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MINERALIZATION AGES OF GOLD-HYDROTHERMAL DEPOSITS IN NORTHERN ZONE OF EASTERN KUNLUN MOUNTAINS BASED ON FISSION TRACK ANALYSIS 被引量:4
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作者 Yuan Wanming 1,Wang Shicheng 1,Mo Xuanxue 2,Wang Lanfen 1 2 China University of Geosciences, Beijing 100083,China) 《地学前缘》 EI CAS CSCD 2000年第S1期329-330,共2页
The age of mineralization in a mining area is a primary factor in various researches related to ore\|forming process. It is that the uncertainty of mineralization ages of gold ore deposits in northern zone of eastern ... The age of mineralization in a mining area is a primary factor in various researches related to ore\|forming process. It is that the uncertainty of mineralization ages of gold ore deposits in northern zone of eastern Kunlun Mountains, Qinghai Province, restrains to probe the relationship of the deposits to the regional tectonic evolution. This paper documents the fission track method used to determine the ages of gold ore deposits in eastern Kunlun Mountains and considers the implication for the origin of the deposits.Eastern Kunlun Mountains is the northern part of the Qinghai—Tibet Plateau and is of three deep\|seated fault belts in about EW extension. This work mainly includes three gold ore districts. All of them, in the north of Mid\|Kunlun fault belt, belong to northern part of eastern Kunlun Mountains. The Yanjingou district, with geographical coordinate 96°00’E and 36°10’N, is located 60 km north of Hongqigou district . Both of them are large, typical tectonoalteration gold deposits and were formed in similar geological setting. Hongshuihe ore district is located 50 km east of Yanjingou district and includes tectonoalteration and magmatic cryptoexplosive gold deposits. Outcroped strata are dominantly Jinshuikou Group metamorphic rocks of Lower Proterozoic erathem. The occurrence area of igneous rocks, especially granitoid, accounts for about 90% in first two districts and become less in Hongshuihe district. The gold deposits occur in NW\|striking fault belts. The Rb\|Sr isochron age and K\|Ar isotopic age of Moyite relevant to the gold mineralization are respectively 228 25Ma and 207 1Ma. Rb\|Sr dating of diorite porphyrite is 209 09Ma. Sericite selected from Yanjingou orebody has 252 9Ma K\|Ar age. The ore in Hongqigou district has 197Ma K\|Ar age and 210Ma model age of Pb isotope of galena. 展开更多
关键词 MINERALIZATION age thermal event FISSION TRACK thermochron ology FISSION TRACK analysis EASTERN KUNLUN mountains
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Ediacarian Volcanic Rocks and Basic Dikes from the Lac Ifni Sector of the Central High Atlas Mountains:Petrographic Studies and Clinopyroxene Chemical Composition
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作者 Sad Belkacim M.Ikenne +3 位作者 S.Arai H.Gahlan A Ahmed Hassan Y.Ishida 《地学前缘》 EI CAS CSCD 北大核心 2009年第S1期198-198,共1页
The Ediacarian volcanic series from the Lac Ifni sector are composed of a large variety of rocks from basalts and rhyolites to intermediates facies such as andesites,rhyodacites and pyroclastites.All these rocks are i... The Ediacarian volcanic series from the Lac Ifni sector are composed of a large variety of rocks from basalts and rhyolites to intermediates facies such as andesites,rhyodacites and pyroclastites.All these rocks are intruded by dolerite dikes.Secondary processes are reflected by total serpentinization of olivine within basic andesite and by albitization 展开更多
关键词 High ATLAS mountains Anti ATLAS mountains volcanism Ediacarian CLINOPYROXENE ICP-MS Laser OROGENIC calc-alcaline THOLEIITIC
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CHEMICAL WEATHERING IN THE BATURA GLACIER BASIN, KARAKORAM MOUNTAINS
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作者 Wang Ninglian 1, Yao Tandong 1,Fu Zongtang 2,Yang Zhiqiang 3 2 China University of Geosciences, Beijing 100083,China 3 Xi’an College of Geology, Xi’an 710054 《地学前缘》 EI CAS CSCD 2000年第S1期440-440,共1页
Glacially driven chemical weathering could make concentration of CO\-2 in the atmosphere decrease, and the process might play a significant role in climate change and the carbon cycle. So the study of chemical compone... Glacially driven chemical weathering could make concentration of CO\-2 in the atmosphere decrease, and the process might play a significant role in climate change and the carbon cycle. So the study of chemical components and their contents of glacial meltwater in an alpine glacier\|covered catchment has important geochemical and climatological significance. 展开更多
关键词 CHEMICAL WEATHERING KARAKORAM mountains Batura GLACIER BASIN
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SIGNIFICANCE AND CHARACTERISTICS OF OPHIOLITE SUITE IN LAJI SHAN, SOUTHERN QILIAN MOUNTAINS, QINGHAI PROVINCE,CHINA
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作者 Yang Weiran,Deng Qinglu,Wu Xiulin (China University of Geosciences,Wuhan 430074,China) 《地学前缘》 EI CAS CSCD 2000年第S1期130-131,共2页
Laji Shan is located in the eastern part of Qinghai Province,sandwiched between Xining and Hualong Basins.It is about 250km long and 10~20km wide from Riyueshan in the west to Minheguanting in the east.Laji Shan belo... Laji Shan is located in the eastern part of Qinghai Province,sandwiched between Xining and Hualong Basins.It is about 250km long and 10~20km wide from Riyueshan in the west to Minheguanting in the east.Laji Shan belongs to the Caledonian orogenic belt.Its basement consists of the rocks of Palaeo\|Protero zoic Hualong Group (Pt 1 hl ) and Neo\|Proterozoic Huangzhong Group (Pt\-3 h ).There are ptygmatic folds,closely linear type folds,strongly structural d ifferentiation and schistosity developed,suggesting that the basement underwent deep seated ductile deformation.The main part of Laji Shan is composed of Early\|Palaeozoic marine facies volcanic rocks and clastic sedimentary rocks,and suffered greenschist facies metamorphism and brittle\|ductile deformation.Others are composed of Ea rly\|Palaeozoic basic and ultrabasic rocks,intermediate\|acidic intruded rocks a nd dike rocks.Devonian molasse formation in Laji Shan is in uncomfortable contac t with underlying strata.Jurassic and Cretaceous systems are intermont basin dep osits,corresponding to a cover. 展开更多
关键词 OPHIOLITE SUITE Qinghai—Xizang PLATEAU QILIAN mountains Laji Shan
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THE EVOLUTIONARY HISTORY OF THE WEST KUNLUN MOUNTAINS: A TECTONIC RECONSTRUCTION BASED ON STUDIES OF MAGMATISM
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作者 Yuan Chao 1,2 , Sun Min 2, Li Jiliang 3 2.Department of Earth Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China 3.Institut 《地学前缘》 EI CAS CSCD 2000年第S1期262-263,共2页
The Kunlun Mountains is situated in the north margin of the Tibetan plateau and is one of crucial areas for unraveling the tectonic evolutionary history of the plateau and Eurasia. However, there is no widely accepted... The Kunlun Mountains is situated in the north margin of the Tibetan plateau and is one of crucial areas for unraveling the tectonic evolutionary history of the plateau and Eurasia. However, there is no widely accepted model for this area. One of the reasons is that some basic issues for the tectonic reconstruction have not been well settled, they are: (1) Is the Kunlun Mountains an ancient accretion prism, or a mini continent with old basement?(2) What is the age of the Kudi ophiolite, early Paleozoic or late Paleozoic?(3) When did the South Kunlun Block accrete to the Tarim Block?(4) Do the fifth and the forth sutures represent different oceans, or they are just the chronologically different relics of the same ocean?(5) Did the Kunlun Mountains experience continuous subduction since Neoproterozoic?(6) When did the Paleo\|Tethys closed in the West Kunlun range? 展开更多
关键词 West KUNLUN mountains Proto\|Tethys Paleo\|Tethys BONINITE series rocks accretion prism magmatic gap TECTONIC RECONSTRUCTION
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DEFORMATIONAL AND METAMORPHIC HISTORY OF THE CENTRAL LONGMEN MOUNTAINS, SICHUAN CHINA
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作者 Chris J.L. Wilson 1, Brenton A. Worley 1, Shefa Chen 1, Mathew J. Harrowfield 1,Liu Shugen 2,Luo Zhili 2 2 Chengdu University of Technology, Chengdu 6 《地学前缘》 EI CAS CSCD 2000年第S1期273-274,共2页
The Longmen Mountains and adjacent regions on the eastern margin of the Tibetan plateau can be divided into three tectonic units: the eastern Songpan—Garzê fold belt, the Longmen Mountains (Longmen Shan) Thrust... The Longmen Mountains and adjacent regions on the eastern margin of the Tibetan plateau can be divided into three tectonic units: the eastern Songpan—Garzê fold belt, the Longmen Mountains (Longmen Shan) Thrust—Nappe belt and the Western Sichuan foreland basin that occupies the western part of the Sichuan basin. The Longmen Shan Thrust—Nappe belt is subdivided by six northwest\|dipping major listric thrusts, with accompanying duplexes and imbricate fans, into five large\|scale nappes (Chen & Wilson, 1996). In the inner Longmen Shan, the nappe units have incorporated both Mesoproterozoic basement and Sinian (Neoproterozoic) to Triassic cover sequences as “thick\|skinned" horses. Whereas, in the frontal Longmen Shan, Sinian to Cretaceous cover sediments have been stripped from the basement as “thin\|skinned" fold and thrust sheets, including extensively distributed klippen structures. Pre\|thrusting extension during Devonian to middle Late Triassic times resulted in syndepositional normal faults. Structural inversion of these faults initiated the “Peng Xian—Guan Xian basement complex", Jiuding Shan and Tangwangzhai nappes, during an early episode of the Indosinian Orogeny (Norian to Rhaetian). This was followed by episodic thrusting during latest Triassic to Early Cretaceous times to develop the Guan Xian—An Xian and Southeastern Marginal nappes that have incorporated sediments from the neighbouring foreland basin into the frontal part of the Thrust—Nappe belt. Differential thrusting occurred across the Thrust—Nappe belt during a Late Miocene reactivation of the pre\|existing faults. 展开更多
关键词 Longmen mountains Songpan—Garzê fold BELT Wenchuan—Mouwen SHEAR zone Wenchuan—Mouwen fault METAMORPHIC BELT transpressional SHEAR Himalayan OROGENY Indosinian OROGENY
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Statistical Downscaling Retrieval of Land Surface Temperature in an Area with Complex Landforms in the Eastern Qinling Mountains of China Based on Sentinel-2/3 Satellite Data
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作者 Yuan Yuan Zheng Wei +2 位作者 Zhao Shi-fa Meng Ming-xia Hu Juan 《Journal of Northeast Agricultural University(English Edition)》 CAS 2023年第3期60-68,共9页
The study of land surface temperature(LST)is of great significance for ecosystem monitoring and ecological environmental protection in the Qinling Mountains of China.In view of the contradicting spatial and temporal r... The study of land surface temperature(LST)is of great significance for ecosystem monitoring and ecological environmental protection in the Qinling Mountains of China.In view of the contradicting spatial and temporal resolutions in extracting LST from satellite remote sensing(RS)data,the areas with complex landforms of the Eastern Qinling Mountains were selected as the research targets to establish the correlation between the normalized difference vegetation index(NDVI)and LST.Detailed information on the surface features and temporal changes in the land surface was provided by Sentinel-2 and Sentinel-3,respectively.Based on the statistically downscaling method,the spatial scale could be decreased from 1000 m to 10 m,and LST with a Sentinel-3 temporal resolution and a 10 m spatial resolution could be retrieved.Comparing the 1 km resolution Sentinel-3 LST with the downscaling results,the 10 m LST downscaling data could accurately reflect the spatial distribution of the thermal characteristics of the original LST image.Moreover,the surface temperature data with a 10 m high spatial resolution had clear texture and obvious geomorphic features that could depict the detailed information of the ground features.The results showed that the average error was 5 K on April 16,2019 and 2.6 K on July 15,2019.The smaller error values indicated the higher vegetation coverage of summer downscaling result with the highest level on July 15. 展开更多
关键词 Eastern Qinling mountains Sentinel-2/3 land surface temperature statistical downscaling
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造山带中成对出现的高压麻粒岩与榴辉岩及其地球动力学意义 被引量:50
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作者 张建新 于胜尧 +1 位作者 孟繁聪 李金平 《岩石学报》 SCIE CAS CSCD 北大核心 2009年第9期2224-2234,共11页
在一些典型碰撞造山带中,高压麻粒岩与榴辉岩在空间和时间上密切相关,它们之间的关系对揭示碰撞造山带的造山过程和造山机制具有重要意义。本文以中国西部的南阿尔金、柴北缘及中部的北秦岭造山带为例,详细陈述了这3个地区榴辉岩和相关... 在一些典型碰撞造山带中,高压麻粒岩与榴辉岩在空间和时间上密切相关,它们之间的关系对揭示碰撞造山带的造山过程和造山机制具有重要意义。本文以中国西部的南阿尔金、柴北缘及中部的北秦岭造山带为例,详细陈述了这3个地区榴辉岩和相关的高压麻粒岩的野外关系、变质演化和形成时代,目的是要建立大陆碰撞造山带中榴辉岩和相关高压麻粒岩形成的地球动力学背景模式。南阿尔金榴辉岩呈近东西向分布在江尕勒萨依-玉石矿沟一带,与含夕线石副片麻岩、花岗质片麻岩和少量大理岩构成榴辉岩-片麻岩单元,榴辉岩中含有柯石英假象,其峰期变质条件为P=2.8~3.0GPa,T=730~850℃,并在抬升过程中经历了角闪岩-麻粒岩相的叠加;大量年代学研究显示其峰期变质时代为485~500Ma。南阿尔金高压麻粒岩分布在巴什瓦克地区,包括高压基性麻粒岩和高压长英质麻粒岩,它们与超基性岩构成了一个大约5km宽的构造岩石单元,与周围角闪岩相的片麻岩为韧性剪切带接触。长英质麻粒岩和基性麻粒岩的峰期组合均具有蓝晶石和三元长石(已变成条纹长石),形成的温压条件为T=930~1020℃,P=1.8~2.5GPa,并在退变质过程中经历了中压麻粒岩相变质作用叠加。锆石SHRIMP测定显示巴什瓦克高压麻粒岩的峰期变质时代为493~497Ma。都兰地区的榴辉岩分布柴北缘HP-UHP变质带的东端,在榴辉岩和围岩副片麻岩中均发现有柯石英保存,形成的峰期温压条件为T=670~730℃和,P=2.7~3.25GPa,退变质阶段经过了角闪岩相的叠加;榴辉岩相变质时代为420~450Ma。都兰地区的高压麻粒岩分布在阿尔茨托山西部,高压麻粒岩包括基性麻粒岩长英质麻粒岩,基性麻粒岩的峰期矿物组合为Crt+Cpx+Pl±Ky±Zo+Rt±Qtz,长英质麻粒岩的峰期矿物组合为:Grt+Kf+Ky+Pl+Qtz。峰期变质条件为T=800~925℃,P=1.4~1.85GPa,退变质阶段经历了角闪岩-绿片岩的改造,高压麻粒岩的变质时代为420~450Ma。北秦岭榴辉岩分布在官坡-双槐树一带,榴辉岩的峰期变质组合为Grt+Omp±Phe+Qtz+Rt,所计算的峰期温压条件为T=680~770℃和P=2.25~2.65GPa,年代学数据显示榴辉岩的变质时代为500Ma左右。北秦岭高压麻粒岩分布在含榴辉岩单元的南侧松树沟一带,包括高压基性麻粒岩和高压长英质麻粒岩,与超基性岩在空间上密切伴生,高压麻粒岩的峰期温压条件为T=850~925℃,P=1.45~1.80GPa,锆石U-Pb年代学研究显示其峰期变质时代为485~507Ma。以上三个实例显示,出现在同一造山带、在空间上伴生的高压麻粒岩和榴辉岩有各自不同的变质演化历史,但榴辉岩中的榴辉岩相变质时代和相邻的高压麻粒岩中的高压麻粒岩相变质作用时代相同或相近,这种成对出现的榴辉岩和高压麻粒岩代表了它们同时形成在造山带中不同的构造环境中,即榴辉岩的形成于大陆俯冲带中,而高压麻粒岩可能形成在俯冲带之上增厚的大陆地壳根部。 展开更多
关键词 柴北缘 都兰 高压麻粒岩 变质演化 动力学 North Qaidam mountains area 高压基性麻粒岩 multistage metamorphism high thermal relaxation continental crust 石榴子石 矿物学 高角闪岩相 单斜辉石 变质条件 mafic GRANULITES Mineral 岩石学
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The first discovery of Holocene Ailuropoda melanoleuca subfossils from Xiangxi,Hunan,China
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作者 TONG Guang-Hui LIU Li +2 位作者 LI Yong-Xiang WANG Wen-Zhe CAI Xing-Lin 《古脊椎动物学报(中英文)》 北大核心 2025年第3期242-247,共6页
A new cranium and two mandibles of Ailuropoda melanoleuca from Xiangxi,Hunan Province are described here.The materials were discovered in a karst cave on the Bamian Mountain at an altitude of 1200 m,with AMC carbon-fo... A new cranium and two mandibles of Ailuropoda melanoleuca from Xiangxi,Hunan Province are described here.The materials were discovered in a karst cave on the Bamian Mountain at an altitude of 1200 m,with AMC carbon-fourteen isotope dating indicating an age of 2800±30 BP.Historically,the giant panda was widely distributed in southern China and parts of Southeast Asia during the Pleistocene epoch,but it is now confined and isolated to six mountain ranges in southwest China’s Sichuan,Shaanxi,and Gansu provinces.The subfossil materials reported here represent the first discovery of the living species of giant panda in Xiangxi,Hunan.This extends their geographical distribution in southern China during the Holocene epoch eastward to the eastern edge of the Yunnan-Guizhou Plateau and their recent altitude range down to 1200 m. 展开更多
关键词 Xiangxi Hunan Bamian Mountain HOLOCENE Ailuropoda melanoleuca
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Numerical study on the water inflow and hydraulic pressure of mountain tunnel underpassing a reservoir
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作者 LIU Dongdong SONG Wenjie +3 位作者 WANG Xintong YANG Tao HUANG Bo ZHONG GUO 《中国水利水电科学研究院学报(中英文)》 北大核心 2025年第5期580-589,共10页
Prediction of water inflow into a tunnel is a crucial prerequisite for the waterproof and drainage design of mountain tunnels in water-rich areas.Based on the proposed Baiyun Mountain Tunnel project in Guangzhou,a num... Prediction of water inflow into a tunnel is a crucial prerequisite for the waterproof and drainage design of mountain tunnels in water-rich areas.Based on the proposed Baiyun Mountain Tunnel project in Guangzhou,a numerical percolation model of random fractured rock of a tunnel underpassing a water reservoir is established to study the seepage characteristics of surrounding rock,the law of water inflow,and the change of lining water pressure,considering the local artificial boundary conditions for seepage in large rock mass,.In addition,the influences of rock permeability,fracture aperture,grouting circle thickness,and penetration are analyzed.The results show that:(1)Only fractures with aperture wider than 0.1 mm can play a significant role in water conduction in rocks with the permeability lower than 10^(-11)m^(2);(2)The greater the permeability difference between the fractures and rocks,the more remarkable the effects of fractures on the surrounding rock seepage field and cavern water inflow;(3)The sensitivity of grouting waterproof function to grouting circle thickness,grouting ring penetration,and rock permeability is significantly higher than that of tunnel buried depth and fracture aperture;(4)The lining water head is much more sensitive to the grouting circle thickness and penetration than to the tunnel buried depth;(5)With the grouting range enlarging,the impact of grouting circle permeability on the precipitation pressure role of the grouting ring increases;(6)For the interesting tunnel designed to be built at the depth of 70 m,the grouting circle with the thickness of 0.5 m and permeability of 10-^(14)m^(2)is recommended. 展开更多
关键词 mountain tunnel water inflow into a tunnel lining water pressure grouting circle stochastic fracture networks
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践行“两山”理论 建设森林云南 争当生态文明建设排头兵——赴云南省考察调研报告 被引量:6
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作者 岳太青 章升东 +3 位作者 张建辉 张坤 段经华 陈昱 《国家林业局管理干部学院学报》 2017年第3期3-9,共7页
云南省生态区位重要,生态系统类型和生态景观多样,为长江、珠江等6大江河的上游或发源地,不仅是我国林业资源大省,而且是我国乃至全球生物多样性最丰富、最集中的地区之一。云南省践行"两山"理论的一系列林业行动,取得了令人... 云南省生态区位重要,生态系统类型和生态景观多样,为长江、珠江等6大江河的上游或发源地,不仅是我国林业资源大省,而且是我国乃至全球生物多样性最丰富、最集中的地区之一。云南省践行"两山"理论的一系列林业行动,取得了令人瞩目的成绩,并探索积累了许多宝贵的经验。面对云南省林业建设和生态保护任务艰巨,生态产品短缺局面尚未得到根本改变等困难和挑战,建议全面推进重点区域生态治理与保护,实施森林质量提升工程,推进林业重点领域改革和配套改革,做优做强林业产业,全力实施林业科技创新驱动战略。 展开更多
关键词 YUNNAN Two mountains Theory ecological civilization
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大别山高压-超高压片麻岩锆石的拉曼光谱学研究 被引量:3
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作者 刘文元 刘景波 《岩石学报》 SCIE EI CAS CSCD 北大核心 2009年第9期2157-2164,共8页
对大别山高压-超高压片麻岩的锆石进行了激光拉曼探针、阴极发光(CL)、U-Pb年龄和U、Th等微量元素的测定分析。研究结果表明:锆石拉曼光谱1008cm^(-1)峰的半高宽普遍小于20cm^(-1),指示锆石结晶程度较好到中等程度的蜕晶化;早期继承锆... 对大别山高压-超高压片麻岩的锆石进行了激光拉曼探针、阴极发光(CL)、U-Pb年龄和U、Th等微量元素的测定分析。研究结果表明:锆石拉曼光谱1008cm^(-1)峰的半高宽普遍小于20cm^(-1),指示锆石结晶程度较好到中等程度的蜕晶化;早期继承锆石在三叠纪高压-超高压变质作用中经历了退火和重结晶作用,所受的放射性通量是从200Ma的早侏罗纪开始积累的,表明高压-超高压岩石在这一时间已出露地表;北大别白垩纪岩浆热事件对高压-超高压岩石的影响很小;大多数锆石数据都落在天然锆石的放射性破坏趋势(RDT)中,表明锆石在高压、超高压过程中基本发生了完全的重结晶。 展开更多
关键词 大别山 高压片麻岩 锆石拉曼光谱 激光拉曼探针 光谱学研究 DABIE mountains HP-UHP 超高压岩石 metamorphic rocks radiation damage 超高压变质作用 trace elements 重结晶作用 放射性 during significant North DABIE Laser Raman the earth 阴极发光
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Checklist and Zoogeographical Region Analysis of Hawkmoths(Lepidoptera:Sphingidae)in the Guokui Mountain,Heilongjiang Province
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作者 Zhao Jiaqi Zhang Jiake Xie Tongyin 《Journal of Northeast Agricultural University(English Edition)》 2025年第2期10-22,共13页
This paper conducted a systematic survey and zoogeographical region analysis of the family Sphingidae in the Guokui Mountain,Heilongjiang Province.Collections were made from May 2023 to August 2024 using the light-tra... This paper conducted a systematic survey and zoogeographical region analysis of the family Sphingidae in the Guokui Mountain,Heilongjiang Province.Collections were made from May 2023 to August 2024 using the light-trap method.A total of 14 species and 11 subspecies from 18 genera and three subfamilies were recorded.One species(Ambulyx tobii)and two subspecies(Ambulyx japonica koreana and Clanis undulosa undulosa)were new records for Heilongjiang Province.The study showed that the subfamily Smerinthinae had the most species(subspecies),while the subfamily Sphinginae had the fewest.Among the world's zoogeographical region,most species(subspecies)in the Guokui Mountain belonged to the palearctic region,with eight species and seven subspecies were also found in the oriental region.This indicated a close biogeographic connection between the two regions.Among the Chinese zoogeographical regions,the northeastern territory,northern territory and northwestern territory had the most abundant species(subspecies).It was also found that the distribution pattern types of hawkmoths in the Guokui Mountain were diverse,with the'northeastern territory-northern territory-northwestern territory'and'northeastern territory-northern territorynorthwestern territory-western plateau-southwestern territory-central territory-southeastern territory'types having the most species(subspecies).In addition,the Guokui Mountain hawkmoths were mostly distributed interregionally.The distribution patterns that contained the northeastern territory were the most numerous,followed by the northern territory.The rich diversity of the family Sphingidae in the Guokui Mountain was closely related to the unique climate,environment and vegetation types in the area.The results could help to improve the biodiversity database of Heilongjiang Province and researches on hawkmoths. 展开更多
关键词 SPHINGIDAE zoogeographical region diversity LIGHT-TRAP the Guokui Mountain
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一种用于连续动作空间的最小二乘行动者-评论家方法 被引量:9
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作者 朱斐 刘全 +1 位作者 傅启明 伏玉琛 《计算机研究与发展》 EI CSCD 北大核心 2014年第3期548-558,共11页
解决具有连续动作空间的问题是当前强化学习领域的一个研究热点和难点.在处理这类问题时,传统的强化学习算法通常利用先验信息对连续动作空间进行离散化处理,然后再求解最优策略.然而,在很多实际应用中,由于缺乏用于离散化处理的先验信... 解决具有连续动作空间的问题是当前强化学习领域的一个研究热点和难点.在处理这类问题时,传统的强化学习算法通常利用先验信息对连续动作空间进行离散化处理,然后再求解最优策略.然而,在很多实际应用中,由于缺乏用于离散化处理的先验信息,算法效果会变差甚至算法失效.针对这类问题,提出了一种最小二乘行动者-评论家方法(least square actor-critic algorithm,LSAC),使用函数逼近器近似表示值函数及策略,利用最小二乘法在线动态求解近似值函数参数及近似策略参数,以近似值函数作为评论家指导近似策略参数的求解.将LSAC算法用于解决经典的具有连续动作空间的小车平衡杆问题和mountain car问题,并与Cacla(continuous actor-critic learning automaton)算法和eNAC(episodic natural actor-critic)算法进行比较.结果表明,LSAC算法能有效地解决连续动作空间问题,并具有较优的执行性能. 展开更多
关键词 强化学习 行动者-评论家算法 连续动作空间 最小二乘法 小车平衡杆问题 MOUNTAIN car问题
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THE ALTUN—NORTH QAIDAM ECLOGITE BELT IN WESTERN CHINA—ANOTHER HP-UHP METAMORPHIC BELT TRUNCATED BY LARGE SCALE STRIKE-SLIP FAULT IN CHINA 被引量:4
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作者 Zhang Jianxin, Xu Zhiqin, Yang Jingsui, Li Haibing, Wu Cailai(Institute of Geology, Chinese Academy of Geological Sciences, 26 Baiwanzhuang, Beijing 100037,China, E\|mail: zjx66@yeah.net) 《地学前缘》 EI CAS CSCD 2000年第S1期254-255,共2页
The Altun and North Qaidam Mountains at the northern margin of Qinghai\|Tibet plateau are separated by the Altyn Tagh sinistral strike\|slip fault, which is one of the largest strike\|slip fault systems in the world a... The Altun and North Qaidam Mountains at the northern margin of Qinghai\|Tibet plateau are separated by the Altyn Tagh sinistral strike\|slip fault, which is one of the largest strike\|slip fault systems in the world and was considered as the key element in the escape tectonics model for Euraisa\|India continent\|continent collision.Recently,the eclogites within quratzifeldspathic gneisses or pelitic gneisses characterized by amphibolite\|facies paragenesis were discovered in the Altun and the North Qaidam Mountains(Fig.1). They occur as lens or boundins within the Altun Group and Dakendaban Group respectively which previously were considered as metamorphic basement of Tarim block and Qaidam block. Our studies indicate that the eclogites outcrop in both the Altun and North Qaidam Mountains show similar occurrences, associated country rocks, rock and mineral assemblages, p\|T\% estimates, geochemistryand protolith feature and ages of peak metamorphism (see table) . The garnet\|omphacite\|phengite geothermobarometer gave equilibrium condition of \%p\%=2 8~3 0GPa and t =820~850℃ for the Altun eclogite and p =2 8GPa and \%t\%=730℃ for North Qaidam eclogite respectively(Fig..2). These p\|T conditions are in the coesite stability field. Moreover, Po lycrystalline quartz pseudomorphs after coesite have been identified in the Dulan area, North Qaidam Mountains (Song et al, in review). Therefore, these features suggest that both eclogites of Altun and North Qaidam Mountains probably are a same HP\|UHP metamorphic belt formed from the same of Early Paleozoic age deep subduction and collision, and subsequently displaced by the Altyn Tagh fault.The case is similar to the Dabie\|Sulu HP\|UHP metamorphic zone which was truncated by the Tanlu sinistral strike\|slip fault and splitted it into two distincts, the Dabie region and Sulu region. These correlations support an about 350~400km displacement of the Altyn Tagh sinistral strike\|slip fault (Fig.1). 展开更多
关键词 Altun mountains North Qaidam mountains HP\|UHP METAMORPHIC b ELT Altyn Tagh fault
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南方复杂山地三维地震勘探实践与效果分析 被引量:12
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作者 敬朋贵 殷厚成 陈祖庆 《石油物探》 EI CSCD 北大核心 2010年第5期495-499,19,共5页
南方海相碳酸盐岩油气勘探历史较长,以前虽有所发现,但规模有限。近几年来,随着三维地震勘探技术的发展及其在南方复杂山地的大规模实施,中国石油化工股份有限公司相继在川东北地区海相油气勘探领域取得了巨大发现。勘探实践表明,三维... 南方海相碳酸盐岩油气勘探历史较长,以前虽有所发现,但规模有限。近几年来,随着三维地震勘探技术的发展及其在南方复杂山地的大规模实施,中国石油化工股份有限公司相继在川东北地区海相油气勘探领域取得了巨大发现。勘探实践表明,三维地震勘探技术大幅度改善了该地区的地震资料品质,为解决复杂地质问题奠定了良好的资料基础,从而提高了碳酸盐岩储层预测和描述的精度,大大加快了油气勘探节奏。从普光大型气田的探明到元坝大型礁滩体的发现,充分表明三维地震勘探技术在南方复杂海相油气勘探中发挥了不可替代的作用。 展开更多
关键词 南方 山地三维地震 勘探实践 效果分析 Southern China mountainous area effect analysis practice seismic exploration 三维地震勘探技术 油气勘探领域 海相碳酸盐岩 股份有限公司 地震资料品质 油气勘探中 川东北地区 石油化工 勘探历史 复杂山地 地质问题
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西大别浒湾变质带洋壳和陆壳耦合俯冲的锆石U-Pb年龄记录及其动力学意义 被引量:6
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作者 刘小驰 吴元保 +2 位作者 汪晶 彭敏 焦文放 《岩石学报》 SCIE EI CAS CSCD 北大核心 2009年第9期2209-2223,共15页
西大别浒湾高压变质带是研究秦岭-大别-苏鲁造山带演化的关键区域。本文对该变质带熊店和学河两地的两个榴辉岩样品进行了LA-(MC)-ICPMS锆石U-Pb定年、微量元素分析及Hf同位素测定。熊店榴辉岩岩浆锆石得到的年龄为406±14Ma,具有... 西大别浒湾高压变质带是研究秦岭-大别-苏鲁造山带演化的关键区域。本文对该变质带熊店和学河两地的两个榴辉岩样品进行了LA-(MC)-ICPMS锆石U-Pb定年、微量元素分析及Hf同位素测定。熊店榴辉岩岩浆锆石得到的年龄为406±14Ma,具有高的ε_(Hf)(t)值(ε_(Hf)(t)=11.3±1.3),年轻的亏损地幔模式年龄(t_(DM)=578±52Ma),其来源可能为亏损地幔,进而说明它们的原岩可能为古特提斯洋壳物质;学河榴辉岩岩浆锆石的年龄为703±8Ma,具有略低的ε_(Hf)(t)值(ε_(Hf)(t)= 4.11±0.94),较老的亏损地幔模式年龄(t_(DM)=1105±37Ma),其原岩可能为扬子克拉通新元古代裂谷岩浆作用产生的新生陆壳物质。这些结果表明浒湾地区存在原岩形成于新元古代和志留纪两个时期的榴辉岩。熊店榴辉岩中变质锆石的微量元素特征与岩浆锆石类似,可能为完全重结晶成因锆石,其^(206)pb/^(238)U加权平均年龄为316±1Ma,代表了洋壳榴辉岩榴辉岩相峰期变质的最早时间。学河榴辉岩变质锆石以低Th/U、Nb/Ta比值为特征,其REE组成模式为不明显的Eu负异常,HREE呈平坦型。这些特征反映了这些锆石形成时出现了较大数量的石榴子石与金红石,而缺乏长石。根据锆石Ti温度计计算学河榴辉岩变质锆石形成的温度范围是704~741℃,与榴辉岩相变质温度一致。它们对应的^(206)Pb/^(238)U加权平均年龄为312±3Ma,可作为浒湾变质带榴辉岩相峰期变质年龄,这一结果表明浒湾变质带陆壳成因榴辉岩存在石炭纪榴辉岩相变质事件。空间上相近的古生代洋壳和新元古代陆壳具有相同的榴辉岩相变质年龄表明,浒湾变质带的洋壳和陆壳榴辉岩可能存在石炭纪的耦合俯冲作用。 展开更多
关键词 西大别 变质带 耦合 岩浆锆石 U-Pb年龄 记录 动力学 shear zone PROTOLITH ages DABIE mountains western 榴辉岩相变质 trace element continental crust 新元古代 亏损地幔 变质锆石 平均年龄为 模式年龄 峰期变质
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中强地震随机有限断层模型应力降参数的确定方法 被引量:1
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作者 高阳 潘华 汪素云 《震灾防御技术》 CSCD 2014年第4期733-747,共15页
随机有限断层模型是模拟地震动加速度时程的一个重要工具。但将其应用于中强地震时,由于震源信息的准确性较差从而使模型参数具有较大的不确定性。尤其针对其中最为关键的应力降参数,目前相关研究较为缺乏且尚未形成系统的确定方法。本... 随机有限断层模型是模拟地震动加速度时程的一个重要工具。但将其应用于中强地震时,由于震源信息的准确性较差从而使模型参数具有较大的不确定性。尤其针对其中最为关键的应力降参数,目前相关研究较为缺乏且尚未形成系统的确定方法。本文基于美国Little Skull Mountain MW5.6级地震2个近场台站记录的地震动模拟,详细研究了采用随机有限断层法拟合中强地震地震动伪加速度反应谱(PSA)来确定应力降参数值的方法,并在计算应力降时引入了其它震源参数的不确定性,随后对此方法的可行性进行了验证。研究表明:采用不同频段反应谱残差和计算得到的应力降值差别较大,确定中强地震应力降较为合适的反应谱频段是中高频,采用该频段确定的应力降参数值模拟的反应谱和峰值加速度与实际记录较为符合;脉冲子断层百分比、断层长宽、倾角和深度等震源参数按截断的正态分布或均匀分布随机抽样,拟合得到的应力降参数值与通过实际震源模型参数得到的值相近。以上研究结果对确定一个区域中强地震应力降或中强地震近场强震动模拟研究提供了更进一步的研究方法和研究方向。 展开更多
关键词 随机有限断层法 应力降 中强地震 LITTLE SKULL Mountain地震
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TRIASSIC OROGENESIS IN SOUTHWEST CHINA: THE STRUCTURAL ORIGINS OF THE NORTHEAST TIBETAN PLATEAU 被引量:2
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作者 Mathew J. Harrowfield,Christopher J.L. Wilson cjlw@myriad.its.unimelb.edu.au) 《地学前缘》 EI CAS CSCD 2000年第S1期293-293,共1页
Whilst the topographic relief of the Tibetan Plateau’s northeast margin reflects recent Himalayan Orogenesis, its position and geometry reflect much older structures that developed during the Indosinian Orogeny c.200... Whilst the topographic relief of the Tibetan Plateau’s northeast margin reflects recent Himalayan Orogenesis, its position and geometry reflect much older structures that developed during the Indosinian Orogeny c.200Ma. The Indosinian Orogeny was responsible for closure and shortening of the Songpan Garzê Basin, a Palaeo\|Tethyan relict, during accretion of the Cimmerian Continental Chain to the southern margin of Laurasia. Sandwiched between Laurasia and the Cimmerian fragments of the Qangtang (North Tibet) and Yangtze (South China) blocks, this basin evolved into the Songpan Garzê Fold Belt—a major accretionary prism which now forms the northeast portion of the Tibetan Plateau. 展开更多
关键词 HIMALAYAN OROGENY INDOSINIAN OROGENY Qingling OROGENY Long men mountains Songpan\|Garzê fold belt Palaeo\|Tethys Yangtze block
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北祁连山高压变质带的变形和变质特征及其对俯冲带折返的意义 被引量:2
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作者 曹毅 宋述光 CA0 《岩石学报》 SCIE EI CAS CSCD 北大核心 2009年第9期2235-2246,共12页
北祁连造山带是早古生代大洋板块"冷"俯冲的典型地区,形成了一系列高压低温变质的岩石组合。基性榴辉岩是俯冲洋壳变质的产物,根据其结构构造特征可以划分为(1)粒状榴辉岩,峰期变质矿物组合为Grt+Omp+Phn+Rut±Lws,硬柱... 北祁连造山带是早古生代大洋板块"冷"俯冲的典型地区,形成了一系列高压低温变质的岩石组合。基性榴辉岩是俯冲洋壳变质的产物,根据其结构构造特征可以划分为(1)粒状榴辉岩,峰期变质矿物组合为Grt+Omp+Phn+Rut±Lws,硬柱石呈包裹体和假象分布于石榴石内,变质温压条件T=465~508℃,p=2.30~2.60GPa。(2)片状榴辉岩,岩石具片状构造,其共生矿物组合Omp+Czo/Ep+Phn+Gln构成透入性面理S_1和线理L_1,以及宏观和显微同斜褶皱F_1。其峰期变质温压条件为T=466~510℃,P=1.9~2.2GPa。(3)蓝片岩相退化变质榴辉岩,蓝片岩相变质矿物Gln+Ep+Phn±Ab强烈交代榴辉岩相矿物,并发生强烈D_2期变形作用,岩石形成明显的透入性面理S_2和线理L_2,以及同斜剪切褶皱F_2。蓝闪石和多硅白云母线理的统计揭示D_2期变形以斜向走滑剪切为主,与D_1期变形的榴辉岩的运动学特征大体相似。D_2同变质的温压条件为T=422~487℃,P=1.15~1.37GPa。高压变质带晚期的绿片岩相叠加和D_3期变形,形成透入性面理S_3和线理L_3,其运动特征为近于垂直构造线的逆冲剪切。结合榴辉岩变形特征,变质温压条件和同位素年代学资料,我们认为退变质的强弱与变形程度有密切关系。峰期变质后的榴辉岩经过早期绿帘石榴辉岩相到蓝片岩相斜向走滑剪切,和晚期绿片岩相逆冲,在泥盆纪早期快速折返的出露地表。 展开更多
关键词 北祁连山 高压变质带 变形 变质特征 俯冲带 折返 implications 榴辉岩相 峰期变质温压条件 mineral assemblage 蓝片岩相 North Qilian mountains isotopic geochronology 走滑剪切 线理 绿片岩相 矿物组合 变质矿物 movement Early Paleozoic
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