Impact of Upwelling On Heterozoan, Biosiliceous, and Organic-rich Deposits: Jurassic (oxfordian) Hanifa Formation, Saudi Arabia

Abstract

Research Article| December 05, 2017 Impact of Upwelling On Heterozoan, Biosiliceous, and Organic-rich Deposits: Jurassic (oxfordian) Hanifa Formation, Saudi Arabia Hassan A. Eltom; Hassan A. Eltom 1Kansas Interdisciplinary Carbonates Consortium, Department of Geology, University of Kansas, Lawrence, Kansas, U.S.A. Search for other works by this author on: GSW Google Scholar Eugene C. Rankey; Eugene C. Rankey 1Kansas Interdisciplinary Carbonates Consortium, Department of Geology, University of Kansas, Lawrence, Kansas, U.S.A. Search for other works by this author on: GSW Google Scholar Stephen T. Hasiotis; Stephen T. Hasiotis 1Kansas Interdisciplinary Carbonates Consortium, Department of Geology, University of Kansas, Lawrence, Kansas, U.S.A. Search for other works by this author on: GSW Google Scholar Luis A. Gonzalez; Luis A. Gonzalez 1Kansas Interdisciplinary Carbonates Consortium, Department of Geology, University of Kansas, Lawrence, Kansas, U.S.A. 2King Fahd University of Petroleum and Minerals, Dhahran, Saudi Arabia Search for other works by this author on: GSW Google Scholar Dave A. Cantrell Dave A. Cantrell 2King Fahd University of Petroleum and Minerals, Dhahran, Saudi Arabia Search for other works by this author on: GSW Google Scholar Author and Article Information Hassan A. Eltom 1Kansas Interdisciplinary Carbonates Consortium, Department of Geology, University of Kansas, Lawrence, Kansas, U.S.A. Eugene C. Rankey 1Kansas Interdisciplinary Carbonates Consortium, Department of Geology, University of Kansas, Lawrence, Kansas, U.S.A. Stephen T. Hasiotis 1Kansas Interdisciplinary Carbonates Consortium, Department of Geology, University of Kansas, Lawrence, Kansas, U.S.A. Luis A. Gonzalez 1Kansas Interdisciplinary Carbonates Consortium, Department of Geology, University of Kansas, Lawrence, Kansas, U.S.A. 2King Fahd University of Petroleum and Minerals, Dhahran, Saudi Arabia Dave A. Cantrell 2King Fahd University of Petroleum and Minerals, Dhahran, Saudi Arabia Publisher: SEPM Society for Sedimentary Geology First Online: 05 Dec 2017 Online Issn: 1938-3681 Print Issn: 1527-1404 Copyright © 2017, SEPM (Society for Sedimentary Geology) Journal of Sedimentary Research (2017) 87 (12): 1235–1258. https://doi.org/10.2110/jsr.2017.71 Article history First Online: 05 Dec 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Hassan A. Eltom, Eugene C. Rankey, Stephen T. Hasiotis, Luis A. Gonzalez, Dave A. Cantrell; Impact of Upwelling On Heterozoan, Biosiliceous, and Organic-rich Deposits: Jurassic (oxfordian) Hanifa Formation, Saudi Arabia. Journal of Sedimentary Research 2017;; 87 (12): 1235–1258. doi: https://doi.org/10.2110/jsr.2017.71 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyJournal of Sedimentary Research Search Advanced Search Abstract The Middle East contains some of the world's most prolific source rocks and carbonate hydrocarbon reservoirs. Deposition of these strata were controlled by a range of local, regional, and global geologic processes. To better understand part of one Middle East hydrocarbon system, this study describes and interprets the sedimentology and total organic content (TOC) of an illustrative outcrop of the Upper Jurassic Hanifa Formation in Saudi Arabia, a unit correlative to nearby prolific subsurface source and reservoir strata. The 109-m-thick Hanifa section includes nine lithofacies, grouped into four lithofacies associations, interpreted to represent deposition on a carbonate ramp flanking the Arabian intrashelf basin. The bottom third of the section includes abundant biosiliceous deposits (mainly sponge spicules, which can constitute up to 50% of the grains) and early silicification; these strata also include a dominantly heterozoan grain association (crinoids, echinoderms). Strata higher in the section include a progressive decrease in abundance of biosiliceous grains and increase in abundance of photozoan-assemblage organisms, but include elevated TOC (up to several %). Although the bottom third of the section reflects deposition in a paleo-equatorial setting, these strata, dominated by a biosiliceous and heterozoan association and with elevated TOC, are interpreted to indicate conditions other than warm, shallow, oligotrophic conditions. Instead, these patterns are interpreted to reflect the influence of cooler and nutrient-rich water ultimately derived from monsoonal upwelling, equatorial upwelling, or both. In this conceptual model, upwelled water drives radiolite deposition off the Tethyan continental shelf, but subsequently the upwelled water moves westward into the Arabian intrashelf basins and onto adjacent shelves. These regional processes may explain organic-rich source rocks in nearby subsurface Hanifa Formation equivalents, and likely have analogs in other paleo-equatorial systems. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.