一、基底问题到现在为止,扬子准地台上还没有大片出露大于20亿年的基底岩石。零星的报道见于大别山为(20.8亿年,可达23—24亿年)鲁苏地盾(大于19亿年),康滇“地轴”(22—24亿年)。扬子准地台大片出露的是小于20亿年的基底岩石,所以华南的基底是较年轻的,不存在古壳。最近的大地电磁测深证实,湖南雪峰两侧的岩石圈厚度为160—200公里,在江苏也证明具有和湖南相同的地壳结构,扬子准地台是一个冷壳。航磁推断在川中、鄂中和南黄海中部,以及 First, the substrate problem Until now, the Yangtze quasi-platform has not been large exposed more than two billion years of basement rock. Sporadic reports are found in the Dabie Mountains (2.08 billion years, up to 23-24 billion years) Lusu shield (more than 1.9 billion years), Kang Dian “axis” (2.2-2.4 billion years). The basement of the Yangtze platform is exposed less than 2 billion years of basement rock, so the basement of South China is younger, there is no ancient shell. The recent MTF confirms that the lithosphere on both sides of Xuefeng in Hunan Province is 160-200 km thick and has the same crustal structure in Hunan Province as that of Hunan. The quasi-platform of the Yangtze is a cold shell. Airspace inferred in central Sichuan, Hubei and southern Central Yellow Sea, as well