East Boundary of the Collision Belt Between Sion-Korean and Yangtze Plates in Eastern China and Their Extension in the Sea
Abstract:In this study, we summarized the latest research achievements in the Collision belt between the Sino-Korean and Yangtze Plates based on the integration of gravity and magnetic anomaly data, fault characteristics, high resolution seismic profiles, petrology, stratigraphic chronology and paleomagnetic data as well as the data collected from the Chinese Continental Scientific Drilling program, and then discussed the character of the gravity and magnetic anomaly field, the faults distribution pattern in this area, and the Sulu HP-UHP metamorphism terrane and its extension into the South Yellow Sea. The geochemical and isotope geochronology characteristics of eclogite, gneiss of Chaolian island and Qianliyan island of Qianliyan uplift were studied as well.
It is proposed that Collision belt of Sino-Korean and Yangtze Plates was Sulu HP-UHP metamorphic belt - Qianliyan uplift. Qianliyan eclogite protolith was probably formed in the late Proterozoic, and its metamorphism time of coesite eclogite-facies was 222±15Ma. The Qianliyan uplift was caused by the northward subduction of the Yangtze plate beneath the Sino-Korean craton during the Indosinian, as part of Sulu HP-UHP metamorphism terrane. The Southern Qianliyan Fault is the boundary fault of the uplift in the south and the north margin of the uplift might be bounded by the extended part of the Qingdao-Rongcheng Fault in the Yellow Sea. And in the east, the uplift is probably ended at the East Marginal Fault of Yellow Sea. The Qianliyan uplift was eroded after the Indosinian and intruded by granite during Early Cretaceous. The southern Qianliyan Fault was reversed to a normal fault at Late Cretaceous, and it controlled Cenozoic deposition of the Northern South Yellow Sea Basin.