Iditarod pioneer., 1917-02-03
DEPOSITS OF ANTIMONY
 IN IDITAROD AND INNOKO
 REPORTED BY THE SURVEY

United States Geological Survey, consider
 able space IS devoted to the Iditarod and
 Innoko districts as possible future factors in the production of this metal. The re
 port ls by Alfred II. Brooks, head of the
 Alaska division of tue survey, and says:
 "Stibnite (&ntimony sulphide) deposits have been found in mneralizel zone l marked by several gold placer districts,
 which stretches from the lower kuskokwiln river northeasterIy to the northern part of
 the Innoko district. The mct2iEzaton of this zone by no means extends throughout it's length, but as will be shown, Is limited to certain ceEters determined by the intru- don of igneous rocks. AS here defined 1t includes the antlmony hearing clnnahar
 prospects of the Kuskokwim and the ldlta-
 rod and Innoko gold-placer districts It IS reported that stibnite has been found in the Tuluksak -Aniak gold placer districts, still farther to the southwest but this has not been verified There has been no produc- ton of antimony ln this region, and none of he lodes has been sufficiently prospocted 70 prove it's value The wide distribution of stibnite bearing veins Is favor: b.c to the discovery of workable antimony lodcs. Or
 he other hand, much of the region IS now difficult of access, and 1t l, at least an open question whether antimoEy ores can be mined in this region, even at the preSen; high value of the metal. Some of tAe d~ 1 poslts are, however fuvorably located for
 water transportation. notably those near or on the kuskokWim river. These deposits
 and some which are near Idtarod would seem to offer the best hope of development
 under the present conditions of transports
 ton.
 "Stibnite is common in the gold placers of the Iditarod district and mostly occurs l in the concentrates with clnnabar in places with scheelite Mining operations at a num-
 Der of localities have uncovered stibnlte- bearing veins and stringcrS, all of which are closely associated with monzonlte lntru- siycs.
 "A little work has been done on a stiDnite ode, staked under the name Mohawk claim located about mile north of the settlement called Discovery, on Otter creek. The shaft md pits which exposed this lode were in
 accessible at the time of the writers visit, that little information could be obtained except that yiel led by the dump. More ovcr the claim ls located on the flat sum nit, covered with moss and timber, between Glen gulch and Slate creek, where no bed ock is exposed Monzonite occurs to the south in Glen gulch and to the north lie he Cretaceous sandstones and slates, to- ether with some basalt Fragments of ba- satic rock were seen on the ridge, so that rrobably this rock occurs clcse at hand. The lode is reported to occur at the con- tact of slate and 'diorte' by those who have had access to the workings. The term
 .orIte' may refer to either the mon2onlte the basalt In any event, the deposit
 not fer from the margin of the monzon te stock
 "The lode appears to trend northoastward which is parallel to the major structure of the sediments. IL dips about fortyfve de trees southeast A shaft said to be thirty five feet deep and few pits are the only openings seen on the lode The distrlbu ton of these workings indicates that the lode has been traced about fifty feet, but IS no one vqs nro~en+ on the property and
 examination was hurried there are pos ibly other openings by which it may have been traced a greater distance. The width
 7f the lode is reported to be two to two and a half feet Though this statement could not be verified by observation, yet he size of the fragments of ore on the dump indicates that they came from lode at least
 re to two feet wide.
 The lode consists of an intergrowth of quartz and stibnite, and 1t Is reported to contain gold values The stibnite occurs chiefly as granular aggregates, with some columnar masses. Nitreous quartz Is rather evenly distributed among the stibnlte in grains, in partly developed crystals end in irregular aggregates Some cavities lined with quartz crystals occur in the ore, and the heavy iron stains on some of this quartz suggest the oxidation of pyrite, though none of this mineral was actually observed. The stibnite itself shows very little oxidation
 "In this section the ore shows a mosaic of quartz in which some idiomorphic crys- tals are recognizable The quartz has been in part fractured and granulated along mar
 rns Subsequent to this granulation the Stbnite has been deposited ln part In lrregu- lar masses in the granulated areas in part as thin films along the lines of fracture. This metallization appears to have been ac- companied by some deposition of quartz. The noteworthy feature is that the deposl tlOu Ol lIt SUI IIIlNIt Has tdNNll Ei|1SC Gti'St the specialization and deformation of most of the quartz.
 "The commercial value of the deposit as an antimony ore would seem to depend on the discovery of shoots of purer stibnlte than most of that which was seen on the dump. However, some fairly pure specimens of stlb- nite from this lode were seen. In regard to it's value as gold ore the writer has no information other than that given above.
 According to observations by Maddren some stibnite-bearing veins have been un- covered by placer mining on Gen gulch and on Black creek Both these streams are tributary to Otter creek from the south The exact location by placer claims of these veins cannot be given, but the occurrences on both streams are about 1,200 feet in air line from Otter creek. It is probable that the Black creek vein IS on the fraction claim below Mo- below Discovery, and the Glen gulch vein on No. l above dis covcry.
 Both veins strike about north 50 degrees east, and their relative position indicates hat they may be on the same zone of frac L,,ro b,,+ +bo1, ora eeporo+ed bv O Iictennp