Results 61 to 70 of about 191 (175)

Geochemistry of podiform chromitite and host rocks within the Buem Structural Unit, Northwestern Benin Republic: Implications for the geodynamic evolution of the Dahomeyide orogenic belt

open access: yesResults in Earth Sciences
The paper presents the geochemistry, origin and geodynamic setting of podiform chromitite and host rocks from the Buem Structural Unit (BSU) in the northwestern Benin Republic.
Daniel N. Kouagou N’Dah   +7 more
doaj   +1 more source

Multi‐geophysical methods for characterizing fractures in an open pit mine, western Bushveld Complex, South Africa

open access: yesGeophysical Prospecting, Volume 72, Issue 5, Page 1950-1970, June 2024.
Abstract In the Bushveld Complex, South Africa, open pit mines are faced with a challenge of rock slope stability due to geological structures (fractures, faults and dykes) that compartmentalize the rock mass. Geophysical surveys (seismics, magnetics and electrical methods) were conducted in a 0.2 km2 area at Tharisa mine, with the goal to delineate ...
Moyagabo K. Rapetsoa   +7 more
wiley   +1 more source

Probing the 186Os/188Os Precision Barrier: New Recommended Values for the DROsS Reference Material and an Assessment of Mixed 1011 and 1012 Ω Amplifier Arrays

open access: yesGeostandards and Geoanalytical Research, Volume 48, Issue 1, Page 109-132, March 2024.
Key Points Most precise 184Os/188Os ratio yet measured: 0.0013036 ± 0.0000007. New recommended values for DROsS: 186Os/188Os = 0.1199319 ± 0.0000024, 187Os/188Os = 0.1609227 ± 0.0000022, 189Os/188Os = 1.219709 ± 0.000010, 190Os/188Os = 1.983793 ± 0.000011.
Pedro Waterton   +4 more
wiley   +1 more source

A revised map of volcanic units in the Oman ophiolite: insights into the architecture of an oceanic proto-arc volcanic sequence [PDF]

open access: yesSolid Earth, 2019
Numerous studies have revealed genetic similarities between Tethyan ophiolites and oceanic “proto-arc” sequences formed above nascent subduction zones. The Semail ophiolite (Oman–U.A.E.) in particular can be viewed as an analogue for this proto-arc crust.
T. M. Belgrano   +6 more
doaj   +1 more source

Exhumed Serpentinites and Their Tectonic Significance in Non‐Collisional Orogens

open access: yesGeochemistry, Geophysics, Geosystems, Volume 25, Issue 2, February 2024.
Abstract Exhumed serpentinites are fragments of ancient oceanic lithosphere or mantle wedge that record deep fluid‐rock interactions and metasomatic processes. While common in suture zones after closure of ocean basins, in non‐collisional orogens their origin and tectonic significance are not fully understood.
Damián Donoso‐Tapia   +4 more
wiley   +1 more source

Conversion of low-pressure chromitites to ultrahigh-pressure chromitites by deep recycling: A good inference

open access: yesEarth and Planetary Science Letters, 2013
AbstractPodiform chromitites have been interpreted as a peridotite/melt reaction product within the upper mantle (= low-P chromitites). Some of them, however, contain ultrahigh-pressure (UHP) minerals such as diamond and coesite (= UHP chromitites). The UHP chromitites can be produced by deep recycling of low-P chromitites via mantle convection. Carbon-
openaire   +1 more source

PETROLOGICAL EVIDENCES OF SYNDEFORMATION SEGREGATION OF CHROMITES DURING DUNITE FORMATION: EXAMPLE OF KRAKA OPHIOLITES, SOUTH URALS [PDF]

open access: yesМинералогия, 2016
Results of structural and mineralogical studies of chromitite-bearing zone localized in spinel peridotites of the Middle Kraka ophiolite massif are presented.
D.E. Saveliev   +4 more
doaj  

Hydrated Peridotite–Basaltic Melt Interaction Part II: Fast Assimilation of Serpentinized Mantle by Basaltic Magma

open access: yesFrontiers in Earth Science, 2020
The most abundant terrestrial lavas, mid-ocean ridge basalt (MORB) and ocean island basalt (OIB), are commonly considered to be derived from a depleted MORB-mantle component (DMM) and more specific, variably enriched mantle plume sources.
Anastassia Y. Borisova   +13 more
doaj   +1 more source

LA-MC-ICP-MS dating of zircon from chromitite of the Archean Bangur Gabbro Complex, Orissa, India – Ambiguities and constraints

open access: yesGeologica Acta, 2015
The Mesoarchean chromitites in the Singhbhum craton provide the main source of chromium in India. We report here results of dating zircon grains that were found in the chromitite of ultramafic rocks belonging to the southern part of the Archean Baula ...
P. V. SUNDER-RAJU, E. HANSKI, Y. LAHAYE
doaj  

Mineralogical and geochemical features of chromitites of the Apshak area (South Kraka ultramafic massif, South Urals) [PDF]

open access: yesМинералогия
Mineral composition of chromitites of the Apshak area in the northwestern part of the South Kraka massif (the largest representative of the Kraka group ophiolites), which is confined to the northern closure of the Zilair Synclinorium on the western slope
T.D. Shabutdinov   +2 more
doaj   +1 more source

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