Distribution characteristics of burnt metamorphic rocks in the Northern Shaanxi Energy and Chemical Industry Base and their hydrogeological significance

The authors summarize and describe the distribution characteristics of burnt metamorphic rocks and hydrological characteristics and formation conditions of groundwater in areas of burnt metamorphic rocks based on an analysis of the lithologic characteristics and formation conditions of burnt metamorphic rocks, and briefly discuss their water storage capacity and hydrogeological significance. Burnt metamorphic rocks are mainly distributed on both sides of the Tuwei River and Kuye River and their tributary gullies. They are elongated with a length ranging from ten to tens of kilometers and a width of 1-2 km, covering an area of nearly 700 km2. Fractures and pores are well developed in the burnt metamorphic rocks, which is very favorable to the leakage recharge from the upstream groundwater of the Salawusu Formation. The groundwater generally discharges in the form of big springs near the source of grooves, with stable flow and water quality; or the water concentrates in the bathtub-shaped structure on the bottom of burnt metamorphic rocks. The water can alleviate the situation of shortages of water supply in the energy base in the near term.