Geological and Geochemical Characteristics of Metamorphic Volcanic Rocks of the Dongshengmiao Ore District,Inner Mongolia and its Significance

In order to investigate the geological and geochemical characteristics of metamorphic volcanic rocks of Dongshengmiao ore district and its significance,this paper studied the occurrence characteristics,petrology,petrochemistry,geochemistry and isotopes of metamorphic volcanic rocks.The results showed that the metamorphic volcanic rocks were bimodal volcanic rocks,and its primary rocks were the alkali-basalt and the calc-alkaline rhyolite which both had the similar geochemical characteristics with those of the volcanic arc volcanic rocks.The model of rare earth element(REE) and Nd isotope geochemical characteristics of the basaltic volcanic rocks showed that its rock-forming elements came from depleted mantle.On the basis of researches of the rock-forming environment and the regional geology,it was confirmed that the metamorphic volcanic rocks of Dongshengmiao ore district was formed in continental marginal volcanic arc orogenic belt environment.