National Geochronological Database sample #859

Quarry, Monzonite

Geographic location
-115.005556, 39.261111
115° ' 20" W, 39° 15' 40" N
White Pine county, NV
Riepetown 1:24,000 scale map quadrangle
Accurate to within 1 minute (~1 mile)
SW1/4 SW1/4 SEC. 9, T16N, R62E, EMMA OPEN-PIT COPPER MINE NEAR RUTH , ROBINSON MINING DISTRICT
Source of sample Quarry
Rock name Monzonite
Description ALTERED MONZONITE PORPHYRY COMPOSED OF ORTHOCLASE (WELL SERICITIZED), QUARTZ, AND BIOTITE (VERY LIGHT BROWN, CLUSTERED) PHENOCRYSTS IN A GROUNDMASS OF QUARTZ AND SERICITE.
Laboratories Lamont (Columbia University)
Compiler name Marvin, R.F.
Date compiled 1975 10
Precision of location Accurate to within 1 minute (~1 mile)
Location comment SW1/4 SW1/4 SEC. 9, T16N, R62E, EMMA OPEN-PIT COPPER MINE NEAR RUTH , ROBINSON MINING DISTRICT
Bibliographic reference Mcdowell, F.W., 1971, K-Ar Ages Of Igneous Rocks From The Western United States: Isochron/West, No. 2, p. 1-16.
(click for info)
Geologic map unit -115.005556, 39.261111
Nearby scientific data Find additional scientific data near this location

K-Ar age determinations

Age estimate 111.12 ± 3Ma
age of intrusion
Type of analysis conventional K-Ar
Rock or mineral analyzed biotite
80-100 MESH AND ANALYZED SEPARATE CONTAINED 5% IMPURITIES
Analytical details
Lab sample ID L-1014
Decay constants 4.72E-04, 0.585E-04, 1.19E-04*
K2O concentration 10.06 %
Radiogenic 40Ar concentration 16.6
Radiogenic Ar 96 %
Comments THIS ANALYSIS ALSO REPORTED IN MCDOWELL AND KULP (1967)