Relation Between Tectonics and Metallogenesis in Peripheral Sea-Island-Arc Complex of Japan and Vicinity: ABSRACT

Abstract

Several attempts have been made to discover the genetic relation between the tectonic development and metal concentration in this area. A brief synthesis of the relations in the following four geologic periods and their respective major ore deposits in Japan and vicinity indicates: (1) Quaternary-recent, sulfur deposits; (2) Miocene, Kuroko deposits; (3) end of Mesozoic, Mo-W and base-metal deposits; and (4) end of Paleozoic, standard massive sulfide deposits. The distribution of these mineral deposits is related to the tectonic development of the area. Although more revisions and refinements are needed, the following conclusions may be of practical use. 1. The theory of plate consumption at the subduction zone is compatible with the distribution of mineral deposits in general. 2. Large scale distribution patterns of certain mineral deposits are influenced closely by the tectonic development of large geologic units, such as island arcs. 3. Localization of richly mineralized areas is controlled by the deep structural features of the subducting plate and magmatic activities most probably initiated at or above the upper friction surface of these plates. 4. The hypothesis of the oceanward migration of arcs leaving peripheral seas behind near Japan is compatible with the ore distribution. A prevailing tension environment in the rear, and the resulting tension breaks or basins, could produce favorable locations for metal concentration. 5. Amount of erosion after the final emplacement of the ore deposits is another controlling factor of ore distribution at the presently feasible depth. End_of_Article - Last_Page 1452------------