Integrated paleontologic and paleomagnetic stratigraphy of the upper Neogene deposits around Limon, Costa Rica: A coastal emergence record of the Central American Isthmus

Abstract

Research Article| July 01, 2000 Integrated paleontologic and paleomagnetic stratigraphy of the upper Neogene deposits around Limon, Costa Rica: A coastal emergence record of the Central American Isthmus D.F. McNeill; D.F. McNeill 1Division of Marine Geology and Geophysics, Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Causeway, Miami, Florida 33149, USA Search for other works by this author on: GSW Google Scholar A.G. Coates; A.G. Coates 2Smithsonian Tropical Research Institute, Box 2072, Balboa, Republic of Panama Search for other works by this author on: GSW Google Scholar A.F. Budd; A.F. Budd 3Department of Geology, University of Iowa, Iowa City, Iowa 52242, USA Search for other works by this author on: GSW Google Scholar P.F. Borne P.F. Borne 4Louisiana Sea Grant College Program, Louisiana State University, Baton Rouge, Louisiana 70803, USA Search for other works by this author on: GSW Google Scholar Author and Article Information D.F. McNeill 1Division of Marine Geology and Geophysics, Rosenstiel School of Marine and Atmospheric Science, University of Miami, 4600 Rickenbacker Causeway, Miami, Florida 33149, USA A.G. Coates 2Smithsonian Tropical Research Institute, Box 2072, Balboa, Republic of Panama A.F. Budd 3Department of Geology, University of Iowa, Iowa City, Iowa 52242, USA P.F. Borne 4Louisiana Sea Grant College Program, Louisiana State University, Baton Rouge, Louisiana 70803, USA Publisher: Geological Society of America Received: 28 Feb 1999 Revision Received: 23 Aug 1999 Accepted: 30 Aug 1999 First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (2000) 112 (7): 963–981. https://doi.org/10.1130/0016-7606(2000)112<963:IPAPSO>2.0.CO;2 Article history Received: 28 Feb 1999 Revision Received: 23 Aug 1999 Accepted: 30 Aug 1999 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 D.F. McNeill, A.G. Coates, A.F. Budd, P.F. Borne; Integrated paleontologic and paleomagnetic stratigraphy of the upper Neogene deposits around Limon, Costa Rica: A coastal emergence record of the Central American Isthmus. GSA Bulletin 2000;; 112 (7): 963–981. doi: https://doi.org/10.1130/0016-7606(2000)112<963:IPAPSO>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 A chronostratigraphic study of mixed carbonate and siliciclastic sediments (Limon Group) along the Caribbean side of the Central American Isthmus was conducted to provide refined depositional ages on the uplifted, nearshore marine sequence exposed near Limon, Costa Rica. These upper Neogene sediments provide a rich faunal history that spanned the closure of the isthmus and cessation of marine circulation between the Pacific Ocean and Caribbean Sea. This faunal archive provides a critical link in regional assessment of evolutionary changes that resulted from the development of the Central American Isthmus.Results from this study have shown that integrated biostratigraphic and magnetostratigraphic techniques can be successfully combined to provide refined age dating in shallow-marine sediments, even where some microfossil reworking has occurred. We propose the new Quebrada Chocolate Formation to represent latest early–early late Pliocene mixed reefal and siliciclastic deposits that overlie the early Pliocene Rio Banano Formation. The superjacent Moin Formation is expanded to include a second reefal interval deposited near the late Pliocene-Pleistocene boundary as well as fine-grained, mollusk-rich deposits in the forereef and lagoon. The style of mixed-system reef geometry between the two units is distinct. The Quebrada Chocolate Formation reefs consist of a lower interval of alternating reefal units buried by siliciclastic sediment and an upper unit comprised of stacked, reefal buildups with relatively minor siliciclastic matrix. These stacked reefs formed on a rising sea level. In contrast, the Moin Formation reefs are isolated corals and patch reefs within a siliciclastic matrix that were deposited during the peak (maximum flooding) of the sea-level highstand.Our refined age model for the Limon Group sediments allows reassessment of Pleistocene uplift rates. We calculate a rate of about 50 m/m.y., slightly less than previous rate estimates, attributed to the shallow subduction in the Pacific of the Cocos Ridge beneath the Central American island-arc system.Development of similar high-resolution age models from other marine basins should provide the chronostratigraphic control necessary to assess environmental events and evolutionary trends in shallow-marine faunas separated and isolated by the Central American Isthmus. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.