Trench 7--Divide Zone Prospect (Bonanza Hill), Nome Mining District, Nome Census Area, Alaska, USAi

Regional Level Types
Trench 7--Divide Zone Prospect (Bonanza Hill)	Prospect
Nome Mining District	Mining District
Nome Census Area	Census Area
Alaska	State
USA	Country

Location: The Trench 7--Divide deposit is at an elevation of 450 to 465 feet about 1,200 to 1,500 feet due east of the rounded top of Bonanza Hill. The map location is in the northwest corner of section 36, T. 10 S., R. 34 W., Kateel River Meridian, and it is accurate.
Geology: The Trench 7--Divide deposit was identified from exploration by BHP in 1990 and by Newmont Mining Company in 1992; there are some old trenches and cuts of uncertain age on the deposit. The area was mapped by Thomas Borovicka for Newmont in 1992; his map was modified for Kennecott Exploration Company by C.C. Hawley in 1993 and 1994. The Trench 7--Divide deposit appears to be bounded on the northwest by a steep fault that strikes N 50 E. The apparent displacement, evidenced by offset of a calcareous quartz-mica schist layer, is about 10 feet. Southeast of the fault, the deposit is about 200 feet across. Locally, there are sheeted veins of calcite and quartz; older sloughed trenches show accumulations of vein quartz boulders. The deposit is irregular; locally it contains 0.05 to 0.07 ounce of gold per ton. It is possible that the deposit continues to the northeast to Placer Dome trenches 88-3, -4 and -5 (NM223). Bonanza Hill is mainly underlain by nearly horizontal calcareous quartz-muscovite schist and marble probably of early Paleozoic protolith age (Hummel, 1962 [MF 247]; Sainsbury, Hummel, and Hudson, 1972 [OFR 72-326]; Till and Dumoulin, 1994; Bundtzen and others, 1994).
Workings: This prospect has been explored by numerous trenches and shallow drill holes.
Age: Mid-Cretaceous; veins cross cut regionally metamorphosed schist; see NM207.

Commodities (Major) - Au
Development Status: None
Deposit Model: Low-sulfide Au-quartz veins (Cox and Singer, 1986; model 36a).

Other Databases

Link to USGS - Alaska:	NM224

Other Regions, Features and Areas containing this locality

References