GEOLOGICAL FEATURES AND ORE-CONTROLLING CHARACTER OF CRYPTOEXPLOSION BRECCIA BODIES IN THE NANJING-WUHU VOLCANIC TERRANE

On the basis of an investigation, the cryptoexplosion breccia bodies in the Nanjing-Wuhu volcanic terrane is classified into three types. From an analysis of the data and observations of the deeply excavated site of the Aoshan breccia body and others, it has been confirmed that they are of cryptoexplosion origin. They were formed through a series of physico-chemical changes such as differentiasion. evolution, cooling, pressure-releasing, ebullition, boiling and explosion under closed conditions. They were controlled by the same paleogeothermal and geochemical field as the ore-bearing residual magma and fluids and thus were closely related to the latters in space and time. So they can furnish clues leading to the discovery of hidden orebodies.