Crust Evolutional Process Of Yangtze Craton During Archean-Paleoproterozoic Period

Cratons are old and stable parts of continental lithosphere, they usually evolved with multiple collision and breakup events. Only sporadic Archean basement exposed in the Yangtze Craton especially along its northern margin. Whole-rock major and trace elements analysis and zircon U-Pb-Hf analysis were made from gneiss, amphibolite, migmatite, metasediments from the Kongling Complex. Combined with previous research data, several results are acquired:(1) The depositional period of the Kongling metasedimentary rocks was 2.15-2.0 Ga. This depositional event was responding to 2.2-2.1 Ga arc-related growth and reworking event of the Yangtze Craton, which formed the 2.1 Ga Houhe gneiss and provided granitic source material for the Kongling metasedimentary rocks. Yangtze Craton experienced continent-arc-continent collisional events and following breakup event during Paleoproterozoic 2.4-1.85 Ga.(2) Southern part of the Kongling Complex experienced Archean 2.9 Ga, 2.7-2.6 Ga, and Paleoproterozoic 2.4 Ga,1.77 Ga as well as Neoproterozoic 0.8 Ga growth and reworking events. Besides, zircons from southern part of the Kongling Complex also recorded 2.5 Ga,2.14 Ga,2.0 Ga geological event information. Both northern part and southern part of the Kongling Complex have similar Archean-Paleoproterozoic crustal evolution history. Southern part of Kongling Complex is equal to the west section of the northern part Kongling Complex.(3) Prescribe the scope of Yangtze Craton during Paleoproterozoic period, and then use data from Geophysics, Geochemistry and Geochronology to recover the north-south trend Paleoproterozoic collisonal belt, which is along the Huangtuling-Kongling-Ningxiang-Sibao area.(4) Based on all the available information, we provided the Archean to Paleoproterozoic crustal evolution history of Yangtze Craton. Being compared with other Archean Craton, the Yangtze Craton could be possibly involved with the cratons exchange process between supercraton "Vaalbara" and "Zimgarn" during 3.5-1.8 Ga.