40Ar/39 Dates from the Harquahala and Little Harquahala Mountains, west-central Arizona. Part I

Richard, S.M.; McWilliams, M.O.; Gans, P.B.

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Richard, S.M., McWilliams, M.O., and Gans, P.B., 1998, 40Ar/39 Dates from the Harquahala and Little Harquahala Mountains, west-central Arizona. Part I. Arizona Geological Survey Open File Report, OFR-98-25, 25 p.

Description

This report includes the analytical data for four 40Ar/39Ar cooling dates from samples collected in the Harquahala and Little Harquahala Mountains of west-central Arizona. The samples were collected to constrain the cooling history and timing of mineralization in this area [Richard et aI., 1990; Richard, 1988]. Analyses were done at Stanford University. For each of the 4 samples described here, an incremental thermal release age spectra is included, along with a table summarizing the data used to calculate ages, and a table of raw data from each temperature increment. Argon correlation diagrams are included for each sample, on which the ratio of 4°Ar (radiogenic and atmospheric) to 36Ar is plotted against the ratio 39 ArP6Ar. The regression lines used to calculate isochron ages are indicated on the plots. Regressions were calculated using a simple least squares method. For the hornblende samples, a K/Ca ratio plot is included above the age spectra to provide an indication of the compositional consistency of the degassed material in each temperature increment.

URI

http://hdl.handle.net/10150/629622

Additional Links

http://repository.azgs.az.gov/uri_gin/azgs/dlio/980

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Series/Report no.

OFR-98-25

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Documents in the AZGS Document Repository collection are made available by the Arizona Geological Survey (AZGS) and the University Libraries at the University of Arizona. For more information about items in this collection, please contact azgs-info@email.arizona.edu.

North Bounding Coordinate

33.9141

South Bounding Coordinate

33.6173

West Bounding Coordinate

-113.601

East Bounding Coordinate

-113.11

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AZGS Document Repository