National Geochronological Database sample #15449

Outcrop or artificial surface exposure, Granodiorite

Geographic location
-110.9525, 33.396667
110° 57' 9" W, 33° 23' 48" N
Gila county, AZ
Inspiration 1:24,000 scale map quadrangle
Accurate to within 1 minute (~1 mile)
GLOBE-MIAMI DISTRICT
Source of sample Outcrop or artificial surface exposure
Rock name Granodiorite
Description WILLOW SPRING GRANODIORITE
Laboratories USGS Menlo Park
Compiler name Marvin, R.F.
Date compiled 1984 11
Precision of location Accurate to within 1 minute (~1 mile)
Location comment GLOBE-MIAMI DISTRICT
Bibliographic reference Creasey, S.C., 1980, Chronology Of Intrusion and Deposition Of Porphyry Copper Ores, Globe-Miami District, Arizona: Economic Geology, v. 75, p. 830-844.
(click for info)
Geologic map unit -110.9525, 33.396667
Nearby scientific data Find additional scientific data near this location

K-Ar age determinations

Age estimate 57.2 ± 0.6Ma
Type of analysis conventional K-Ar
Rock or mineral analyzed biotite
Analytical details
Lab sample ID 46
Decay constants 4.962E-04, 0.581E-04, 1.1167E-04
K2O concentration 7.96 %
Radiogenic 40Ar concentration 6.5884
Radiogenic Ar 67 %
Comments RESET AGE; PLUTON IS AROUND 1600 M.Y. OLD