Block P Mine, Hughesville, Barker Mining District, Judith Basin County, Montana, USAi

Regional Level Types
Block P Mine	Mine
Hughesville	- not defined -
Barker Mining District	Mining District
Judith Basin County	County
Montana	State
USA	Country

Includes the mines: Wright and Edwards, Barker, Grey Eagle, and Belt. These were combined with a number of other patented and unpatented claims to form the Block P mine. Produced 405,852 tons of ore from 1915 to 1948. The ore contained 3332.13 ounces of gold, 2,578,224 ounces of silver, 775,112 pounds of copper, 42,750,417 pounds of lead, and 17,848,398 pounds of zinc
Structure: Zone Of Laccoliths And Other Igneous Intrusions Covering Over 800 Square Km Domal Uplift Caused By Intrusion Of Snow Creek Porphyry, Hughesville Stock With Conjugate Fracture System

Tectonics: Rocky Mountain Foreland

Commodity: Sulfide minerals occur in bands, lenses, and As disseminations; The galena is fine grained, but occurs As masses. It contains a few scattered and rounded blebs of tetraherite and chalcopyrite. It also contains numerous pyrite fragments which may be As large As 1 mm in diameter. Sphalerite contains abundant chalcopyrite inclusions. Chalcopyrite also occurs As jagged grains and veinlets in galena. Tetrahedrite occurs predominantly As grains near chalcopyrite, As inclusions in chalcopyrite, and in veinlets cutting pyrite. The tetrahedrite is associated with the other minerals other than galena, but occurs predominantly with these other minerals where they cut galena. (young and others, 1962) tetrahedrite is main silver-bearing mineral (spiroff, 1938). Some disseminated pyrite, most sulfides confined to fissures or at the contact of the syenite with dikes. (spiroff, 1938).

Deposit: ore minerals at the block p occur in veins localized along tension fractures in a porphyritic syenite plug. (young and others, 1962). Shear and tensional fractures are found within the mine. These fractures have been mineralized and were followed by dikes. (spiroff, 1938). The block p vein forms a crude semi-circle, about two-thirds of a mile in diameter, entirely within the hughesville quartz monzonite stock. Spiroff (1938) described the arcuate vein As following portions of five planar features. Two are adjacent to the mafic dikes and one is parallel to a nearby felsic dike. Walker suggests that the vein was a cone sheet above a concealed granite pluton.? (baker and others, 1991). Fissures were the most important producers merged data from deposit id's: 10245440 (grey eagle) 10196660 (barker crosscut of block p mine) 10124398 (equator tunnel of block p mine) 10196718 (thorson tunnel of block p mine) 10270681 (200-ft. Level, wright & edwards) 10270332 (wright and edwards shaft- block p) 10245650 (a tunnel of block p mine) 10173138 (b tunnel of block p mine) 10148735 (maytee tunnel of block p mine) 10221364 (barker shaft of block p mine)

Deposit type: Polymetallic veins

Rock formation(s): Madison Limestone
Galena Creek Porphyry;Hughesville Stock, Hughesville Quartz Monzonite;Mixes Baldy Laccolith, Wolf Porphyry;Clendennin Laccolith, Clendennin Mountain Porphyry


Ore(s): Northwest-Northeast Joint System, Hughesville Stock

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Link to USGS MRDS:	10089197

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References