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Isotopic ratios and element concentrations of U-Pb and Sm-Nd for scheelite petrochronology

Metadata Updated: October 30, 2025

Instrument, standard, and sample data from application of in situ laser ablation-inductively coupled plasma-mass spectrometry (LA-ICPMS) dating of scheelite in thin section, and sample data from isotope dilution thermal ionization mass spectrometry (ID-TIMS) scheelite dating are in this data release. Fractionation factor and ratio data in between NIST glass and natural scheelite as well as isotope dilution Sm-Nd scheelite data are also included. Scheelite is from two ore deposits within the Stibnite-Yellow Pine mining area, and analyses yielded bimodal U-Pb ages with major growth of scheelite in the range of 61.3 ± 4.1 to 55.1 ± 3.8 Ma and a second growth event involving both scheelite and stibnite at 45.8 ± 2.6 Ma. In situ analyses were calibrated and confirmed by ID-TIMS U-Pb lower intercept ages of two coarsely crystalline scheelite samples yielded ages of 56.62 ± 0.16 Ma and 57.52 ± 0.22 Ma. These results, in good agreement with 40Ar/39Ar ages of 57.08 ± 0.12 to 56.2 ± 1.2 Ma from adularia petrographically linked to scheelite, confirm primary scheelite mineralization occurred ca. 57.5 Ma. This geochronology resolves a long-standing debate about the formation age of scheelite and stibnite within the United States’ largest antimony source. Calibration with ID-TIMS provided reliable ages, and crystals from the same sample were used as a matrix-matched primary standard material for LA-ICPMS. No matrix-match standard was previously characterized accentuating the importance of this newly characterized matrix-matched scheelite standard.

Access & Use Information

Public: This dataset is intended for public access and use. License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

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Dates

Metadata Created Date September 14, 2025
Metadata Updated Date October 30, 2025

Metadata Source

Harvested from DOI USGS DCAT-US

Additional Metadata

Resource Type Dataset
Metadata Created Date September 14, 2025
Metadata Updated Date October 30, 2025
Publisher U.S. Geological Survey
Maintainer
Identifier http://datainventory.doi.gov/id/dataset/usgs-5ef247fb82ced62aaae3bc40
Data Last Modified 2020-08-20T00:00:00Z
Category geospatial
Public Access Level public
Bureau Code 010:12
Metadata Context https://project-open-data.cio.gov/v1.1/schema/catalog.jsonld
Metadata Catalog ID https://ddi.doi.gov/usgs-data.json
Schema Version https://project-open-data.cio.gov/v1.1/schema
Catalog Describedby https://project-open-data.cio.gov/v1.1/schema/catalog.json
Harvest Object Id ede7adcd-5af8-4ecc-802b-9719bc63c03e
Harvest Source Id 2b80d118-ab3a-48ba-bd93-996bbacefac2
Harvest Source Title DOI USGS DCAT-US
Metadata Type geospatial
Old Spatial -115.3380900, 44.8992800, -115.3377400, 44.9271400
Source Datajson Identifier True
Source Hash c8faa32e34a15f46a5ac1040b8b70e9ed3562c2383316002742ac904e416ae72
Source Schema Version 1.1
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