The upper age limitation of Mesozoic lithospheric thinning in NE China：
Chronology restriction of Yingcheng Formation in Songliao Basin
Xu Yan1,2 Chen Hanlin1,2 Zhang Fengqi1,2,3 Dong Chuanwan1,2 Yu Xing1,2 Xiao Jun1,2 Pang Yanming3 Shu Ping3 Ding Rixin3
1.Department of Earth Sciences|Zhejiang University|Hangzhou 310027； 2.Structural Research Center of Oil & Gas Bearing Basin ministry of education|Hangzhou 310027； 3. Exploration and Development Research Institute of Daqing Oil Field Company Lid Daqing|Heilongjiang 163712
The Songliao Basin is a largescale petroliferous extensional sedimentary basin in Late Mesozoic. It is characterized by strong rifting and volcanism in the early stage of the basin evolution. With the SHRIMP UPb chronology studies for Yincheng Formation volcanic rocks from Shengshengeng2 well and Xushen 92 well in Xujiaweizhi fault depression，northern part of Songliao Basin，it is indicated that the age of volcanic rock of Yingcheng Formation is about 114～112 Ma and it represents the upper age limitation of Mesozoic volcanic event in Songliao Basin. The statistic result of published UPb age of Mesozoic volcanic rock in NE China shows that there are four periods of volcanic events，and the age distribution is 166～150 Ma， 140～130 Ma， 130～120 Ma， 114～109 Ma. The age of volcanic rock of Yingcheng Formation in Songliao Basin is the same as the age of the last volcanic event in NE China，and it can represents the last volcanic event of Mesozoic in NE China. Since，the chronological results of this paper can provide strict constraint on the upper limit age of the lithospheric thinning in NE China.