浙西地区新元古代骆家门组SHRIMP锆石U-Pb 年龄及其地质意义     

张恒  高林志  李廷栋  耿树方  刘燕学  丁孝忠  史志刚 《地质通报》2015,34(203):447-455

对河上镇群底部骆家门组2个凝灰岩样品进行锆石测年,得到的2组SHRIMP 锆石U-Pb年龄分别为824±5Ma和832±6Ma、791±15Ma。同时,对骆家门组底部花岗岩砾石中的锆石进行了测试,获得的SHRIMP 锆石U-Pb年龄为901±9Ma。由此进一步约束了骆家门组的形成时代。骆家门组年龄的标定对于浙江地区神功运动界面上、下地层双溪坞群和河上镇群年龄的完善,进而确定江南造山带的地层格架和地层对比具有重要意义。这些地层年龄和已经获得的角度不整合于骆家门组之下双溪坞群的年龄数据,为神功运动时限的约束和对比提供了重要依据。  相似文献   

西藏那曲地区嘎加组闪长玢岩LA-ICP-MS锆石U-Pb年龄与地球化学特征     

彭智敏  耿全如  刘书生  张璋  关俊雷  丛峰 《地质通报》2015,(Z1):354-363

西藏那曲地区的中—晚三叠世嘎加组中存在一套闪长玢岩,对这套闪长玢岩进行了LA-ICP-MS锆石U-Pb同位素测定,获得的年龄为115.4±0.6Ma,属早白垩世,与区域上多尼组和则弄群时代一致。闪长玢岩Si O2含量均值为57.96%,富集Rb、Th元素,亏损Nb、P、Ti元素,与上地壳具有相似的蛛网图曲线。εHf(t)值在2.0~4.1之间,平均值为3.0,岩浆来自新生地壳。结合地球化学和构造环境综合分析,闪长玢岩可能形成于拉萨地块和羌塘地块碰撞环境,115Ma时研究区洋壳俯冲作用已结束,进入陆—陆碰撞的演化阶段,随着羌塘地块与拉萨地块的碰撞,地壳不断加厚,慢慢聚集在浅部岩浆房中的大量岩浆把已经加厚的地壳不断加热,从而引起上覆地壳的部分熔融。  相似文献   

Geochronology and Tectonic Evolution of the West Section of the Jiangnan Orogenic Belt   总被引：1，自引：1，他引：0  

ZHANG Heng  LI Tingdong  XIE Ying  ZHANG Chuanheng  GAO Linzhi  GENG Shufang  CHEN Tingyu  YOU Guoqing 《《地质学报》英文版》2015,89(5):1497-1515

As an important part of South China Old Land, the Jiangnan Orogenic Belt plays a significant role in explaining the assembly and the evolution of the Upper Yangtze Block and Cathaysia, as well as the structure and growth mechanism of continental lithosphere in South China.The Lengjiaxi and the Banxi groups are the base strata of the west section of the Jiangnan Orogenic Belt.Thus, the research of geochronology and tectonic evolution of the Lengjiaxi and the Banxi groups is significant.The maximum sedimentary age of the Lengjiaxi Group is ca.862 Ma, and the minimum is ca.822 Ma.The Zhangjiawan Formation, which is situated in the upper part of the Banxi Group is ca.802 Ma.The Lengjiaxi Group and equivalent strata should thus belong to the Neoproterozoic in age.The Jiangnan Orogenic Belt consisting of the Lengjiaxi and the Banxi groups as important constituents is not a Greenville Orogen Belt(1.3 Ga–1.0 Ga).The Jiangnan Orogenic Belt is a recyclic orogenic belt, and the prototype basin is a foreland basin with materials derived from the southwest and the sediments belong to the active continental sedimentation.By combining large amounts of dating data of the Lengjiaxi and the Banxi groups as well as equivalent strata, the evolutionary model of the western section of the Jiangnan Orogenic Belt is established as follows: Before 862 Ma, the South China Ocean was subducted beneath the Upper Yangtze Block, while a continental island arc was formed on the side near the Upper Yangtze Block.The South China Ocean was not closed in this period.From 862 Ma to 822 Ma, the Upper Yangtze Block was collided with Cathaysia; and sediments began to be deposited in the foreland basin between the two blocks.The Lengjiaxi Group and equivalent strata were thus formed and the materials might be derived from the recyclic orogenic belt.From 822 Ma to 802 Ma, Cathaysia continued pushing to the Upper Yangtze Block, experienced the Jinning-Sibao Movement(Wuling Movement); as result, the folded basement of the Jiangnan Orogenic Belt was formed.After 802 Ma, Cathaysia and the Upper Yangtze Block were separated from each other, the Nanhua rift basin was formed and began to receive the sediments of the Banxi Group and equivalent strata.These large amounts of dating data and research results also indicate that before the collision of the Upper Yangtze Block with Cathaysia, materials of the continental crust became less and less from the southwest to the east in the Jiangnan Orogeneic Belt; only island arc and neomagmatic arc were developed in the eastern section.Ocean-continent subduction or continent-continent subduction took place in the western and southern sections, while intra-oceanic subduction occurred in the eastern section.Comprehensive analyses on U-Pb ages and Hf model ages of zircons, the main provenance of the Lengjiaxi Group is Cathaysia.  相似文献   

泰安—莱芜地区幔枝构造与铁金铜矿床成矿潜力   总被引：1，自引：0，他引：1       下载免费PDF全文

宗信德  石周清  彭超  杨东  耿文涛  田忠平  王航 《地质找矿论丛》2015,30(2):182-189

泰莱幔枝构造包括幔枝核部(岩浆-变质杂岩)、外围沉积盖层中的拆离滑脱构造和上部幔枝上叠构造三部分构成。认为泰安—莱芜地区铁金铜矿找矿突破很大可能在泰莱幔枝滑脱层构造中,也可能是寒武系、奥陶系中的隐爆角砾岩型金矿或夕卡岩型金矿;崅峪岩体近EW向与近SN向交汇处为含矿流体活动主通道,EW向构造成铁矿,崅峪岩体深部可能有大规模铁矿;NNW向构造成金矿,崅峪岩体中部深处可能有富金矿。  相似文献   

基于KQGIS集体土地所有权数据库建设技术的研究     

张建新  蔡冬梅  耿丽艳  魏磊 《测绘与空间地理信息》2015,(3):125-126,129

以苍穹集体土地集体土地所有权管理系统软件为例,对农村集体土地所有权建库的工艺流程进行了优化设计,深入细致地探讨了各工序具体工作,并采用C#语言开发了Easy Map_Kq Tool.exe程序,提高了属性录入的工作效率,实现了地籍档案的自动生成,对同类工程的开展提供了经验借鉴。  相似文献   

农村集体土地所有权数据库建设方法研究     

耿丽艳 《测绘与空间地理信息》2015,(3):179-181

结合鹤壁市农村集体土地确权登记发证工作,探讨建设内业数据库的路线和方法。  相似文献   

采用Levenberg Marquardt的逐步递进波形分解方法   总被引：1，自引：0，他引：1  

李鹏程  徐青  邢帅  刘志青  耿迅  侯晓芬 《测绘科学技术学报》2015,(3):256-260,265

针对机载全波形Li DAR波形数据分解问题,提出一种采用Levenberg Marquardt的逐步递进波形分解方法。该方法基于Levenberg Marquardt的非线性最小二乘拟合算法,选取高斯函数模型并采用逐步递进的波形分解方式得到准确的模拟波形。对Riegl数据中的2条典型波形进行分解实验,并与普通非线性最小二乘方法的结果进行对比分析,证明该方法是可行有效的。  相似文献   

山东旧店金矿金矿物特征及其意义     

李洪奎  禚传源  单伟  耿科  梁太涛 《山东国土资源》2015,31(8)

以山东平度旧店金矿床中金矿物作为研究对象,通过对金矿物的形态、物性、主成分及微量元素等特征的研究,认为旧店金矿中主要金矿物为银金矿、自然金,主要载金矿物为石英、黄铁矿、黄铜矿、方铅矿、闪锌矿等。金主要以银金矿形式产出,金银矿少量,自然金很少。金矿物赋存状态主要为裂隙金、包体金、晶隙金等,呈粒状、板状、针状产出,银金矿与石英、黄铁矿依存关系最为密切。旧店金矿金的成色集中在600～800之间,平均744.13,说明旧店金矿经历了中温成矿环境,且成矿时间较短,是以金石英多金属硫化物阶段为主成矿期。  相似文献   

长治市区浅部地层及剪切波速度结构特征     

耿伟  徐朝繁  刘妍  冯宁  石磊 《大地测量与地球动力学》2015,35(5):840-843

利用长治市区工程场地地震安全性评价项目中已完成的43个钻孔及剪切波速测井资料,基于克里金插值方法,构建长治市区浅部地层及剪切波速度结构模型。结果表明,长治市区浅部地层及剪切波速具有较强的横向非均匀性结构特征,其沉积建造明显受水文地质环境及主要断裂的控制。  相似文献   

黑龙江省高松山浅成低温热液金矿床围岩蚀变元素迁移特征、定量计算与形成机制     

郑硌  顾雪祥  章永梅  刘瑞萍  耿会青  王艳忠  赵红海  李亚军 《地球化学》2015,(1)

高松山浅成低温热液金矿床赋存于下白垩统安山岩等中基性火山岩中。矿体受围岩中断裂破碎带的控制,呈脉状产出。矿区围岩蚀变主要发育硅化、黄铁矿化、冰长石化、伊利石化、绢云母化、碳酸盐化和绿泥石化等。根据蚀变矿物组合和蚀变岩地球化学特征,可将围岩蚀变由近矿至远矿分为3个带:强硅化-冰长石化带、硅化-伊利石化-冰长石化带、伊利石化-青磐岩化带。对各蚀变带进行了全岩元素地球化学分析,利用元素迁移定量计算和图解等方法详细估算和拟定了蚀变过程中元素的迁移规律及其与蚀变矿物学之间的联系。结果表明,安山岩蚀变过程与金矿化密切相关,特别是硅化、冰长石化和黄铁矿化蚀变阶段。根据围岩蚀变形成过程与成矿之间的联系,探讨了高松山金矿床围岩蚀变的形成机制。  相似文献