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Jim Prospect Confluence; Jim River; Jim River Confluence Occurrence, Koyukuk Mining District, Yukon-Koyukuk Census Area, Alaska, USAi
| Regional Level Types | |
|---|---|
| Jim Prospect Confluence; Jim River; Jim River Confluence Occurrence | Occurrence |
| Koyukuk Mining District | Mining District |
| Yukon-Koyukuk Census Area | Census Area |
| Alaska | State |
| USA | Country |
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Latitude & Longitude (WGS84):
66° 47' 29'' North , 150° 45' 10'' West
Latitude & Longitude (decimal):
Type:
Köppen climate type:
Location: These two placer-gold occurrences are along the Jim River. One is at the mouth of Prospect Creek (locally called the Jim Prospect Confluence). The second is in the canyon of Jim Creek about 6 miles downstream. The coordinates at at the Jim Prospect Confluence, just northwest of the center of section 26, T. 23 N., R. 15 W. of the Fairbanks Meridian, and about 0.5 mile southwest of Prospect Creek Camp.
Geology: Fine placer gold, identified in panned concentrates occurs at two sites along Jim River (Kurtak and others, 2002). At the 'Jim Prospect Confluence', a panned -concentrate contained a single, very fine grained, gold particle, with abundant magnetite. An analysis of this concentrate indicated that it contained 1,590 ppb gold. Another placer sample from the same site contained 13 very fine gold particles and an analysis showed that it has a value of 0.0003 ounce of gold per cubic yard. At a site on Jim River about 6 miles downstream from the mouth of Prospect Creek, very fine gold flakes were observed in a panned-concentrate; an analysis showed a value of 1,230 ppb gold (Kurtak and others, 1999). Kurtak and others (1999) suspect that the gold is derived from the Jim River pluton, which crops out north of the Jim River canyon. The rocks in the region are Triassic to Jurassic mafic volcanic and intrusive rocks, and mid-Cretaceous granitic, plutonic rocks (Patton and Miller, 1973). The rocks in the vicinity of the occurrences on the Jim River are altered volcanics, including pillow basalts (Kurtak and others, 2002). No bedrock was observed at the 'Jim Prospect Confluence' occurrence.
Workings: In the 1970's, claims were located at the Jim Prospect Confluence occurrence, and the occurrence about 6 miles below Prospect Creek (BT008) the other site on the Jim River (Kurtak and others, 2002).
Age: Quaternary.
Commodities (Major) - Au
Development Status: None
Deposit Model: Placer Au (Cox and Singer, 1986; model 39a)
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
2 valid minerals.
Detailed Mineral List:
| ⓘ Magnetite Formula: Fe2+Fe3+2O4 |
| ⓘ Native Gold Formula: Au |
Gallery:
List of minerals arranged by Strunz 10th Edition classification
| Group 1 - Elements | |||
|---|---|---|---|
| ⓘ | Native Gold | 1.AA.05 | Au |
| Group 4 - Oxides and Hydroxides | |||
| ⓘ | Magnetite | 4.BB.05 | Fe2+Fe3+2O4 |
List of minerals for each chemical element
| O | Oxygen | |
|---|---|---|
| O | ⓘ Magnetite | Fe2+Fe23+O4 |
| Fe | Iron | |
| Fe | ⓘ Magnetite | Fe2+Fe23+O4 |
| Au | Gold | |
| Au | ⓘ Native Gold | Au |
Other Databases
| Link to USGS - Alaska: | BT007 |
|---|
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