Oronogo Circle Mine, Oronogo Field, Jasper County, Missouri, USAi

Regional Level Types
Oronogo Circle Mine	Mine
Oronogo Field	Mining Field
Jasper County	County
Missouri	State
USA	Country

Oronogo Circle Mine, Oronogo Field, Tri-State Mining District, USA

The Circle diggings, whose general outlines are well shown on the map, consisted of a large number of different shafts arranged in a circle. Within this circle, the surface of the ground dipped toward the center, forming a flat basin of 400 to 500 ft. in diameter. The shafts in this circle were in ground composed of broken chert, disturbed chert layers, massive “quartzite” and blocks of bituminous limestone; through this the ore was distributed in the usual forms. Sometimes the “quartzite" contained large gashes filled with galena. The shafts numbered 23, a little outside of the circle, struck solid limestone at a depth of 12 or 15 ft. A shaft was sunk in the center of this circle 104 ft. deep, and passed, first, through nearly 50 ft. of clay, then through 12 ft. of black clay, with lumps of coal, overlying other black clays and slate and sandstone, aggregating about 40 ft.; under this, blocks of limestone were passed through, and, at the bottom, 3 ft of the usual chert breccia was encountered, cemented by sandy limestone, containing blende, galena and calcite; the last blast opened a fissure running in a N.-S. direction, causing a flow of water into the shaft.