Open system Re-Os isotope behavior in platinum-group minerals during laterization?

TY - JOUR

T1 - Open system Re-Os isotope behavior in platinum-group minerals during laterization?

AU - Aiglsperger, Thomas

AU - González-Jiménez, José M.

AU - Proenza, Joaquín A.

AU - Galí, Salvador

AU - Longo, Francisco

AU - Griffin, William L.

AU - O’Reilly, Suzanne Y.

N1 - Copyright the Author(s) 2021. Version archived for private and non-commercial use with the permission of the author/s and according to publisher conditions. For further rights please contact the publisher.

PY - 2021/10

Y1 - 2021/10

N2 - In this short communication, we present preliminary data on the Re-Os isotopic systematics of platinum-group minerals (PGM) recovered from different horizons in the Falcondo Ni-laterite in the Dominican Republic. The results show differences in the Os-isotope composition in different populations of PGM: (i) pre-lateritic PGM yield187 Os/188 Os varying from 0.11973 ± 0.00134 to 0.12215 ± 0.00005 (2σ uncertainty) whereas (ii) lateritic PGM are more radiogenic in terms of187 Os/188 Os (from 0.12390 ± 0.00001 to 0.12645 ± 0.00005; 2σ uncertainty). We suggest that these differences reflect the opening of the Re-Os system in individual grains of PGM during lateritic weathering. The implications of these results are twofold as they will help to (1) elucidate the small-scale mobility of noble metals in the supergene setting and therefore the possible formation of PGM at these very low temperatures, (2) better refine the Os-isotopic datasets of PGM that are currently being used for defining dynamic models of core–mantle separation, crustal generation, and fundamental plate-tectonic processes such as the opening of oceans.

AB - In this short communication, we present preliminary data on the Re-Os isotopic systematics of platinum-group minerals (PGM) recovered from different horizons in the Falcondo Ni-laterite in the Dominican Republic. The results show differences in the Os-isotope composition in different populations of PGM: (i) pre-lateritic PGM yield187 Os/188 Os varying from 0.11973 ± 0.00134 to 0.12215 ± 0.00005 (2σ uncertainty) whereas (ii) lateritic PGM are more radiogenic in terms of187 Os/188 Os (from 0.12390 ± 0.00001 to 0.12645 ± 0.00005; 2σ uncertainty). We suggest that these differences reflect the opening of the Re-Os system in individual grains of PGM during lateritic weathering. The implications of these results are twofold as they will help to (1) elucidate the small-scale mobility of noble metals in the supergene setting and therefore the possible formation of PGM at these very low temperatures, (2) better refine the Os-isotopic datasets of PGM that are currently being used for defining dynamic models of core–mantle separation, crustal generation, and fundamental plate-tectonic processes such as the opening of oceans.

KW - Re-Os isotopes

KW - platinum-group minerals

KW - Ni laterite

KW - Dominican Republic

UR - http://www.scopus.com/inward/record.url?scp=85116125573&partnerID=8YFLogxK

U2 - 10.3390/min11101083

DO - 10.3390/min11101083

M3 - Article

AN - SCOPUS:85116125573

SN - 2075-163X

VL - 11

SP - 1

EP - 8

JO - Minerals

JF - Minerals

IS - 10

M1 - 1083

ER -