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LITHO‐ AND MICROFACIES OF UPPER JURASSIC CARBONATE ROCKS OUTCROPPING IN CENTRAL SAUDI ARABIA
Author(s) -
Okla Saleh M.
Publication year - 1986
Publication title -
journal of petroleum geology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.725
H-Index - 42
eISSN - 1747-5457
pISSN - 0141-6421
DOI - 10.1111/j.1747-5457.1986.tb00381.x
Subject(s) - geology , outcrop , carbonate , carbonate rock , breccia , geochemistry , paleontology , structural basin , deposition (geology) , anhydrite , sedimentary rock , geomorphology , materials science , metallurgy , gypsum
A study of surface sections of Upper Jurassic rock units near the city of Riyadh has revealed a total thickness of 500 m. These rock units are the Tuwaiq Mountain Limestone, Hanifa Formation, Jubaila Limestone, Arab Formation and Hith Anhydrite. The characteristic microfacies of Tuwaiq Mountain Limestone include spicular biomicrites in the lower part of the formation, and corals, stromatoporoids and algal biomicrites in the upper part. The characteristic microfacies of the Hanifa, Jubaila and Arab Formations include spicular biomicrites with some argillaceous shales alternating with pelsparities and oosparites. Conglomeratic micrites, dolomites and breccia are found in the upper Jubaila Limestone and the Arab Formation. The total thickness of these rock units increases in the east to more than 900 m where the Arabian and Gotnia Basins are defined. Central Saudi Arabia is best described as being the site of differential carbonate shelf deposition during Upper Jurassic time. Intra‐shelf basins with euxinic conditions were formed. Over these basins, petroleum source rocks were deposited within each rock unit.