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1.
<正>The Tian Shan Orogenic Belt,which is a subsidiary of the Central Asian Orogenic Belt,is the largest accretion area of continental crust on the Earth during the Phanerozoic.It has experienced several accretionary processes during the Palaeozoic period and has attracted much concern among geologists.An Early Palaeozoic intrusive rock belt extends  相似文献   

2.
1. IntfoductionThe eastern Guangdong province is located in the southern part of the NE trending Chinacoastal volcanic belt and also is the intersection part of the E-W trending Namingtectonic-magmatic belt. Mesozoic orcks and intrusive rocks (dominated by acidic) widelycrop out over the area. The outcrop area of the intrusive rocks is l/2 of the whole district,and that of the volcanic rocks is 1/4 of the magmatic rocks formed in Yanshanian. Only afew of basic stocks and pillars formed in …  相似文献   

3.
Continental- Margin Structure of Northeast China and Its Adjacent Areas   总被引：10，自引：0，他引：10  
The continental margin of Northeast China and its adjacent areas is composed of two tectonic belts. The inner belt is a collage made up of fragments resulting from breakup of an old land with the north part related to the evolution of the Palaeo-Asian Ocean and the south part to the evolution of the Palaeo - Pacific Ocean. The outer belt is a Mesozoic terrane, which is a melange made up of fragments of the Late Palaeozoic to Early Mesozoic oceanic crust and the Late M esozoic trench accumulations.There existed another ocean-the Palaeo - Pacific Ocean during the period from the closing of the Palaeo-Asian Ocean to the opening of the modern Pacific Ocean or from the Devonian to Jurassic, and the ocean-floor spreading of the Palaeo - Pacific Ocean led to the formation of the above-mentioned tectonic belts. The development of the strike-slip fault system after the Late Jurassic and the formation of an epicontinental volcano -plutonic rock belt in the Late Cretaceous to Early Tertiary are attributed to the i  相似文献   

4.
This paper deals with the geochemical features of the two Early Paleozoic ophiolite zones in the central-southem Tianshan region and the central Tianshan igneous rock belt between them.Study results suggest that the central Tianshan belt was an Ordovician volcanic arc with an affinity of continental crust, and the Kumux-Hongluhe ophiolitic zone that is located on the southern margin of central Tianshan has a crustal affinity to back-arc marginal sea.The Aqqikkudug-Weiya ophiolitic zone is an accretionary boundary between the Tuha continental block and the central Tianshan volcanic arc during Late Silurian to Devoniann;Ordovician ophi-olitic blocks,Silurian flysch sequence and HP metamorphic rock relics are distributed along the Aqqikkudug-Weiya zone.Geochemically,ophiolitic rocks in the Aqqikkudug-Weiya zone have an affinity to oceanic crust,reflecting a tectonic setting of paleo-trench or subduction zone .The Early Carboniferous red molasses were deposited unconformably on the pre-Carboniferous meta-mrophosed and ductile sheared volcanic and flysch rocks,providing an upper limit age of the central and southern Tianshan belts.  相似文献   

5.
The Duobaoshan ore concentration area, located in Nenjiang County of Heilongjiang Province, is an important porphyry Cu-Mo ore concentration area in China, which is characterized by complex magmatic activities and multi–phase overprinting metallogenesis. On the basis of field geological observation, systematic sampling, in-lab analysis and the metallogenic regularity in the Xiang'an–Mongolian metallogenic belt, this work carried out high-precision dating and geochemical analysis on the Yuejin, 173-kilometer and Wolihedingzi rock bodies. These rock bodies are renamed monzonitic granite and their consistent age(238 Ma) show that they were formed not in Variscan but in Indosinian. Therefore, it is inferred that the ore spots formed in the potassium silicate and sericite alteration zones of the rock mass also belong to Indosinian. In addition, we collected granodiorite from the Tongshan mining pit, and its zircon age is 223.1±2.8 Ma and the Cu content of the sample is high. The Tongshan mineralization is inferred to undergo the superimposition of Indosinian diagenetic mineralization. The age of the granodiorite porphyry related to copper-molybdenum mineralization in the Xiaoduobaoshan area is 222.1±5.5 Ma, and the earlier age of granodiorite is 471.8±7.4 Ma, indicating that the initial magmatic activities belong to the Duobaoshan porphyry system in the Caledonian period. The geochemical characteristics of the Indosinian rock samples show continental arc features, with reference to tectonic-magmatic activities of the whole Daxing'anling area. We consider that the magmatic activities and mineralization of the Indosinian period are affected by the southward subduction of Okhotsk Ocean since Late Permian. By combining the mineralization rules of Daxinganling area and the structural systems of Duobaoshan ore concentration area, we divide two rock-mineralization belts in this area including the Yuejin–Duobaoshan–Tongshan belt and 173-kilometer–Xiaoduobaoshan–Wolihedingzi belt, which are distributed nearly parallel along the NW-trending fractures and show similar geotectonic settings and the timing of the magmatic activities. It is favorable for discovering porphyry Cu-Mo deposits in these two metallogenic belts, especially in the Yuejin, 173-kilometer and Wolihedingzi areas where less research work has been made.  相似文献   

6.
<正>Objective The Qinling orogenic belt is a typical complex continental orogenic belt which has experienced multiperiod tectonic evolution and where some important tectonic belts formed.The Luoluan fault is one of the most important belts,which is the boundary fault of the North China Plate and the Qinling orogenic belt.The Shirenshan block is located in the north section between Luanchuan and Fangcheng of the Luoluan fault.The north part is  相似文献   

7.
In the Central Orogenic Belt, China, two UHP metamorphic belts are discriminated mainly based on a detailed structural analysis of the Kanfenggou UHP metamorphic fragment exposed in the eastern Qinling orogen, and together with previous regional structural, petrological and geochronological data at the scale of the orogenic domain. The first one corresponds to the South Altun-North QaidamNorth Qinling UHP metarnorphic belt. The other is the Dabie-Sulu UHP and HP metamorphic belts. The two UHP metamorphic belts are separated by a series of tectonic slices composed by the Qiniing rock group, Danfeng rock group and Liuling or Foziling rock group etc. respectively, and are different in age of the peak UHP metamorphism and geodynamic implications for continental deep subduction and collision. Regional field and petrological relationships suggest that the Kanfenggou UHP metamorphic fragment that contains a large volume of the coesite- and microdiamond-bearing eclogite lenses is compatible with the structures recognized in the South Altun and North Qaidam UHP metamorphic fragments exposed in the western part of China, thereby forming a large UHP metamorphic belt up to 1000 km long along the orogen strike. This UHP metamorphic belt represents an intercontinental deep subduction and collision belt between the Yangtze and Sino-Korean cratons, occurred during the Paleozoic. On the other hand, the well-constrained Dabie-Sulu UHP and HP metamorphic belts occurred mainly during Triassic time (250-220 Ma), and were produced by the intracontinental deep subduction and collision within the Yangtze craton. The Kanfenggou UHP metamorphic fragment does not appear to link with the DabieSulu UHP and HP metamorphic belts along the orogen. There is no reason to assume the two UHP metamorphic belts as a single giant deep subduction and collision zone in the Central Orogenic Belt situated between the Yangtze and Sino-Korean cratons. Therefore, any dynamic model for the orogen must ac-count for the development of UHP metarnorphic rocks belonging to the separate two tectonic belts of different age and tectono-metamorphic history.  相似文献   

8.
The Tashisayi nephrite deposit is located in South Altyn Tagh.in Qiemo County,Xinjiang Province,northwest China.It is a recent discovery in the vast,well-known Kunlun-Altyn nephrite belt distributed along the south of the Tarim Basin,producing more than half of the nephrite from the whole belt in 2017.Field investigations revealed that it is a dolomitic marble-related(D-type)nephrite deposit,but little is known about its age of formation and relationships between the granites and marble.Here we report field investigations,petrography of the neph rite,as well as petrography,geochemistry,geochronology of the zoisite-quartz altered intrusive rock and adjacent granites.An A-type granite is identified with a SHRIMP U-Pb zircon age of 926± 7 Ma,suggesting it was emplaced in an extensional tectonic environment at that time.The altered intrusive rock has a cluster of U-Pb zircon age of 433± 10 Ma.with similar trace element features to the A-type granite,suggesting it was formed in an extensional regime at this later time.Nephrite formed because of the metasomatism of dolomite marble by hydrothermal fluids.It is inferred that Ca~(2+) was released from the dolomitic marble by metasomatism forming Ca-rich fluids,which caused alteration of both the intrusive rocks(6.00-8.22 wt.% CaO)and granite(1.76-3.68 wt.% CaO)near the nephrite ore bodies.It is also inferred that Fe2+ from the granite migrated towards the dolomite marble.The fluids gave rise to the formation of Ca-minerals.such as zoisite,in the nephrite and altered intrusive rock,and epidote in the granite.Based on the contact relationships.similarity in hydrothermal processes,and consumption of Ca~(2+),the Tashisayi nephrite is considered to have formed at the same time as the alteration of the intrusive rocks,i.e.～433 Ma.The geochronological similarity(～926 Ma.433 Ma)of South Altyn and North Qaidam may suggest that tectonically they belong to one single complex in the past,which was offset by the Altyn Tagh fault(ATF).The similar formation ages of the nephrites from Altyn Tagh(433 Ma)and the previously studied areas of West Kunlun(378-441 Ma)and East Kunlun(416 Ma)indicate that these nephrites formed during the closure of Proto-Tethys and in the accompanving post-collisional.extensional environment.  相似文献   

9.
A mosaic of terranes or blocks and associated Late Paleozoic to Mesozoic sutures are characteristics of the north Sanjiang orogenic belt (NSOB). A detailed field study and sampling across the three magmatic belts in north Sanjiang orogenic belt, which are the Jomda–Weixi magmatic belt, the Yidun magmatic belt and the Northeast Lhasa magmatic belt, yield abundant data that demonstrate multiphase magmatism took place during the late Paleozoic to early Mesozoic. 9 new zircon LA–ICP–MS U–Pb ages and 160 published geochronological data have identified five continuous episodes of magma activities in the NSOB from the Late Paleozoic to Mesozoic: the Late Permian to Early Triassic (c. 261–230 Ma); the Middle to Late Triassic (c. 229–210 Ma); the Early to Middle Jurassic (c. 206–165 Ma); the Early Cretaceous (c. 138–110 Ma) and the Late Cretaceous (c. 103–75 Ma). 105 new and 830 published geochemical data reveal that the intrusive rocks in different episodes have distinct geochemical compositions. The Late Permian to Early Triassic intrusive rocks are all distributed in the Jomda–Weixi magmatic belt, showing arc–like characteristics; the Middle to Late Triassic intrusive rocks widely distributed in both Jomda–Weixi and Yidun magmatic belts, also demonstrating volcanic–arc granite features; the Early to Middle Jurassic intrusive rocks are mostly exposed in the easternmost Yidun magmatic belt and scattered in the westernmost Yangtza Block along the Garzê–Litang suture, showing the properties of syn–collisional granite; nearly all the Early Cretaceous intrusive rocks distributed in the NE Lhasa magmatic belt along Bangong suture, exhibiting both arc–like and syn–collision–like characteristics; and the Late Cretaceous intrusive rocks mainly exposed in the westernmost Yidun magmatic belt, with A–type granite features. These suggest that the co–collision related magmatism in Indosinian period developed in the central and eastern parts of NSOB while the Yanshan period co–collision related magmatism mainly occurred in the west area. In detail, the earliest magmatism developed in late Permian to Triassic and formed the Jomda–Wei magmatic belt, then magmatic activity migrated eastwards and westwards, forming the Yidun magmatic bellt, the magmatism weakend at the end of late Triassic, until the explosure of the magmatic activity occurred in early Cretaceous in the west NSOB, forming the NE Lhasa magmatic belt. Then the magmatism migrated eastwards and made an impact on the within–plate magmatism in Yidun magmatic belt in late Cretaceous.  相似文献   

10.
Large-scale Cenozoic magmatic rocks from the interplay between the Indian and Eurasian plate are exposed in the Yulong porphyry copper belt in the northern Jinshajiang–Ailaoshan domain. Alkali-rich magmas along the Yulong porphyry copper belt can reveal the tectono-magmatic processes in the Sanjiang region. In this study, we present new zircon U–Pb–Hf isotopes and whole rock geochemistry of Cenozoic granitoids from the Zhalaga area in the northern Yulong porphyry copper belt. The Zircon U–Pb dating results show that the Zhalaga granitic porphyry crystallized at ca. 42–38 Ma. These porphyry deposits are depleted in Nb, Ta, Sr, and Ti enriched in alkaline and rare earth elements (REEs), and exhibit high zircon saturation temperatures, that strongly indicate A-type affinity. These data and the generally positive εHf(t) values (2.0–4.5) suggest the magmas originated from a hybrid of partial melting of subduction-modified lithospheric mantle, possibly triggered by upwelling of the asthenospheric mantle. Geochronological and geochemical data of the current and previous studies distinguish three magmatic phases during the Cenozoic in the Jinshajiang–Ailaoshan region: (1) ca. 62–48 Ma; (2) ca. 44–30 Ma; and (3) ca. 28–16 Ma. The strong collision between the Indian and Eurasian plates produced relatively fast convergence rates during the first episode (ca. 62–48 Ma), whereas the subsequent right-lateral strike-slip faulting in the Jinshajiang fault zone initiated at ca. 43 Ma is associated with the relatively low India–Eurasia convergence rates during ca. 44–30 Ma. These significantly impacted the nature and spatial distribution of the magmatism and the large-scale metallogeny during the Cenozoic in the Sanjiang region. We suggest that the Zhalaga alkali-rich magmas occurred in a transition period from involving soft to hard collisional settings. This remarkable example demonstrates that alkali-rich magmas with A-type affinity are also generated in an orogenic tectonic setting.  相似文献   

11.
The newly discovered three alkali-rich intrusive rock belts in the Mt. Kunlun Mt.Altun region of southern Xinjiang are the Lapeiquan-Yitunbulak alkali-rich intrusive rock belt,the Gez-Taxkorgan alkali-rich intrusive rock belt and the Beilisai-Abulash alkali-rich intrusive rock belt. The former two belts were formed during the Yanshanian period, and the third one was formed during the Himalayan period, which is the youngest alkali-rich intrusive rock belt in China. The discovery of the alkali-rich intrusive rock belts is of great significance in shedding light on the history of tectono-magmatic activities in this region.  相似文献   

12.
东秦岭北部富碱侵入岩岩石化学与分布特征   总被引：5，自引：1，他引：5  
在东秦岭北部，富碱侵入岩的侵位与空间分布受同一个区域构造带（华并陆块南缘）控制，构成一个区域性的富碱岩浆岩带。根据岩石学和岩石化学研究，岩石类型主要分为三大类：（1）碱性岩类，即含有似长石或碱性暗色矿物的正长岩类；（2）碱性花岗岩类，包括钠铁闪石花岗岩及孪生的钾长花岗岩类；（3）石英正长岩类，包括碱性长石为主的石英正长岩、英碱正长岩和花岗正长（斑）岩类。根据富碱岩浆岩带的岩石化学特征，自北而南可以划分为三个亚带：北部碱性岩亚带，以SiO2饱和而l2O3不饱和出现碱性暗色矿物为特征；中部碱性花岗岩亚带，以SiO2强饱和而Al2O3不饱和出现碱性暗色矿物和大量石英为特征；南部石英正长岩亚带，以SiO2和Al2O3都饱和但CaO强烈亏损，缺乏Ca质斜长石，出现碱性长石占长石总量的绝对优势（一般＞95％）为特征。三个亚带富碱岩浆在化学成分方面虽有差异，但共同具有富碱高钾钙征，ALK＝10－15，K2O含量范围5％－15％，K2O／Na2O＝1．26－8．30。  相似文献   

13.
东秦岭北部富碱侵入岩带岩石地球化学特征及构造意义   总被引：4，自引：0，他引：4  
在东秦岭北部,富碱侵入岩的侵位与空间分布受同一个区域构造带(华北陆块南缘)控制,构成一个区域性的富碱岩浆岩带。根据岩石学和岩石化学研究,岩石类型主要分为碱性正长岩、碱性花岗岩和石英正长岩三大类。富碱岩浆岩带自北而南可以划分为3个亚带:北部碱性正长岩亚带,中部碱性花岗岩亚带,南部石英正长岩亚带。3个亚带富碱岩浆在化学成分方面虽有差异,但都具有富碱高钾特征,ALK=9～15,ω(K_2O)为5％～15％,ω(K_2O)/ω(Na_2O)=1.26～8.30。岩石中的暗色矿物辉石类主要为霓辉石和霓石,角闪石类主要为钙质浅闪石、阳起石质闪石、镁质角闪石、钠钙质绿闪石,黑云母类主要为铁云母和金云母。岩石中的长石类主要为K-Na系列富K端员的微斜长石和最大微斜长石,少量钠长石,极少Na-Ca系列的斜长石。霞石类主要为钾霞石和钙霞石。根据岩石地球化学研究,有以下显示:(1)REE总量200～1100μg/g,LREE/HREE比值4～15,δEu表现为无Eu异常或轻微正负Eu异常,(La/Yb)_n值多为10～30;(2)部分岩石类型富集大离子亲石元素,不相容元素分布模式曲线总斜率为负,Ba,Nb,Zr具明显负异常,表明他们具有大陆裂谷碱性花岗岩的特征;(3)岩石Nd、Sr和Pb同位素的研究表明,富碱侵入体的源区应是以下地壳为主,带入少量地幔和上地壳物质。  相似文献   

14.
西藏冈底斯地块中新生代中酸性侵入岩浆活动与构造演化   总被引：4，自引：0，他引：4  
冈底斯地块上的中新生代中酸性岩浆活动,是北部班公湖-怒江和南部雅鲁藏布两个特提斯演化及其后的陆内汇聚碰撞造山和后造山伸展等大地构造事件的完整记录.地块上的中酸性岩浆活动可划分为3个带,其中北部岩带岩浆岩形成于燕山期,其类型从早期的Ⅰ型到中期的过渡型演化为晚期的S型,分别形成于板块俯冲-缝合-碰撞等构造条件下,是北部班公湖-怒江特提斯演化的集中反映.中部和南部岩浆岩带则集中体现了雅鲁藏布特提斯时空演化的完整经历.其中,南部岩带岩体以燕山晚期为主,喜马拉雅早期次之,成因及形成环境与特提斯洋壳向北俯冲作用密切相关(燕山晚期),同时俯冲结束后的同碰撞条件下的岩浆活动在该岩带内也有明显的反映(喜马拉雅早期);中部岩带岩体以喜马拉雅早期为主,燕山晚期次之.岩体大部分为同碰撞环境下岩浆活动的产物,它表征了随着洋壳板块向北俯冲程度的加深和强度的加剧,岩浆活动中心在不断向北迁移,并最终缝合碰撞的过程.因此该岩带内岩浆岩主要形成于俯冲的晚阶段及缝合后的同碰撞条件下.喜马拉雅晚期的小斑岩体实际上广泛出露于整个冈底斯地块上,它反映的是该区在经历了碰撞造山后发生的陆内伸展的构造过程.  相似文献   

15.
郯庐断裂带是中国东部一条巨大的深大断裂带,它纵切华北克拉通、扬子克拉通、兴蒙-吉黑造山带和大别-苏鲁造山带四个大地构造单元,特别是在该断裂带出露许多晚中生代富碱侵入岩体,构成一条长达近2000km的富碱侵入岩带.本文是在前人研究基础上首次从大尺度对整个郯庐断裂带富碱侵入岩的Nd、Sr、Pb同位素做了比较系统深入的研究,发现四个大地构造单元的富碱侵入岩具有明显不同的Nd、Sr、Pb同位素特征,暗示四大构造单元富碱侵入岩的源区性质差别较大:兴蒙-吉黑造山带晚中生代富碱侵入岩源于和亏损地幔有成因联系的年青地壳(εNd(t)为ft.,平均值 2.25);华北克拉通、扬子克拉通和大别-苏鲁造山带三大构造单元晚中生代富碱侵入岩都主要源于EMI型富集地幔(εNd(t)均为负值).但是这三大构造单元岩石圈地幔富集程度差别较大.大别-苏鲁造山带岩石圈地幔相对富集程度最高(εNd(t)平均值为-17.06);华北克拉通次之(εNd(t)平均值为-10.03);扬子克拉通岩石圈地幔富集程度最低(εNd(t)平均值为-6.41).本文认为大别.苏鲁造山带岩石圈地幔相对最富集的原因可能是在早中生代扬子克拉通陆壳向华北克拉通深俯冲之后的折返过程中,因压力释放有利于熔/流体的形成、析出和向上交代并改造华北岩石圈地幔使之成为富集地幔.  相似文献   

16.
在喀雅克登塔格地区古元古代金水口群片麻岩、大理岩中,发现了一套变质侵入体。岩性为眼球状黑云二长片麻岩,经同位素年龄测定时代为新元古代,侵入体具有过铝钙碱性系列的特征,是同碰撞环境下岩浆作用产物。该套变质侵入岩的发现,对于东昆仑西段前震旦纪基底的深入研究及更进一步恢复和确定喀雅克登塔格构造岩浆带发展演化具有重要意义。  相似文献   

17.
铜厂斑岩型Cu(Mo-Au)矿床位于金沙江-红河富碱侵入岩带的南段,其含矿的石英正长斑岩侵入体属金沙江-红河富碱侵入岩带的重要组成部分.对铜厂石英正长斑岩开展详细的地球化学研究结果表明,其具有高碱、富钾及准铝质-弱过铝质等特征,属钾玄岩系列岩石;微量和稀土元素分析表明,铜厂石英正长斑岩明显富集Rb、Ba、Th、U、K、La和Sr等大离子亲石元素,相对亏损Nb、Ta和Ti等高场强元素,具有明显的“TNT”负异常,稀土总量高,明显富集轻稀土而亏损重稀土,轻重稀土分馏显著;(87Sr/86Sr)i为0.707097～0.707138,εNd(t)为-7.1 ～ -6.8,在Sr-Nd同位素相关图上,与EMII来源岩石相似.对比金沙江-红河富碱侵入岩带北段的玉龙含矿的二长花岗斑岩和中段的马厂箐含矿的花岗斑岩的地球化学特征,铜厂含矿斑岩具有高的全碱、微量元素和稀土元素含量、高的(87Sr/86Sr)i值和低的εNd(t)值、不具埃达克质岩属性等特征.综合研究表明,铜厂含矿的石英正长斑岩在成因类型上属于A型花岗岩类,形成于～35 Ma的晚碰撞走滑环境且直接起源于EMII地幔的部分熔融铜厂与玉龙及马厂箐斑岩型Cu( Mo-Au)矿床含矿斑岩地球化学特征和成矿规模存在差异,与源区物质的部分熔融程度和地壳物质的混染程度密切相关.  相似文献   

18.
西藏冈底斯地块中新生代中酸性侵入岩特征与构造环境   总被引：4，自引：0，他引：4  
冈底斯地块上的中新生代中酸性岩浆活动，是北部班公湖一怒江和南部雅鲁藏布两个特提斯演化及其后的陆内汇聚碰撞造山和后造山伸展等大地构造事件的完整记录。地块上的中酸性岩浆活动可划分为三个带，其中北部岩带岩浆岩形成于燕山期，其类型从早期的Ⅰ型到中期的过渡型再演化为晚期的S型，分别形成于板块俯冲-缝合-碰撞等构造条件下，是北部班公湖一怒江特提斯演化的集中反映。中部和南部岩浆岩带则集中体现了南部雅鲁藏布特提斯时空演化的完整经历，其中，南部岩带岩体以燕山晚期为主，喜山早期次之，成因及形成环境与特提斯洋壳向北俯7中作用密切相关(燕山晚期)，同时俯冲结束后的同碰撞条件下的岩浆活动在该岩带内也有明显的反映(喜山早期)；中部岩带岩体以喜山早期为主，燕山晚期次之，岩体大部分为同碰撞环境下岩浆活动的产物，它表征了随着洋壳板块向北俯冲程度的加深和强度的加剧，岩浆活动中心在不断向北迁移，并最终缝合碰撞的过程。因此，该岩带内岩浆岩主要形成于俯冲的晚阶段及缝合后的同碰撞条件下。喜山晚期的小斑岩体实际上广泛出露于整个冈底斯地块上，它反映的是该区在经历了碰撞造山后发生的陆内伸展的构造过程。  相似文献   

19.
滇西马厂箐斑岩铜(钼)矿床成岩成矿时限的厘定   总被引：24，自引：1，他引：23  
滇西马厂箐富碱侵入岩为一复式岩体,存在多期次岩浆侵入活动;最早岩浆活动始于52Ma,中期岩浆活动为42～47Ma,晚期岩浆活动最强烈,其时间为33～37Ma,末期岩浆活动为29～32Ma。马厂箐铜钼矿床早期成矿发生在37～40Ma左右,晚期成矿大约在34—35Ma;与区域上其它与富碱侵入岩有关矿床的形成时间相当吻合。马厂箐矿床在时、空上与矿区富碱侵入岩关系密切,其成矿作用主要与晚期的岩浆侵入活动有关。  相似文献   

20.
甘肃北山成矿带处于我国古亚洲成矿域的中段,工作程度较低,但从近年来取得的进展说明,该带矿产资源潜力、经济意义和前景不亚于古亚洲域的东部和西部,因此,应加强对该带的认识和采取更有利的找矿措施。该带在中、晚元古代及古生代成矿作用的基础上又叠加了中生代强烈的成矿作用,特别是酸性和富碱岩浆活动及有关矿化十分活跃。本文从区域成矿...  相似文献   

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