Regional Studies is a collection of papers that deals with strata-bound mineral deposits in the Eastern Alps, in the Canadian Cordillera, in north-central, and southwest England. Other papers describe southern African stratiform ore deposits and the genesis of Irish base-metal deposits. One paper compares the various types of volcanogenic mineral deposits and their depositional environments characterized by distinct assemblages of volcanic rocks, which formed in the Northern Appalachians during certain episodes of the tectonic evolution. The paper notes that the youngest volcanogenic deposits of economic interest are tungsten-molybdenum-tin-bismuth base metal deposits in highly altered rhyolitic sub-volcanic complexes at Mount Pleasant, New Brunswick. Another paper reviews the mineral occurrences in southern Africa that include stratiform, non-magmatic, ore deposits, The paper considers a subdivision of deposits formed from surficial chemical processes during previous (or current) cycles of weathering and erosion. Many ore bodies have a dual origin: for example, the iron in the high-grade hematite deposits is partly syngenetic and partly epigenetic. The paper also illustrates the time-dependence of some stratiform ore deposits in southern Africa in a schematic diagram. Geologists, researchers, or engineers whose works are related with ore deposits and mining will benefit tremendously from the collection.