← Search
Sample USGSD82MTz1935
NavDat sample number 19143 · ANDESITE
Sample
| Sample ID | USGSD82MTz1935 |
|---|
| Rock name | ANDESITE |
|---|
| Rock type | VOLCANIC |
|---|
| Composition | INTERMEDIATE |
|---|
| Material | IGNEOUS |
|---|
| Collected by | R.G. Tysdal |
|---|
| Comment | porphyritic hornblende andesite; hornblende phenocrysts show some alteration; calculated age considered too old |
|---|
Location
| Latitude | 45.0042 |
|---|
| Longitude | -111.112 |
|---|
| Location | SE end of the Madison Range; Gallatin County |
|---|
| State / province | Montana |
|---|
| Volcanic field | Gallatin laccolith |
|---|
Age
| Age (Ma) | Error | Min | Max | Geologic age | Dated by |
|---|
| 105 |
|
102 |
108 |
|
|
Analyses
No chemical analyses are stored for this sample.
References
- Marvin, Richard F; Mehnert, Harald H; Naeser, Charles W; Zartman,Robert E (1989) U. S. Geological Survey radiometric ages; Compilation C; Part five;Colorado, Montana, Utah, and Wyoming. Isochron/West, vol.53, pp.14-19, Jun 1989
