Closure of the Isthmus of Panama: The near-shore marine record of Costa Rica and western Panama

Research Article| July 01, 1992 Closure of the Isthmus of Panama: The near-shore marine record of Costa Rica and western Panama ANTHONY G. COATES; ANTHONY G. COATES 1Department of Geology, The George Washington University, Washington, D.C. 20052 Search for other works by this author on: GSW Google Scholar JEREMY B. C. JACKSON; JEREMY B. C. JACKSON 2Smithsonian Tropical Research Institute, Box 2072, Balboa, Republic of Panama Search for other works by this author on: GSW Google Scholar LAUREL S. COLLINS; LAUREL S. COLLINS 3Museum of Paleontology, University of Michigan, Ann Arbor, Michigan 48109-1079 Search for other works by this author on: GSW Google Scholar THOMAS M. CRONIN; THOMAS M. CRONIN 4U.S. Geological Survey, 970 National Center, Reston, Virginia 22092 Search for other works by this author on: GSW Google Scholar HARRY J. DOWSETT; HARRY J. DOWSETT 4U.S. Geological Survey, 970 National Center, Reston, Virginia 22092 Search for other works by this author on: GSW Google Scholar LAUREL M. BYBELL; LAUREL M. BYBELL 4U.S. Geological Survey, 970 National Center, Reston, Virginia 22092 Search for other works by this author on: GSW Google Scholar PETER JUNG; PETER JUNG 5Naturhistorisches Museum, Augustinergasse 2, CH 4051, Basel, Switzerland Search for other works by this author on: GSW Google Scholar JORGE A. OBANDO JORGE A. OBANDO 6RECOPE, S.A., Apartado 4351, Zone 1000, San Jose, Costa Rica Search for other works by this author on: GSW Google Scholar Author and Article Information ANTHONY G. COATES 1Department of Geology, The George Washington University, Washington, D.C. 20052 JEREMY B. C. JACKSON 2Smithsonian Tropical Research Institute, Box 2072, Balboa, Republic of Panama LAUREL S. COLLINS 3Museum of Paleontology, University of Michigan, Ann Arbor, Michigan 48109-1079 THOMAS M. CRONIN 4U.S. Geological Survey, 970 National Center, Reston, Virginia 22092 HARRY J. DOWSETT 4U.S. Geological Survey, 970 National Center, Reston, Virginia 22092 LAUREL M. BYBELL 4U.S. Geological Survey, 970 National Center, Reston, Virginia 22092 PETER JUNG 5Naturhistorisches Museum, Augustinergasse 2, CH 4051, Basel, Switzerland JORGE A. OBANDO 6RECOPE, S.A., Apartado 4351, Zone 1000, San Jose, Costa Rica Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1992) 104 (7): 814–828. https://doi.org/10.1130/0016-7606(1992)1042.3.CO;2 Article history First Online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Tools Icon Tools Get Permissions Search Site Citation ANTHONY G. COATES, JEREMY B. C. JACKSON, LAUREL S. COLLINS, THOMAS M. CRONIN, HARRY J. DOWSETT, LAUREL M. BYBELL, PETER JUNG, JORGE A. OBANDO; Closure of the Isthmus of Panama: The near-shore marine record of Costa Rica and western Panama. GSA Bulletin 1992;; 104 (7): 814–828. doi: https://doi.org/10.1130/0016-7606(1992)1042.3.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 final closure of the Isthmus of Panama at ∼3.5 Ma divided the American tropical ocean into two separate and different oceanographic regions. Consequences for the marine biota were profound, but, hitherto, correlation of the Pacific and Caribbean coastal sections has not been precise enough to track biologic patterns. We present here a correlation of 31 sections from the Pacific and Caribbean coasts of Costa Rica and western Panama. Using calcareous nannofossils and planktonic foraminifera at both the tops and bottoms of each formation, we estimate that the Caribbean section ranges from 8.2 Ma to 1.7 Ma; and the Pacific sequence, from 3.6 Ma to <1.7 Ma. These intervals bracket postulated dates for final closure of the Isthmus and provide the first well-dated record of middle and late Pliocene faunas from the region.The Caribbean and Pacific sections include very different environments of deposition, yet there is sufficient overlap and diversity of habitats to permit meaningful biological comparisons. On the Caribbean side, formations tied together by the overlap of the upper Pliocene markers Sphenolithus abies and Pseudoemiliana lacunosa (3.5 Ma to 3.6 Ma) range from very shallow to shallow inner shelf (<200 m) and upper slope (200-800 m). The Pacific coast sections were mostly deposited in a trench slope environment, which is absent on the Caribbean side. These sections fortuitously include abundant thick intra-formational slumps containing shallow-water fauna more appropriate for biological comparison with the Caribbean biota. Similarly, the ∼1.9 Ma to 1.5 Ma interval, well constrained by various taxa, includes middle- to outer-shelf, and inner-shelf to upper-slope deposits on the Caribbean side, and marginal-marine to inner-shelf deposits on the Pacific coast.Using our new biostratigraphic framework to correlate previously poorly constrained mollusc collections, we show that evolutionary divergence of the Pacific and Caribbean near-shore marine faunas had occurred by 3.5 Ma. This strongly suggests that the Isthmus was effectively closed by this time. 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.