华北克拉通东南部新元古界碳酸盐岩沉积古地理及有利岩溶热储分布OA

The Neoproterozoic strata in the southeastern North China Craton are primarily distributed in the western part of Shandong,the Xuzhou-Suzhou area,and the Huainan area,spanning several administrative regions and tectonic units.The coeval Neoproterozoic strata in these areas have been named differently within separate areas,which has created significant challenges for regional stratigraphic correlation.This has further hindered the comprehensive and systematic studies on the sedimentary environment evolution,paleogeographic patterns,and geothermal resource distribution in the southeastern North China Craton during the Neoproterozoic.Based on the historical stratigraphic classification and abundant data of specific stratigraphic sections,especially the field sections measured by this study,we establishes a stratigraphic correlation framework for the Neoproterozoic strata of the southeastern North China Craton.Through field-based lithological and sedimentary structural descriptions,combined with the micro-scopic identification of sedimentary components and textures,five sedimentary facies zones have been identified within the Neoproterozoic carbonate strata.They are Evaporitic facies,Platform interior restricted,Open marine,Platform-margin reef and shoals,and Carbonate ramp slope facies zones.The statistic of the carbonate strata thick-nesses from various sections reveals that the relatively deep-water Platform-margin reefs and shoals facies zone are predominantly distributed in the southeastern part of the study area.Toward the western and northwestern parts of the study area,the depositional environment shallows progressively and Open marine and Platform interior restricted facies zones developed,accompanied by a gradual thinning of the strata.This facies zone transition reflects a Neo-proterozoic paleogeographic pattern of low in southeast and high in northwest,with marine water transgressed from the southeastern part to the northwestern part of the study area.Based on the facies and paleogeographic analysis,and in combination with geothermal reservoir evaluation criteria,it can be inferred that the reef-shoal facies bearing Niyuan,upper Wangshan,and Jinshanzhai formations on the southern part of Huaibei,the dolostones bearing Sid-ingshan Formation on the northwestern part of Huainan,and the Platform-margin reefs and shoals facies zone bear-ing Jiuliqiao and Sidingshan formations on the eastern part of Bengbu have great potential for the development of karst geothermal reservoir.These findings provide targeted areas for future geothermal exploration and development.