Portal de Periódicos da CAPES

The volcanic geology and petrology of Isla Pinta, Galapagos archipelago

1987; Geological Society of America; Volume: 98; Issue: 3 Linguagem: Inglês

10.1130/0016-7606(1987)98 2.0.co;2

1943-2674

Andrew Cullen, Alexander R. McBirney,

Coral and Marine Ecosystems Studies

Research Article| March 01, 1987 The volcanic geology and petrology of Isla Pinta, Galapagos archipelago ANDREW CULLEN; ANDREW CULLEN 1School of Geology and Geophysics, University of Oklahoma, Norman, Oklahoma 73069 Search for other works by this author on: GSW Google Scholar A. R. McBIRNEY A. R. McBIRNEY 2Center of Volcanology, University of Oregon, Eugene, Oregon 97403 Search for other works by this author on: GSW Google Scholar Author and Article Information ANDREW CULLEN 1School of Geology and Geophysics, University of Oklahoma, Norman, Oklahoma 73069 A. R. McBIRNEY 2Center of Volcanology, University of Oregon, Eugene, Oregon 97403 Publisher: Geological Society of America First Online: 01 Jun 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 Geological Society of America GSA Bulletin (1987) 98 (3): 294–301. https://doi.org/10.1130/0016-7606(1987)98 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 Email Permissions Search Site Citation ANDREW CULLEN, A. R. McBIRNEY; The volcanic geology and petrology of Isla Pinta, Galapagos archipelago. GSA Bulletin 1987;; 98 (3): 294–301. doi: https://doi.org/10.1130/0016-7606(1987)98 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 Pinta, one of the northern islands in the Galapagos archipelago, is the top of a shield volcano which became emergent ∼0.7 m.y. ago. A regional north-north west-trending fracture system influenced the locus of volcanism. Pinta's geologic development can be divided into an older, shield stage and a younger, fissure stage. Each stage produced a similar, yet distinct, series of evolved olivine tholeiites (magnesium number = 52). The shield series underwent some additional shallow-level fractionation in a periodically replenished chamber. Rare-earth-element data indicate that the mantle source for both of the series has residual garnet. Higher concentrations of incompatible trace elements iri the fissure series imply a lower degree of partial melting. 143Nd/144Nd and 87Sr/86Sr ratios suggest that both series have an enriched, hotspot-type source. Despite close proximity to the Galapagos spreading ridge, Pinta's lavas lack features characteristic of mid-ocean ridge basalts. The isotopic and rare-earth-element data from Pinta and the other northern islands are consistent with previous models for the Galapagos spreading ridge, which require north-south axially directed transfer of enriched asthenosphere and/or melts from the Galapagos hotspot to the Galapagos Ridge. 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.