Trace element and isotope geochemistry of depleted peridotites from an N-MORB type ophiolite (Internal Liguride, N. Italy)
Article Abstract:
Analysis of clinopyroxenes, representing trace elements of the peridotite from an N-mid ocean ridge basalt type ophiolite, shows a decoupling between severe depletion in the light rare earth elements Sr, Na, Ti and less pronounced depletion in Ca, Al, Sc and V. Compositional features of peridotites suggest low degree fractional melting as the most appropriate depletion mechanism. The Sr and Nd isotopic composition suggests an extremely depleted level. The Sm/Nd model ages indicate that peridotites from N type mid ocean ridge basalt melted most likely during Permian times.
Publication Name: Contributions to Mineralogy and Petrology
Subject: Earth sciences
ISSN: 0010-7999
Year: 1996
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Crystal size distribution in Jurassic Ferrar flows and sills (Victoria Land, Antarctica): evidence for processes of cooling, nucleation, and crystallisation
Article Abstract:
Though cooling is crucial in the determination of the growth and nucleation rate, chemical profile is also needed to distinguish sills and flows. Study of three different magma cooling bodies from the Jurassic Ferrar group in Victoria Land, Antarctica show that in Colonnade flow, silicic residual melts are located in the lower half. In the Thumb Point sills, it is in the upper third of the thickness. The growth and nucleation rates of the HiTi-unit are difficult to categorize because they are intermediate between sills and flows.
Publication Name: Contributions to Mineralogy and Petrology
Subject: Earth sciences
ISSN: 0010-7999
Year: 1996
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Four- and five-phase peridotites from a continental rift system: evidence for upper mantle uplift and cooling at the Ross Sea margin (Antarctica)
Article Abstract:
A study was conducted to evaluate peridotites as possible sources of evidence to explain upper mantle uplift. The study examines the Cenozoic McMurdo volcanic group found between the western trough of the Ross Sea rift system and the upper lift shoulder of the Transantarctic Mountains. Texture and composition of peridotites and determined temperatures and formation pressures are then analyzed. Results show that uplift timing of events correlates with mantle temperature increase of magmatic activity.
Publication Name: Contributions to Mineralogy and Petrology
Subject: Earth sciences
ISSN: 0010-7999
Year: 1992
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