Investigation of an early Pleistocene marine osmium isotope record from the eastern equatorial Pacific

Reconstructing the Evolution of the Submarine Monterey Canyon System From Os, Nd, and Pb Isotopes in Hydrogenetic Fe‐Mn Crusts

“…Rivers draining shale deposits frequently have high 187 Os/ 188 Os, and it has been proposed that black shale can provide a more radiogenic flux of Os than other rock types (Dalai & Ravizza, ; Ravizza & Esser, ; Singh et al, ). However, Os released from shale can be incorporated into secondary iron oxides and clay minerals during weathering and in rivers, which may restrict the flux of labile radiogenic Os (Dalai & Ravizza, ; Pierson‐Wickmann et al, ). It is possible that a river or tributary sourced near the Big Pine Volcanic Field flowed through shale deposits in the San Joaquin Basin or near the coast resulting in a mixed particulate and dissolved load with an even more radiogenic 187 Os/ 188 Os signature flowing into the MC.…”

“…As radiogenic Os is efficiently mobilized during weathering of organic-rich shale and can lose 45-90% of its initial Os (Peucker-Ehrenbrink & Blum, 1998;Peucker-Ehrenbrink & Ravizza, 2000;Ravizza & Esser, 1993), such contributions can be even more radiogenic than average continental runoff ( 187 Os/ 188 Os 1.4). Rivers draining shale deposits frequently have high 187 Os/ 188 Os, and it has been proposed that black shale can provide a more radiogenic flux of Os than other rock types (Dalai & Ravizza, 2010;Ravizza & Esser, 1993;Singh et al, 1999). However, Os released from shale can be incorporated into secondary iron oxides and clay minerals during weathering and in rivers, which may restrict the flux of labile radiogenic Os (Dalai & Ravizza, 2010;Pierson-Wickmann et al, 2002).…”

Determination of Os by isotope dilution-inductively coupled plasma-mass spectrometry with the combination of laser ablation to introduce chemically separated geological samples

“…To address the volatility of OsO 4 , its vapor phase is directly introduced into ICP by online sparging of the digested samples in which Os is changed into OsO 4 [13,19] or by distilling Os via an oxidizing reagent in a mini-apparatus [20]. In practice, the former can be more readily handled than the latter, thus presenting more applications [21][22][23]. With sparging or distilling, however, OsO 4 is slowly released from the target samples, and this can be clearly demonstrated even with an electrothermal ware for heating [24].…”