Abstract
Hypogene epigenetic ore deposits are commonly compared in groups based on the so-called genetic scheme of classification. Such correlation is of value in studies of the physical chemistry of ore deposition; but from the standpoint of the searcher for ore, mining districts should be compared on the basis of any shared features even remotely connected with the localization of ore shoots. Comparison of the hypothermal Hog Mountain deposits with the shallower-type Paracale deposits brings out interesting similarities in structure and ore control, and leads to generalizations concerning some factors that localize ore.The Hog Mountain and Paracale veins are found to have formed in "tension joints," but not immediately following the formation of the joints. Local ore controls appear to have operated in each camp in the form of intra-mineral fault movements along the veins, and at Hog Mountain transverse to them as well. But the major ore control in each district is thought to have been exercised by a soft schist "trap" above the vein fractures.Reasons are given why tension joints in general may be likely localities in which to hunt for ore, and the significance to the ore-hunter of the fact that many ore shoots seem to have formed under flat-lying "traps" is discussed.
