Geotectonic Evolution and Subsidence of Bahama Platform

Research Article| July 01, 1970 Geotectonic Evolution and Subsidence of Bahama Platform ROBERT S DIETZ; ROBERT S DIETZ Environmental Science Services Administration, Atlantic Oceanographic and Meteorological Laboratories, Miami, Florida 33130 Search for other works by this author on: GSW Google Scholar JOHN C HOLDEN; JOHN C HOLDEN Environmental Science Services Administration, Atlantic Oceanographic and Meteorological Laboratories, Miami, Florida 33130 Search for other works by this author on: GSW Google Scholar WALTER P SPROLL WALTER P SPROLL Environmental Science Services Administration, Atlantic Oceanographic and Meteorological Laboratories, Miami, Florida 33130 Search for other works by this author on: GSW Google Scholar GSA Bulletin (1970) 81 (7): 1915–1928. https://doi.org/10.1130/0016-7606(1970)81[1915:GEASOB]2.0.CO;2 Article history received: 10 Nov 1969 first online: 02 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 ROBERT S DIETZ, JOHN C HOLDEN, WALTER P SPROLL; Geotectonic Evolution and Subsidence of Bahama Platform. GSA Bulletin 1970;; 81 (7): 1915–1928. doi: https://doi.org/10.1130/0016-7606(1970)81[1915:GEASOB]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 SocietyGSA Bulletin Search Advanced Search Abstract The thick section (greater than 5 km) of flat-lying Cretaceous and younger carbonates capping the Bahama platform implies an unusual geotectonic history, characterized by great subsidence. We suggest that this platform is underlain neither by sial nor by a volcanic foundation creating a "mega-atoll." Instead we propose a basement of oceanic crust about 11 km down which has undergone slow subsidence. Triassic rifting in the Atlantic probably initially created a closed small ocean basin, or mediterranean, in the Bahama region. This was accomplished by a rotational movement of the North American plate away from North Africa accompanied by shearing across the top of the South American plate which remained stationary and attached to Africa. A wedge-shaped sphenochasm resulted which became a sediment trap within Pangaea and quickly filled to sea level with turbidites. With renewed continental drift, the Bahama platform became a subsiding marginal plateau attached to the North American craton upon which algal-coral growth explosively flourished under holo-oceanic conditions, providing sufficient upbuilding to offset subsidence and maintain a sea level freeboard.This interpretation obviates the overlap of the Bahama salient onto the African craton when the Atlantic Ocean is closed under continental drift reconstruction. It accounts for the long history of subsidence without calling on "oceanization." It also explains the inference, based on some Cuban-Soviet geophysical evidence, that there is a thick sedimentary section beneath the Bahamian carbonates. An underlying clastic sequence could also include the source of the probable salt domes at the bottom of Exuma Sound. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.