Results 251 to 260 of about 53,167 (298)

The Re‐Os Isotopic System: A Review of Analytical Techniques

Geostandards Newsletter, 2002
Over the past twenty years, successive technological advances have transformed the Re‐Os isotopic system into one of the most powerful tools in isotope geochemistry. We present here a brief historical review of these advances and then describe and compare the methods most commonly used today.
Reisberg, Laurie, Meisel, Thomas
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Re–Os elemental and isotopic systematics in crude oils

Geochimica et Cosmochimica Acta, 2007
Analysis of 12 worldwide oil samples show that Re and Os abundances are positively correlated with the asphaltene content of oil. Light oils with 83%), with
David Selby, Robert A. Creaser, Martin G. Fowler   +2 more
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The Aguablanca Ni-Cu Deposit: A Re-Os Isotope Study

International Geology Review, 2008
The Aguablanca Ni-Cu ore deposit is hosted by subvertical magmatic breccia bodies in which fragments of pyroxenite are cemented by sulfides. It is located within the Aguablanca Stock, which includes diorite, gabbro, norite and gabbronorite. Re-Os isotope data of magmatic pyrrhotite, chalcopyrite, and pentlandite and hydrothermal pyrite show that the Os
Ryan Mathur, Fernando Tornos, Fernando Barra   +2 more
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Re-Os isotope systematics of sediments of the Brahmaputra River system

Geochimica et Cosmochimica Acta, 2003
Re-Os analyses were performed on suspended loads and coarser grained bank sediments of the Brahmaputra River system. Re and Os concentrations of these sediments vary from 7 to 1154 ppt and from 3 to 173 ppt, respectively. 187Os/188Os ratios range from 0.178 to 6.8, and thus vary from nearly mantle to very radiogenic crustal values.
Singh, Sunil, Reisberg, Laurie, France-Lanord, Christian   +2 more
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Re‐Os Isotopic Measurements at the Femtomole Level in Natural Samples

Geostandards Newsletter, 1997
Here we describe a new chemical separation method for Os and an improved mass spectrometric procedure for Re and Os. This technique is based on the selective extraction of OsO4 from aqueous solution in liquid bromine. Among other advantages, this procedure avoids the cumbersome distillation procedure for Os and uses only commercial “off the shelf” PFA ...
Jean Louis Birck, Matthieu Roy Barman, Françoise Capmas   +2 more
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Re-Os isotopic evidence for early differentiation of the Martian mantle

Geochimica et Cosmochimica Acta, 2000
Variations in the short-lived systems of 182Hf-182W and 146Sm-142Nd in the SNC meteorites indicate an early isolation of, and subsequent inefficient mixing between, mantle reservoirs in Mars. Correlations of eW and e142Nd with initial γOs are consistent with the Re-Os isotopic systematics of these meteorites being set during the earliest ...
A.D. Brandon, R.J. Walker, J.W. Morgan, G.G. Goles   +3 more
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Paragenesis, Stable Isotopes, and Molybdenite Re-Os Isotope Age of the Lala Iron-Copper Deposit, Southwest China

Economic Geology, 2012
The Lala Fe-Cu deposit in the Kangdian iron oxide copper-gold (IOCG) metallogenic province, SW China, is hosted in the Paleoproterozoic Hekou Group. This volcanic-sedimentary sequence has undergone upper greenschist-lower amphibolite facies metamorphism at ~850 Ma.
Chen, WT, Zhou, MF
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Enriched Pt-Re-Os Isotope Systematics in Plume Lavas Explained by Metasomatic Sulfides

Science, 2008
To explain the elevated osmium isotope ( 186 Os- 187 Os) signatures in oceanic basalts, the possibility of material flux from the metallic core into the crust has been invoked. This hypothesis conflicts with theoretical constraints on Earth's thermal and dynamic history.
Ambre, Luguet, D, Graham Pearson, Geoff M, Nowell, Scott T, Dreher, Judith A, Coggon, Zdislav V, Spetsius, Stephen W, Parman   +6 more
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Re–Os isotopic evidence for a lower crustal origin of massif-type anorthosites

Nature, 2000
Massif-type anorthosites are large igneous complexes of Proterozoic age. They are almost monomineralic, representing vast accumulations of plagioclase with subordinate pyroxene or olivine and Fe-Ti oxides--the 930-Myr-old Rogaland anorthosite province in southwest Norway represents one of the youngest known expressions of such magmatism.
, Schiellerup, , Lambert, , Prestvik, , Robins, , McBride, , Larsen   +5 more
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Re‐Os isotopic constraints on the formation of mantle and crustal reservoirs

Australian Journal of Earth Sciences, 1991
The measured 187Os/186Os of uncontaminated oceanic peridotites and basalts ranges between 1.0032 ± 0.0072 and 1.111 ± 0.011 (2σx). This range reflects chemical fractionation of the incompatible parent element Re from compatible Os in the mantle during crust production and subsequent isolation of the Re depleted regions of the mantle for time periods in
C.E. Martin, B.K. Esser, K.K. Turekian
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