Matches in SemOpenAlex for { <https://semopenalex.org/work/W1599863721> ?p ?o ?g. }
- W1599863721 endingPage "24" @default.
- W1599863721 startingPage "1" @default.
- W1599863721 abstract "Abyssal peridotites, fragments of residual upper oceanic mantle, are believed to have less radiogenic Os compositions and higher Os concentrations than primitive upper mantle (PUM, 187 Os/ 188 Os = 0.129 [ Meisel et al. , 1996 ]). We have measured 187 Os/ 188 Os in 10 whole rock abyssal peridotites representing non‐plume‐influenced mid‐ocean ridge segments. The 187 Os/ 188 Os ratios range from 0.1183–0.1582. This large range in Os composition, to both less radiogenic and more radiogenic values than primitive upper mantle, can be attributed to ancient melting and subsequent sequestering of isotopic signatures, melt‐rock reaction, or secondary alteration, or a combination of any of the three. Petrographic, electron microprobe, and hand‐sample inspection show the peridotites to have experienced varying amounts of serpentinization and weathering, accompanied by heterogeneity in 187 Os/ 188 Os values. In addition, a majority of the peridotites studied here are spatially associated with gabbros having equally, if not more highly, heterogeneous Os isotopic compositions and N‐MORBs with homogeneous Sr, Nd, and Pb isotopic signatures. This suggests secondary seawater alteration as the dominant influence on present‐day Os signatures. We show that careful separation, leaching, and analysis of Cr‐spinel from abyssal peridotite largely removes the radiogenic seawater Os isotopic signature, allowing a more accurate assessment of the Os signature of depleted mid‐ocean ridge basalt mantle (DMM). Cr‐spinel is a highly refractory mantle mineral and commonly host to tiny sulfide inclusions, which are carrier phases for Os. These sulfides are well protected by the Cr‐spinel from high‐temperature serpentinization and low‐temperature seafloor weathering, thereby preserving nonradiogenic DMM‐like Os isotopic signatures. Our analyses of treated Cr‐spinel fractions finds 187 Os/ 188 Os ratios that are dominantly less radiogenic (0.1238–0.1482) than corresponding whole rock compositions. Nonmagnetic Cr‐spinels show more highly variable Os compositions and concentrations than magnetic Cr‐spinels, overlapping with the more radiogenic whole rock values. Magnetic Cr‐spinels are dominantly less radiogenic than PUM, with high but variable Os concentrations, possibly resulting from a sulfide “nugget” effect. The systematically lower 187 Os/ 188 Os in Cr‐spinels compared to whole rocks shows that whole rock abyssal peridotites are largely compromised by radiogenic seawater interaction, often obscuring the mantle signature. Measurements of treated abyssal peridotite Cr‐spinels in some cases can circumvent this seawater alteration problem allowing more straightforward interpretation of isotopic values and thus further constraining the Os isotopic signature for the depleted upper mantle. Our results suggest that the 187 Os/ 188 Os for the upper mantle lies in the range 0.120–0.125." @default.
- W1599863721 created "2016-06-24" @default.
- W1599863721 creator A5010832994 @default.
- W1599863721 creator A5017423154 @default.
- W1599863721 creator A5028488670 @default.
- W1599863721 creator A5068739247 @default.
- W1599863721 creator A5070273832 @default.
- W1599863721 date "2002-01-01" @default.
- W1599863721 modified "2023-10-18" @default.
- W1599863721 title "Abyssal peridotite osmium isotopic compositions from cr-spinel" @default.
- W1599863721 cites W1488681283 @default.
- W1599863721 cites W1494545736 @default.
- W1599863721 cites W1509335520 @default.
- W1599863721 cites W1528656643 @default.
- W1599863721 cites W1659288539 @default.
- W1599863721 cites W1865949348 @default.
- W1599863721 cites W1965350012 @default.
- W1599863721 cites W1966685022 @default.
- W1599863721 cites W1966942623 @default.
- W1599863721 cites W1968554206 @default.
- W1599863721 cites W1969859799 @default.
- W1599863721 cites W1970111092 @default.
- W1599863721 cites W1977811562 @default.
- W1599863721 cites W1990306083 @default.
- W1599863721 cites W1992356046 @default.
- W1599863721 cites W1992704749 @default.
- W1599863721 cites W1998762489 @default.
- W1599863721 cites W2001860086 @default.
- W1599863721 cites W2005123945 @default.
- W1599863721 cites W2009446927 @default.
- W1599863721 cites W2016701904 @default.
- W1599863721 cites W2016778781 @default.
- W1599863721 cites W2021959819 @default.
- W1599863721 cites W2022050148 @default.
- W1599863721 cites W2037155919 @default.
- W1599863721 cites W2037832103 @default.
- W1599863721 cites W2041825120 @default.
- W1599863721 cites W2045894980 @default.
- W1599863721 cites W2046098057 @default.
- W1599863721 cites W2055558516 @default.
- W1599863721 cites W2060472760 @default.
- W1599863721 cites W2063776800 @default.
- W1599863721 cites W2067876904 @default.
- W1599863721 cites W2068464003 @default.
- W1599863721 cites W2070259366 @default.
- W1599863721 cites W2074072796 @default.
- W1599863721 cites W2078237579 @default.
- W1599863721 cites W2078259155 @default.
- W1599863721 cites W2079448816 @default.
- W1599863721 cites W2080973789 @default.
- W1599863721 cites W2088644964 @default.
- W1599863721 cites W2090090002 @default.
- W1599863721 cites W2091060229 @default.
- W1599863721 cites W2092192237 @default.
- W1599863721 cites W2093827788 @default.
- W1599863721 cites W2107820993 @default.
- W1599863721 cites W2113810005 @default.
- W1599863721 cites W2142817706 @default.
- W1599863721 cites W2166632770 @default.
- W1599863721 cites W2167754329 @default.
- W1599863721 cites W2169111811 @default.
- W1599863721 cites W2170866675 @default.
- W1599863721 cites W2314202908 @default.
- W1599863721 cites W2477875434 @default.
- W1599863721 doi "https://doi.org/10.1029/2001gc000161" @default.
- W1599863721 hasPublicationYear "2002" @default.
- W1599863721 type Work @default.
- W1599863721 sameAs 1599863721 @default.
- W1599863721 citedByCount "95" @default.
- W1599863721 countsByYear W15998637212012 @default.
- W1599863721 countsByYear W15998637212013 @default.
- W1599863721 countsByYear W15998637212014 @default.
- W1599863721 countsByYear W15998637212015 @default.
- W1599863721 countsByYear W15998637212016 @default.
- W1599863721 countsByYear W15998637212017 @default.
- W1599863721 countsByYear W15998637212018 @default.
- W1599863721 countsByYear W15998637212019 @default.
- W1599863721 countsByYear W15998637212020 @default.
- W1599863721 countsByYear W15998637212021 @default.
- W1599863721 countsByYear W15998637212022 @default.
- W1599863721 countsByYear W15998637212023 @default.
- W1599863721 crossrefType "journal-article" @default.
- W1599863721 hasAuthorship W1599863721A5010832994 @default.
- W1599863721 hasAuthorship W1599863721A5017423154 @default.
- W1599863721 hasAuthorship W1599863721A5028488670 @default.
- W1599863721 hasAuthorship W1599863721A5068739247 @default.
- W1599863721 hasAuthorship W1599863721A5070273832 @default.
- W1599863721 hasConcept C111368507 @default.
- W1599863721 hasConcept C127313418 @default.
- W1599863721 hasConcept C161509811 @default.
- W1599863721 hasConcept C173815673 @default.
- W1599863721 hasConcept C17409809 @default.
- W1599863721 hasConcept C199289684 @default.
- W1599863721 hasConcept C2779417233 @default.
- W1599863721 hasConcept C57016615 @default.
- W1599863721 hasConcept C67236022 @default.
- W1599863721 hasConcept C79572550 @default.
- W1599863721 hasConcept C84372278 @default.