基于媒体事件的中亚、东盟区域对中国地缘关系判别研究     

魏中胤  沈山  贾广宇  马跃 《世界地理研究》2021,30(4):732-743

基于GDELT数据,通过构建语气指数、冲突语气均衡度、冲突事件集中度、事件时维记忆性等指标,定量分析2013—2020年中亚、东盟国家在有关中国的事件上的语气态度,辨识异常时段并追踪事件,从媒体事件角度识别和判断区域风险,进而揭示对中国的地缘关系。结论如下：中亚、东盟关于中国事件的语气态度以合作为主,语气指数表现出“尖峰肥尾”和对称性等特征,两区域存在冲突语气频繁波动的相同时段;相较东盟,中亚关于我国的冲突语气更不均衡、冲突事件高集中度时段更短少;以半月为单位,两地冲突事件的前时段会对后时段产生正向影响,以季度为单位,中亚仍为正向影响,而东盟则倾向产生逆向影响;中亚主要风险为公共卫生健康、恐怖袭击和民族宗教问题;东盟主要风险有公共卫生健康、领土主权受侵、境外犯罪、边境风险、空难、项目受阻、恐怖袭击等。研究建议,我国应加强对中亚、东盟的媒体舆论引导的影响力,对待中亚区域风险当以“重视阶段性”的防范方针,采取“积极平复和审慎对待”的策略,优化民族和宗教政策;对待东盟当以“重视长时距”的合作布局,在法律完善、防暴防恐、打击犯罪、提升公民文明行为等方面强化地缘合作,优化地缘关系。  相似文献   

Vertical distribution changes in land cover between 1990 and 2015 within the Koshi River Basin,Central Himalayas     

WU Xue  PAUDEL Basanta  ZHANG Yili  LIU Linshan  WANG Zhaofeng  XIE Fangdi  GAO Jungang  SUN Xiaomin 《地理学报(英文版)》2021,31(10):1419-1436

The study of mountain vertical natural belts is an important component in the study of regional differentiation.These areas are especially sensitive to climate change and have indicative function,which is the core of three-dimensional zonality research.Thus,based on high precision land cover and digital elevation model (DEM) data,and supported by MATLAB and ArcGIS analyses,this paper aimed to study the present situation and changes of the land cover vertical belts between 1990 and 2015 on the northern and southern slopes of the Koshi River Basin (KRB).Results showed that the vertical belts on both slopes were markedly dif-ferent from one another.The vertical belts on the southern slope were mainly dominated by cropland,forest,bare land,and glacier and snow cover.In contrast,grassland,bare land,sparse vegetation,glacier and snow cover dominated the northern slope.Study found that the main vertical belts across the KRB within this region have not changed substantially over the past 25 years.In contrast,on the southern slope,the upper limits of cropland and bare land have moved to higher elevation,while the lower limits of forest and glacier and snow cover have moved to higher elevation.The upper limit of alpine grassland on the northern slope retreated and moved to higher elevation,while the lower limits of glacier and snow cover and vegetation moved northward to higher elevations.Changes in the vertical belt were influenced by climate change and human activities over time.Cropland was mainly controlled by human activities and climate warming,and the reduced precipitation also led to the abandonment of cropland,at least to a certain extent.Changes in grassland and forest ecosystems were predominantly influenced by both human activities and climate change.At the same time,glacier and snow cover far away from human activities was also mainly influenced by climate warming.  相似文献   

高速公路引导下中原经济区交通可达性空间格局   总被引：3，自引：0，他引：3  

孟德友  李小建  樊新生 《地域研究与开发》2016,(2)

以中原经济区为研究区域,采用网络分析和栅格分析相结合的方法,运用加权平均旅行时间、相对可达性和区域平均可达性指标在对各县市可达性及改善状况进行比较分析的基础上,对区域可达性空间格局及演化特征进行探讨。结果显示:各县市可达性均获得了较大的提升,但县市可达性在不同地区和不同时期还存在较大差距;区域平均可达性呈现出以中原城市群为核心向外围地区递减的态势,可达性中心区的范围逐步拓展,交通干线指向性明显,平原地区可达性优于山区、丘陵或盆地;不同发展阶段的可达性变化幅度也不均匀,可达性水平较差的地区改善程度明显,高速公路建设有利于推动地区间可达性的均衡发展。  相似文献   

Tectonic Framework of Late Paleozoic Intrusions in Xingxingxia: Implications for Final Closure of South Tianshan Ocean in East Tianshan   总被引：1，自引：1，他引：0  

ZHOU Hai  CHEN Liang  SUN Yong  ZHU Tao 《《地质学报》英文版》2016,90(2):604-627

This work carried out systematic geological field investigation, petrography observation, zircon geochronology and whole rock geochemistry on Late Paleozoic intrusions in the Xingxingxia region near the Xinjiang-Gansu provincial boundary, western China, aiming to constrain the Late Paleozoic tectonic framework of the Xingxingxia region and the final closure time of South Tianshan Ocean in the East Tianshan. The Xingxingxia area is located in the east part of the Tianshan orogen, and adjacent to the north of the Tarim Basin. The Late Paleozoic magma activities in the Xingxingxia region can be mainly divided into three stages. The first stage includes intrusive magma activities under a collision setting between Late Ordovician to the Late Devonian. The second stage is intrusive magma activities under a subduction setting during(304±3)–(278±3) Ma, and the third stage involves intrusive magma activities under a collision and post-collision setting during(268±5)–(259.9±2.6) Ma. The final suture zone of South Tianshan Ocean should be between the Central Tianshan Block and South Tianshan accretionary complex. Based on previous work, both the first stage magma activities(i.e., intrusive magmatic activities between the Late Ordovician to Late Devonian) and the Hongliuhe ophiolitic complex indicate a close event between Central Tianshan Block and South Tianshan Accretionary Complex. The 304±3 Ma dioritic metamorphic gneiss of the XingX ingxia complex and the 278±3 Ma diorite are all island arc calc-alkaline rocks, the 289±3 Ma gabbro is island arc tholeiitic gabbro formed by magma from metasomatic enrichment mantle. All these results indicate that the second stage of magmatic activities is under a subduction setting. The third stage magma activities i.e. the granitic magma activities of(268±5)–(259.9±2.6) Ma occurred at a transitional setting from compressional to post-collision extensional tectonic setting. Thus, around(268±5)–(260±3) Ma, the final closure of the South Tianshan Ocean occurred and the Tianshan orogen shifted into the intracontinental evolution stage. During and after the closure process, a wide range of metamorphism and large dextral strike-slip faults developed.  相似文献   

中-新生代塔里木与中亚盐湖链蒸发岩沉积及其控制因素初探     

曹养同  刘成林  颜辉  焦鹏程  张华  吕凤琳  丁婷 《矿床地质》2016,35(3):591-604

全球性的构造运动末期一般伴着海退和干旱的气候环境,而蒸发岩沉积与大地构造条件紧密相关。中亚卡拉库姆盆地、阿富汗_塔吉克盆地、塔里木盆地自晚侏罗世至中新世以来至少发生了3次大规模海侵_海退旋回,每次海侵_海退均受特提斯构造事件控制。卡拉库姆盆地、阿富汗_塔吉克盆地为晚侏罗世—早白垩世蒸发岩沉积、塔里木盆地的莎车次级盆地为晚白垩世—古新世蒸发岩沉积,库车次级盆地为古新世—中新世蒸发岩沉积,形成特提斯构造域自西向东蒸发岩沉积时代逐渐变新的盐湖链。中亚及塔里木盐湖链在海侵_海退旋回的控制下,至少发生5次大规模的蒸发岩沉积,发育2种不同的蒸发岩沉积序列,分别对应3次海退期蒸发岩沉积序列及2次断续海侵期蒸发岩沉积序列,具体为晚侏罗世晚期(海退期)卡拉库姆盆地、阿富汗_塔吉克盆地蒸发岩沉积;早白垩世—晚白垩世早期(断续海侵期)阿富汗_塔吉克盆地蒸发岩沉积;晚白垩世晚期(海退期)莎车次级盆地蒸发岩沉积;古新世—中新世(断续海侵期)莎车次级盆地、库车次级盆地蒸发岩沉积;中新世晚期—上新世早期(海退期)库车次级盆地蒸发岩沉积。塔里木与中亚古盐湖发育受控于特提斯构造事件及海侵_海退旋回,而海侵_海退旋回又控制2种不同的蒸发岩沉积序列。蒸发岩沉积序列、古盐湖演化阶段、蒸发岩物质来源、沉积环境决定了盐类矿物沉积类型(单一化学岩型、陆缘碎屑岩_化学岩型),卡拉库姆盆地、阿富汗_塔吉克盆地盐类矿物与塔里木盆地相比,种类简单,反映了盆地化学岩与陆源碎屑_化学岩沉积的区别及后期构造运动对盐类矿物种类的主控作用。  相似文献   

Tithonian–early Berriasian perisphinctoid ammonites from the Štramberk Limestone at Kotouč Quarry near Štramberk,Outer Western Carpathians (Czech Republic)     

《Cretaceous Research》2016

The present contribution deals with the taxonomy of 11 species of perisphinctoid ammonite recovered recently from the Štramberk Limestone as exposed at the Kotouč Quarry (Štramberk, Moravia). The majority of these are described from this unit for the first time. In the stratigraphic evaluation, finds of ammonites from other localities within the quarry, which were published by us in 2013 and 2014, are included. Ammonites recorded from beyond the continuous section document a stratigraphic range from upper lower Tithonian to lower Berriasian inclusive. In addition to taxonomy and new ontogenetic data of some species, we also present information on the distribution of species recognised and on their palaeogeographic distribution, as well as data on the structural composition of the Homole Block at Kotouč Quarry.  相似文献   

Regional metamorphism and the alteration response of selected Silurian to Devonian mineral systems in the Nymagee area,Central Lachlan Orogen,New South Wales: a HyLogger™ case study     

P. M. Downes  D. B. Tilley  J. A. Fitzherbert  M. E. Clissold 《Australian Journal of Earth Sciences》2016,63(8):1027-1052

The southern Cobar Superbasin includes the Mount Hope, Cobar and Rast troughs and adjacent Winduck, Mouramba and Kopyje shelves. These stratotectonic units host a range of mineral systems within deformed upper Silurian to Lower Devonian rocks. Despite the metallogenic importance of the terrane the regional metamorphic- and alteration-related mineral assemblages have not been systematically described until now. Here, we present a study using the HyLogger? spectral scanner to systematically map changes in both background and alteration-related mineralogy for 14 mineral systems across the Nymagee area. The study found that, with the exception of the late diagenetic zone assemblages associated with the Winduck Shelf, the mineral assemblages for zones away from mineralisation are consistent with uniform sub- to lowest-greenschist facies metamorphic conditions, with no evidence for a regional, thermal field gradient across the basin. By contrast, proximal to mineralisation, there are significant changes in alteration-related mineral abundances and species reflecting elevated fluid temperatures. For several zones, including Browns Reef, Great Central, Hera, May Day, Nymagee and Shuttleton, there is a systematic change in chlorite composition from Fe- and/or Fe–Mg-chlorites to more Mg-rich varieties towards mineralisation. In addition, talc was noted for May Day, Mineral Hill and Shuttleton. The change in chlorite composition suggests that these ore-forming fluids were undersaturated with respect to iron. Furthermore, although present in discrete zones, carbonate alteration is not a dominant alteration type. However, at Manuka and Blue Mountain, the mineralisation is associated with carbonate-rich (calcite, ankerite, dolomite) units that have been dolomitised (Mg alteration) but not all dolomite-rich zones are mineralised. For Mineral Hill, there are systematic changes to mineral species/chemistry with observed data consistent with Parkers Hill being proximal to the centre of a mineralising system. The G and H Lode area (Southern Ore Zone) is slightly more distal whereas the Pearse deposit may represent a zone more distal again.  相似文献   

Relationship between chemical composition and magnetic susceptibility in sediment cores from Central Indian Ocean Basin     

J. N. Pattan  G. Parthiban  V. K. Banakar  A. Tomer  M. Kulkarni 《Journal of Earth System Science》2008,117(2):113-119

Three sediment cores in a north-south transect (3°N to 13°S) from different sediment types of the Central Indian Ocean Basin (CIOB) are studied to understand the possible relationship between magnetic susceptibility (χ) and Al, Fe, Ti and Mn concentrations. The calcareous ooze core exhibit lowest χ (12.32 × 10⁻⁷ m³ kg⁻¹), Al (2.84%), Fe (1.63%) and Ti (0.14%), terrigenous clay core with moderate χ (29.93 × 10⁻⁷ m³ kg⁻¹) but highest Al (6.84%), Fe (5.20%) and Ti (0.44%), and siliceous ooze core with highest χ (38.06 × 10⁻⁷ m³ kg⁻¹) but moderate Al (4.49%), Fe (2.80%) and Ti (0.19%) contents. The distribution of χ and detrital proxy elements (Al, Fe, and Ti) are identical in both calcareous and siliceous ooze. Interestingly, in terrigenous core, the behaviour of χ is identical to only Ti content but not with Al and Fe suggesting possibility of Al and Fe having a non-detrital source. The occurrence of phillipsite in terrigenous clay is evident by the Al-K scatter plot where trend line intersects K axis at more than 50% of total K suggesting excess K in the form of phillipsite. Therefore, the presence of phillipsite might be responsible for negative correlation between χ and Al (r = −0.52). In siliceous ooze the strong positive correlations among χ, Al_exc and Fe_exc suggest the presence of authigenic Fe-rich smectite. High Mn content (0.5%) probably in the form of manganese micronodules is also contributing to χ in both calcareous and siliceous ooze but not in the terrigenous core where mean Mn content (0.1%) is similar to crustal abundance. Thus, χ systematically records the terrigenous variation in both the biogenic sediments but in terrigenous clay it indirectly suggests the presence of authigenic minerals.  相似文献   

塔里木盆地中央地区的断裂系统:几何学、运动学和动力学背景   总被引：24，自引：11，他引：13       下载免费PDF全文

李曰俊  吴根耀  孟庆龙  杨海军  韩剑发  李新生  董立胜 《地质科学》2008,43(1):82-118

塔中低凸起位于塔里木盆地中央隆起的中段,发育4组不同方向的断裂,以北西向的塔中Ⅰ号断裂带为主干断裂,其南的近北西向断裂和近东西向断裂与之组成"入"字形构造,向西撒开;剖面上则因塔中Ⅰ号断裂带活动强度自东向西减弱而出现不同的断裂组合样式。基于地层记录和区域演化分析了该区断裂系统的活动时期和活动方式,两次重大的挤压—剪切事件分别发生在奥陶纪末和晚志留-中泥盆世,因而塔里木盆地中央隆起可能是晋宁期山体在后期重新活动形成的加里东期陆内造山带。北西向断裂是二叠纪岩浆侵入或玄武岩喷溢的通道,之后全区断裂基本处于平静状态。结合塔里木周边造山带的演化,认为古生代—三叠纪时塔中地区的盆地发育主要受西昆仑造山带演化制约,同时叠加有古阿尔金剪切造山带的影响,这是为塔中地区特殊的构造位置决定的。侏罗纪—新近纪,该地的盆地主要与阿尔金断裂的剪切造山作用耦合发育,仅早白垩世时与塔北—库车地区同属南天山的"盆""山"系统。断裂的运动学特征取决于其动力学背景,实际上受制于邻侧的造山带发育。断裂系统的发育是塔中地区能形成复式油气田的关键条件之一,本文的研究对推进复式油气成藏的机理研究、明确近期的重点勘探靶区等有积极意义。  相似文献   

Detrital-zircon geochronology of Paleozoic sedimentary rocks in the Hangay–Hentey basin, north-central Mongolia: Implications for the tectonic evolution of the Mongol–Okhotsk Ocean in central Asia     

Thomas K. Kelty  An Yin  Batulzii Dash  George E. Gehrels  Angela E. Ribeiro 《Tectonophysics》2008,451(1-4):290-311

Understanding the development of the Central Asian Orogenic System (CAOS), which is the largest Phanerozoic accretionary orogen in the world, is critical to the determination of continental growth mechanisms and geological history of central Asia. A key to unraveling its geological history is to ascertain the origin and tectonic setting of the large flysch complexes that dominate the CAOS. These complexes have been variably interpreted as deep-marine deposits that were accreted onto a long-evolving arc against large continents to form a mega-accretionary complex or sediments trapped in back-arc to fore-arc basins within oceanic island-arc systems far from continents. To differentiate the above models we conducted U–Pb geochronological analyses of detrital-zircon grains from turbidites in the composite Hangay–Hentey basin of central Mongolia. This basin was divided by a Cenozoic fault system into the western and eastern sub-basins: the Hangay Basin in the west and Hentey basin in the east. This study focuses on the Hentey basin and indicates two groups of samples within this basin: (1) a southern group that were deposited after the earliest Carboniferous ( 339 Ma to 354 Ma) and a northern group that were deposited after the Cambrian to Neoproterozoic ( 504 Ma to 605 Ma). The samples from the northern part of the basin consistently contain Paleoproterozoic and Archean zircon grains that may have been derived from the Tuva–Mongol massif and/or the Siberian craton. In contrast, samples from the southern part of the basin contain only a minor component of early Paleozoic to Neoproterozoic zircon grains, which were derived from the crystalline basement bounding the Hangay–Hentey basin. Integrating all the age results from this study, we suggest that the Hangay–Hentey basin was developed between an island-arc system with a Neoproterozoic basement in the south and an Andean continental-margin arc in the north. The initiation of the southern arc occurred at or after the early Carboniferous, allowing accumulation of a flysch complex in a long-evolving accretionary complex.  相似文献