The relationship between Hainan Island and Yangtze and Cathaysia Block: Evidence from the U-Pb age of detrital zircons of the Lower Permian Echa Formation in Hainan Island

The relationship of Hainan Island with Yangtze and Cathaysia Block has been of considerable controversy. This paper presents a study of geochronology of detrital zircon from the Echa Formation, Baicha Village, Dongfang City, Hainan Island. The results show 4 major age peaks, i.e., ~1700Ma, ~1580Ma, 1073Ma and 680Ma, recording the events of Columbia (1700Ma and 1580 Ma), Rodinia (1073Ma) and Pan-African (680Ma). The presence of ~1700Ma, ~1580Ma and 1073Ma age peaks is similar to that of Antarctica, Song Hien in Vietnam, Cathaysia orogenic belt and southeast margin of Yangtze Block, revealing that they all experienced the Columbia and Grenville (Rodinia) orogenic activities. The ~1700Ma and ~1580Ma age peaks only appear on the southeast margin of Yangtze Block, but have not been reported inside the Yangtze Block. The 680 Ma age peak appears in the Hainan Island but not in the Yangtze Block, indicating that the Hainan Island was separated or far away from the Yangtze Block, but was adjacent to Cathaysia Block, Vietnam and Antarctica during the Meso-to Neoproterzoic period.