Drowned 14-m.y.-old Galápagos archipelago off the coast of Costa Rica: Implications for tectonic and evolutionary models

Abstract

Research Article| June 01, 1999 Drowned 14-m.y.-old Galápagos archipelago off the coast of Costa Rica: Implications for tectonic and evolutionary models Reinhard Werner; Reinhard Werner 1Geomar, Wischhofstraße 1-3, D-24148 Kiel, Germany Search for other works by this author on: GSW Google Scholar Kaj Hoernle; Kaj Hoernle 1Geomar, Wischhofstraße 1-3, D-24148 Kiel, Germany Search for other works by this author on: GSW Google Scholar Paul van den Bogaard; Paul van den Bogaard 1Geomar, Wischhofstraße 1-3, D-24148 Kiel, Germany Search for other works by this author on: GSW Google Scholar Cesar Ranero; Cesar Ranero 1Geomar, Wischhofstraße 1-3, D-24148 Kiel, Germany Search for other works by this author on: GSW Google Scholar Roland von Huene; Roland von Huene 1Geomar, Wischhofstraße 1-3, D-24148 Kiel, Germany Search for other works by this author on: GSW Google Scholar Dietmar Korich Dietmar Korich 2Universität Greifswald, Friedrich-Ludwig-Jahn-Straße 17a, 17489 Greifswald, Germany Search for other works by this author on: GSW Google Scholar Author and Article Information Reinhard Werner 1Geomar, Wischhofstraße 1-3, D-24148 Kiel, Germany Kaj Hoernle 1Geomar, Wischhofstraße 1-3, D-24148 Kiel, Germany Paul van den Bogaard 1Geomar, Wischhofstraße 1-3, D-24148 Kiel, Germany Cesar Ranero 1Geomar, Wischhofstraße 1-3, D-24148 Kiel, Germany Roland von Huene 1Geomar, Wischhofstraße 1-3, D-24148 Kiel, Germany Dietmar Korich 2Universität Greifswald, Friedrich-Ludwig-Jahn-Straße 17a, 17489 Greifswald, Germany Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1999) 27 (6): 499–502. https://doi.org/10.1130/0091-7613(1999)027<0499:DMYOGP>2.3.CO;2 Article history First Online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Reinhard Werner, Kaj Hoernle, Paul van den Bogaard, Cesar Ranero, Roland von Huene, Dietmar Korich; Drowned 14-m.y.-old Galápagos archipelago off the coast of Costa Rica: Implications for tectonic and evolutionary models. Geology 1999;; 27 (6): 499–502. doi: https://doi.org/10.1130/0091-7613(1999)027<0499:DMYOGP>2.3.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 SocietyGeology Search Advanced Search Abstract Volcanic rocks were dredged from the Cocos and Fisher ridges and seamounts along a 250 km profile parallel to the Pacific coast of Costa Rica. The composition and laser 40Ar/39Ar ages of the Cocos Ridge and Seamounts are consistent with their formation above the Galápagos hotspot 13.0–14.5 Ma. The reconstructed paleoenvironment and chemistry of the Fisher Ridge are consistent with it having originated at a mid-oceanic ridge system. Laser 40Ar/39Ar dating of fresh basalt glass from the Fisher Ridge yielded isochron ages of 19.2 ± 0.3 Ma and 30.0 ± 0.5 Ma. The Fisher Ridge is along a lithospheric fault that may represent an extensional fracture formed when the oceanic floor rode over the Galápagos hotspot. Even though the younger structures are currently at water depths of >1000 m, volcanological, geochemical, and geophysical observations indicate that they once formed an emerged archipelago very similar in morphology to the Galápagos islands. The diversity of the biota on the isolated Galápagos islands, as first described by Charles Darwin, has had an important influence on the development of the theory of evolution. The existence of a now-drowned Galápagos archipelago 14.5 Ma considerably increases speciation times for the Galápagos biota and provides a complete solution to a long-standing controversy concerning the divergence of the Galápagos marine and land iguanas from a single ancestral species. 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.