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stratigraphic framework of late Paleozoic in northeastern China

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Global Geology 2013年第1期16卷 1-18页

作者： WANG Chengwen LI Ning SUN Yuewu ZONG Pu ZHAO Guowei LIU Hui MA Xiaoqin College of Earth Sciences Jilin University Research Center of Paleontology & Stratigraphy Jilin University Institute of Geology Chinese Academy of Geological Sciences

Late Paleozoic strata in northeastern China are distributed in a zonal pattern around the old-land on the Jiamusi-Mongolia Block. They are composed of active deposits in the regular distributed tectonic lithofacies zones. This indicates that the late Paleozoic strata belong to continental margin deposits. According to the strong conformability of the sedimentary strata in the same continental margin and distinct differences among the three continental margins, three stratigraphical regions of the Jiamusi-Mongolia stratigraphical Province are recognized along the northern, southern and eastern margins of the Jiamusi-Mongolia Block, named respectively as Xing＇an stratigraphical Region, Inner Mongolia grass-Songhua River stratigraphical Region and Baoqing-Hunchun Stra- tigraphical Region. Due to the characteristics of continental margin deposits and active sediments, the strata can be correlated on the level of formation by the methods of analysing the rock association in the same stratigraphic region. Therefore, some revisions of the lithologieal formations of the late Paleozoic strata in northeastern China have been made, and a new chart of lithostratigraphic correlation has been proposed. Furthermore, the present stratigraphic framework is setting on the International stratigraphic Chart on the level of stage, after comprehen- sive researches to lithostratigraphy, biostratigraphy and chronostratigraphy, especially the conodont biostratigra- phy and isotopic ages of volcanic rocks obtained in recent years.

关键词： northeastern China late Paleozoic strata continental margin deposits stratigraphic provincialism stratigraphic correlation

A Study on the Quaternary Activity of the Tianjin Fault

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Earthquake Research in China 2010年第3期24卷 353-362页

作者： Shao Yongxin Li Zhenhai Chen Yukun Ren Feng Yao Zhengquan Earthquake Administration of Tianjin Municipality Tianjin 300201 China State Key Laboratory of Loess and Quaternary Geology Institute of Earth Environment CAS Xi＇an 710075 China

The Tianjin fault includes South Tianjin fault and North Tianjin fault. Based on the results of artificial seismic exploration,four borehole profiles were laid out respectively west of Jinghai county town,Chaomidian village of Xiqing district,Xiaonanhe village of Xiqing district and Zhutoudian village of Ninghe county,to implement the exploration of these faults. Through identification of microfossils,the locations of marine beds in boreholes were obtained in this work,and through stratigraphic dating,the ages of the first,second and third marine beds were determined. Through strata correlation with the marine beds as key marker beds and integrating with the test results of paleo geomagnetism of boreholes BZ2 and TN3,the activity in the North and South Tianjin faults was analyzed and studied. The results indicate that there is no evidence of movement of the South Tianjin fault since the Late Pleistocene,but may have had weak activity before the Middle Pleistocene. No evidence of activity in the North Tianjin fault was found since the Late Pleistocene either,but might have been active in the early stage of the Early Pleistocene. These show that the activity of the South Tianjin fault is stronger than that of the North Tianjin fault. At the same time,we find that the second,third and fourth marine beds are lacking to some extent in different areas. So,before they are used in strata correlation, the age of marine beds must be determined,otherwise the results of strata correlation may lead to errors. For the second marine bed,where there has been dispute about its age,we consider the age to be about 70ka.

关键词： Tianjin fault Marine bed stratigraphic correlation Fault activity

correlation methods of base-level cycle based on wavelet neural network

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Global Geology 2007年第1期10卷 25-28页

作者： Xingke XU Changwei CHEN Jing SUN Qinglong MENG College of Earth Sciences Jilin University Changchun 130061 China

The authors discussed the method of wavelet neural network （WNN） for correlation of base-level cycle. A new vectored method of well log data was proposed. Through the training with the known data set, the WNN can remenber the cycle pattern characteristic of the well log curves. By the trained WNN to identify the cycle pattern in the vectored log data, the ocrrdation process among the well cycles was completed. The application indicates that it is highly efficient and reliable in base-level cycle correlation.

关键词： wavelet neural network stratigraphic correlation base-level cycle vector

Global synchronous initiation of the 2nd episode of Sturtian glaciation:SIMS zircon U–Pb and O isotope evidence from the Jiangkou Group,South China

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Global synchronous initiation of the 2nd episode of Sturtian...