首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 296 毫秒
1.
<正>A series of Ni-Cu sulfide deposits hosted in Early Permian mafic-ultramafic complexes occur along the~500km long linear Huangshan-Jingerquan belt in the East Tianshan at the southern margin of the Central Asian Orogenic Belt(Fig.1)(Zhou et al.,2004;Song and Li,2009;Song et al.,2011;Qin et al.,2011;Deng et al.,2014).Questions for genetic link between these deposits and the  相似文献   

2.
1 Introduction The early Precambrian basement of the North China Craton (NCC) consists mainly of the Eastern Continental Block, the Western Continental Block and the Trans-North China Orogen (TNCO, or “the Central Tectonic Zone”), which formed by continental collision between the Eastern and Western Blocks (Zhao et al., 1998). This evolutionary model has now been widely accepted (Wu and Zhong, 1998; Guan et al., 2002; Guo et al., 2002; Liu et al., 2002a, b; Liu et al., 2004a, b;…  相似文献   

3.
http://www.sciencedirect.com/science/article/pii/S167498711400156X   总被引:1,自引:0,他引:1  
<正>Continental reconstructions in Central Asia are represented by orogenesis along some large orogenic belts in the Altaid collage(Fig.1)or Central Asian Orogenic Belt(CAOB),which separate the East European and Siberian cratons to the north from the Tarim and North China cratons to the south(Sengor et al.,1993;Jahn et al.,2004;Windley et al.,2007;Qu et al.,2008;  相似文献   

4.
<正>The Central Asian Orogenic Belt(CAOB)is an immense accretionary orogen and is an important site of Phanerozoic crustal growth(Fig.1a;Seng?r et al.,1993;Jahn,2004;Windley et al.,2007;Xiao et al.,2008;Safonova and Santosh,2014).The West Junggar,situated  相似文献   

5.
正Numeral Permian mafic-ultramafic complexes occur in the Beishan terrane atthe northeastern margin of the Tarim craton,southwestern Central Asian Orogenic Belt,including the Pobei,Cantoushan,Bijiashan,Hongshishan,Xuanwoling,Zhongposhan and Luodong etc.,intrusions (Qin et al.,2011;Zhang et al.,2017;Xue et al.,2018).These Beishan mafic-ultramafic complexes are composed of peridotite,pyroxenite,troctolite and gabbro with significant cumulate rhythmic layers of magmatic  相似文献   

6.
The Changning-Menglian Belt in West Yunnan, Southwest China is well-known as a closed remnant of the Paleo-Tethys Ocean in East Asia (Wu et al., 1995; Liu et al., 1996). It is delineated to the east with the Lincang Massif by the Changning-Shuangjiang Fault and to the west with the Baoshan Block by the Kejie-Nandinghe Fault, and is generally subdivided into three zones: east, central, and west zones. In the central zone, various kinds of oceanic rocks such as harzburgite, cumulate websterite, gabbro, both mid-oceanic ridge basalt and oceanic island basalt, Devonian-Triassic radiolarian chert, and Carbonifer-ous-Permian massive and huge carbonates with basaltic effusives as their pedestal are exposed (Liu et al., 1991, 1996; Wu et al., 1995; Ueno et al., 2003). These Central zone rocks are now interpreted to have been emplaced as nappes structurally overlying the East and West zones, which are considered as consisting mainly of passive margin sediments of the Baoshan Block (Wu, 1991; Ueno et al., 2003).  相似文献   

7.
<正>1. Objective The Wenquan Group is one of the important medium-to low-grade metamorphic units within the Wenquan metamorphic complexes which distributes in Chinese segment of the Tianshan Belt, the southern part of the Central Asian Orogenic Belt. It mainly consists of pre-Neoproterozoic metamorphosed volcanic and sedimentary rocks(Wang B et al., 2014).  相似文献   

8.
正Objective The Khondalite Belt is a nearly E–W-trending Paleoproterozoic Himalayan-type orogen in the Western Block of the North China Craton. It is regarded as a result of the collision between the northern Yinshan Block and the southern Ordos Block at ~1.95 Ga, which led to the formation of the united basement of the Western Block(e.g., Zhao et al., 2005; Yin et al., 2011). The Khondalite Belt has undergone long-term continent-continen collisional orogenic processes, and a remarkable series of late-stage orogen-parallel ductile shear zones developed(e.g., Huang et al., 2013; Gong et al., 2014).  相似文献   

9.
Throughout the Phanerozoic the eastern margin of Gondwana and related fragments such as New Caledonia and New Zealand that are now dispersed from it grew through the addition of ophiolites and associated intra-oceanic island arc assemblages.Exactly how and why this occurred remains controversial with two main competingmodelsreferredtoaseither‘quantum’or‘accordion’tectonics.The quantum model envisages continental growth through the additional of discrete intra-oceanic assemblages analogous to contemporary tectonic settings in Taiwan,Timor and Papua New Guinea(Aitchison and Buckman,2012).The alternative regards eastern Australia as the type example of a different style of convergent plate margin referred to as an‘extensional accretionary orogeny’(Collins,2002).The oldest Phanerozoic ophiolites and intra-oceanic island arc assemblages are of Cambrian age and are widely reported from the Lachlan Fold Belt in the eastern Australian states of Victoria and NSW(Spaggiari et al.,2003;Greenfield et al.,2011).Similar rocks are also known from Mount Read in Tasmania(Berry and Crawford,1988;Crawford and Berry,1992;Mulder et al.,2016),the Weraerai terrane and its correlatives in the New England orogen further east in northeastern NSW(Aitchison et al.,1994;Aitchison and Ireland,1995)and Queensland,the Takaka terrane in NW Nelson,New Zealand(Münker and Cooper,1999)and the Bowers terrane in Northern Victoria Land,Antarctica(Weaver et al.,1984;Münker and Crawford,2000;Rocchi et al.,2011;Palmeri et al.,2012).The Late Ordovician saw the development of the intra-oceanic Macquarie island arc(Glen et al.,1998;Glen et al.,2007).This system contains important economic mineral deposits.The way in which these arcrocks developed and were juxtaposedagainst a surrounding suite of Lachlan Fold Belt,eastern Australia remains the subject of investigation(see Aitchison and Buckman,2012 for discussion).In a similar area,enigmatic rocks of the Tumut ophiolite also crop out(Graham et al.,1996;Belousova et al.,2015).Further to the east in the New England orogeny Siluro-Devonian rocks of the Gamilaroi terrane and it’s along strike correlatives near Mt Morgan in Queensland represent another intra-oceanic island arc assemblage emplaced onto the Gondwana margin in the Late Devonian(Aitchison and Flood,1994;Offler and Murray,2011).The Late Carboniferous-Permian saw development of significant intra-oceanic island arc and ophiolitic complexes remnants of which crop out in New Zealand,eastern Australia,and New Caledonia.These include the Brook Street terrane(Spandler et al.,2005;Mc Coy-West et al.,2014)and Dun Mountain Ophiolite Belt in New Zealand(Coombs et al.,1976;Stewart et al.,2016),the Gympie terrane in southeast Queensland(Waterhouse and Sivell,1987;Sivell and Waterhouse,1988)and the Koh terrane in New Caledonia(Meffre et al.,1996;Ali and Aitchison,2002).The youngest on-land association of ophiolitic and intra-oceanic island arc rocks in the region is of Eocene age.Ultramafic rocks are well exposed in New Caledonia where they structurally overlie continental rocks of Gondwana margin affinity that,in the northeast of the island,have experienced eclogite facies metamorphism(Aitchison et al.,1995).The emplacement of these rocks was a widespread regional event with potentially correlative rocks exposed in Papua New Guinea(Parrot and Dugas,1980)as well as Northland and East Cape in New Zealand(Whattam et al.,2005;Whattam et al.,2008).  相似文献   

10.
http://www.sciencedirect.com/science/article/pii/S1674987112000874   总被引:3,自引:1,他引:2  
<正>1.Introduction The continental crust,covering nearly a third of the Earth's surface,is dominantly made up of granites and granodiorites(Rudnick and Gao, 2003).Although the vast majority of these granitoids are amphiboleand /or biotite-bearing,orthopyroxene-bearing granitoids form a minor but important component of the lower continental crust in many high-grade terrains(e.g.,Bohlender et al.,1992;Kilpatrick and Ellis,1992;Sheraton et al.,1992;Berger et al.,1995;Zhou et al., 1995;Peucat et al.,1996;Duchesne and Wilmart,1997;Hughes et al.,1997;Prame.1997;Frost et al.,2000;Janasi,2002;Mendes  相似文献   

11.
The study of the physicochemical behaviour of colloids and particles in nature has emerged as a scientific problem of critical importance because of the widespread acknowledgement of their significance in controlling the speciation and fate of essential nutrients and contaminants in the aquatic and soil environments (Ledin et al., 1995; Lead et al., 1999, Doucet et al., 200 l; McCarthy et al., 1989; Koterba et al., 1993; Kretzschmar et al., 1999). Se'quaris and Lewandowski (2003) developed a method based on sedimentation and centrifugation steps to fractionate agricultural top soils after suspension in water. However, progress in the field has been limited by the lack of appropriate techniques for the isolation and characterization of colloids and particles in their native form (Lead et al., 1997). The primary difficulties in separation and analysis are colloidal instability and their small size and low concentration. As a result, reliable, unbiased and minimally perturbing methods for sampling and fractionation are primary requirements for the study of colloids and particles if valuable information is to be obtained. In recent years, cross-flow ultra-filtration (CFUF) has become one of the most commonly used techniques for collecting and separating freshwater and marine colloids and particles (Petrus evski et al., 1995; Gustafsson et al., 1999; Benoit et al., 1999; Sigg et al., 2000; Gue'guen et al., 2002; Benedetti et al., 2003). CFUF has hitherto been used for studies of the biogeochemical cycling of a variety of elements, such as carbon (Benner et al., 1992; Santschi et al., 1998), radionuclides (Moran et al., 1992), trace metals (Reitmeyer et al., 1996) and nutrients (Bauer et al., 1996). The purpose of this study was to develop a protocol to fractionate particles in soil, to measure particle size distributions and to quantify chemical characteristics within different particle size fractions.  相似文献   

12.
1 Introduction The tectono-thermal evolution of the North China Craton (NCC) in Late Archean to Paleoproterozoic times has long been attractive to many researchers (Wan et al., 2000; Zhao et al., 2000, 2002; Guo et al., 2001; Liu et al., 2002; Zhai and Liu 2003; Zhai, 2004; Yu et al., 2004; Kr?ner et al., 2005; Wilde et al., 2005). Zhao et al. (2000, 2002) proposed a tectono-thermo framework for the evolution of the NCCbased on detailed petrological and geochronological data, and they …  相似文献   

13.
正1 Introduction Although a mumerous of papers were reported for the chemcial or instrumental analysis of inorganic elements for the geocheical samples(Sun and Xie,2014;Sun et al.,2014;Rao et al.,2004).However,the analytical methods  相似文献   

14.
Mongolia is located within the Central Asian Orogenic Belt. The belt is consist of numerous tectonic blocks or terranes, which resulted from collisions during the Early Paleozoic (Caledonian orogeny), Late Paleozoic (Hercynian orogeny) and partly in Early Mesozoic (Indosinian orogeny) (Seng?r et al., 1993; Heubeck, 2001; Badarch et al., 2003). These collisions had a profound effect on the coal-bearing sedimentary basins in Carboniferous, Permian, Jurassic and Cretaceous periods of Mongolia. A total of more than 200 coal occurrences and deposits are known, of which about 70 have been explored.  相似文献   

15.
<正>1 Introduction East Kunlun orogen(EKO)stretching more than 1000km in E-W extension is located in the western segment of Central Orogen Belt(COB),China(Xu et al.,2006,Li et al.,2014).There outcropped Cambrian ophiolites  相似文献   

16.
正With the rapid development of technology,geological big data is increasing explosively,and plays an increasingly important position in the national economy (Zhang and Zhou,2017;Zhou et al.,2018).Governments and agencies attach great importance to the open internet service of geological big data and information at home,and abroad (Yan et al.,2013;Guo et al.,2014).The basic norms of western countries'geological data information services are rich and varied products,efficient and  相似文献   

17.
1. IntroductionThe Mianlue (Mianxian-Lueyang) suture zone is one of the components of the Qinling orogenic belt and the latest major suture zone between North and South China. The data available suggest that it is a complicated ophiolitic tectonic melange zone including many tectonic slabs of different origins (Zhang et al., 1995; Lai et al., 1996; Lai et al.,1997; Lai et al.,1998; Xu et al.,1996). Up to now, however, there is not definite evidence of volcanic rock assemblage and geochemi…  相似文献   

18.
1. IntroductionThe discovery of delicately persevered multicellular algae and possible animal embryos from the terminal Proterozoic Doushantuo Formation has greatly changed our views on the origin and early evolution of metaphyte and metazoan (Chen et al., 1991, 1992; Zhang et al., 1992, 1998; Li et al., 1997; Xiao et al., 1998), and encourages us to look for the evidences of advanced lives in older rocks. Some jellyfish fossils were reported in the Piyuancun Formation (equated with Dengyi…  相似文献   

19.
1 Introduction Voluminous literature has resulted from study of the geology and tectonic evironments of post-orogenic granitoids in eastern Tianshan (He et al., 1995; Han et al., 1997; Gu et al., 1999, 2001; Li et al., 2003; Chen et al., 2004). Previous contributions (Hu et al., 1997; Li et al., 2003) indicate that major events of continental collision in northern Xinjiang occurred around 300 Ma. Then, the tectonics converted from compression to extension, resulting in the uplifting of th…  相似文献   

20.
<正>The identification of large-giant bedrock landslides triggered by earthquake aims to the landslide prevention and control.Previous studies have described the basic characteristics,distribution,and the formation mechanism of seismic landslides(Bijan Khazai et al.,2003;Chong Xu et al.,2013;Lewis a.Owen et al.,2008;Randall W.Jibson et al.,2006).However,few researches have focused on the early identification indicators of large-giant  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号