Solidus of carbonated fertile peridotite under fluid-saturated conditions

Abstract

Listen

Translate article

Research Article| March 01, 1990 Solidus of carbonated fertile peridotite under fluid-saturated conditions Trevor J. Falloon; Trevor J. Falloon 1Geology Department, University of Tasmania, Hobart, Tasmania 7001, Australia Search for other works by this author on: GSW Google Scholar David H. Green David H. Green 1Geology Department, University of Tasmania, Hobart, Tasmania 7001, Australia Search for other works by this author on: GSW Google Scholar Author and Article Information Trevor J. Falloon 1Geology Department, University of Tasmania, Hobart, Tasmania 7001, Australia David H. Green 1Geology Department, University of Tasmania, Hobart, Tasmania 7001, Australia Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1990) 18 (3): 195–199. https://doi.org/10.1130/0091-7613(1990)018<0195:SOCFPU>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 MailTo Tools Icon Tools Get Permissions Search Site Citation Trevor J. Falloon, David H. Green; Solidus of carbonated fertile peridotite under fluid-saturated conditions. Geology 1990;; 18 (3): 195–199. doi: https://doi.org/10.1130/0091-7613(1990)018<0195:SOCFPU>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 The solidus for a fertile peridotite composition ("Hawaiian pyrolite") in the presence of a CO2-H2O fluid phase has been determined from 10 to 35 kbar. The intersection of the decarbonation reaction (olivine + diopside + CO2 ←→ orthopyroxene + dolomite) with the pyrolite solidus defines the point Q′, located at 22 kbar and 940 °C. At pressures less than Q′, the solidus passes through a temperature maximum at 14 kbar, 1060 °C. The solidus is coincident with amphibole breakdown at pressures less than 16 kbar. At pressures above Q′, the solidus is defined by the dissolution of crystalline carbonate into a sodic, dolomitic carbonatite melt. The solidus is at a temperature of 925 °C at ∼28 kbar. The solidus temperature above the point Q′ is similar to the solidus determined for Hawaiian pyrolite-H2O-CO2 for small contents of H2O (<0.3 wt%) and CO2 (<5 wt%), thus indicating that the primary sodic dolomitic carbonatite melt at both solidi has a very low and limited H2O solubility. The new data clarify the roles of carbonatite melt, carbonated silicate melt, and H2O-rich fluid in mantle conditions that are relatively oxidized (fO2 ∼ MW to FMQ). In particular, a carbonatite melt + garnet lherzolite region is intersected by continental shield geothermal gradients, but such geotherms only intersect regions with carbonated silicate melt if perturbed to higher temperatures ("kinked geotherm"). 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.