Outcrop or artificial surface exposure, Anorthosite
| Geographic location |
-110.083333, 45.466667
110°
5'
"
W,
45°
28'
"
N
Sweet Grass or Stillwater county,
MT
Bozeman or Billings
1:250,000 scale map quadrangle
Accurate to within 30 minutes (~30 miles)
NORTHERN BEARTOOTH MOUNTAINS
|
|---|---|
| Source of sample | Outcrop or artificial surface exposure |
| Rock name | Anorthosite |
| Description | ANORTHOSITE FROM THE STILLWATER COMPLEX |
| Laboratories | Ohio State University |
| Compiler name | Marvin, R.F. |
| Date compiled | 1980 02 |
| Precision of location | Accurate to within 30 minutes (~30 miles) |
| Location comment | NORTHERN BEARTOOTH MOUNTAINS |
| Bibliographic reference | Fenton, M.D., and Faure, G., 1969, The Age Of The Igneous Rocks Of The Stillwater Complex Of Montana: Geological Society of America Bulletin, v. 80, p. 1599-1604. |
| (click for info) | |
| Geologic map unit | -110.083333, 45.466667 |
| Nearby scientific data | Find additional scientific data near this location |
| Age estimate | 2398.3 ± 210Ma minimum age of intrusion
|
|---|---|
| Type of analysis | 87Sr/86Sr-87Rb/86Sr isochron (whole rock) 5-POINT WHOLE-ROCK ISOCHRON; RB=6.59, 5.55 PPM; SR=155.8, 156.5 PPM; 87SR/86SR=0.7072, 0.7077
|
| Rock or mineral analyzed | whole rock |
| Analytical details | |
| Lab sample ID | R4186 |
| Sample suite # | 300 |
| Decay constants | 0.0000139* |
| Rubidium concentration | 6.07 ppm |
| Strontium concentration | 156.15 ppm |
| Initial 87Sr/86Sr | 0.7029 |
| Ratio 87Rb/86Sr | 0.113 |
| Ratio 87Sr/86Sr | 0.7074 |
| Normal? | T |