地质学报2018，Vol.92Issue(2)：197-214,18.
大兴安岭中段龙江盆地热河生物群化石组合及生存时限——来自生物地层、年代地层新证据
Fossil Assemblage and Survival Timing of Jehol Biota in the Longjiang Basin, Middle of Da Hinggan Mountains: New Evidence from Biostratigraphy and Chronostratigraphy
摘要
Abstract
The Guanghua Formation in Longjiang Basin deposited continuously and is exposed in integrity,with abundant fossils of Jehol Biota,making it one of the key sections to probe the origin,evolution and radiation of the Jehol Biota in the middle of Da Hinggan Mountains.This study carried out a precise measurement for the section of Guanghua Formation.It is believed that the Guanghua Formation conformably overlies andesitic welded tuff of the Longjiang Formation,with part covered unconformably by basalt of the Ganhe Formation.Three lithological units have been recognized from bottom to top.Systematic sampling and identification for corresponding biota fossils were carried out,and this has greatly enriched the biota category of Jehol Biota in the middle of Da Hinggan Mountains.Based on newly collected fossils and previously published data,authors established the assemblages of various fossils in the middle of Da Hinggan Mountains,which include limbs,ostracods,plant fossils,insects and others,and further discussed their characteristics.The LA-ICP-MS U-Pb zircon chronology study of the lower to middle sections of Guanghua Formation reveals that the Jehol Biota in the Longjiang Basin occurred at time of 125.4t±1.4Ma to 120.1±1.1Ma,with an span of roughly about 500 million years,reflecting that the Jehol Biota throve from early to middle Apter period.According to paleontological characteristics and our previous studies,it can be concluded that the paleoenvironment of the Jehol Biota in the Longjiang Basin may be the intermittent or seasonal lakes,and the paleoclimate should be in the warm and humid seasonally-changing warm zone,accompanied by the short term arid climate.关键词
热河生物群/生物地层/年代地层/龙江盆地/大兴安岭中段Key words
Jehol Biota/biostratigraphy/chronostratigraphy/Longjiang Basin/Middle of Da Hinggan Mountains引用本文复制引用
张渝金,杨雅军,蔡闹,吴新伟,张超,郭威..大兴安岭中段龙江盆地热河生物群化石组合及生存时限——来自生物地层、年代地层新证据[J].地质学报,2018,92(2):197-214,18.基金项目
本文为中国地质调查局项目(编号DD20160048-04、12120113053900、DD121201102000150012-17、DD20160345-17)和国家自然科学青年基金项目(编号41702032)联合资助的成果. （编号DD20160048-04、12120113053900、DD121201102000150012-17、DD20160345-17）
