共和盆地是我国西北地区比较典型的一个中、新生代断陷盆地。其内堆积了一套发育良好的第四纪河湖相地层。早在1936年,孙健初教授就将其内的晚第三纪及第四纪早、中更新世红色地层命名为共和统。1959年,青海省水文队在该区进行水文地质普查工作时,在这套地层中采到了一批脊椎动物化石。后经周本雄、刘后一鉴定研究,发现其中有我国北方第四纪早、中更新世动物群的标准种属:三门马、中国鬣狗等。并依此将该套地层时代确定为早、中更新世。至此,这套河湖相地层便引起了国内许多研究第四纪地质的学者们注意和重视,并与我国北方早更 The Republican Basin is a typical Cenozoic and Cenozoic rift basin in Northwest China. A well-developed Quaternary river and lake facies has been deposited in it. As early as 1936, Professor Sun Jianchu named the red strata of the Early and Middle Pleistocene in the Late Triassic and Quaternary Periods as republics. In 1959, when the Hydrological Team of Qinghai Province conducted a hydrogeological survey in the area, a number of vertebrate fossils were collected in this formation. After Zhou Benxiong, Liu Houyi identification study found that there are the Quaternary in North China early, middle Pleistocene animal species standard species: Sanmenma, Chinese hyenas and so on. Based on this, the era of the strata was determined as early and middle Pleistocene. At this point, the river-lake facies caused many scholars in Quaternary geology to pay attention to and pay attention to it, and earlier with the north of our country