Quaternary Chronostratigraphy of Borehole S3-7 in Dongting Basin
Zhao Juxing
Li Changan
Zhang Yufen
Qiang Xiaoke
Xiong Deqiang
Abstract：The formation and evolution of the Dongting basin are important for understanding the geological environmental evo-lution of the middle Yangtze drainage and even central China.However,Quaternary chronostratigraphy is still controversial in the area.In this study,one continuous borehole S3-7 with a depth of 255.1 m was taken from the Yuanjiang depression,the deposition center of the Dongting basin.Based on detailed stratigraphic and lithological interpretations,the borehole was dated by paleomagnetism,ESR and AMS1 4 C,to establish its chronostratigraphic sequence.Compared with other two typical bore-holes,the Quaternary chronostratigraphic sequence of the Dongting basin was established.The results suggest that the Plio-Pleistocene and Early-Middle Pleistocene boundaries of the central Dongting basin are located at the depths of 240-300 m and 90-95 m,respectively,and the boundaries of Middle-Late Pleistocene and Pleistocene/Holocene are located at the depths of 28-50 m and 1.5-3.1 m,respectively.Average deposition rate and piecewise linear equation show that the timing of litholog-ical units in coverage area are as follows:2 590-1 600 ka BP for the Huatian Formation,1 600-920 ka BP for the Xiangyin Formation,920-120 ka BP for the Dongtinghu Formation,120-1 1 ka BP for the Anxiang Formation and younger than 1 1 ka BP for the Holocene.
Keywords：Dongting basinQuaternarychronostratigraphypaleomagnetismgeochronologystratigraphy
Publication Date：2016-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：11( 633-643 )