LPP Occurrence, Tok Mining District, Southeast Fairbanks Census Area, Alaska, USAi

Regional Level Types
LPP Occurrence	Occurrence
Tok Mining District	Mining District
Southeast Fairbanks Census Area	Census Area
Alaska	State
USA	Country

The unpublished data that is cited can be seen by contacting Grayd Resources Inc. in Vancouver, B.C., Canada (www.grayd.com), or Northern Associates Inc. in Fairbanks, Alaska.
Location: The LPP occurrence is located about 2 miles north of Dry Tok Creek at an elevation of about 4,300 feet. It is about one-half mile northwest of the center of section 36, T. 16 N., R. 7 E., Copper River Meridian. It is accurately located about 8,000 feet southeast along strike from the PP prospect (MH352), but it corresponds to just one point along the mineralized layer or unit.
Geology: The LPP occurrence is at the southeastern end of a series of massive sulfide occurrences (MH327-MH328, MH350-MH353) that are intermittently exposed along a strike length of 7 miles in a thrust-repeated section of the lower Lagoon unit (Dashevsky and others, 2003). The rocks in the vicinity of the occurrence are metamorphosed felsic siliceous, sericitic to chloritic schists of volcaniclastic origin. The metavolcanic rocks are interlayered with metasedimentary rocks consisting of quartzite, carbonaceous phyllite, black calcareous schist, and marble. Small, nonresistant, weathered diabase dikes intrude the metamorphic rocks in the area (R.A. Blakestad and others, unpublished Resource Associates of Alaska Inc. report, 1976). The LPP occurrence is one of several deposits along a Devonian stratigraphic unit. Abundant iron-stained float of sponge-textured siliceous material occurs along this series of deposits; this gossan-like material is the product of oxidization of pyrite in a siliceous matrix (S.S. Dashevsky, written communication, 2003). At several locations, disseminated pyritic sulfide bands 0.5 to 3.0 feet thick have appreciable sphalerite and chalcopyrite contents. Samples contain as much as 0.5 percent copper, to 0.5 percent lead, 0.5 to 2.5 percent zinc, and 10 to 30 parts per million silver (Rodney A. Blakestad and others, unpublished Resource Associates of Alaska Inc. report, 1976). No high-grade mineralization has been located at the LPP occurrence, but it is one of several that together define a favorable massive sulfide unit (E. Hunter, unpublished data, 1998).
Workings: Only surface sampling and mapping has been done near the LPP occurrence.
Age: The lower Lagoon unit, which is part of the metamorphic sequence that includes the rocks at this deposit, has been dated as Devonian on the basis of one SHRIMP U-Pb zircon age of 372 +/- 6 Ma at the nearby LZ East prospect (MH328) (Dashevsky and others, 2003).
Alteration: Weak dolomite alteration (Lange and others, 1993).

Commodities (Major) - Cu, Pb, Zn; (Minor) - Ag
Development Status: None
Deposit Model: Kuroko massive sulfide (Cox and Singer, 1986; model

Other Databases

Link to USGS - Alaska:	MH353

Other Regions, Features and Areas containing this locality

References