Preliminary study of mollusk fossils in the Qinan Miocene loess-soil sequence in western Chinese Loess Plateau  

作　　者：Denis-Didier Rousseau 

机构地区：[1]Université Montpellier II, Institut des Sciences de l’Evolution (UMR CNRS 5554), Case 61, Place E. Bataillon, 34095 Mont-pellier Cedex 05, France Lamont-Doherty Earth Observatory of Columbia University, Palisades, New York 10964, USA

出　　处：《Science China Earth Sciences》2006年第7期724-730,共7页中国科学（地球科学英文版）

基　　金：This work was supported by the National Basic Research Program of China(Grant No.2004CB720203);the National Natural Science Foundation of China(Grant Nos.40231001 and 40372083);the Chinese Academy of Sciences(Grant No.KZCX3-SW-139).

摘　　要：The first near continuous mollusk fossil record from the Qinan Miocene loess-soil se-quence is presented. Results show that mollusk species are abundant in the QA-I section between 22 and 6.2 Ma, and both loess layers and soil layers yield mollusk fossil individuals. All mollusk species are terrestrial and well preserved in the section. Most species are identical to those identified in the Quaternary loess-soil sequence of the Loess Plateau. The thermo-humidiphilous group generally is distributed in soil layers, whereas cold-aridiphilous group can be observed in loess layers. From the Miocene to Quaternary, the occurrence and divergence of new species of Metodontia and Cathaica correspond to the crucial periods of regional and global environmental changes, indicating that mol-lusk species are sensitive to environmental variations. Preliminary study on the QA-I mollusk record indicates that the Qinan Miocene loess-soil sequence may have a similar sedimentary environment to the Quaternary loess-soil sequence of the Loess Plateau.The first near continuous mollusk fossil record from the Qinan Miocene loess-soil se-quence is presented. Results show that mollusk species are abundant in the QA-I section between 22 and 6.2 Ma, and both loess layers and soil layers yield mollusk fossil individuals. All mollusk species are terrestrial and well preserved in the section. Most species are identical to those identified in the Quaternary loess-soil sequence of the Loess Plateau. The thermo-humidiphilous group generally is distributed in soil layers, whereas cold-aridiphilous group can be observed in loess layers. From the Miocene to Quaternary, the occurrence and divergence of new species of Metodontia and Cathaica correspond to the crucial periods of regional and global environmental changes, indicating that mol-lusk species are sensitive to environmental variations. Preliminary study on the QA-I mollusk record indicates that the Qinan Miocene loess-soil sequence may have a similar sedimentary environment to the Quaternary loess-soil sequence of the Loess Plateau.

关 键 词：MOLLUSK fossils  MIOCENE loess  LOESS Plateau  MOLLUSK evolution  SEDIMENTARY environment. 

分 类 号：Q915.2[天文地球—古生物学与地层学]