According to the traditional petroleum geology theory, oil is only produced for marine life. For a long time, the traditional petroleum geology theory holds that oil is only produced for marine life. 1863, T.S. Hunt, a famous Canadian petroleum geologist, clarified that the original substance of oil is lower marine life. B.A. Benakoyi, the father of geochemistry in the former Soviet Union, also clearly pointed out in his masterpiece Introduction to Geochemistry that oil is generated by marine life. In 1943, American geologist W.E. Pratt once again emphasized that "oil is an integral part of marine strata of unmodified offshore origin." 194 1 year, the radiant epoch-making paper "Cretaceous terrestrial oil generation in northern China and Sichuan" was first read out at the meeting of American petroleum geologists association. The brand-new proposition of "China's terrestrial origin" comes from Pan Zhongxiang, a young man from China who was studying for a doctorate at the University of Kansas at that time. 193 1 year, after graduating from Peking University, Pan Zhongxiang conducted four petroleum geological surveys in northern Shaanxi and made many field trips in Sichuan and other places. He pointed out that oil in northern Shaanxi is produced in terrestrial Triassic and Jurassic, and artesian wells producing natural gas in Sichuan are undoubtedly terrestrial strata. After studying in the United States, he also found examples in voluminous documents, such as the crude oil in PaoDevas oilfield in northwest Colorado, USA, which was produced in terrestrial tertiary.

The theory of "continental oil generation" provides a basis for finding a large amount of oil in China continental basin. In the mid-1940s, the paleontological research carried out by Chinese geologists in Yumen Oilfield provided new evidence for the confirmation of "continental strata" for oil generation. Since 1955, Karamay oil field has been discovered in Junggar basin, Xinjiang, and oil and gas fields have been discovered in Jiuquan, Qaidam, Tarim, Sichuan and Ordos basins, all of which fully show the oil and gas potential of continental strata.

By the end of 1950s, geologists were still analyzing the crude oil from continental strata found all over the world. Although there are different sources and explanations, the theory of continental oil generation came into being and will become an important part of petroleum geology, impacting the absolute dominant position of marine oil generation theory. However, it should be noted that although some Chinese and foreign scholars admitted that there was continental oil generation and accumulation in this period, they could not prove the fact that there was large-scale accumulation, transformation and migration of organic matter and formed large oil and gas fields.