Miocene Brackish Water and Lacustrine Deposition in the Suez Rift, Sinai, Egypt

Abstract

Other| February 01, 2000 Miocene Brackish Water and Lacustrine Deposition in the Suez Rift, Sinai, Egypt WILLIAM A. WESCOTT; WILLIAM A. WESCOTT 1Geological Consultant, 1214 Krist Drive, Houston, TX 77055 Search for other works by this author on: GSW Google Scholar WILLIAM N. KREBS; WILLIAM N. KREBS 2Geological Consultant, 2811 Autumn Lake Drive, Katy, TX 77450 Search for other works by this author on: GSW Google Scholar PETER A. BENTHAM; PETER A. BENTHAM 3BP Amoco plc, 550 WestLake Park Boulevard, Houston, TX 77079-2696 Search for other works by this author on: GSW Google Scholar DAVID T. POCKNALL DAVID T. POCKNALL 3BP Amoco plc, 550 WestLake Park Boulevard, Houston, TX 77079-2696 Search for other works by this author on: GSW Google Scholar Author and Article Information WILLIAM A. WESCOTT 1Geological Consultant, 1214 Krist Drive, Houston, TX 77055 WILLIAM N. KREBS 2Geological Consultant, 2811 Autumn Lake Drive, Katy, TX 77450 PETER A. BENTHAM 3BP Amoco plc, 550 WestLake Park Boulevard, Houston, TX 77079-2696 DAVID T. POCKNALL 3BP Amoco plc, 550 WestLake Park Boulevard, Houston, TX 77079-2696 Publisher: SEPM Society for Sedimentary Geology Accepted: 10 Nov 1999 First Online: 03 Mar 2017 Online ISSN: 1938-5323 Print ISSN: 0883-1351 Society for Sedimentary Geology PALAIOS (2000) 15 (1): 65–72. https://doi.org/10.1669/0883-1351(2000)015<0065:MBWALD>2.0.CO;2 Article history Accepted: 10 Nov 1999 First Online: 03 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation WILLIAM A. WESCOTT, WILLIAM N. KREBS, PETER A. BENTHAM, DAVID T. POCKNALL; Miocene Brackish Water and Lacustrine Deposition in the Suez Rift, Sinai, Egypt. PALAIOS 2000;; 15 (1): 65–72. doi: https://doi.org/10.1669/0883-1351(2000)015<0065:MBWALD>2.0.CO;2 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 SocietyPALAIOS Search Advanced Search Abstract From its inception during the early Miocene, the Suez Rift has been dominated by marine sedimentation. New high-resolution biostratigraphic and sedimentologic analyses of synrift deposits have resulted in the recognition of late Burdigalian-early Langhian brackish water and lacustrine deposits in the Wadi Abu Gaada-Gebel Gushia area, Sinai Peninsula. The Abu Gaada section is unique because: (1) it is an anomalously thick section of non-calcareous shale and mudstone in the Lagia Member of the Ayun Musa Formation; and (2) the mudstones contain an abundant microflora consisting of marine and nonmarine diatoms and freshwater algae that indicate they were deposited in a freshwater to brackish water environment. The abundant freshwater and shallow marine algae include the nonmarine diatoms Aulacoseira Thwaites, Fragilaria construens (Ehrenberg) Grunow, Synedra ulna (Nitzsch) Ehrenberg, and SurrirellaTurpin, as well as the freshwater algae Botryococcus Kutzing and Pediastrum Meyen. Shallow marine diatoms are represented by Actinoptychus Ehrenberg, Actinocyclus ehrenbergii Ralfs, Paralia sulcata (Ehrenberg) Cleve, Rhaphoneis Ehrenberg, and HyalodiscusEhrenberg. Correlations with other coeval stratigraphic sections in the Sinai Peninsula indicate that brackish water and lacustrine deposition was localized in the Wadi Abu Gaada-Gebel Gushia area. This is explained by uplift and tilting of the bounding faults separating the Wadi Abu Gaada-Gebel Gushia block from adjacent rift blocks where normal marine conditions prevailed. The increased freshwater influence was the result of a rising water table during a period of rising sea level. As transgression continued, the barrier that separated the Wadi Abu Gaada depression from marine waters was eventually breached. Brackish water then filled the depression. Eventually a hypersaline lagoon formed in what previously had been a fresh waterlake, depositing the Markha Anhydrite. Correlative brackish water/lacustrine shales also have been found in the subsurface of the Gulf of Suez and thin coeval deposits are present on its southwestern margin. This reflects that the local occurence of these depositional environments was controlled by structural reorganization of fault blocks in the Suez Rift in response to the “mid-clysmic” tectonic event. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.