scholarly journals Re-Os isotope constraints on the ages of diamonds from Mwadui, Tanzania

2019 ◽  
Keyword(s):  
Os Isotope

Relationship between copper tonnage of Chilean base-metal porphyry deposits and Os isotope ratios

Geology ◽  
2000 ◽  
Vol 28 (6) ◽  
pp. 555-558
Author(s):  
Ryan Mathur ◽  
Joaquin Ruiz ◽  
Francisco Munizaga
Keyword(s):  
Base Metal ◽  
Isotope Ratios ◽  
Porphyry Deposits ◽  
Os Isotope

Re-Os isotope characteristics of postorogenic lavas: Implications for the nature of young lithospheric mantle and its contribution to basaltic magmas

Geology ◽  
2000 ◽  
Vol 28 (6) ◽  
pp. 563-566 ◽  
Author(s):  
Bruce F. Schaefer ◽  
Simon P. Turner ◽  
Nick W. Rogers ◽  
Chris J. Hawkesworth ◽  
Helen M. Williams ◽  
...  
Keyword(s):  
Lithospheric Mantle ◽  
Basaltic Magmas ◽  
Os Isotope

COMPARISON OF OS ISOTOPE AND BE-10 AGES OF HYDROGENOUS FERROMANGANESE CRUSTS

2017 ◽  
Author(s):  
Kosuke T. Goto ◽  
◽  
Aya Sakaguchi ◽  
Maria Luisa G. Tejada ◽  
Johannes Lachner ◽  
...  
Keyword(s):  
Ferromanganese Crusts ◽  
Os Isotope

New approaches to crustal evolution studies and the origin of granitic rocks: what can the Lu-Hf and Re-Os isotope systems tell us?

1996 ◽  
Vol 87 (1-2) ◽  
pp. 339-352 ◽  
Author(s):  
Clark M. Johnson ◽  
Steven B. Shirey ◽  
Karin M. Barovich
Keyword(s):  
Continental Crust ◽  
Isotope Ratios ◽  
Granitic Rocks ◽  
Nd Isotope ◽  
Volcanic Arcs ◽  
Depleted Mantle ◽  
Os Isotopes ◽  
Isotope System ◽  
Os Isotope

ABSTRACT:The Lu-Hf and Re-Os isotope systems have been applied sparsely to elucidate the origin of granites, intracrustal processes and the evolution of the continental crust. The presence or absence of garnet as a residual phase during partial melting will strongly influence Lu/Hf partitioning, making the Lu–Hf isotope system exceptionally sensitive to evaluating the role of garnet during intracrustal differentiation processes. Mid-Proterozoic (1·1–1·5Ga ) ‘anorogenic’ granites from the western U.S.A. appear to have anomalously high εHf values, relative to their εNd values, compared with Precambrian orogenic granites from several continents. The Hf-Nd isotope variations for Precambrian orogenic granites are well explained by melting processes that are ultimately tied to garnet-bearing sources in the mantle or crust. Residual, garnet-bearing lower and middle crust will evolve to anomalously high εHf values over time and may be the most likely source for later ‘anorogenic’ magmas. When crustal and mantle rocks are viewed together in terms of Hf and Nd isotope compositions, a remarkable mass balance is apparent for at least the outer silicate earth where Precambrian orogenic continental crust is the balance to the high-εHf depleted mantle, and enriched lithospheric mantle is the balance to the low-εHf depleted mantle.Although the continental crust has been envisioned to have exceptionally high Re/Os ratios and very radiogenic Os isotope compositions, new data obtained on magnetite mineral separates suggest that some parts of the Precambrian continental crust are relatively Os-rich and non-radiogenic. It remains unclear how continental crust may obtain non-radiogenic Os isotope ratios, and these results have important implications for Re-Os isotope evolution models. In contrast, Phanerozoic batholiths and volcanic arcs that are built on young mafic lower crust may have exceptionally radiogenic Os isotope ratios. These results highlight the unique ability of Os isotopes to identify young mafic crustal components in orogenic magmas that are essentially undetectable using other isotope systems such as O, Sr, Nd and Pb.

Re-Os isotope studies of Mindanao adakites: Implications for sources of metals and melts

Geology ◽  
2005 ◽  
Vol 33 (12) ◽  
pp. 957 ◽  
Author(s):  
Scott T. Dreher ◽  
Colin G. Macpherson ◽  
D. Graham Pearson ◽  
Jon P. Davidson
Keyword(s):  
Isotope Studies ◽  
Os Isotope

scholarly journals Zircon U-Pb and Pyrite Re-Os Isotope Geochemistry of ‘Skarn-Type’ Fe-Cu Mineralization at the Shuikoushan Polymetallic Deposit, South China: Implications for an Early Cretaceous Mineralization Event in the Nanling Range

Minerals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 480
Author(s):  
Shengbin Li ◽  
Yonghua Cao ◽  
Zeyou Song ◽  
Dan Xiao
Keyword(s):  
Contact Zone ◽  
Early Cretaceous ◽  
South China ◽  
Isotope Geochemistry ◽  
Time Interval ◽  
Mean Square ◽  
Geochronological Data ◽  
Nanling Range ◽  
Calcite Veins ◽  
Os Isotope

The Shuikoushan deposit is an economic ‘skarn-type’ polymetallic Pb-Zn deposit in South China. The deposit is located at the southern margin of the Hengyang basin in the northern part of the Nanling Range. Recently, economic Fe-Cu mineralization that occurs spatially connected to skarns along the contact zone between the granodiorite and limestones was discovered in the lower part of this deposit. Detailed zircon U-Pb geochronological data indicate that the granodiorite was emplaced at 153.7 ± 0.58 Ma (Mean Square of Weighted Deviates (MSWD) = 2.4). However, the pyrite Re-Os isochron age reveals that Fe-Cu mineralization formed at 140 ± 11 Ma (MSWD) = 8.1), which post-dates the emplacement of the granodiorite, as well as the previously determined timing of Pb-Zn mineralization (157.8 ± 1.4 Ma) in this deposit. Considering that Fe-Cu mineralization was connected with the contact zone and also faults, and that sulfide minerals commonly occur together with quartz and calcite veins that crosscut skarns, we interpret this mineralization type as being related to injection of post-magmatic hydrothermal fluids. The timing of Fe-Cu mineralization (140 ± 11 Ma) is inconsistent with a long-held viewpoint that the time interval of 145 to 130 Ma (e.g., Early Cretaceous) in the Nanling Range is a period of magmatic quiescence with insignificant mineralization, the age of 140 Ma may represent a new mineralization event in the Nanling Range.

The Age of Gold Mineralization in the Yana–Kolyma Metallogenic Belt, Northeastern Russia: First Data of Re–Os Isotope Geochronology of Native Gold

2021 ◽  
Vol 15 (4) ◽  
pp. 293-306
Author(s):  
V. Yu. Fridovsky ◽  
N. A. Goryachev ◽  
R. Sh. Krymsky ◽  
M. V. Kudrin ◽  
B. V. Belyatsky ◽  
...  
Keyword(s):  
Native Gold ◽  
Gold Mineralization ◽  
Northeastern Russia ◽  
Isotope Geochronology ◽  
Metallogenic Belt ◽  
Os Isotope

Re-Os isotope and Pd/Ru variations in chromitites from the Critical Zone, Bushveld Complex, South Africa

1999 ◽  
Vol 63 (6) ◽  
pp. 911-923 ◽  
Author(s):  
Tom E. McCandless ◽  
Joaquin Ruiz ◽  
B.Ivan Adair ◽  
Claire Freydier
Keyword(s):  
South Africa ◽  
Bushveld Complex ◽  
Critical Zone ◽  
Os Isotope
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