Tectonic Controls on the Sedimentation and Thermal History of Supra-detachment Basins: A Case Study of the Early Cretaceous Fuxin Basin, NE China

A crustal-scale detachment system, linking cooler hanging wall basins and the hotter footwall Yiwulushan metamorphic core complex (MCC), is located in the Fuxin area of NE China. The relationship between detachment tectonism and sedimentation along supra-detachment basins remains a challenging topic, and the effect of detachment tectonism on basin-fill and thermal histories is poorly understood. Based on the detailed sedimentological, seismic, and geochemical analysis, we reconstruct the sedimentation and thermal history of the Fuxin Basin in the context of detachment tectonism. Two depositional systems, including a fan delta-shore-shallow lake and a subaqueous fan-semi-deep lake, developed during the early Cretaceous. The sedimentation history reveals that the lake-basin scale started with expansion, and then gradually declined toward the eastern depocenter. During the early Cretaceous, a reconstructed dynamic model for basin-range evolution reveals the three evolution phases of proto-rift, fault subsidence, and transpression in the Fuxin area. We infer that the evolution of the supra-detachment basin, sedimentation, and thermal records were controlled by detachment tectonism associated with the uplift and exhumation of the Yiwulushan MCC. Thermal parameters and burial history indicate a general increase in the maximum paleotemperature toward the eastern part of the basin. Effects of sedimentary fill, shear heating, transpression, and fault displacement from detachment tectonism dominated the thermal evolution of this basin. Our results illustrate the importance of the dynamic evolution of the MCC in characterizing the sedimentation and thermal history of supra-detachment basins that contribute to the understanding of subduction systems and their resource development.