Deep-water sediments and evolution of the Lower Triassic Xikou Formation in southwestern Fujian, China |
| |
Authors: | Peijun Li Quanlin Hou Shu Sun Jiliang Li |
| |
Institution: | (1) Institute of Remote Sensing and Geographic Information System, Peking University, 100871 Beijing, China;(2) Institute of Geology, Chinese Academy of Sciences, 100029 Beijing, China |
| |
Abstract: | The Lower Triassic Xikou Formation in southwestern Fujian, China is a set of complex deep-water sediments which includes turbidites,
sandy contourites and isolated olistoliths. Five facies and seven subfacies are recognized in the deep-water turbidites, which
are considered to belong to five facies associations of upper, middle and lower fans, respectively. The sandy contourites,
which occur within turbidites as isolated thin layers with structures of traction current, are formed by reworking turbidites.
They occur in discrete units, not as a part of a vertical sequence of structures, such as Bouma sequence. Paleocurrent directions
derived from sandy contourites are perpendicular to or at a large angle of those derived from turbidites. In some areas, within
the Formation there exist large oolitic limestone blocks slided from shallow sea. The temporal-spatial distribution of three
types of sediments mentioned above and the related evidences could indicate that a passive continental margin from shallow
sea to bathyal-abyssal region, dipping toward southeast, once occurred in study area during the early Triassic. The early
Triassic represents a period of sealevel uprising. The uprising of sea level and the development of isolated olistoliths probably
imply gradual shrinking of an ocean basin at that time.
Project supported by the National Natural Science Foundation of China (Grant Nos. 49490011, 49702036). |
| |
Keywords: | turbidites sandy contourites isolated olistoliths early Triassic Xikou Formation southwestern Fujian |
本文献已被 SpringerLink 等数据库收录! |
|