Mesozoic tectono-magmatic activities in South China: Retrospect and prospect

Abstract

The South China Block was formed through the collisional orogeny between the Cathaysia Block and the Yangtze Block in the Early Neoproterozoic. The northern, western and southern sides of the South China Block were affected by disappearance of the Paleo-Tethyan Ocean during the Paleozoic. The southern and northern sides of the South China Block were respectively collided with the Indo-China Block and North China Block in the latest Paleozoic to form the basic framework of the Eastern China. The Eastern China has been affected by the westward subduction of the Pacific Plate since the Mesozoic. Therefore, the South China Block was influenced by the three major tectonic systems, leading to a superposed compound tectonics. The comparative study of the Mesozoic geology between the South China Block and its surrounding areas suggests that although the Mesozoic South China Block was adjacent to the subduction zone of the western Pacific, no juvenile arc-type crust has been found in the eastern margin. The main Mesozoic geology in South China is characterized by reworking of ancient continental margins to intracontinental tectonics, lacking oceanic arc basalts and continental arc andesites. Therefore, a key to understanding of the Mesozoic geology in South China is to determine the temporal-spatial distribution and tectonic evolution of Mesozoic magmatic rocks in this region. This paper presents a review on the tectonic evolution of the South China Block through summarizing the magmatic rock records from the compressional to extensional tectonic process with the transition at the three juncture zones and using the deformation and geophysic data from the deep part of the South China continental lithosphere. Our attempt is to promote the study of South China’s geology and to make it as a typical target for development of plate tectonic theory.