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Palynomorph assemblages from the Fenghuoshan Group,southern Qinghai,China:their age and palaeoenvironmental significance 被引量:7
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作者 李建国 彭俊刚 D.J.Batten 《Science Bulletin》 SCIE EI CAS CSCD 2015年第4期470-476,M0004,共8页
The varicoloured Fenghuoshan Group occurs widely in the Qiangtang-Hoh Xil region of the northern Qinghai-Xizang Plateau. Few fossils have been found to date in this sedimentary succession because lithological conditio... The varicoloured Fenghuoshan Group occurs widely in the Qiangtang-Hoh Xil region of the northern Qinghai-Xizang Plateau. Few fossils have been found to date in this sedimentary succession because lithological conditions are not conducive to their preservation. As a result, there has been a long-term disagreement among geologists about its age. Despite a few lists of fossil names in individual publi- cations, no detailed research on the palaeontology, including palynology, has been reported previously. In this study, we recovered many pollen grains and spores from two samples that were collected on the northern slope of Fenghuo Moun- tain. They indicate an age no younger than Maastrichtian for the upper part of the Fenghuoshan Group. It is considered likely that the entire Fenghuoshan Group represents deposi- tion between the late Early Cretaceous (possibly Albian) and the Maastrichtian. The palynoflora consists mainly of angio- sperm pollen, gymnosperm pollen and fern and bryophyte spores being subordinate. Pollen grains referable to the Ephedrales and the Taxaceae-Cupressaceae groups dominate the assemblage, implying a warm, arid climate and subtropical forest-shrub vegetation at the time of deposition. 展开更多
关键词 Palynology - Fenghuoshan Group latecretaceous QIANGTANG Qinghai-Xizang Plateau
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滇西北红山晚白垩世花岗斑岩型Cu-Mo成矿系统及其大地构造学意义 被引量:62
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作者 徐兴旺 蔡新平 +3 位作者 屈文俊 宋保昌 秦克章 张宝林 《地质学报》 EI CAS CSCD 北大核心 2006年第9期1422-1433,共12页
红山铜多金属矿床位于滇西北中甸红山一带,其一直被认为是印支期夕卡岩型矿床。新的研究结果表明红山矿区存在两个成矿系统:①与印支期石英二长斑岩有关的夕卡岩型铜多金属成矿系统,其典型矿床是与石榴子石夕卡岩伴生的含铜磁铁矿体... 红山铜多金属矿床位于滇西北中甸红山一带,其一直被认为是印支期夕卡岩型矿床。新的研究结果表明红山矿区存在两个成矿系统:①与印支期石英二长斑岩有关的夕卡岩型铜多金属成矿系统,其典型矿床是与石榴子石夕卡岩伴生的含铜磁铁矿体与磁黄铁矿体;②与花岗斑岩有关的斑岩型Cu—Mo~Pb—Zn成矿系统,其包括地表喷溢沉积成因的含铁钙硅质岩、可能为流体通道相的Cu—Mo多金属石英网脉与大脉、充填于岩溶洞穴中的层状Pb—Zn矿体、花岗斑岩内部的浸染状Cu—Mo矿化、及岩体外接触带夕卡岩型多金属矿床。含矿石英脉6个辉钼矿样品Re—Os模式年龄介于75.46~78.46Ma之间,等时线年龄为77Ma,红山矿区花岗斑岩型Cu~Mo矿床形成时代为晚白垩世。红山矿区晚白垩世花岗斑岩及其伴生斑岩型Cu—Mo矿床和大规模流体活动是滇西地区晚白垩世区域构造一流体一成矿体系的一部分,其形成与印度亚洲大陆碰撞有关,据此可推断印度~亚洲大陆的碰撞作用及其伴生的大规模成矿作用在77Ma就已开始。红山矿区晚白垩世斑岩型Cu—Mo矿床成矿系统的厘定对于斑岩型矿床成矿流体结构模型和区域成矿与构造学的研究具重要的启示意义。 展开更多
关键词 花岗斑岩型 Cu—Mo矿床 成矿系统 晚白垩世 红山 滇西北
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