Unnamed Occurrences (ARDF - TK018; upper Portage Creek), Valdez Creek Mining District, Matanuska-Susitna Borough, Alaska, USAi
| Regional Level Types | |
|---|---|
| Unnamed Occurrences (ARDF - TK018; upper Portage Creek) | - not defined - |
| Valdez Creek Mining District | Mining District |
| Matanuska-Susitna Borough | Borough |
| Alaska | State |
| USA | Country |
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Latitude & Longitude (WGS84):
62° 59' 5'' North , 148° 50' 5'' West
Latitude & Longitude (decimal):
Köppen climate type:
Nearest Settlements:
| Place | Population | Distance |
|---|---|---|
| Cantwell | 219 (2011) | 45.6km |
Mindat Locality ID:
202069
Long-form identifier:
mindat:1:2:202069:6
GUID (UUID V4):
430fbcab-75a3-4e7b-830e-d207397850af
MAS/MIL number 20760109.
Location: This site is a 1.5-mile-long, northeast-trending area of mineral occurrences near the headwaters of Portage Creek. The center of the area is at an elevation of about 3,700 feet, in the NE1/4NW1/4 sec. 26, T. 22 S., R. 7 W., Fairbanks Meridian. The location is accurate.
Geology: The occurrences at the southwest end of the area are quartz-veined, mafic(?), aphanitic and hornfelsed volcanic rocks and rusty weathering argillite; at the northeast end, they are brecciated tuffs(?) (J. Schmidt, written commun., 2001). Samples of the hornfelsed volcanic rocks contain 260 parts per million copper, 0.5 part per million gold, 0.4 part per million silver, and 0.27 part per million mercury. Argillite samples contain 1 part per million silver; and the breccia contains 0.4 part per million silver and 215 parts per million copper. (The 0.5-part-per-million gold value is an ICP analysis from XRAL Laboratories; a fire assay of the same sample gives less than 0.005 part per million gold. The cause of the discrepancy is not known.)
Workings: Only surface sampling by U.S. Geological Survey (J. Schmidt, written commun., 2001).
Alteration: Iron-oxide alteration.
Commodities (Major) - Ag, Au, Cu; (Minor) - Hg
Development Status: None
Select Mineral List Type
Standard Detailed Gallery Strunz Chemical ElementsCommodity List
This is a list of exploitable or exploited mineral commodities recorded at this locality.Mineral List
1 valid mineral.
Gallery:
List of minerals arranged by Strunz 10th Edition classification
| Group 4 - Oxides and Hydroxides | |||
|---|---|---|---|
| ⓘ | Quartz | 4.DA.05 | SiO2 |
Other Databases
| Link to USGS - Alaska: | TK018 |
|---|
Other Regions, Features and Areas containing this locality
North America PlateTectonic Plate
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References
