Kayakedengtage Area Two Basic Dike Rocks Geochemistry and Significance

The two periods of basic dyke developed in Kyakedengtage area are Variscan Period and Yanshan Period, with isotopic age of 380.3±1.5 Ma (U-Pb) and 176.2±3.5 Ma (K-Ar) respectively. As indicated, in late Devonian (Variscan) and early Jurassic (Yanshanian), the studied area had two significant crusts of intracontinental extension tectonic movements. The basic dyke intrusion in Variscan Period represents that the intracontinental extension changes from stable to active, with a northwest distribution of basic dyke in the geological body before late Devonian; In contrast, the basic dyke intrusion in Yansanian Period represents that the movable intracontinental extension turns to stable delamination. The basic dyke runs nearly north-south or east-west in geological body before Jurassic Period.