Outcrop or artificial surface exposure, Rhyodacite
| Geographic location |
-117.165278, 37.704167
117°
9'
55"
W,
37°
42'
15"
N
Esmeralda county,
NV
Goldfield
1:62,500 scale map quadrangle
Accurate to within 1 minute (~1 mile)
|
|---|---|
| Source of sample | Outcrop or artificial surface exposure |
| Rock name | Rhyodacite |
| Description | COARSE ALUNITE FROM ALUNITE-JAROSITE BRECCIA FILLING IN SILICIFIED PORPHYRITIC RHYODACITE |
| Laboratories | USGS Menlo Park |
| Compiler name | Nichols, S.L. |
| Date compiled | 1978 04 |
| Precision of location | Accurate to within 1 minute (~1 mile) |
| Bibliographic reference | Ashley, R.P., and Silberman, M.L., 1976, Direct Dating Of Mineralization At Goldfield, Nevada, By Potassium-Argon and Fission-Track Methods: Economic Geology, v. 71, p. 904-924. |
| (click for info) | |
| Geologic map unit | -117.165278, 37.704167 |
| Nearby scientific data | Find additional scientific data near this location |
| Age estimate | 20.49 ± 0.4Ma |
|---|---|
| Type of analysis | conventional K-Ar 9.97%, 10.09%, 10.06% K2O; ARGON EXTRACTION SYSTEM NOT BAKED-OUT OVERNIGHT
|
| Rock or mineral analyzed | alunite |
| Analytical details | |
| Lab sample ID | 185-79B |
| Decay constants | 4.72E-04, 0.585E-04, 1.19E-04* |
| K2O concentration | 10.04 % |
| Radiogenic 40Ar concentration | 2.979 |
| Radiogenic Ar | 33 % |
| Comments | TIME OF ALTERATION OR MINERALIZATION |