Magmatic‐Hydrothermal Mineralization Sequence in Xinlu Ore Field,Guangxi, South China: Constraints from Zircon U‐Pb,Molybdenite Re‐Os,and Muscovite Ar‐Ar Dating     

Yangyang Feng  Zuohai Feng  Wei Fu  Zhiqiang Kang  Jian Jiang  Along Guo  Xi Wang  Meng Feng  Chunzeng Wang 《Resource Geology》2019,69(4):430-447

The Xinlu Sn‐polymetallic ore field is located in the western Nanling Polymetallic Belt in northeastern Guangxi, South China, where a number of typical skarn‐, hydrothermal vein‐type tin deposits have developed. There are two types of Sn deposits: skarn‐type and sulfide‐quartz vein‐type. The tin mineralizations mainly occur on the south side of the Guposhan granitic complex pluton and within its outer contact zone. To constrain the Sn mineralization age and further understand its genetic links to the Guposhan granitic complex, a series of geochronological works has been conducted at the Liuheao deposit of the ore field using high‐precision zircon SHRIMP U‐Pb, molybdenite Re‐Os, and muscovite Ar‐Ar dating methods. The results show that the biotite‐monzogranite, which is part of the Xinlu intrusive unit of the Guposhan complex pluton, has a SHRIMP U‐Pb zircon age of 161.0 ± 1.5 Ma. The skarn‐type ore has a ⁴⁰Ar‐³⁹Ar muscovite plateau age of 160 ± 2 Ma (same as its isochron age), and the sulfide‐quartz vein‐type ore yields an Re‐Os molybdenite isochron age of 154.4 ± 3.5 Ma. The magmatic‐hydrothermal geochronological sequence demonstrated that the hydrothermal mineralization took place immediately following the emplacement of the monzogranite, with the skarn metasomatic mineralization stage predating the sulfide mineralization stage. Geochronologically, we have compared this ore field with 26 typical Sn deposits distributed along the Nanling Polymetallic Belt, leading to the suggestion of the magmatic‐metallogenic processes in the Xinlu ore field (ca. 161–154 Ma) as a component of the Early Yanshanian large‐scale Sn‐polymetallic mineralization event (peaked at 160–150 Ma) in the Nanling Range of South China. Petrogenesis of Sn‐producing granite and Sn‐polymetallic mineralization were probably caused by crust–mantle interaction as a result of significant lithospheric extension and thinning in South China in the Late Jurassic.  相似文献   

Basaltic and Solution Reference Materials for Iron,Copper and Zinc Isotope Measurements     

Jin Li  Suo‐han Tang  Xiang‐kun Zhu  Zhi‐hong Li  Shi‐Zhen Li  Bin Yan  Yue Wang  Jian Sun  Yao Shi  Aiguo Dong  Nick S. Belshaw  Xingchao Zhang  Sheng‐ao Liu  Ji‐hua Liu  Deli Wang  Shao‐yong Jiang  KeJun Hou  Anthony S. Cohen 《Geostandards and Geoanalytical Research》2019,43(1):163-175

Iron, Cu and Zn stable isotope systems are applied in constraining a variety of geochemical and environmental processes. Secondary reference materials have been developed by the Institute of Geology, Chinese Academy of Geological Sciences (CAGS), in collaboration with other participating laboratories, comprising three solutions (CAGS‐Fe, CAGS‐Cu and CAGS‐Zn) and one basalt (CAGS‐Basalt). These materials exhibit sufficient homogeneity and stability for application in Fe, Cu and Zn isotopic ratio determinations. Reference values were determined by inter‐laboratory analytical comparisons involving up to eight participating laboratories employing MC‐ICP‐MS techniques, based on the unweighted means of submitted results. Isotopic compositions are reported in per mil notation, based on reference materials IRMM‐014 for Fe, NIST SRM 976 for Cu and IRMM‐3702 for Zn. Respective reference values of CAGS‐Fe, CAGS‐Cu and CAGS‐Zn solutions are as follows: δ⁵⁶Fe = 0.83 ± 0.07 and δ⁵⁷Fe = 1.20 ± 0.13, δ⁶⁵Cu = 0.57 ± 0.06, and δ⁶⁶Zn = ?0.79 ± 0.12 and δ⁶⁸Zn = ?1.65 ± 0.24, respectively. Those of CAGS‐Basalt are δ⁵⁶Fe = 0.15 ± 0.07, δ⁵⁷Fe = 0.22 ± 0.10, δ⁶⁵Cu = 0.12 ± 0.08, δ⁶⁶Zn = 0.17 ± 0.13, and δ⁶⁸Zn = 0.34 ± 0.26 (2s).  相似文献   

辽河盆地西部凹陷古近系沙四上亚段沉积相及演化     

王夏斌  姜在兴  胡光义  范廷恩  王俊辉  卢欢 《吉林大学学报(地球科学版)》2019,49(5):1222-1234

薄互层砂体研究是湖盆沉积学的研究难点。本文针对辽河西部凹陷沙四上亚段（Es^4上）薄互层砂体,以层序地层学、沉积学、测井地质学等理论为指导,综合岩心、测录井和地震等多种资料,对西部凹陷的薄互层砂体进行精细描述和深入剖析。结果表明,研究区主要发育辫状河三角洲和湖泊沉积相,其中,滩坝砂体是湖泊相的主力砂体。通过考虑不同沉积背景下滩坝在岩相组合、发育位置和成因机理的差异性,将滩坝划分成侧缘改造型滩坝、前缘改造型滩坝、基岩改造型滩坝、淹没改造型滩坝和风暴改造型滩坝5种沉积模式;对薄层滩坝砂体的控制因素进行分析,认为其受到"风场-物源-盆地"三端元的控制。  相似文献   

川南煤田龙潭组煤系泥页岩气与煤层气组合模式及合采前景分析     

尹中山  蒋琦  熊建龙  罗勇  琚宜文 《中国煤炭地质》2019,(5):30-35

文中研究的上二叠统龙潭组煤层及其顶底板泥页岩含气性特征、组合模式及合采对煤系气勘探开发意义重大。为改变煤层气产业低产低效长周期的现状,实现综合效益的目标,将龙潭组作为目标层进行研究;简述了川南煤田龙潭组含气泥页岩与煤层的组合模式,并初步探讨了上述组合模式合探合采的必要性、条件和前景,并提出了开展综合勘探开采的建议。  相似文献   

从自然控制论看黄河上游人工增雨   总被引：4，自引：4，他引：0  

雷恒池  曾庆存  李仑格  朱江 《气候与环境研究》2001,6(4):391-399

用自然控制论原理和方法,从理论上探讨了用人工增雨来解决黄河断流所遇到的一些问题及解决方案.结果表明,只有在黄河上游地区增加降水才可以缓解黄河断流问题,河曲地区是最佳人工增雨区.针对河曲有限区域人工调控天气问题,首次提出了解决人工增雨的正问题与反问题的概念.在此基础上,给出了河曲地区人工增雨的概念模型.  相似文献   

海面环境下舰船目标的RCS测试建模分析          下载免费PDF全文

王雅芬  江志浩  黄猛  张振杰 《数字海洋与水下攻防》2021,4(3):183-187

在分析国内外海面环境下舰船目标电磁散射特性测试建模技术研究现状和海面环境下舰船目标电磁散射特点的基础上,提出了一种“半确定性”的海面环境下舰船目标的电磁散射特性建模仿真计算方法。 该方法可以在不具备外场全尺寸测试或造浪条件下电磁缩比试验条件时,以一定的置信度获取海面舰船的耦合电磁散射特性,为研究海面舰船雷达隐身设计验证提供支撑。  相似文献   

城镇增长下的收缩：以武汉为例     

高喆  尹宁玮  童馨仪  李东欣  顾江 《热带地理》2019,39(1):29-36

首先从人口、经济、用地3个维度综合考察武汉市增长与收缩的全貌，并采用县区及街道2个尺度的数据定量描述了武汉市增长与收缩的特征与空间格局，发现武汉市下辖青山区、硚口区、汉阳区和蔡甸区存在局部较严重的收缩现象，空间上形成集聚，形态上呈“穿孔式”。进一步以青山区为案例，着重从资本视角探讨发生局部收缩的内在机制，发现其存在老龄化、少子化趋势，但局部收缩的主因是资本从产业部门的“逃逸”。  相似文献   

我国瓯江口和珠江口凤鲚洄游模式和生境利用研究     

姜涛  刘洪波  黄洪辉  杨健 《海洋学报(英文版)》2019,38(8):35-40

Habitat use of the tapertail anchovy(Coilia mystus Linnaeus, 1758) from the Oujiang River Estuary and the Zhujiang(Pearl) River Estuary was studied by examining the environmental signatures of Sr and Ca in otoliths using electron probe microanalysis. Individuals from the Oujiang River had higher and varied Sr:Ca ratios(expressed as(Sr:Ca)×1 000, 3.83–13.0 average) in the otolith core regions, suggesting that they were born in brackish or sea waters, and that a freshwater habitat might not be necessary for egg hatching and larval growth.While, individuals from the Zhujiang River had lower Sr:Ca ratios(0.39–2.51 average) in the core regions,suggesting a freshwater origin. After hatching, anchovies from the Zhujiang River migrate downstream to the river estuary close to brackish water. Our results demonstrated varied habitat use for spawning during stages of early life history between the two populations, and suggested that such variations are promoting diversity of life history strategies of this species.  相似文献   

Multi-color light curves and orbital period research of eclipsing binary V1073 Cyg     

Xiao-Man Tian  Li-Ying Zhu  Sheng-Bang Qian  Lin-Jia Li  Lin-Qiao Jiang 《天文和天体物理学研究(英文版)》2018,(2)

New multi-color BV RcIcphotometric observations are presented for the W UMa type eclipsing binary V1073 Cyg. The multi-color light curve analysis with the Wilson-Devinney procedure yielded the absolute parameters of this system, showing that V1073 Cyg is a shallow contact binary system with a fill-out factor f = 0.124(±0.011). We collected all available times of light minima spanning 119 yr,including CCD data to construct the O-C curve, and performed detailed O-C analysis. The O-C diagram shows that the period change is complex. A long-term continuous decrease and a cyclic variation exist. The period is decreasing at a rate of P =-1.04(±0.18) × 10~(-10) d cycle~(-1) and, with the period decrease, V1073 Cyg will evolve to the deep contact stage. The cyclic variation with a period of P_3= 82.7(±3.6) yr and an amplitude of A = 0.028(±0.002) d may be explained by magnetic activity of one or both components or the light travel time effect caused by a distant third companion with M_3(i′= 90?) = 0.511 M_⊙.  相似文献   

超慢速扩张环境下超镁铁质岩系统的热液硫化物成矿机理以及启示     

曹红  孙治雷  刘昌岭  姜学钧  何拥军  黄威  尚鲁宁  王利波  张喜林  耿威  施美娟  李东义 《海洋学报》2018,40(4):61-75

西南印度洋63.5°E热液区是在超慢速扩张洋脊发现的首个超镁铁质岩热液系统。对取自该区的热液硫化物样品进行了系统的矿物学和地球化学分析，矿物学分析结果表明:该热液区硫化物为富Fe型高温硫化物，且经历了较深程度的氧化蚀变，大量中间态的Fe氧化物充填在硫化物矿物间的孔隙及内部解理中；这些硫化物相以白铁矿为主，其次是等轴古巴矿和少量铜蓝，缺乏黄铁矿、闪锌矿。据推断，该区的热液成矿作用分为4个阶段:低温白铁矿阶段→高温等轴古巴矿阶段→自形白铁矿阶段→后期海底风化阶段（少量铜蓝以及大量的Fe的羟氧化物）。与之相对应，地球化学分析结果表明这些硫化物的Fe含量较高（31.57%~44.59%），Cu含量次之（0.16%~7.24%），而Zn含量普遍较低（0.01%~0.11%）；微量元素较为富集Co（328×10-6~2 400×10-6）和Mn（48.5×10-6~1 730×10-6）。该区硫化物中较高含量的Fe、Co与超镁铁质岩热液系统相似，明显高于镁铁质岩热液系统。独特的热液硫化物矿物学特征和元素组成可能与该区普遍出露的地幔岩、橄榄岩蛇纹石化作用以及拆离断层的广泛发育的环境有关。  相似文献