereh, B. S. Petrography and geochemistry of some Jordanian oil shales from North Jordan. J. Petrol. Geol., 1983, 5(3), 261–274.

7.       Abed, A. M., Fakhouri, K. On the chemical variability of phosphatic particles from Jordanian phosphorite deposits. Chem. Geol., 1996, 131(1–4), 1–13.

8.       Abed, A. M., Arouri, K., Amiereh, B. S., Al-Hawari, Z. Characterization and genesis of some Jordanian oil shales. Dirasat, Pure Sciences, 2009, 36(1), 7–17.

9.       Alqudah, M., Ali Hussein, M., Podlaha, O. G., Van den Boorn, S., Kolonic, S., Mutterlose, J. Calcareous nannofossils biostratigraphy of oil shales from Jordan. GeoArabia, 2014, 19(1), 117–140.

10.    Alqudah, M., Ali Hussein, M., Van den Boorn, S., Podlaha, O. G., Mutter­lose, J. Biostratigraphy and depositional setting of Maastrichtian–Eocene oil shales from Jordan. Mar. Petrol. Geol., 2015, 60, 87–104.

11.    Abed, A. M. The eastern Mediterranean phosphorite giants: an interplay between tectonics and upwelling. GeoArabia, 2013, 18(2), 67–94.

12.    Hamarneh, Y. Oil Shale Resources Development in Jordan. Natural Resources Authority, Hasemite Kingdom of Jordan, Amman, 1998.

13.    Hamarneh, Y., Alali, J., Sawaged, S. Oil Shale Resources Development in Jordan. Natural Resources Authority of Jordan (updated report), Amman, 2006, 19.

14.    Enefit Outotec Technology. (accessed 15.11.2015).

15.    Voolma, M., Soesoo, A., Hade, S., Hints, R., Kallaste, T. Geochemical hetero­geneity of Estonian graptolite argillite. Oil Shale, 2013, 30(3), 377–401.

16.    Einsele, G. Sedimentary Basins. Evolution, Facies, and Sediment Budget. Springer-Verlag, Berlin, Heidelberg, 2000.

17.    Boggs, S. Jr. Principles of Sedimentology and Stratigraphy. 3rd edition. Prentice Hall, New Jersey. 2001.

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