Outcrop or artificial surface exposure, Granodiorite
| Geographic location |
-117.266667, 41.141667
117°
16'
"
W,
41°
8'
30"
N
Humboldt county,
NV
Osgood Mountains
1:62,500 scale map quadrangle
Accurate to within 1 minute (~1 mile)
OSGOOD MOUNTAINS; EAST-CENTRAL PART OF SEC. 29, T38N, R42E; 3,000 FT. SOUTH OF MOUNTAIN VIEW MINE
|
|---|---|
| Source of sample | Outcrop or artificial surface exposure |
| Rock name | Granodiorite |
| Description | SOUTH LOBE, OSGOOD MOUNTAINS STOCK; MEDIUM-GRAINED BIOTITE-HORNBLENDE GRANODIORITE |
| 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 | OSGOOD MOUNTAINS; EAST-CENTRAL PART OF SEC. 29, T38N, R42E; 3,000 FT. SOUTH OF MOUNTAIN VIEW MINE |
| Bibliographic reference | Silberman, M.L., and Mckee, E.H., 1971, K-Ar Ages Of Granitic Plutons In North-Central Nevada: Isochron/West, No. 1, p. 15-32. |
| (click for info) | |
| Geologic map unit | -117.266667, 41.141667 |
| Nearby scientific data | Find additional scientific data near this location |
| Age estimate | 94.47 ± 1.8Ma age of intrusion
|
|---|---|
| Type of analysis | conventional K-Ar |
| Rock or mineral analyzed | biotite |
| Analytical details | |
| Lab sample ID | 2. USGS(M)-MB34 |
| Decay constants | 4.72E-04, 0.585E-04, 1.19E-04* |
| K2O concentration | 8.73 % |
| Radiogenic 40Ar concentration | 12.19 |
| Radiogenic Ar | 86 % |
| Age estimate | 90.49 ± 1.8Ma age of intrusion
|
| Type of analysis | conventional K-Ar |
| Rock or mineral analyzed | hornblende 3% PYROXENE
|
| Analytical details | |
| Lab sample ID | 2. USGS(M)-MB34 |
| Decay constants | 4.72E-04, 0.585E-04, 1.19E-04* |
| K2O concentration | 0.694 % |
| Radiogenic 40Ar concentration | 0.9272 |
| Radiogenic Ar | 62 % |
| Comments | HORNBLENDE AGE REVISED TO 89.5 M.Y. BY SILBERMAN, BERGER, AND KOSKI, 1974, BASED ON NEW POTASSIUM ANALYSES |