Download it on the download page. Xi 'an Quality Resource Education Sharing Platform can download the certificate on the download page. The geological structure of Xi 'an is divided into two units: Qinling geosyncline fold belt and North China platform. The great fault at the northern foot of Qinling Mountains occurred during the Yanshan Movement 654.38+300 million years ago. Since the Neogene about 3 million years ago, the neotectonic movement in the Qinling geosyncline fold belt south of the great fault has been extremely active, and the mountains have fallen sharply from north to south, creating the Qinling Mountains. At the same time, the Weihe fault depression, which belongs to the North China platform to the north of the great fault, continued to subside, and the Weihe plain was formed under the combined action of aeolian loess cover and Weihe alluvial.