On July 25, 1976, the Institute of Geomechanics of the Institute of Geological Sciences recently used the paleomagnetic method to measure the age of Yuanmou Man in Yunnan for the first time about 1.70 million years ago, thus pushing forward the earliest ape man in our country by more than 1 million years; at the same time, it was determined that the Yuanmou Formation was formed 1.50 million to 3.10 million years ago, thus pushing the history of Quaternary geology 2 million years ago.