Precambrian Geochronology, Chronotectonic Framework and Model of Chronocrustal Structure of the Zhongtiao Mountains
The Zhongtiao Mountains, a typical exposure area of Precambrian rocks, are a concentration area of various types of copper deposit. The rocks were dated using several dating methods. Based on the age data obtained by means of three methods, several aspects are dealt with: (1) the dating results obtained by different methods and their geological implications have been compared; (2) a chronotectonic framework has been constructed by means of these reliable ages, which indicates that the ages of the rocks of the Proterozoic mobile belt fall in a time span of 2400 to 2000 Ma during which global magmatic records are lacking and reflects the ages of important events in the mobile belt; (3) according to the ages of inherited zircons, neodymium model age of the depleted mantle sources (TDM) and geochemical and geological data, a model of Precambrian chronocrustal structure has been constructed, representing a typical for the North China craton.