High Point Mine, Moniteau County, Missouri, USAi

Regional Level Types
High Point Mine	Mine
Moniteau County	County
Missouri	State
USA	Country

High Point Mine, Central Missouri District, Missouri, USA

This mine is located in the NE. 1/4 of the SE. 1/4 of section 17, township 43 N., 15 W. Work has not been done here for many years, and on a recent visit to the locality by the writer, the excavation was filled with water. The deposit was discovered in 1841, and by 1845 had produced 1000 tons of ore. It was reopened in 1854, and was at that time visited by Prof. Meek. He deecribed it as a circular pit, 100 ft in diameter and about 80 ft. deep, widening downward. A cone of broken rock occupied the center, and around this an annular space was worked ont. This latter was filled with broken blocks of limestone of different kinds, irregularly mixed, between which there was finer material of the same kind. In this comminated rock much galena was found, but the larger masses were in cavities, principally filled with red clay. Most of the ore was found in the softer portions, and principally close to the surrounding wall. The central mass was of the same structure, but contained much less galena. The galena was very pure, and with it some little blende was found. Calcite occurred in small quantities, and Schmidt noticed a little barite in the debris in 1874. The wall rocks were composed of a thin cap of sandstone, succeeded by a thinly-bedded, gray cotton rock, and this followed lower down by a somewhat open-textured magnesian limestone. These rocks were comparatively undisturbed and exhibited no dip, though they were fractured and traversed by joint-planes.

The depth of the body was undetermined at the time. Schmidt notes that in 1857 a depth of 90 ft. had been reached, and that galena was still in sight, though the ore body was less rich than at higher leyels. From the presence of vertical slickensided striæ, Meek concluded that the brecciated condition of the rocks was due to a "powerful elevating force acting from beneath." He was unable to indicate the source of the ore, however, and saw no evidence of igneous action. This is one of the largest of the peculiar circular deposits of this district.