| 摘 要： | 109 isotopic ages have been determined and collected in the recentten years, Most of them belong to Yenshanian, within which an early period (140--180m.y.) and a mid.late period (120-130m.y.) are distinguished. Granodiorite is predominant in early Yenshanian, and the related ore deposits are mainly of skarn character with mesothermal vein fillings being secondary in importance. During the mid-late Yenshanian, granite prevails and are accompanied by iron mineralization. From early to mid-late Yenshanian, the magmatie activity exhibites a striking regularity of variation in composition from intermediateacid servations, indicate that pegmatites in the Tanba region are related to Caledonian migmatization and have been reworked by two separated events at 120--130 m.y. (northern zone) and 70--80m.y. (southern zone) respectively. The migmatization progress has resulted in the formation of muscovite and biotite, thus offering an important eluc to the genesis of industrial muscovite. Three episodes of magmatic emplacement (590--720 m.y., 800-900 m.y., and more than 960 m.y.) in late Proterozoic times are also reeognized in this region.
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