黑龙江多宝山古生代海盆闭合的岩石学证据  

Petrological evidence of Paleozoic marine basin closure in Duobaoshan of Heilongjiang

作　　者：赵焕利 刘旭光 刘海洋 朱春艳 

机构地区：[1]黑龙江省第五地质勘察院,黑龙江黑河164300 [2]黑龙江地质调查研究总院齐齐哈尔分院,黑龙江齐齐哈尔161005 [3]黑龙江省有色金属地质勘查研究总院,哈尔滨150046

出　　处：《世界地质》2011年第1期18-27,共10页World Geology

基　　金：中国地质调查局1:25万黑河市等二幅区调项目(1212010510608)

摘　　要：综合研究黑龙江多宝山地区古生代沉积地层、生物化石,通过分析侵入岩岩石地球化学及其锆石U--Pb同位素测年资料,表明该地区早奥陶世至晚泥盆世早期为海相沉积地层,晚泥盆世晚期为海陆交互相沉积地层,早石炭世为陆相河湖沉积地层。多宝山海盆东南侧出露一套年龄为(300±3～357±4)Ma的花岗岩,其中正长、二长花岗质糜棱岩为后造山花岗岩,碱长花岗岩为造山后A型花岗岩。表明多宝山海盆于晚泥盆世开始闭合,至早石炭世为陆相河湖沉积,晚石炭世—早二叠世为抬升剥蚀阶段。表现为多宝山地区于早石炭世开始造山,晚石炭世晚期或延至早二叠世发生造山后伸展作用。The Paleozoic sedimentary strata,fossils,geochemistry of intrusive rocks and the zircon U——Pb isotopic dating of Duobaoshan in Heilongjiang Province have been comprehensively studied.They are the marine sedimentary strata from Early Ordovician to the early Late Devonian,sea-land interbeddind sediments in the late Late Devonian,and the continental fluvial and lacustrine deposits in Early Carboniferous.It is exposed a set of granites with（300± 3 ~ 357±4） Ma in southeastern Duobaoshan marine basin.Syenite fine-grained and adamellite fine-grained mylonites are post-orogenic granites,and alkali granites are post-orogenic granites in A-type.That means the Duobaoshan marine basin closed from Late Devonian,became continental sedimentary in Early Carboniferous,and in uplift and erosion stage in Late Carboniferous-Early Permian.The fact performed that the orogeny of Duobaoshan area began in Early Carboniferous,and post-organic extension continued from Late Carboniferous to Late or Early Permian.

关 键 词：多宝山地区 海盆 化石 锆石U--Pb同位素测年 

分 类 号：P597.3[天文地球—地球化学]