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多种组合模型的区域滑坡易发性及精度评价 被引量:50
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作者 杨强 王高峰 +3 位作者 丁伟翠 李荣建 高幼龙 邓兵 《自然灾害学报》 CSCD 北大核心 2021年第2期36-51,共16页
以滑坡灾害高易发的陇南白龙江流域中游及其岷江支流段作为研究对象,依托流域内2093处滑坡灾害点样本数据,开展多种组合模型区域滑坡易发性区划及精度评价研究。首先选取坡度、坡高、距断层距离、地层岩性、流域沟壑密度、植被归一化指... 以滑坡灾害高易发的陇南白龙江流域中游及其岷江支流段作为研究对象,依托流域内2093处滑坡灾害点样本数据,开展多种组合模型区域滑坡易发性区划及精度评价研究。首先选取坡度、坡高、距断层距离、地层岩性、流域沟壑密度、植被归一化指数等6项影响滑坡发生的孕灾因子作为易发性的评价指标,依据各指标条件下的信息量值、确定性系数值和证据权重值曲线突变规律,并结合滑坡面积及分级面积频率比曲线作为等级划分的临界值来确定因子分级状态。其次,基于指标因子状态分级和相关性分析结果,采用信息量法、确定性系数法、证据权法分别与逻辑回归组合的3种模型开展区域滑坡灾害易发性区划,并从模型结果、适用性和精度等方面采用多手段对3种组合模型进行比较和讨论。研究结果表明:在区域滑坡易发性评价方面3组模型均表现较为理想,信息量和逻辑回归组合模型的预测精度为94.6%,其预测精度和准确性优于其它两种组合模型;研究区滑坡极高易发区主要分布白龙江两岸,尤其分布在两河口至桔柑乡段白龙江左岸区域,易发性评价结果成果可为该区域地质灾害防治和国土空间用规划及用途管制决策提供依据。 展开更多
关键词 滑坡易发性 信息量模型 逻辑回归模型 精度评价 白龙江流域
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西准噶尔地区最晚期岩浆侵入活动--来自早二叠世-早三叠世接特布调岩体的证据 被引量:7
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作者 徐盛林 陈宣华 +4 位作者 李廷栋 丁伟翠 李冰 张垚垚 马飞宙 《地质学报》 EI CAS CSCD 北大核心 2020年第4期1067-1090,共24页
西准噶尔地区晚古生代构造运动复杂,岩浆侵入活动强烈,地壳生长显著,处在洋陆构造转换的关键时期。接特布调岩体位于连接西准噶尔地区、天山造山带和准噶尔盆地的重要位置,岩石类型以碱长花岗岩、二长花岗岩和花岗闪长岩为主。碱长花岗... 西准噶尔地区晚古生代构造运动复杂,岩浆侵入活动强烈,地壳生长显著,处在洋陆构造转换的关键时期。接特布调岩体位于连接西准噶尔地区、天山造山带和准噶尔盆地的重要位置,岩石类型以碱长花岗岩、二长花岗岩和花岗闪长岩为主。碱长花岗岩矿物组成以碱性长石(55%~60%)、斜长石(15%~20%)和石英(23%~25%)为主,几乎不含暗色矿物,岩石内部无暗色微粒包体;二长花岗岩和花岗闪长岩矿物组成以斜长石(30%~40%和~16%)、碱性长石(30%~40%和~50%)和石英(20%~25%和~18%)为主,含少量黑云母和角闪石,内部存在不同数量和规模的暗色微粒包体。通过高精度锆石U-Pb定年,将接特布调岩体的成岩年龄限定为287~250 Ma,岩体内早三叠世(250.4Ma)二长花岗岩是迄今为止在整个西准噶尔地区发现的最年轻的侵入岩,该期花岗岩的就位标志着西准噶尔地区深成岩浆侵入活动的终结。接特布调岩体整体具有高硅(SiO2=67.04%~77.01%)、富碱(K2O=3.45%~4.63%,Na2O=3.62%~4.18%),贫钙(CaO=0.45%~0.3.05%)、贫镁(MgO=0.16%~1.51%)、低铁(Fe2O3=0.99%~4.40%)的特征,属于高钾钙碱性系列,准铝质-弱过铝质(A/CNK=0.93~1.03)。球粒陨石标准化稀土元素配分图具有明显的右倾海鸥型特征,富集轻稀土元素和Rb、Th、K元素,亏损重稀土元素和Eu、Ba、Nb、Sr、P、Ti元素。碱长花岗岩具有比A性花岗岩低的岩浆结晶温度,属于高分异的I型花岗岩,来源于新生地壳部分熔融;二长花岗岩和花岗闪长岩整体具有较高的岩浆结晶温度,属于壳幔混源的I型花岗岩。接特布调地区在早二叠-早三叠世处于高温、低压、地壳减薄的后造山伸展的陆内演化阶段。 展开更多
关键词 接特布调岩体 地球化学 U-PB年代学 LU-HF同位素 I型花岗岩 后造山 西准噶尔
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西准噶尔晚古生代地壳组成与生长:来自Sr-Nd-Pb同位素填图的证据 被引量:7
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作者 徐盛林 丁伟翠 +5 位作者 陈宣华 李廷栋 韩乐乐 刘勇 马飞宙 王叶 《地学前缘》 EI CAS CSCD 北大核心 2022年第2期261-280,共20页
西准噶尔地区晚古生代岩浆活动剧烈,地壳的垂向和侧向增生显著,地壳生长和演化存在多阶段性。本文重点通过Sr-Nd-Pb同位素填图研究,发现西准噶尔地区ε_(Nd)(t)值为2.29~8.75,(^(87)Sr/^(86)Sr)_(i)值为0.697397~0.708336,(^(206)Pb/^(2... 西准噶尔地区晚古生代岩浆活动剧烈,地壳的垂向和侧向增生显著,地壳生长和演化存在多阶段性。本文重点通过Sr-Nd-Pb同位素填图研究,发现西准噶尔地区ε_(Nd)(t)值为2.29~8.75,(^(87)Sr/^(86)Sr)_(i)值为0.697397~0.708336,(^(206)Pb/^(204)Pb)_(i)值为17.4975~19.0352,整体表现为高正ε_(Nd)(t)、低(^(87)Sr/^(86)Sr)_(i)和年轻的地壳模式年龄特征,源区以古生代新生地壳为主,地幔贡献值整体大于50%,深部地壳几乎不存在古老的结晶基底,可以与区域构造地质、地球物理资料作较好匹配。区域晚古生代主要经历3个时期的造山阶段,分别对应造山带演化的第一阶段(中晚石炭世,岛弧为代表的侧向生长为主)、第二阶段早期(晚石炭世—早二叠世,后碰撞阶段的垂向生长为主)和第二阶段晚期(早二叠世—早三叠世,壳幔混源背景下的垂向生长),区域造山作用结束于早三叠世。 展开更多
关键词 晚古生代 同位素填图 地壳组成 地壳生长 造山演化 西准噶尔
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地质图数据库现状与地质制图发展趋势 被引量:6
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作者 杨星辰 吴珍汉 +7 位作者 张素梅 高曦 韩乐乐 丁伟翠 杨艳 张宇 叶梦旎 杨亚琦 《高校地质学报》 CAS CSCD 北大核心 2020年第1期100-110,共11页
地质图是地质信息最重要的载体之一,凝聚了人们对地质理论的研究成果和对地质过程的理解。随着大数据时代的到来,地质制图的指导理论和方法手段发生了翻天覆地的变化,全球的科学家运用新方法新技术建立了OneGeology、OpenGeoscience、NG... 地质图是地质信息最重要的载体之一,凝聚了人们对地质理论的研究成果和对地质过程的理解。随着大数据时代的到来,地质制图的指导理论和方法手段发生了翻天覆地的变化,全球的科学家运用新方法新技术建立了OneGeology、OpenGeoscience、NGMDB、地质云等一系列地质图相关的优秀数据库,这些数据库的有效运行为全球的地质工作者提供了海量的地学数据和便捷的信息服务。此次研究重点调研了国内外已有的地质图相关数据库及运行情况,为Deep-Time Digital Earth(DDE)计划整合全球地质图相关数据库、建设相关数据平台提供经验和基础;同时,回顾了地质制图的发展历史,介绍了与地质制图相关的技术手段和常用软件;最后,为了满足大数据时代经济社会对地质图信息资料服务的需求,结合DDE相关任务,对深化国际合作编图、创新计算机智能地质制图及网络共享服务等核心技术提出了新的展望。 展开更多
关键词 地质图 数据库 地质制图 GIS
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构造高差分析原理及其在地学研究中的应用 被引量:1
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作者 陈宣华 陈正乐 +4 位作者 邵兆刚 张义平 李冰 丁伟翠 王叶 《地质学报》 EI CAS CSCD 北大核心 2022年第1期284-296,共13页
构造高差分析是构造解析及平衡剖面制作与恢复的基础。长期以来,构造高差并没有一个严格的定义,也缺乏原理性描述;构造高差分析也主要局限在构造地貌和地形高差的分析。本文在分析前人有关构造解析、地貌高差和构造高差研究的基础上,提... 构造高差分析是构造解析及平衡剖面制作与恢复的基础。长期以来,构造高差并没有一个严格的定义,也缺乏原理性描述;构造高差分析也主要局限在构造地貌和地形高差的分析。本文在分析前人有关构造解析、地貌高差和构造高差研究的基础上,提出构造高程概念,将构造高差定义为构造高程之差,拓展了构造高差的内涵;并将构造高程定义为地质点所在构造形成时的有效深度,通常用相对高程的负值来表示。提出构造高差分析的基本理念,将构造高差的本质理解为构造势能,赋予其时间和空间涵义。由此给出了构造高差的估算方法,以及不同构造环境下构造高程的厘定与构造高差的分析原则,探讨了构造高差的形成与地质作用过程之间的关系。本文提出的构造高差理论拓展了传统构造地质学关于构造高差的认识,为构造高差分析在地球科学研究中的拓展应用给出了理论基础。 展开更多
关键词 构造解析 构造高程 构造高差 构造变形 平衡剖面
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柴达木盆地西部岩石圈电性结构研究 被引量:1
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作者 徐盛林 邵兆刚 +7 位作者 李冰 陈宣华 王振东 徐大兴 马英 丁伟翠 周鹏超 王叶 《地质通报》 CAS CSCD 北大核心 2024年第11期1907-1920,共14页
柴达木盆地油气、矿产等资源丰富,其成因演化、物质组成和深部结构特征在青藏高原地质研究中更是举足轻重。大地电磁测深作为研究岩石圈电性结构的重要方法之一,可以为盆地动力学、资源勘查、矿床成因研究等提供重要支撑。在柴达木盆地... 柴达木盆地油气、矿产等资源丰富,其成因演化、物质组成和深部结构特征在青藏高原地质研究中更是举足轻重。大地电磁测深作为研究岩石圈电性结构的重要方法之一,可以为盆地动力学、资源勘查、矿床成因研究等提供重要支撑。在柴达木盆地西部的油泉子—花海子地区,布设了一条长约255 km的(超)宽频大地电磁测深测线,并获得二维反演剖面,结合区域地质资料和已有的地球化学、地球物理等研究成果,初步分析了研究区岩石圈尺度各重点电性层的构造意义。柴达木盆地西部新生界发育上、下2个变形强度不同的电性层,上部变形较弱的电性层含一套低于2Ω·m的超低阻层,与盆地深层优质卤水层对应,指示了良好的深层卤水找矿前景;下部电性层变形较强烈,底部可见一套生长电性层,推测盆地深部存在的主柴达木拆离断层在新生代控制了盆地的新生界沉积与构造变形。研究区深部电性结构差异明显,深部约50 km处有一条高低起伏的电性莫霍面,柴达木和苏干湖盆地深部以中低阻体为主,赛什腾山地区为有根的高阻体,油泉子—碱山地区中—下地壳为一套低阻体,昆特依地区深部可能存在软流圈物质的上涌。 展开更多
关键词 柴达木盆地西部 赛什腾山 大地电磁测深 电性结构 深层卤水找矿
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甘肃龙首山—合黎山晚志留世—早泥盆世花岗岩类的成因及其对阿拉善地块西南缘早古生代构造演化的约束 被引量:9
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作者 王增振 陈宣华 +7 位作者 邵兆刚 李冰 丁伟翠 张义平 王永超 张垚垚 徐盛林 秦翔 《地质学报》 EI CAS CSCD 北大核心 2020年第8期2243-2261,共19页
阿拉善地块西南缘在中志留世—早泥盆世究竟是处于古亚洲洋俯冲的构造环境,还是因受控于祁连造山带而处于后碰撞伸展环境?这是探讨该区早古生代构造演化不可回避的重要科学问题。阿拉善地块西南缘出露的早古生代岩浆岩是探讨该问题的重... 阿拉善地块西南缘在中志留世—早泥盆世究竟是处于古亚洲洋俯冲的构造环境,还是因受控于祁连造山带而处于后碰撞伸展环境?这是探讨该区早古生代构造演化不可回避的重要科学问题。阿拉善地块西南缘出露的早古生代岩浆岩是探讨该问题的重要研究对象,但前人的工作集中于北大山和龙首山的东段。本文在龙首山西段及更西部的合黎山地区选择三个花岗岩体进行了LA-ICP-MS锆石U-Pb定年和元素及同位素地球化学研究。结果表明,龙首山西段的大佛寺碱性长石花岗岩形成于晚志留世(426±2 Ma),主量元素具有高SiO2(78.03%)、富碱(ALK=7.96%)、低CaO(0.60%)、贫MgO(0.13%)的特征,稀土分布呈明显的"V"型,大离子亲石元素(LILEs)高度富集而高场强元素(HFSEs)中等富集,Ba、Sr、Eu负异常显著,属于铝质A2型花岗岩。合黎山地区的五坝黑云母花岗岩和张家窑花岗闪长岩分别形成于晚志留世(421±2 Ma)和早泥盆世(406±4 Ma),都属于高钾钙碱性I型花岗岩,轻、重稀土分异((La/Yb)N=10.69~13.79),Eu负异常显著(δEu=0.56~0.77),LILEs富集,HFSEs亏损,Nb、Ta负异常和Zr、Hf正异常同时出现。此外,三个岩体的岩浆源区均显示富集型Sr-Nd同位素特征,具有中元古代的二阶段Nd模式年龄,暗示中元古代地壳物质在不同温度下的部分熔融。结合区域资料,阿拉善地块西南缘中志留世—早泥盆世具有钙碱性—高钾钙碱性I型花岗岩、铝质A2型花岗岩和碱性—过碱性花岗岩的岩石组合,指示后碰撞伸展环境,而该区早古生代俯冲阶段(中奥陶世—早志留世;ca.461~441 Ma)和后碰撞阶段(中志留世—早泥盆世;ca.432~397 Ma)的划分与祁连造山带的构造演化是可对比的。 展开更多
关键词 阿拉善地块西南缘 早古生代 花岗岩 岩石成因 大地构造背景
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西准噶尔红山地区晚古生代赞岐岩锆石U-Pb年代学、地球化学特征及其地质意义 被引量:9
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作者 马飞宙 陈宣华 +4 位作者 徐盛林 马芬 韩乐乐 丁伟翠 王叶 《地质学报》 EI CAS CSCD 北大核心 2020年第5期1462-1481,共20页
中亚造山带西部西准噶尔地区红山花岗岩体内部发育多期似岩墙状安山质暗色条带,LA-ICP-MS锆石U-Pb同位素定年和岩石化学与同位素分析表明,它们具有不同的形成年龄、相同的源区和相似的形成过程。其中,具有不规则状或环状形态的暗色条带... 中亚造山带西部西准噶尔地区红山花岗岩体内部发育多期似岩墙状安山质暗色条带,LA-ICP-MS锆石U-Pb同位素定年和岩石化学与同位素分析表明,它们具有不同的形成年龄、相同的源区和相似的形成过程。其中,具有不规则状或环状形态的暗色条带,其锆石U-Pb年龄为319.1±2.9 Ma和313.3±2.4 Ma,远大于红山岩体花岗岩锆石结晶年龄(305~301Ma),可能是红山岩体侵位过程中所捕掳的围岩;具有线性展布特征的安山质暗色条带,其锆石U-Pb年龄为295±2Ma,形成于红山岩体侵位之后,构成伸展岩墙群。红山岩体中的安山质暗色条带和线状岩墙群具有相似的岩石化学组成,富SiO2(56.48%~63.09%)、MgO(3.56%~6.31%),具有高的Mg#值(51.74~62.40)及Na2O/K2O值(1.34~3.43);球粒陨石标准化稀土元素(REE)配分模式呈明显的右倾型,富集轻稀土元素(LREE)和大离子亲石元素(LILE)Rb、K、Ba、U、Sr,亏损高场强元素(HFSE)Th、Nb、Ce、P和重稀土元素,具较弱的负铕异常;其同位素组成特征为(87 Sr/86 Sr)i=0.703295~0.703620,(143 Nd/144 Nd)i=0.512612~0.512618,εNd(t)=6.91~7.62,(206 Pb/204 Pb)t为17.6883~17.9876,(207 Pb/204 Pb)t为15.5313~15.5686,(208Pb/204Pb)t为37.4460~38.0581。它们具有与赞岐岩类似的地球化学特征,总体表现出与弧岩浆作用相关的地球化学特征,可能具有共同的物质来源,为准噶尔洋板片俯冲消减后同一地幔源区在不同阶段的产物。其中,形成于弧岩浆作用时期的赞岐岩(319~313 Ma),构成与岛弧花岗岩类伴生的环状似岩墙状安山质暗色条带;形成于后造山伸展岩浆作用晚期的赞岐岩(~295Ma),构成与达拉布特左行走滑作用相关的陆内伸展岩墙群。安山质暗色条带(岛弧火山作用)、红山岩体(后造山伸展)和线状岩墙群(陆内伸展)记录了西准噶尔红山地区洋陆转换的全过程。 展开更多
关键词 赞岐岩 LA-ICP-MS锆石U-PB年龄 Sr-Nd-Pb同位素示踪 洋陆转换 西准噶尔 中亚造山带
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北山南部西山煤窑地区晚中生代陆内构造变形特征与时限约束 被引量:3
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作者 韩乐乐 陈宣华 +7 位作者 邵兆刚 丁伟翠 张义平 李冰 徐盛林 王叶 刘奎 杨欣茹 《地质通报》 CAS CSCD 北大核心 2024年第11期1950-1969,共20页
北山南部西山煤窑地区侏罗系与白垩系的构造变形记录了中亚地区晚中生代的主要构造演化过程,对揭示中亚地区的陆内变形具有重要意义。综合应用遥感影像、野外地质观测、构造解析及磷灰石(U-Th)/He(AHe)年代学方法,对北山南部西山煤窑地... 北山南部西山煤窑地区侏罗系与白垩系的构造变形记录了中亚地区晚中生代的主要构造演化过程,对揭示中亚地区的陆内变形具有重要意义。综合应用遥感影像、野外地质观测、构造解析及磷灰石(U-Th)/He(AHe)年代学方法,对北山南部西山煤窑地区的构造变形特征及时限进行了详细分析,并在此基础上探讨了动力学机制。西山煤窑地区发育逆冲推覆构造,以二叠纪花岗岩和晚石炭世辉长岩NE向逆冲至下—中侏罗统煤系地层之上为特征,上盘岩系经历剥蚀形成飞来峰,下盘发育叠瓦状逆冲断层,逆冲推覆距离约10 km。晚石炭世辉长岩的磷灰石AHe年龄显示160~130 Ma的快速冷却事件,指示该地区经历了中晚侏罗世—早白垩世早期的挤压变形,可能是亚洲南缘班公-怒江洋与北缘蒙古-鄂霍茨克洋闭合的远程效应。变形的侏罗系的AHe年龄(120~100 Ma)揭示了早白垩世晚期的隆升事件。结合区域构造事件,表明研究区经历了早白垩世晚期的伸展断陷,可能与早期地壳增厚的伸展垮塌作用有关。晚白垩世之后,正断层反转为逆冲断层,将变形的侏罗系与上覆岩系共同压覆在下白垩统之上,指示北山南部构造背景由伸展转为挤压,局部地区经历了弱挤压变形,并改造了先存挤压与伸展构造。 展开更多
关键词 北山南部 晚中生代 陆内构造变形 构造解析 磷灰石U-Th/He定年
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Construction of the Continental Asia in Phanerozoic:A Review 被引量:17
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作者 CHEN Xuanhua DONG Shuwen +5 位作者 SHI Wei ding weicui ZHANG Yiping LI Bing SHAO Zhaogang WANG Ye 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2022年第1期26-51,共26页
This is a review of the formation and tectonic evolution of the continental Asia in Phanerozoic.The continental Asia has formed on the bases of some pre-Cambrian cratons,such as the Siberia,India,Arabia,North China,Ta... This is a review of the formation and tectonic evolution of the continental Asia in Phanerozoic.The continental Asia has formed on the bases of some pre-Cambrian cratons,such as the Siberia,India,Arabia,North China,Tarim,South China,and Indochina,through multi-stage plate convergence and collisional collages in Phanerozoic.The north-central Asia had experienced the expansion and subduction of the Paleo-Asian Ocean(PAO)in the early Paleozoic and the closure of the PAO in the late Paleozoic and early Mesozoic,forming the PAO regime and Central Asian orogenic belt(CAOB).In the core of the CAOB,the Mongol-Okhotsk Ocean(MOO)opened with limited expansion in the Early Permian and finally closed in the Late Jurassic–Early Cretaceous.The south-central Asia had experienced mainly multi-stage oceanic opening,subduction and collision evolution in the Tethys Ocean,forming the Tethys regime and Himalaya-Tibetan orogenic belt.In eastern Asia,the plate subduction and continental margin orogeny on western margin of the Pacific Ocean,forms the West Pacific regime and West Pacific orogenic belt.The PAO,Tethys,and West Pacific regimes,together with Precambrian cratons among or surrounding them,made up the major tectonic and dynamic systems of the continental Asia in Phanerozoic.Major tectonic events,such as the Early Paleozoic Qilian,Uralian,and Dunhuang orogeneses,the late Paleozoic East Junggar,Tianshan and West Junggar orogeneses,the Middle to Late Permian Ailaoshan orogeny and NorthSouth Lhasa collision,the early Mesozoic Indochina-South China and North-South China collisions,the late Mesozoic Mongolia-Okhotsk orogeny,Lhasa-Qiangtang collision,and intra-continental Yanshanian orogeny,and the Cenozoic IndoAsian,Arab-Asian,and West Pacific margin collisions,constrained the formation and evolution of the continental Asia.The complex dynamic systems have left large number of deformation features,such as large-scale strike-slip faults,thrustfold systems and extensional detachments on the continental Asia.Based on past tectonics,a future supercontinent,the Ameurasia,is prospected for the development of the Asia in ca.250 Myr. 展开更多
关键词 Paleo-Asian Ocean TETHYS West Pacific tectonic events geodynamic systems continental Asia PHANEROZOIC
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The Late Carboniferous–Early Permian Ocean-Continent Transition in the West Junggar,Central Asian Orogenic Belt: Constraints from Columnar Jointed Rhyolite 被引量:11
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作者 XU Shenglin CHEN Xuanhua +7 位作者 LI Tingdong SHI Jianjie ding weicui LI Bing HUANG Penghui ZHANG Yiping ZHANG Yaoyao MA Feizhou 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2019年第2期265-282,共18页
The West Junggar of the western Central Asian Orogenic Belt is one of the typical regions in the term of ocean subduction, contraction and continental growth in the Late Paleozoic. However, it is still controversial o... The West Junggar of the western Central Asian Orogenic Belt is one of the typical regions in the term of ocean subduction, contraction and continental growth in the Late Paleozoic. However, it is still controversial on the exact time of ocean-continent transition so far. This study investigates rhyolites with columnar joint in the West Junggar for the first time.Based on zircon U-Pb dating, we determined that the ages of the newly-discovered rhyolites are between 303.6 and 294.5 Ma, belonging to Late Carboniferous–Early Permian, which is the oldest rhyolite with columnar joint preserved in the world at present. Geochemical results show that the characteristics of the major element compositions include a high content of SiO_2(75.78–79.20 wt%) and a moderate content of Al_2O_3(12.21–13.19 wt%). The total alkali content(K_2O +Na_2O) is 6.14–8.05 wt%, among which K_2O is 2.09–4.72 wt% and the rate of K_2O/Na_2O is 0.38–3.05. Over-based minerals such as Ne, Lc, and Ac do not appear. The contents of TiO_2(0.09–0.24 wt%), CaO(0.15–0.99 wt%) and MgO(0.06–0.18 wt%) are low. A/CNK=0.91–1.68, A/NK=1.06–1.76, and as such, these are associated with the quasi-aluminum-weak peraluminous high potassium calc-alkaline and some calc-alkaline magma series. These rhyolites show a significant negative Eu anomaly with relative enrichment of LREE and LILE(Rb, Ba, Th, U, K) and depletion of Sr, HREE and HFSE(Nb, Ta, Ti, P). These rhyolites also have the characteristics of an A2-type granite, similar to the Miaoergou batholith,which indicates they both were affected by post-orogenic extension. Combining petrological, zircon U-Pb dating and geochemical characteristics of the rhyolites, we conclude that the specific time of ocean-continent transition of the West Junggar is the Late Carboniferous–Early Permian. 展开更多
关键词 RHYOLITE columnar joint zircon U-Pb dating geochemistry ocean-continent TRANSITION West JUNGGAR
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Phanerozoic Tectonic Evolution,Metallogenesis and Formation of Mineral Systems in China 被引量:9
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作者 CHEN Xuanhua HAN Lele +6 位作者 ding weicui XU Shenglin TONG Ying ZHANG Yiping LI Bing ZHOU Qi WANG Ye 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2024年第4期819-842,共24页
The continental Asia is mainly composed of three major tectonic regimes,the Tethys,Paleo Asian Ocean,and West Pacific.It underwent multi-stage plate convergences,ocean-continent transformations,and subductions,collisi... The continental Asia is mainly composed of three major tectonic regimes,the Tethys,Paleo Asian Ocean,and West Pacific.It underwent multi-stage plate convergences,ocean-continent transformations,and subductions,collisions and/or collages,and post collisional(orogenic)extensions in Phanerozoic.Tectonic evolution of the Asia brings up a unique fault system and tectonic geomorphological features in the China's Mainland.Also,it provides a geodynamic background for the formation and evolution of metallogeneses and mineral systems,resulting in nonuniform distribution of tectono-metallogenic systems and metallogenic belts.The spatiotemporal distribution of mineral deposits in China and adjacent areas exhibits periodic variation under controlling of the full life Wilson cycle and tectonic evolution,forming the plate convergence-related mineral system in East Asia.Porphyry Cu deposits are mainly related to compressional systems in Paleozoic and early Mesozoic,and more closely related to post-collision extensional settings in late Mesozoic and Cenozoic.Orogenic Au deposits mainly formed in post-orogeny extensional setting.Alkaline rock related rare earth element deposits formed mainly at margins of the North China and Yangtze cratons.Granite-pegmatite Li and other rare metal deposits formed mainly in early Mesozoic,related to Indosinian post-orogeny extension.Tectono-metallogenic systems provide important basis for the prospecting of mineral resources. 展开更多
关键词 tectonic evolution geodynamic system post-orogenic extension METALLOGENESIS tectono-metallogenic system East Asia
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Early Cretaceous Thrust and Nappe Tectonics in North Qilian Shan,Northern Tibetan Plateau:Evidence from Field Mapping,Geochronology,and Deep Structural Analysis 被引量:5
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作者 HAN Lele ding weicui +9 位作者 CHEN Xuanhua SHAO Zhaogang ZHANG Da XIAO Yongjun HE Chengguang WANG Zengzhen LI Bing ZHANG Yiping XU Shenglin WANG Ye 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2023年第4期1058-1077,共20页
The North Qilian Shan fold and thrust belt,located at the northern Tibetan Plateau and southern margin of the Hexi Corridor,is a key tectonic unit to decode the formation and expansion of the plateau.Previous studies ... The North Qilian Shan fold and thrust belt,located at the northern Tibetan Plateau and southern margin of the Hexi Corridor,is a key tectonic unit to decode the formation and expansion of the plateau.Previous studies emphasize the Cenozoic deformation due to the far-field response to the Indo-Asian collision,but the Mesozoic deformations are poorly constrained in this area.We conducted detailed field mapping,structural analysis,geochronology,and structural interpretation of deep seismic reflectional profiling and magnetotelluric(MT)sounding,to address the superposed results of the Mesozoic and Cenozoic deformation.The results recognized the North Qilian thrust and nappe system(NQTS),the root and the frontal belt are the North Qilian thrust(NQT),and the Yumu Shan klippe(YK),respectively.The middle belt is located between the NQT and the YK.Monzonitic granite zircon U-Pb dating from the middle belt yields an age of ca.415 Ma,which is similar to south NQT.The thrusting displacement is estimated at ca.48 km by structural interpretation of deep profiles.The timing is constrained in the early stage of the Early Cretaceous by the formation of simultaneous growth strata.We suggest that the NQTS has resulted from the far-field effect of the Lhasa-Qiangtang collision,and the Yumu Shan is uplifted by the superposed Cenozoic deformation. 展开更多
关键词 GEOCHRONOLOGY structural analysis seismic reflectional and MT profiling Early Cretaceous North Qilian thrust and nappe system Tibetan Plateau
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Digital Geological Mapping of Sinus Iridum Area of the Moon Based on the Chang'E-I Data 被引量:3
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作者 ding Xiaozhong HAN Kunying +4 位作者 PANG Jianfeng WANG Liang HAN Tonglin JU Yuanjing ding weicui 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2013年第6期1643-1657,共15页
Based on the CCD images,IIM data and DEM data of China's lunar exploration project (Chang'E-Ⅰ) and related processed and analytic results,an integrated study of regional geology of Sinus Iridum and its adjacent a... Based on the CCD images,IIM data and DEM data of China's lunar exploration project (Chang'E-Ⅰ) and related processed and analytic results,an integrated study of regional geology of Sinus Iridum and its adjacent area was conducted,and a series of relevant researches and analyses were carried out,including analysis of impact craters and their extrusive and accumulative materials,division of stratigraphic and tectonic units and classification of rock types,integrated analysis of chronology and lunar evolution history.In consideration of crater's shape features,quantity and preserving status of filling materials,the lunar impact craters can be divided into 7 types and 11 subtypes,and the accumulative materials of craters are divided into 6 types and 9 accumulative groups.According to the content and distribution of TiO2 and image characteristics,the basalts are divided into high-TiO2,medium-TiO2 and low-TiO2 basalts.Discussion was made on division of tectonic units and evolution features in the study area.The geological map of the Sinus Iridum Quadrangle (LQ-4) at a scale of 1∶2.5 M was preliminarily compiled with the ArcGIS system,and the spatial database of the map was established.Related technical specification,procedure and method for lunar geological mapping have been worked out,so as to lay a foundation for the forthcoming geological mapping of the global Moon in China by using the data of Chang'E-Ⅱ and also for comprehensive study and geological mapping of other celestial bodies in the future. 展开更多
关键词 The Moon Sinus Iridum Area Chang'E-Ⅰ geological mapping geological map database
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Late Paleozoic Element Migration and Accumulation under Intracontinental Sinistral Strike-slip Faulting in the West Junggar Orogenic Belt, NW China 被引量:2
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作者 WANG Ye CHEN Xuanhua +5 位作者 NIE Lanshi ding weicui WANG Xueqiu XU Shenglin MA Feizhou HAN Lele 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2020年第6期2012-2030,共19页
The migration,accumulation and dispersion of elements caused by tectonic dynamics have always been a focus of attention,and become the basis of tectono-geochemistry.However,the effects of faulting,especially strike-sl... The migration,accumulation and dispersion of elements caused by tectonic dynamics have always been a focus of attention,and become the basis of tectono-geochemistry.However,the effects of faulting,especially strike-slip faulting,on the adjustment of geochemical element distribution,are still not clear.In this paper,we select the West Junggar Orogenic Belt(WJOB),NW China,as a case study to test the migration behavior of elements under tectonic dynamics.The WJOB is dominated by NE-trending large-scale sinistral strike-slip faults such as the Darabut Fault,the Mayile Fault,and the Baerluke Fault,which formed during the intracontinental adjustment under N-S compression during ocean-continental conversion in the Late Paleozoic.Geochemical maps of 13 elements,Al,W,Sn,Mo,Cu,Pb,Zn,As,Sb,Hg,Fe,Ni,and Au,are analyzed for the effects of faulting and folding on element distribution at the regional scale.The results show that the element distribution in the WJOB is controlled mainly by two mechanisms during tectonic deformation:first is the material transporting mechanism,where the movement of geological units is consistent with the direction of tectonic movement;second is the diffusion mechanism,especially by tectonic pressure dissolution driven by tectonic dynamics,where the migration of elements is approximately perpendicular or opposite to the direction of tectonic movement.We conclude that the adjustment of element distributions has been determined by the combined actions of transporting and diffusion mechanisms,and that the diffusion mechanism plays an important role in the formation of geochemical Au blocks in the WJOB. 展开更多
关键词 tectono-geochemistry strike-slip fault system element distribution GOLD West Junggar Central Asian Orogenic Belt
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白龙江舟曲段泥石流孕灾条件及发育特征分析
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作者 杨强 王高峰 +2 位作者 杨旭东 丁伟翠 高幼龙 《城市地质》 2022年第1期43-49,共7页
白龙江流域舟曲段是泥石流灾害高易发区和重点防治区,掌握该区泥石流的孕灾背景条件及发育特征对泥石流灾害防治具有重要现实意义。基于白龙江舟曲段241条泥石流调查数据,从地形地貌、地层岩性及致灾岩组、地质构造、降雨及人类工程活... 白龙江流域舟曲段是泥石流灾害高易发区和重点防治区,掌握该区泥石流的孕灾背景条件及发育特征对泥石流灾害防治具有重要现实意义。基于白龙江舟曲段241条泥石流调查数据,从地形地貌、地层岩性及致灾岩组、地质构造、降雨及人类工程活动等方面分析了泥石流孕灾背景条件;应用数理统计的方法,从流域面积与主沟长、沟床比降与相对高差、泥石流沟完整系数、重点泥石流沟发展阶段4个方面探讨了泥石流发育特征。研究结果表明:(1)舟曲段泥石流流域面积小于20 km^(2)占泥石流总数的89.2%,主沟长度主要集中在1~5 km,沟床比降200‰~500‰占泥石流总数的60.2%、大于500‰占泥石流总数33.2%;(2)泥石流相对高差主要集中在500~2000 m,泥石流流域形态主要为长圆形和椭圆形;(3)21条重点泥石流沟均处于幼年—壮年期,潜在危险性巨大。 展开更多
关键词 白龙江舟曲段 泥石流 物源 孕灾条件 发育特征
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