National Geochronological Database sample #3293

Outcrop or artificial surface exposure, Rhyolite porphyry

Geographic location
-116.685556, 40.303333
116° 41' 8" W, 40° 18' 12" N
Lander county, NV
Crescent Valley 1:62,500 scale map quadrangle
Accurate to within 1 minute (~1 mile)
NORTH SHOSHONE RANGE
Source of sample Outcrop or artificial surface exposure
Rock name Rhyolite porphyry
Description DIKE
Laboratories USGS Menlo Park
Compiler name Nichols, S.L.
Date compiled 1978 02
Precision of location Accurate to within 1 minute (~1 mile)
Location comment NORTH SHOSHONE RANGE
Bibliographic reference McKee, E.H., and Silberman, M.L., 1970, Geochronology Of Tertiary Igneous Rocks In Central Nevada: Geological Society of America Bulletin, v. 81, p. 2317-2328.
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Geologic map unit -116.685556, 40.303333
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K-Ar age determinations

Age estimate 35.23Ma
age of intrusion
Type of analysis conventional K-Ar
REPLICATE POTASSIUM ANALYSES
Rock or mineral analyzed biotite
Analytical details
Lab sample ID 1
Decay constants 4.72E-04, 0.585E-04, 1.19E-04*
K2O concentration 8.24 %
Radiogenic 40Ar concentration 4.22
Radiogenic Ar 80 %
Age estimate 36.14Ma
age of intrusion
Type of analysis conventional K-Ar
REPEAT AR ANALYSIS
Rock or mineral analyzed biotite
Analytical details
Lab sample ID 1
Decay constants 4.72E-04, 0.585E-04, 1.19E-04*
K2O concentration 8.24 %
Radiogenic 40Ar concentration 4.33
Radiogenic Ar 81 %
Age estimate 35.57Ma
age of intrusion
Type of analysis conventional K-Ar
REPLICATE POTASSIUM ANALYSES
Rock or mineral analyzed sanidine
Analytical details
Lab sample ID 1
Decay constants 4.72E-04, 0.585E-04, 1.19E-04*
K2O concentration 11.6 %
Radiogenic 40Ar concentration 6
Radiogenic Ar 97 %