National Geochronological Database sample #15408

Geographic location
-110.939444, 33.391944
110° 56' 22" W, 33° 23' 31" N
Gila county, AZ
Inspiration 1:24,000 scale map quadrangle
Accurate to within 1 minute (~1 mile)
GLOBE-MIAMI DISTRICT
Rock name Quartz monzonite
Description MAIN PHASE OF SCHULTZE GRANITE (PORPHYRITIC QUARTZ MONZONITE)
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.
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Geologic map unit -110.939444, 33.391944
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K-Ar age determinations

Age estimate 61.7 ± 0.7Ma
Type of analysis conventional K-Ar
Rock or mineral analyzed biotite
Analytical details
Lab sample ID 4
Decay constants 4.962E-04, 0.581E-04, 1.1167E-04
K2O concentration 9.38 %
Radiogenic 40Ar concentration 8.4747
Radiogenic Ar 93 %
Comments ROCK PROBABLY FORMED 60-65 M.Y. AGO