NEW UNDERSTANDING OF THE LOWER CRETACEOUS LONGJIANG FORMATION IN THE EASTERN DAXINGANLING REGION
DING Qiu-hong1, CHEN Shu-wang1, SHANG Ling2, LI Yong-fei1, WANG Jie1
1. Shenyang Institute of Geology and Mineral Resources, CGS, Shenyang 110034, China; 2. Liaoning Institute of Geology and Mineral Resources, Shenyang 110032, China
Abstract：On the basis of field survey, the stratotype section of Longjiang Formation is researched particularly on the lithostratigraphy, biostratigraphy, isotope chronology and lithogeochemistry. The meaning of Longjiang Formation is redefined. The neologism of Longjiang Formation consists of andesite and dacite with its pyroclastic rocks, rhyolitic pyroclastic rocks and sedimentary clastic rocks. The paleontological fossils belong to Eosestheria-Lycoptera-Ephemeropsis trisetalis fossil assemblage of the Middle Jehol Biota. Among them, Conchostracans are represented by the Eosestheria opima-E. (Dongbeiestheria) guanghuaensis assemblage. The volcanic lithogeochemistry is characterized by SiO2 contents between 63.88% and 75.65%, high Al2O3 (12.19% to 19.39%), high Na2O (1.04% to 5.24%), rich alkalis (Na2O+K2O 3.65% to 6.25%)and strong enrichment in light rare earth elements(LREE). The isotopic age of 40Ar/39Ar is 125.4±1.8 Ma.
丁秋红, 陈树旺, 商翎, 李永飞, 王杰. 大兴安岭东部地区下白垩统龙江组新认识[J]. 地质与资源, 2014, 23(3): 215-221,234.
DING Qiu-hong, CHEN Shu-wang, SHANG Ling, LI Yong-fei, WANG Jie. NEW UNDERSTANDING OF THE LOWER CRETACEOUS LONGJIANG FORMATION IN THE EASTERN DAXINGANLING REGION. GEOLOGY AND RESOURCES, 2014, 23(3): 215-221,234.
2014, Vol. 23 
辽公网安备 21010502000112号