THE FORMING AGE AND TECTONIC ENVIRONMENT OF THE MAOYILETU ROCK BODY IN JARUD, INNER MONGOLIA

With study on its geological background, petrologic and mineralogical characteristics, geology, geochemistry and isotopic chronology, the structural environment and forming age of the Maoyiletu rock body are discussed. The geological and geochemical characteristics show the calc alkaline characteristics. According to the SHRIMP U-Pb isotope chronologic analysis result, the statistical weight average of ²⁰⁶Pb/²³⁸U surface age is 147.97±0.95 Ma, which represents the emplacement age of the rock body, belongs to Late Jurassic period. Combined with the analysis on the evolution characteristics of regional geology, the quartz diorite was formed during the crustal uplifting after the plate collision.