共查询到20条相似文献,搜索用时 843 毫秒
1.
张立生 《沉积与特提斯地质》2000,20(2):74-82
脉冲黝铜矿型铜矿床是产于兰坪-思茅盆地中的一种新的铜矿床类型。碳酸盐及CO2包裹体的δ^13C值大多在-4‰~-7‰之间变化,显示碳来自地幔。矿石中铅同位素组成与盆地中喜马拉雅期碱性岩长石中铅的同位素组成一致,方解石和铁白云石的^87Sr/^86Sr比值接近或稍高于碱性岩的^87Sr/86Sr的比值,显示矿石锶、铅与碱性岩锶、铅是同源的,均来自于上地幔。硫化物中硫的δ^34S值大多集中在0~-4‰ 相似文献
2.
(古)盐度研究的一种重要工具——锶同位素 总被引:1,自引:0,他引:1
本文详细地阐述了海水-陆表水双元体系中锶同位素的混合原理、混合水体中^87Sr/^86Sr值与盐度的定量关系。利用Sr同位素不随生物、何尝作用过程发生分馏作用及Sr与Ca化学性质相似等特征,地层、沉积物中生物壳体和碳酸盐岩^87Sr/^86Sr值可作为沉积水体(古)盐度确定的一种有用工具。文中详细地综述了国内外在这方面的研究进展,并讨论了成岩后生作用对生物壳体和碳酸盐岩^87Sr/^86Sr原始值 相似文献
3.
地球化学成分和其他地质现象一样,在地球发展过程中也表现出节律。文中选择大气中的CO2,海水中的δ^34S和^87Sr/^86Sr,地壳中的K/Na为代表,介绍了地球历史发展中的地球化学节律,同时人出了区域构造演化中的地球化学演化节律的研究实例。 相似文献
4.
以5cm为间隔取得东太平洋5794岩心早中新世超微化石软泥须(24.06~22.06Ma)的55个样品,用同位素质谱仪、耦合等离子光谱仪和化学溶解当分别对尼中可溶碳酸盐组分的^87Sr/^86Sr、全岩的Al2O3和CaCO3含量进行了测定。结果显示,^87Sr/^86Sr和CaCO3呈反射发育了2个完整旋回和1个半旋回。^87Sr/86Sr和CaCO3短期旋回具有重要的古海洋学意义:(1)^87 相似文献
5.
小秦岭303号石英脉流体包裹体Rb—Sr,^40Ar—^39Ar成矿年龄测定 总被引:10,自引:2,他引:8
用石英流体包裹体Rb-Sr、^40Ar-^39Ar法测定了小秦岭303号石英脉的形成时代为石元古代。其流体包裹体属H2O+CO2+CaCl型,盐度为6.5%-12.98%,CO2含量高,Na^+〉K+。303号石英脉Rb-Sr等时线年龄为(2382±336)Ma-(2234±47)Ma,(^87sR/^86Sr)i为(0.7351±0.0019)-(0.7416±0.0004),^40Ar^^39 相似文献
6.
2.5Ma以来大陆风化强度的演变 总被引:1,自引:0,他引:1
本次研究得出了2.5MaBP以来洛川剖面黄土-古土壤序列的酸不深物^87Sr/^86Sr、Rb/Sr、磁化率和沉积速率的变化曲线。黄土和古土壤酸不深物^87Sr/86Sr、Rb/Sr和磁化率的变化具有类似的阶段性和周期性,这与晚新生代以来古气候的主要变化以及行星轨道参数相一致。研究证明,黄土和古土壤酸不深物^87Sr/^86Sr值得化学风化强度的替代指标,沉积速率是物理风化强度的替代指标。自2.5 相似文献
7.
晚麦斯特里希特阶-早达宁阶高分辨的海水^87Sr/^86Sr参考曲线是根据两个白垩纪-和三纪界线(K-T界线)(法国的Bidart和突尼斯的E1 Kef)剖面建立的。^87Sr/^86Sr比率曲线表明,在K-T界线前0.3 ̄0.4Ma和K-T界线处其值最大。第一个最大代表Deccan Traps火山活动主喷出期的开始。第二个最大值是一个快速的0.00006^87Sr/^86Sr变化,变化范围从K- 相似文献
8.
东天山康古尔金矿床成矿流体地球化学特征及其来源 总被引:15,自引:1,他引:14
新疆康古尔金矿床是分布于晚古生代火山岩区受脆韧性剪切带控制的蚀变岩型金矿。该矿床成矿流体具有中低温度(320~100℃)、中等NaCl质量分数(114%~170%)、弱还原等特征。包裹体气相成分以H2O和CO2为主,液相成分中富Na+、Cl-,而贫K+、F-。成矿流体δD为-45‰~-66‰,δ18O为-834‰~298‰,(87Sr/86Sr)i值为07077~07106,反映了成矿流体由变质水、大气降水和岩浆水混合组成的特点 相似文献
9.
10.
四川盆地南北缘志留系的锶和碳、氧同位素演化及其地质意义 总被引:3,自引:0,他引:3
通过对四川盆地北缘广元地区及南缘綦江地区上奥陶统及下志留统地层的87Sr/86Sr、δ13C及δ18O的系统测定,取得了沿地层剖面变化的同位素组成规律。研究结果表明,在盆地南缘87Sr/86Sr值高于地质历史中海水的平均值,其原因是本区为受板块内古陆控制的缓坡环境,大量陆源锶的混入增加了87Sr/86Sr的值。87Sr/86Sr值在上奥陶统至下志留统地层交界处、Rhuddanian/Aeronian(鲁丹期/艾隆期)交界处具正峰波动,反映了此时海平面的短时下降。但从Rhuddanian至Telychian(特里奇期),87Sr/86Sr逐渐降低。从Aeronian至Sheinwoodian(舍因伍德期)早期,盆地南北缘的δ13C值处于逐渐上升的过程之中,而δ18O则相反。同位素的演化特征说明本区当时为海进时期,海平面不断上升,与全球性海平面变化相吻合。由于受区域构造运动的作用,Sheinwoodian之后的全球持续海进对本区无影响。 相似文献
11.
Gilles Serge Odin 《Comptes Rendus Geoscience》2002,334(6):409-414
Lithostratigraphy, physicochemical stratigraphy, biostratigraphy, and geochronology of the 77–70 Ma old series bracketing the Campanian–Maastrichtian boundary have been investigated by 70 experts. For the first time, direct relationships between macro- and microfossils have been established, as well as direct and indirect relationships between chemo-physical and biostratigraphical tools. A combination of criteria for selecting the boundary level, duration estimates, uncertainties on durations and on the location of biohorizons have been considered; new chronostratigraphic units are proposed. The geological site at Tercis is accepted by the Commission on Stratigraphy as the international reference for the stratigraphy of the studied interval. To cite this article: G.S. Odin, C. R. Geoscience 334 (2002) 409–414. 相似文献
12.
13.
Muriel Rocher Stéphane Baize Stéphane Jaillet Edward Marc Cushing Yannick Lozach Francis Lemeille 《Comptes Rendus Geoscience》2003,335(8):701-708
Calcite samples were extracted both from the rock matrix and the superficial coating of a karstified fault plane of an underground quarry, located in the eastern border of the Paris basin. The karstification is dated as Quaternary. Analysis of mechanical calcite twinning reveals that only the calcite matrix has also undergone a compression trending WNW that can be attributed to the Mio-Pliocene alpine collision. Both coating and matrix have undergone a strike-slip regime with σ1 roughly trending north–south, that could correspond to the regional present-day state of stress, a strike-slip compression rather trending NNW, modified by local phenomena. To cite this article: M. Rocher et al., C. R. Geoscience 335 (2003). 相似文献
14.
正20141520 Bo Ying(Key Laboratory of Metallogeny and Mineral Assessment,MLR,Beijing 100037,China);Liu Chenglin Saline Spring Hydrochemical Characteristics and Indicators for Potassium Exploration in Southwestern and Northern Tarim Basin,Xinjiang(Acta Geoscientica Sinica,ISSN1006-3021,CN11-3474/P,34(5),2013,p.594-602,5 illus.,3 tables,28 refs.) 相似文献
15.
正20141243Chen Ge(Hangzhou Research Institute of Petroleum Geology,PetroChina,Hangzhou 310023,China);Si Chunsong Study on Sedimentary Numerical Simulation Method of Fan Delta Sand Body(Journal of Geology, 相似文献
16.
正20142599Chen Sanming(Guangxi Key Laboratory of Concealed Deposits Exploration,Guilin University of Technology,Guilin541004,China);He Yuzhou Block Model and Reserves Estimation of Panzhihua Iron Deposit Based on 3D Geological Modeling(Journal of Guilin University of Technology,ISSN1674-9057,CN45-1375/N,33(4),2013,p.610-615,9illus.,1table,15refs.) 相似文献
17.
正20140594 Bai Daoyuan(Hunan Institute of Geology Survey,Changsha 410016,China);Zhong Xiang Faults in the Jingzhou Basin and Their Tectonic Settings(Geotectonica et Metallogenia,ISSN1001-1552,CN44-1595/P,37(2),2013,p.173-183,6illus.,59refs.)Key words:basin evolution,tectonic setting,South China In the Upper Paleozoic and Jurassic se- 相似文献
18.
正20141912Cao Hui(State Key Laboratory for Continental Tectonics and Dynamics,Institute of Geology,Chinese Academy of Geological Sciences,Beijing 100037,China)Gravitational Collapse and Folding during Orogenesis:A Comparative Study of FIA Trends and Fold Axial Plane Traces(Geology in China,ISSN1000-3657,CN11-1167/P,40(6),2013,p.1818-1828,9illus.,35refs.,with 相似文献
19.
正20141609 Chen Guiying(College of Earth Sciences,Guilin University of Technology,Guilin 541004,China);Han Nairen New Materials of Stylophora from the Upper Cambrian of the Jingxi Area,Guangxi,South China(Acta Palaeontologica Sinica,ISSN0001-6616,CN32-1188Q,52(3),2013,p.288-293,2 illus.,12 refs.)Key words:Stylophora,Guangxi 相似文献
20.
正20140634 Cao Lingmin(Key Laboratory of Marine Geology and Environment,Institute of Oceanology,Chinese Academy of Sciences,Qingdao 266071,China);Xu Yi Finite Difference Tomography of the Crustal Velocity Structure in Tengchong,Yunnan Province(Chinese Journal of Geophysics,ISSN0001-5733,CN11-2074/P,56(4),2013,p.1159-1167,6illus.,35refs.,with English abstract) 相似文献