Characteristics of Gravity and Magnetic Field and their Significance of Helium Resources Exploration in the Southeastern Ordos Basin

Helium is widely used in the fields of national defense, military industry, high−tech industry development and so on, as a rare gas related to the national security and development. China is short of helium resources and highly dependent on foreign countries. There is a good prospect of helium resources in Ordos basin. However, there are fewer study on the characteristics of the helium source rocks and the faults related closely to the helium distribution, which limits the evaluation of the helium resource potential in the basin. In this thesis, the gravity and magnetic data in the southeast of Ordos basin are processed by using the normalized vertical derivative of the total horizontal derivative (NVDR−THDR), vertical derivative and potential field date separation techniques, and inferred the main faults and potential helium source rocks (strong magnetic metamorphic rocks). The distribution of helium resources is controlled by the basement faults and the distribution of helium source rocks. The strong magnetic metamorphic rocks provide gas source conditions for helium enrichment in the basin, and fault activity provides channels for helium migration. There are a large number of metamorphic rocks distributed in Fuxian−Yichuan−Huanglong area. Most of them are located near faults and their intersection areas, which may be potential favorable areas for helium resources.