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1.
扬子南缘沉积岩的Nd同位素演化及其大地构造意义 总被引：36，自引：5，他引：36
本文系统分析了扬子块体南缘中元古代到二叠纪各个时代地层中泥质沉积岩的Ｓｍ－Ｎｄ同位素组成。中元古代（１．６～１．ＯＧａ）沉积岩具有一致的Ｎｄ模式年龄（ｔＤＭ）（≈１．８Ｇａ）；晚元古代早期（０．９～０．７７Ｇａ）沉积岩的ｔＤＭ年龄从≈１．８Ｇａ急剧降低至。１．３Ｇａ；震旦纪晚期到二叠纪（０．６６～０．２７Ｇａ）沉积岩的ｔＤＭ年龄又恢复到大约１．８Ｇａ。晚元古代早期沉积岩ｔＤＭ年龄的显著降低，表明这个时期扬子南缘的沉积物源区加入了大量新的幔源物质。沉积岩的Ｎｄ同位素结果对中国东南部的大地构造演化提供了新的制约。地质、地球化学和年代学资料均表明扬子南缘的板溪群是一正常的元古代地层单位。华南一扬子晚元古代（晋宁期）碰撞造山运动导致了上述沉积岩的“Ｎｄ同位素漂移”。 相似文献
2.
赣中南地区晚元古代变质地层中的同位素年龄及其地质意义 总被引：10，自引：0，他引：10
赣中南地区晚元古代之潭头群、杨家桥群,一直缺乏同位素年龄数据资料。笔者在兴国地区进行１：５万区域地质调查时,发现该套地层中含多层（套）认石英角斑岩,经对其所含锆石进行Ｕ－Ｐｂ法同位素年龄测定,获得１１３２Ｍａ、９９３Ｍａ、７２３Ｍａ３组同位素年龄资料,为赣中南地区之晚元古代地层时代的进一步确定提供了确切年龄数据。 相似文献
3.
胶南造山带形成与演化 总被引：3，自引：0，他引：3
胶南造山带前寒武纪结晶基底由晚太古代胶东岩，早元古代荆山群及粉子山群，中元古代海州岩群、晚元古代震旦纪朋河石组等变质地层和早－中元古代超镁铁质同夺、镁铁质岩、榴辉岩、晚元古代花岗岩类、榴辉岩等组成。这些岩石记录了造山带形成演化历史：２９００－２８００Ｍａ，胶东岩群中基性火山沉积形成，于２５００Ｍａ遭受中压相系角产偿岩相变质变形作用，之后有少量基性岩中基性火沉积岩形成，于２５００Ｍａ遭受中压相系角闪 相似文献
4.
华夏地块前加里东期变质基义匠年代构造格架 总被引：2，自引：0，他引：2
赵风清 《前寒武纪研究进展》1999,22(2):39-46
华夏地块的前加里东期变质基底大致可划分为三大构造层,主体为古元古代的条旋回的结晶基底和新元古代－早古生代的褶皱基底,局部存在裂谷环境下的中元古代变质岩石。大量的单颗粒锆石年龄和Ｓｍ－Ｎｄ同位素测年资料显示出华夏地块的古元古代岩石形成于２４００￣２０００Ｍａ,中元古代的岩石形成于１４００￣１０００Ｍａ。而新古代－早古生代的地层大致形成于７４０￣４３０Ｍａ。中条运动是华夏地块一次重要的造壳运动,奠基了 相似文献
5.
浙闽前寒武纪基底地壳的形成和增长时代 总被引：3，自引：0，他引：3
对浙闽地区变质岩Ｓｍ－Ｎｄ及锆石Ｕ－Ｐｂ年龄资料研究后认为，浙闽地区存在前寒武纪地壳基底，还可能存在晚太古代古陆核，基底地壳具有幕式增长的特点，经历了２４００Ｍａ（早元古代）１８００Ｍａ（中元古代）和１４００Ｍａ（中元古代）三个主要的地壳增长时期。 相似文献
6.
广西北部新元古代花岗石锆石U—Pb年代学及其构造意义 总被引：14，自引：4，他引：10
广西北部（扬子块体南缘）３个代表性的新元古代花岗岩体（本洞,三防和元宝山岩体）的矿物组合,岩石化学,元素和同位素地球化学特征表明,它们均为铝质Ｓ型花岗岩。高精度的ＳＨＲＩＭＰ和颗粒级锆石Ｕ－Ｐｂ定年结果表明,本洞,三防和元宝山岩体的形成时代为（８２０±７）Ｍａ,（８２５±６）Ｍａ和（８２４±４）Ｍａ,在误差范围内基本相同,排除了本区存在中元古代末／新 元古代初形成的花岗岩。结合野外地质关系和扬子块 相似文献
7.
东川铜矿同位素地球化学研究：Ⅰ.地层年代与铅同位素化探应用 总被引：8，自引：3，他引：8
采用Ｐｂ－Ｐｂ等时线法测定了昆阳群中亚群落雪组白云岩、黑山组碳质板岩和上亚群大营盘组碳质板岩样品，获得了（１７１６±５６）Ｍａ、（１６０７±１２８）Ｍａ和（１２５８±７０）Ｍａ的年龄，确定了昆阳群中亚群时代约为１６００－１８００Ｍａ，属晚古元古代，上亚群大营盘组约为１２００－１３００Ｍａ，属中元古代。 相似文献
8.
华北板块北缘元古代年代地层格架及其形成过程 总被引：3，自引：0，他引：3
近年来同位素年代学研究表明，华北板块北缘活动带内存在着２５００～８００Ｍａ的古老地块，可据其同位素等时线年龄初步建立年代地层格架（表１），在此基础上探讨其形成过程。表１华北板块北缘元古代年代地层格架Ｔａｂｌｅ１Ｐｒｏｔｅｒｏｚｏｉｃｃｈｒｏｎｏｓｔｒ... 相似文献
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10.
郯庐断裂中段鲁中基底韧性变形带的形成时代 总被引：2，自引：0，他引：2
郯庐断裂中段鲁中基底的韧性变形带可分为两类;（１）北东向韧性变形带,以发育中深层次的构造片麻岩为特征,形成于早中元古代花岗质岩体（２４８８Ｍａ）侵位之前;（２）北北东向韧性变形带,以中浅层次糜棱岩为特征,形成了晋宁期（９４１）Ｍａ。文中对以上两类韧性变形带的形成机制和时代进行了初步讨论。 相似文献
11.
Inter-regional correlation of transgressions and regressions in the Cretaceous period 总被引：1，自引：0，他引：1
T. Matsumoto 《Cretaceous Research》1980,1(4):359-373
Well investigated platforms have been selected in each continent, and the history of Cretaceous transgressions and regressions there is concisely reviewed from the available evidence. The factual records have been summarized into a diagram and the timing of the events correlated between distant as well as adjoining areas.On a global scale, major transgressions were stepwise enlarged in space and time from the Neocomian, via Aptian-Albian, to the Late Cretaceous, and the post-Cretaceous regression was very remarkable. Minor cycles of transgression-regression were not always synchronous between different areas. Some of them were, however, nearly synchronous between the areas facing the same ocean.Tectono-eustasy may have been the main cause of the phenomena of transgression-regression, but certain kinds of other tectonic movements which affected even the so-called stable platforms were also responsible for the phenomena. The combined effects of various causes may have been unusual in the Cretaceous, since it was a period of global tectonic activity. The slowing down of this activity followed by readjustments may have been the cause of the global regression at the end of the Cretaceous. 相似文献
12.
The Afyon stratovolcano exhibits lamprophyric rocks, emplaced as hydrovolcanic products, aphanitic lava flows and dyke intrusions, during the final stages of volcanic activity. Most of the Afyon volcanics belong to the silica-saturated alkaline suite, as potassic trachyandesites and trachytes, while the products of the latest activity are lamproitic lamprophyres (jumillite, orendite, verite, fitztroyite) and alkaline lamprophyres (campto-sannaite, sannaite, hyalo-monchiquite, analcime–monchiquite). Afyon lamprophyres exhibit LILE and Zr enrichments, related to mantle metasomatism. 相似文献
13.
K.Naganjaneyulu 《地学前缘(英文版)》2014,5(1):1-2
正The Precambrian shields and associated suture zones of the globe preserve important records of continental growth and destruction,the formation and closure of ocean basins,and the early evolution of the Earth in terms of tectonics,resources,and environment.They also offer critical clues on the nature and style 相似文献
14.
Daniel Harlov 《地学前缘(英文版)》2014,5(5):621-625
正1.Introduction This special issue of Geoscience Frontiers is a tribute volume honoring the life and career of Jacques Touret.A set of research papers has been assembled,which broadly reflect his research interests over his 50 plus year career.These papers focus on the role that fluids play during the formation and evolution of the Earth's crust.Below I provide a brief summary of the life of Jacques Touret,along with a select bibliography of his more important papers.This is then followed by a brief introduction to the papers assembled for this special issue. 相似文献
15.
《地学前缘(英文版)》2014,(1):139-141
正1 AIM AND SCOPE GEOSCIENCE FRONTIERS(GSF)is a bi-monthly international journal that publishes in English high quality original research articles and timely reviews in interdisciplinary fields of Earth and Planetary Sciences.GSF aims to bridge innovative,provocative and challenging concepts and models related to various fields of research including petrology and geochemistry in understanding lithospheric architecture and mantle dynamics,global tectonics,economic geology and fuel exploration,geophysics,stratigraphy and paleontology with new 相似文献
16.
正The world petroleum exploration suggests that,about70%of the world’s potash resources were discovered during oil and gas exploration(Zheng et al.,2007).The Kuqa depression in the Tarim basin is abundant with petroleum exploration data,and 相似文献
17.
正Qarhan Salt Lake is located in the eastern part of the Qaidam Basin,which is first discovered the large potash deposit in the late 1950s.The Bieletan section is located in the west of Qarhan Salt Lake,where saline sediment 相似文献
18.
正With the approach of the 45th World Earth Day,China’s Ministry of Land and Resources issued the status of the Chinese geological survey and environments on 22nd April 2013.Regional geological survey in 2013 achieved new results—(why was oceanic in twice?)polar and oceanic expedition were fully completed,a national census of geography was begun,and 相似文献
19.
正1 Introduction The Lop Nor playa,located in the eastern end of the Tarim Basin,capped with a thick salt crust covering an area of approximately 5,500 km2(Ma 2007)that closely resembles a"Great Ear"in satellite images.Understanding the formation of the salt crust can provide important 相似文献
20.
In Liaoning, Hunan, Guangxi, Guizhou, Gansu, Sichuan, Anhui, Jilin and other provinces in China, there is a wide occurrence of metal quantity over 1000 tons of refractory gold ores, principally because of low gold recoveries and become ＂stay mine＂. Features of refi＇actory gold ores are： gold in micro-particles or a microscopic state that is wrapped in pyrite, presence of arsenopyrite and other sulfide minerals or disseminated in the crystal lattice of sulfide minerals; harmful impurity elements such as arsenic, carbon, mercury, antimony, copper with high content are closely related with the gold, and these elements affect the contact reaction between the gold and solvent extraction, making the recovery of the gold extraction process low. In the past 20 years, overseas countries have developed the application of the roasting oxidation method, hot acid （alkali） oxidation, bacterial oxidation and flash chlorination oxidation technology to solve this problem.Among these, biological oxidation has developed rapidly in the domestic market and gold enterprises abroad because of its low investment in infrastructure, low production costs, less environmental pollution, simple process and easy control, etc. 相似文献