Unnamed (Lindblom Pit lode and lode on Byron Association Placer claim, U.S. Mineral Survey No. 1835)

Prospect, Active?

Commodities and mineralogy

Main commodities Au
Other commodities Ag; Pb; Zn
Ore minerals arsenopyrite; galena; gold; pyrite; sphalerite
Gangue minerals albite; calcite; quartz

Geographic location

Quadrangle map, 1:250,000-scale NM
Quadrangle map, 1:63,360-scale C-1
Latitude 64.619
Longitude -165.4362
Nearby scientific data Find additional scientific data near this location
Location and accuracy This prospect is on the lower southwest slopes of Mount Byrnteson between Lindblom Creek and Rock Creek. The map site is on the northeast end line of a patented claim (U. S Mineral Survey 1835), in the SE1/4 section 15, T. 10 S., R. 34 W., Kateel River Meridian. This site is the approximate boundary between a prospect locally called Lindblom Pit (above 250 feet elevation) and a lode on Byron Association patented placer claim U.S. Mineral Survey No. 1835 (below 250 feet elevation). It is accurate to within about 500 feet.

Geologic setting

Geologic description

The informally named Lindblom Pit prospect crops out and is exposed in trenches between elevations of about 300 to 400 feet on the hill slope between Lindblom and Rock Creeks. The deposit consists of sulfide-bearing sheeted quartz veins that cut pelitic schist, marble, and quartzite, 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). The deposit is dominantly arsenic- and albite-rich; grades locally exceed 0.3 ounce of gold per ton, but at least four drill holes found little continuity in the veins. Kennecott Exploration Company subsequently optioned and explored the Byron Association Placer Claim (U.S. Mineral Survey No. 1835), which extends uphill to about 250 feet in elevation about on strike (northeast) with the deposit at Lindblom Pit. Trenches and shallow drill holes on the northeast part of the placer claim disclosed a sheeted vein system, superficially like the one at Rock Creek (NM207). Quartz veins in steep northeast-striking fissures contain arsenopyrite, galena, pyrite, and sphalerite but have relatively low gold contents. The best trench intercept was about 40 feet of material containing 0.02-0.03 ounce of gold per ton. The sheeted vein complex was developed above a low-angle arsenic-rich fault zone (Ben Porterfield, oral communication, 2000).
The Lindblom Pit lode is northeast of the northeast end line of the patented claim (U.S. Mineral Survey No. 1835). Holes drilled on the Lindblom Pit prospect by Newmont Mining Company in 1992 were collared between approximate elevations of 325 and 380 feet. In about 1995, Kennecott Exploration Company obtained a lease on the patented claim and explored the southwest projection of the lode deposit at elevations between 150 and 250 feet. Both prospects are within a very large arsenic soil anomaly. This anomaly was first defined by BHP in about 1989-90 and extended by Kennecott in 1994 and 1995. The anomaly is marked by soils containing greater than 400 ppm arsenic; extensive areas contain more than 2,000 ppm arsenic. The anomalous area is separated from similar arsenic-rich rocks by the Brynteson fault. This fault strikes N 5-10 E; it is almost certainly post-mineral and separates the Lindblom lode prospect area from the Rock Creek area (NM207 to NM215).
Small amounts of placer gold and scheelite are present on Lindblom Creek (NM205) immediately north of this lode prospect. Some placer gold was produced from 4- to 5-foot-thick gravels in the narrow, 25-foot-wide part of the upper creek (Collier and others, 1908; Moffit, 1913). Some scheelite-bearing quartz veins are also reported in the drainage (Coats, 1944; Anderson, 1947; Thorne and others, 1948).
Geologic map unit (-165.43880734864, 64.618234010723)
Mineral deposit model Low-sulfide Au-quartz veins (Cox and Singer, 1986; model 36a).
Mineral deposit model number 36a
Age of mineralization Probably mid-Cretaceous or younger, the time of regional metamorphism of the host rocks.
Alteration of deposit Albitization, silicification, and sulfidization.

Production and reserves

Workings or exploration Prospect pits, small trenches, and drill holes have explored this prospect. It is within a large soil geochemical anomaly characterized by high arsenic content. An association placer claim was located in 1908 and was patented by Elizabeth Joliffe in 1925 (Byron Association, U.S. Mineral Survey No. 1835). The claim was explored by long northeast-aligned cuts that may have exposed small residual placer deposits, which were not extensively developed. The Lindblom Pit area appears to have been discovered or relocated in about 1986 by R.V. Bailey, a geologist of Denver, Colorado, during work on the nearby Rock Creek deposits (for example, NM207). The area was within a large geochemical soil survey carried out by BHP in 1990. The deposit was trenched and drilled by Newmont Mining Company in 1992. Kennecott Exploration Company subsequently optioned the Byron Association claim and explored it with trenches and drill holes (Ben Porterfield, oral communication, 2000).
Indication of production None

References

MRDS Number 10307994

References

Till, A.B., and Dumoulin, J.A, 1994, Geology of Seward Peninsula and St. Lawrence Island, in Plafker, G., and Berg, H.C., eds., The Geology of Alaska: Geological Society of America, DNAG, The Geology of North America, v. G-1, p. 141-152.
Reporters C.C. Hawley and Travis L. Hudson
Last report date 7/10/2000