Affiliation:
1. College of Earth Science and Engineering, Shandong University of Science and Technology, Qingdao 266590, China
2. Library of Shandong Normal University, Shandong Normal University, Jinan 250358, China
Abstract
The varve chronological approach has been applied to older ages (pre-Quaternary) in the Shanwang Basin for the first time. This study focuses on the analysis of diatom shale from the Shanwang Basin, which was formed in Maar Lake (a volcanic crater basin, often filled by a lake). The lacustrine sediments of the basin encapsulate comprehensive geological information. By identifying species and providing systematic paleontological descriptions of diatoms in the profile, two genera and seven species were recognized. A microscopic examination of the thin sections revealed five types of laminae and couplets. On this basis, the study adopted the artificial semi-automatic counting method of the laminae. The calculation results show that the age of the diatom shale section in the Shanwang Basin is 18.524–17.985 Myr B.P, the deposition time is 0.54 Myr, and the deposition rate is 4.06 cm/Kyr. Finally, through the comparative discussion of various dating methods, it can be concluded that the varve chronology is a more accurate and reliable dating method than other dating methods. The research findings contribute to our understanding of the geological history of the region.
Funder
National Natural Science Foundation of China
Natural Science Foundation of Shandong Province
Qingdao National Laboratory for Marine Science and Technology