The differential collapse-filling evolution process of paleo-underground river in Northern Uplift of Tarim Basin Provisionally Accepted

Dong Hongqi^{1, 2} Liang Jiapeng^2*

• ¹China University of Geosciences Wuhan, China
• ²Institute of Karst Geology, Chinese Academy of Geological Sciences, China

The characteristics and stages of collapse-filling in paleo-underground rivers vary in recharge-runoff-discharge zones, constraining the associated fracture-caved reserviors in carbonate strata. This paper comprehensively utilizes core, fluid inclusion, and carbon-oxygen isotope to probe the evolution process and migration of collapse-filling in paleo-underground river in the Northern Uplift of Tarim Basin. The results show that: 1) More than three stages of collapse-filling were identified in recharge-runoff-discharge zones, and a four-stage differential collapse-filling process was proposed to summarize the evolution of paleo-underground river. 2) The collapse-filling process varies spatiotemporally in the recharge, runoff and discharge zones. Hydrodynamic strength and filling capacity migrate gradually from recharge zone to discharge zone. 3) Collapse-filling mechanisms, including gravity, suffusion and suction-erosion mechanisms, also vary along with the collapse-filling evolution process of paleo-underground river. The research provided a new insight to recognize and interpret the differential planar distribution and vertical filling of paleo-underground river system, which can be further applied to probe the fracture-caved karst reservoirs.