McLeod East Occurrence, Kaiyuh Mining District, Yukon-Koyukuk Census Area, Alaska, USAi

Regional Level Types
McLeod East Occurrence	Occurrence
Kaiyuh Mining District	Mining District
Yukon-Koyukuk Census Area	Census Area
Alaska	State
USA	Country

This property is on Doyon, Ltd. selected lands. For more information, contact Doyon, Ltd., in Fairbanks, Alaska.
Location: The McCleod East occurrence is at the southwestern end of the Kaiyuh Mountains, approximately 11.25 miles southeast of Blackburn, an abandoned settlement on the Yukon River. The occurrence is at an elevation of 950 feet, approximately 3400 feet south of hill 1170, in the northeast corner of sec. 6, T. 26 S., R. 3 W., Kateel River Meridian. It is approximately 2200 feet east of the caved trenches at the original McLeod prospect (UL003). The location is accurate within 500 feet.
Geology: This occurrence consists of disseminated molybdenite in talus of quartz-veined and sericitically-altered felsic intrusive rock along the southern margin of a small stock that intrudes Cretaceous strata (Bressler and others, 1979). The strata include poorly sorted, medium- to coarse-grained arkosic sandstone and subordinate siltstone, shale, and lesser intermediate to mafic volcanic rocks. The beds generally strike northwest and dip gently to the northeast and southwest (Bressler and others, 1979). The stock is leucocratic, quartz-feldspar porphyry composed of 20-40% bipyramidal to subhedral quartz and 10-30% feldspar phenocrysts in a matrix dominantly of quartz and feldspar. The stock is exposed in an area of about 2500 by 6000 feet that is elongate to the northeast. The exposure is centered along the boundary of sections 32 and 33, and the stock sends dike swarms into sections 4 and 28 (Bressler and others, 1979). A younger suite of biotite-quartz-feldspar porphyry dikes exposed to the west at the McLeod prospect (UL003) apparently does not occur at this site (Bressler and others, 1979). Also see UL003 and UL004.
Workings: This occurrence was discovered during reconnaissance mapping and sampling during 1979 (Bressler and others, 1979). No further work is documented.
Age: Cretaceous or Tertiary, the presumed age of the mineralized felsic intrusive hostrock.
Alteration: The granitic stock is sericitized and locally intensely silicified.

Commodities (Major) - Mo; (Minor) - Ag, Cu, Mn, Pb, Sn, W
Development Status: None
Deposit Model: Vein and porphyry Mo (Cox and Singer, 1986; model 16a, 21b)

Other Databases

Link to USGS - Alaska:	UL005

Other Regions, Features and Areas containing this locality

References