Unnamed Occurrences (ARDF - TN002; Holonada Creek), Melozitna Mining District, Yukon-Koyukuk Census Area, Alaska, USAi

Regional Level Types
Unnamed Occurrences (ARDF - TN002; Holonada Creek)	- not defined -
Melozitna Mining District	Mining District
Yukon-Koyukuk Census Area	Census Area
Alaska	State
USA	Country

Location: This record represents occurrences of anomalous rock samples in a two mile long area on the west side of Holonada Creek. For this record, the site is ADGGS sample station 92Ha242 (Solie and others, 1993), in the northwest corner of section 7, T. 12 N., R. 22 W. of the Fairbanks Meridian. The location is accurate within 500 feet.
Geology: The Kanuti River region straddles the southeastern boundary of the Yukon-Koyukuk Basin and includes sedimentary and volcanic rocks of the basin sequence as well as metamorphic and plutonic rocks of the adjoining Kokrines-Hodzana Highlands (Patton and Miller, 1970). The Sithylemenkat Pluton, a 170-square mile body of mid-Cretaceous granitic rocks, intrudes metasedimentary rocks on the south side of the Kanuti River. Dikes of pegmatite are locally abundant on the perimeter of the predominantly porphyritic, biotite quartz monzonite pluton. Overlying and intruding the metasedimentary rocks along the northwest flank of the Kokrines-Hodzana Highlands is an ophiolitelike assemblage of Permian to Jurassic, altered pillow basalt, diabase, and gabbro; serpentinized peridotite and dunite; and bedded chert (Patton and Miller, 1970). Six of the ultramafic bodies extend for 65 miles, from Caribou Mountain in the northeast to the upper Melozitna River in the southwest. Numerous smaller bodies also occur in this belt. The ultramafic rocks are crudely layered, tabular bodies dipping gently to steeply northwest. The Holonada body is about 2,500 feet thick. Layering in the Kilolitna body is less well defined, but the width of its outcrops suggests that it is at least as thick. The lower contact of the ultramafic bodies is sharply defined, possibly by a fault, with little evidence of thermal alteration of the underlying rocks. The ultramafic rocks are composed almost entirely of serpentinized peridotite, chiefly harzburgite, and serpentinized dunite. They are cut by veinlets and irregular masses of chalcedony and drusy quartz. Patton and Miller (1970) found one small mass of colloform magnesite in the northern part of the Kilolitna body (in the Bettles quadrangle). In 1992, the Alaska Division of Geological and Geophysical Surveys (ADGGS) collected rock samples for geochemical analysis in the Holonada Creek area as part of a mineral resource evaluation of State-selected lands (Solie and others, 1993). The samples are of volcanic and sedimentary rocks of the Jurassic to Mississippian Rampart Group south of the Holonada ultramafic body (Chapman and others, 1982). Samples having anomalous values included silicic mudstone or waterlaid tuff (sample 92Ha242), with 30 parts per billion (ppb) gold and 20,000 parts per million (ppm) barium; diabase (sample 92MW434), with 291 ppm vanadium, 74 ppm bismuth, 24 ppb platinum, and 64 ppm tin; and chert (sample 92MW43) with 10 ppb platinum (Solie and others, 1993).
Workings: In 1992, the Alaska Division of Geological and Geophysical Surveys (ADGGS) collected rock samples for geochemical analysis in the Holonada Creek area as part of a mineral resource evaluation of State-selected lands (Solie and others, 1993). The samples are of volcanic and sedimentary rocks of the Jurassic to Mississippian Rampart Group south of the Holonada ultramafic body (Chapman and others, 1982). Samples having anomalous values included silicic mudstone or waterlaid tuff (sample 92Ha242), with 30 parts per billion (ppb) gold and 20,000 parts per million (ppm) barium; diabase (sample 92MW434), with 291 ppm vanadium, 74 ppm bismuth, 24 ppb platinum, and 64 ppm tin; and chert (sample 92MW43) with 10 ppb platinum (Solie and others, 1993).

Commodities (Major) - Pt; (Minor) - Au, Ba, Bi, Sn, V
Development Status: None
Deposit Model: Alaskan PGE(Cox and Singer, 1986; model 9) and epithermal veins.

Other Databases

Link to USGS - Alaska:	TN002

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References