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USGS · 70073400

Sm-Nd dating of the giant Sullivan Pb-Zn-Ag deposit, British Columbia

Shao-Yong Jiang·John F. Slack·Martin R. Palmer
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Abstract

We report here Sm and Nd isotope data for hydrothermal tourmalinites and sulfide ores from the giant Sullivan Pb-Zn-Ag deposit, which occurs in the lower part of the Mesoproterozoic Purcell (Belt) Supergroup. Whole-rock samples of quartz-tourmaline tourmalinite from the footwall alteration pipe yield a Sm-Nd isochron age of 1470 ± 59 Ma, recording synsedimentary B metasomatism of clastic sediments during early evolution of the Sullivan hydrothermal system. Data for variably altered (chloritized and/or albitized) tourmalinites from the hanging wall of the deposit, which are believed to have formed originally ca. 1470 Ma, define a younger 1076 ± 77 Ma isochron because of resetting of Sm and Nd isotopes during Grenvillian metamorphism. HCl leachates of bedded Pb-Zn ore yield a Sm-Nd isochron age of 1451 ± 46 Ma, which is consistent with syngenetic-exhalative mineralization ca. 1470 Ma; this age could also reflect a slightly younger, epigenetic hydrothermal event. Results obtained for the Sullivan deposit indicate that the Sm-Nd geochronometer has the potential to directly date mineralization and alteration in stratabound sulfide deposits that are not amenable to dating by other isotope methods.

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90° N90° S · 180° W ← longitude → 180° E
Source-reported bounding extent: 49° to 53.78° latitude; -122.27° to -114.05° longitude. This indicates report coverage, not an exact sampling location. View area on OpenStreetMap.

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Shao-Yong Jiang, John F. Slack, Martin R. Palmer. 2000. Sm-Nd dating of the giant Sullivan Pb-Zn-Ag deposit, British Columbia. https://doi.org/10.1130/0091-7613(2000)28%3C751%3Asdotgs%3E2.0.co%3B2

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