内蒙古鄂温克族自治旗红花尔基一带基岩出露情况差，地质工作程度低，以往工作所发现的侵入岩均划分进入中石炭世。通过对1∶5万区域地质调查工作，对发现的斜长花岗岩进行锆石SHRIMP U Pb定年，所获得年龄为（172．2±1．3）Ma，更改为中侏罗世侵入体。推断红花尔基斜长花岗岩的形成是为中生代中、小块体之间的俯冲碰撞触发了新元古代加入地壳的亏损地幔物质熔融所形成。%The bedrock exposed badly in Honghuaerji area in Ewenki Autonomous Banner in Inner Mongolia. Geo⁃logical work degree is low. Intrusive rocks found in the former work were classified into middle Carboniferous peri⁃od. Through zircon SHRIMP U Pb dating of plagioclase granite which was newly discovered in regional geological survey work with the scale of 1∶50000, the age was gained as 172.2±1.3Ma and classfied int middle Jurassic intru⁃sion. It is conducted that Honghuaerji plagioclase granite was formed by Mesozoic subduction and collision between medium and small blocks in Neoproterozoic period, then meltted after joining depleted mantle materials.
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