A quantitative link between recycling and osmium isotopes.

Osmium-isotope variations in Hawaiian lavas: evidence for recycled oceanic lithosphere in the Hawaiian plume

Isotopic heterogeneity in Hawaiian shield lavas reflects the presence of two distinct recycled components in the Hawaiian plume, both from the same packet of recycled oceanic lithosphere. Radiogenic Os-isotopes and anomalously heavy oxygen-isotopes in Koolau lavas reflect melt generation from recycled oceanic crust plus pelagic sediment. In contrast, Kea lavas have unradiogenic Os-isotopes but ...

Osmium isotopes in hydrothermal £uids from the Juan de Fuca Ridge

We present Os data for axial high-temperature and off-axial low-temperature hydrothermal solutions from the Juan de Fuca Ridge. The high-temperature, H2S-bearing axial fluids have unradiogenic Os isotopes pointing to a nearly complete domination of osmium isotopes from the basalts during hydrothermal circulation. The ridge axis fluids typically do not show large enrichment in osmium concentrati...

s-PROCESS IMPLICATIONS FROM OSMIUM ISOTOPE ANOMALIES IN CHONDRITES

Correlated isotopic anomalies in osmium (Os, Os, Os, measured with respect to Os) extracted from primitive carbonaceous chondrites tightly constrain the ratio to be ( 5%). A 190 188 j ( Os)/j ( Os) 0.859 0.042 n n recent measurement of the Maxwellian-averaged neutron-capture cross sections (MACSs) for 186, 187, Os lowered the jn( Os) by 27% but did not measure jn( Os). From the jn( Os)/jn( Os) ...

Anthropogenic osmium in rain and snow reveals global-scale atmospheric contamination.

Osmium is one of the rarer elements in seawater, with typical concentration of approximately 10 x 10(-15) g g(-1) (5.3 x 10(-14) mol kg(-1)). The osmium isotope composition ((187)Os/(188)Os ratio) of deep oceans is 1.05, reflecting a balance between inputs from continental crust (approximately 1.3) and mantle/cosmic dust (approximately 0.13). Here, we show that the (187)Os/(188)Os ratios measur...

Osmium Isotope Evidence for an S-process Carrier in Primitive