Oceanic Crust Forms Basement of Eastern Panamá

Abstract

Research Article| April 01, 1974 Oceanic Crust Forms Basement of Eastern Panamá J. E. CASE J. E. CASE 1U.S. Geological Survey, P. O. Box 6732, Corpus Christi, Texas 78411 Search for other works by this author on: GSW Google Scholar GSA Bulletin (1974) 85 (4): 645–652. https://doi.org/10.1130/0016-7606(1974)85<645:OCFBOE>2.0.CO;2 Article history first online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share MailTo Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation J. E. CASE; Oceanic Crust Forms Basement of Eastern Panamá. GSA Bulletin 1974;; 85 (4): 645–652. doi: https://doi.org/10.1130/0016-7606(1974)85<645:OCFBOE>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 Basement rocks of parts of eastern Panamá include tholeiitic pillow basalt and diabase overlain by sedimentary rocks typical of deep oceanic environments. Both paleontologic and stratigraphic evidence indicate that some of these rocks are of Late Cretaceous age or older. Regional Bouguer anomalies over the basement terrane exceed +120 mgal, indicating that eastern Panamá is a raised block of oceanic crust. Age relations in the Caribbean region apparently preclude an "Atlantic" or single intra-Caribbean origin for eastern Panamá and the southern Caribbean basin, but multiple intra-Caribbean origins of the basaltic basement rocks are permitted by the age data. An in situ origin of the oceanic basement of Panamá at a position which later became a Cenozoic island arc is likewise consistent with the available geologic and geophysical data.Seismic horizon B″ in the Caribbean is correlative with or overlain by deep-sea sedimentary rocks of Coniacian to Campanian age. This horizon forms the top of the apparent basement of eastern Panamá and, thus, the eastern isthmus is a horstlike block that has been elevated or obducted a minimum of 6 km since Coniacian-Maastrichtian time, partly caused by northeastward underflow of the Pacific plate but possibly related to southwestward movement of the Caribbean plate beneath the isthmus. 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.