Research Article| April 01, 1985 Erosional modification of Bahama Escarpment R. P. FREEMAN-LYNDE; R. P. FREEMAN-LYNDE 1Marine Geology Branch, Seafloor Geosciences Division, Naval Ocean Research and Development Activity, National Space Technology Laboratory, Mississippi 39529 Search for other works by this author on: GSW Google Scholar W.B.F. RYAN W.B.F. RYAN 2Lamont-Doherty Geological Observatory of Columbia University, Palisades, New York 10964 Search for other works by this author on: GSW Google Scholar Author and Article Information R. P. FREEMAN-LYNDE 1Marine Geology Branch, Seafloor Geosciences Division, Naval Ocean Research and Development Activity, National Space Technology Laboratory, Mississippi 39529 W.B.F. RYAN 2Lamont-Doherty Geological Observatory of Columbia University, Palisades, New York 10964 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1985) 96 (4): 481–494. https://doi.org/10.1130/0016-7606(1985)96<481:EMOBE>2.0.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation R. P. FREEMAN-LYNDE, W.B.F. RYAN; Erosional modification of Bahama Escarpment. GSA Bulletin 1985;; 96 (4): 481–494. doi: https://doi.org/10.1130/0016-7606(1985)96<481:EMOBE>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 precipitous (28° to 40°) Bahama Escarpment is characterized by abundant low-energy, restricted peritidal and lagoonal rocks and scarce high-energy, bank-margin rocks of Early and middle Cretaceous age at depths of >2,000 m. This indicates significant erosional modification of the slope. All models of carbonate platforms have high-energy facies at platform edges, with low-energy and restricted facies confined to platform interiors. Erosion has removed marginal deposits that constituted the original slope of the Bahama Platform and exposed peritidal and lagoonal facies rocks.On the basis of widths of facies belts of middle Cretaceous carbonate platforms in eastern Mexico and of erosional benches apparent in seismic profiles across the Bahama and Blake Escarpments, an estimated 5 km of material has been eroded from the base of the escarpment.Greatest erosion occurred between the Cenomanian and Maastrichtian, with additional erosion in the Paleocene and Oligocene, as documented by Tertiary and Late Cretaceous pelagic and forereef deposits that unconformably drape and fill fissures in the older shallow-water rocks. It is unclear whether erosion of the escarpment is occurring at present.Erosion of the slope deeper than 2,500 m is effected, in part, by spalling of joint blocks from shattered exposures. Jointing probably results from expansion of previously buried rocks exposed at the sea floor by erosion.Erosion of the Bahama Escarpment may have occurred by other processes acting in concert, or individually at different times, as well. Dissolution by corrosive water below the calcite compensation depth (CCD) and removal of sediments at the base of the slope by abyssal currents probably contributed most to erosional modification of the Bahama Escarpment. Bioerosion and jointing may aid dissolution by increasing surface area exposed to corrosive waters. Tectonic activity related to movements along fracture-zone trends might have contributed locally to erosion of the Bahama Escarpment.Erosion of the Bahama Escarpment shallower than 2,500 m has been less extensive and apparently proceeds by slumping of large, allochthonous blocks, as indicated by the presence of an apparently intact Eocene forereef deposit in the interval from 3,590 to 3,430 m off Eleuthera Island. 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.