Potential for lode deposits in the Livengood gold placer district, east-central Alaska

Abstract

The Livengood gold placer district of east-central Alaska contains small bedrock deposits that probably were the source of the placer gold. Stream sediments in parts of the district, particularly in the Ruth Creek drainage, are characterized by abnormally high concentrations of gold, arsenic, mercury, antimony, molybdenum, and silver, and Ruth Creek itself is characterized by highly acid water. The area is complex geologically and is cut by many thrust faults, some of which have been invaded by serpentinite. Ruth Creek and some of the other geochemically anomalous areas are in upper plate clastic rocks that may be underlain by siliceous carbonate rocks beneath thrust faults. The small lode deposits in the upper plate rocks may represent leakage anomalies above economicall} significant metal deposits in rocks in or below the thrust faul1 zones.

Rare Earths in Alaska: Proceedings of Office of the Governor's Alaska Science and Engineering Advisory Commission Symposium, held Aug. 17-18, 1988, in Fairbanks, Alaska

“…Present USBM studies have identified monazite and zirkelite in drill core samples (Johnson and McDonald, no date). Subvolcanic rhyolite porphyry stocks like those near Livengood can contain elevated REE and niobium values (Foster 1968). Uranium-bearing vein deposits in the Old Crow batholith, in the Kanuti area, and near Kook Lake on Chichagof Island contain 0.2% to 0.5% REE, nearly all as the cerium subgroup.…”

Occurrence of platinum in gold samples from the Tolovana and Rampart mining districts, Livengood Quadrangle, Alaska

“…Because the contact between the serpentlnlte, mafic, ultramaflc, and other rocks cannot be seen, 1t 1s not known 1f the Igneous rocks were Intruded or technically emp laced 1n the layered sequences (Weber and others,19B5). The serpentlnltes are believed to have been emplaced originally as subhorlzontal sheets associated with regional thrust faults and their present outcrop pattern reflects subsequent upward dragging along high-angle reverse faults (Foster, 1968). The Paleozoic clastic, serpentlnlte, mafic, and ultramaflc units exhibit a possible structural contact (reverse or thrust faults) with the carbonate-chert unit to the north 1n the Tolovana mining district area (Allegro.…”

Geology of the Old Smoky prospect, Livengood C-4 Quadrangle, Alaska

“…Some epidote within quartz veins and sericite selvages on quartz veins also occur in this zone. Foster (1968) described the mineralization at the Old Smoky prospect as "narrow, northwestward-trending auriferous arsenopyrite-quartz veins" with samples from the veins containing 3 to 13 ppm gold. The prospect was also considered to be an antimony prospect at one time.…”