Title Cenozoic thermal evolution of lithospheric mantle in northern Victoria Land (Antarctica); evidences from mantle xenoliths
Author Armienti, P.; Perinelli, C.
Author Affil Armienti, P., Universita di Pisa, Dipartimento di Scienze della Terra, Pisa, Italy
Source Tectonophysics, 486(1-4), p.28-35. Publisher: Elsevier, Amsterdam, Netherlands. ISSN: 0040-1951
Publication Date Apr. 29, 2010
Notes In English. Based on Publisher- supplied data GeoRef Acc. No: 299986
Index Terms Antarctica--Mount Melbourne; Southern Ocean--Ross Sea; Antarctica--Transantarctic Mountains; Antarctica; asthenosphere; Cenozoic; geologic barometry; geologic thermometry; geothermal gradient; heat flow; igneous rocks; inclusions; lithosphere; magmatism; mantle; Mount Melbourne; P-T conditions; peridotites; petrology; plate tectonics; plutonic rocks; rifting; Ross Sea; Southern Ocean; tectonics; thermal circulation; thermal history; Transantarctic Mountains; ultramafics; uplifts; upper mantle; Victoria Land; xenoliths
Abstract Thermobarometry of spinel peridotites collected in northern Victoria Land in Cenozoic basalts of the Mt Melbourne Volcanic Province, reveals warming of local lithospheric mantle, marked by a shift of geothermal gradient from 0.5°C/km to ~3°C/km during the development of Cenozoic magmatism related to the opening of the Ross Sea rift system. We suggest that a significant uplift fraction of the rift shoulder on the West Antarctic margin is due to the change in olivine molar volume induced by mantle heating. The heat source is provided by enhancement of asthenospheric convection induced by an "edge effect" in the mantle circulation, following the opening phase of the Ross Sea. Besides explaining the asymmetric uplift of the rift shoulder corresponding to the Transantarctic Mountains, this mechanism satisfactorily accounts for the time scale (~10 Ma) and most of total uplift (~3000m) of the western border of the Ross Sea in northern Victoria Land.
URL http://hdl.handle.net/10.1016/j.tecto.2010.02.006
Publication Type journal article
Record ID 88416