A study of the genesis of the Krueger zinc deposit and the near-by barite deposits of the Potosi quadrangle, Washington County, Missouri

This thesis deals with the study of the genesis of the Krueger zinc deposit and the near-by barite deposits of the Potosi quadrangle, Washington County, Missouri. The rocks outcropping in the quadrangle embrace Pre-Cambrian and Lower Paleozoic formations, the Potosi and Eminence being the most important formations with regard to the studied deposits. The few structures present in the area of the vertical type and are more abundant in the southern part of the quadrangle. Special emphasis is placed on the relationships between the barite, the associated sulfides, and the host rock. Geometric and geochemical criteria are studied in detail and used to explain the local genesis of the ore deposits. Geometric evidences, either in the outcrops or in the drill cores, suggest the possibility of a syngenetic origin. The geochemistry of barium and the sulfides supports this mode of origin. An attempt to solve the problem of the origin of the ore fluids was made. Both the supergene and hypogene theory are considered. More criteria appear to support the second one --Abstract, page vi