磁异常三维解析信号所揭示的中国东部及邻近海域岩浆岩特征     

张少武  李春峰 《物探与化探》2011,35(3):290-297

根据中国东部及邻近海域总磁异常计算的三维解析信号振幅值比总磁异常,能精确地刻画磁源体的位置、深度和边界。结果显示在中国东部地区不同构造块体内的岩浆岩深度差异很大,华北块体的磁异常解析信号振幅值较高、尺度大,磁源体埋深达10 km左右或更深,反映了这个古老克拉通块体的中—下地壳内部较为强烈的岩浆活动过程与活化。受构造抬升和岩浆上涌影响,苏鲁—大别造山带的岩浆岩体埋深则相对较浅,多小于5 km。中、下扬子块体的岩浆岩体的埋深也普遍较大,但是岩浆活动微弱,解析信号振幅值很低。受晚中生代古太平洋俯冲的影响,华南块体及其东北海域分布比较孤立的岩浆岩体,其深度大都小于5 km。在东海,受新生代张裂作用的影响,岩浆岩体的深度与基底隆起或沉降呈明显对应关系。琉球群岛对应平静的磁异常并显示较深的岩浆岩体分布,表明琉球群岛不是菲律宾海板块俯冲形成的火山弧而可能是由俯冲增生楔物质和部分从欧亚大陆分离出来的块体构成,其西侧的岩浆岩带才是真正的火山弧。  相似文献   

地球化学异常提取的自适应衬值滤波法   总被引：1，自引：0，他引：1  

金俊杰  陈建国 《物探与化探》2011,35(4):526-531

地球化学数据分布,特别是微量元素的频率分布,是正向偏斜的,其异常下限的计算也是基于对数正态分布。当定性分析元素的分布状态时,大部分样本分布状态的结果是可以接受的,但是当定量计算异常下限时,一定要结合具体样本的实际分布情况。引入g-h分布函数对样本数据进行拟合,根据所得到的参数确定异常下限,将异常下限与标准离差分割开来。结合子区中位数衬值滤波法,对个旧及其外围成矿区的化探数据进行处理,同时自适应的调节滤波窗口大小,提取化探异常,从而对预测靶区进行圈定。  相似文献   

Stratigraphy of the Triassic?Jurassic Boundary Successions of the Southern Margin of the Junggar Basin, Northwestern China   总被引：2，自引：1，他引：1  

SHA Jingeng  Vivi VAJDA  PAN Yanhong  Linda LARSSON  YAO Xiaogang  ZHANG Xiaolin  WANG Yaqiong  CHENG Xiansheng  JIANG Baoyu  DENG Shenghui  CHEN Siwei  PENG Bo 《《地质学报》英文版》2011,85(2):421-436

The Triassic?Jurassic (Tr?J) boundary marks a major extinction event, which (~200 Ma) resulted in global extinctions of fauna and flora both in the marine and terrestrial realms. There prevail great challenges in determining the exact location of the terrestrial Tr?J boundary, because of endemism of taxa and the scarcity of fossils in terrestrial settings leading to difficulties in linking marine and terrestrial sedimentary successions. Investigation based on palynology and bivalves has been carried out over a 1113 m thick section, which is subdivided into 132 beds, along the Haojiagou valley on the southern margin of the Junggar Basin of the northern Xinjiang, northwestern China. The terrestrial Lower Jurassic is conformably resting on the Upper Triassic strata. The Upper Triassic covers the Huangshanjie Formation overlaid by the Haojiagou Formation, while the Lower Jurassic comprises the Badaowan Formation followed by the Sangonghe Formation. Fifty six pollen and spore taxa and one algal taxon were identified from the sediments. Based on the key-species and abundance of spores and pollen, three zones were erected: the Late Triassic (Rhaetian) Aratrisporites?Alisporites Assemblage, the Early Jurassic (Hettangian) Perinopollenites?Pinuspollenites Assemblage, and the Sinemurian Perinopollenites?Cycadopites Assemblage. The Tr?J boundary is placed between bed 44 and 45 coincident with the boundary between the Haojiagou and Badaowan formations. Beds with Ferganoconcha (?), Unio?Ferganoconcha and Waagenoperna?Yananoconcha bivalve assemblages are recognized. The Ferganoconcha (?) bed is limited to the upper Haojiagou Formation, Unio?Ferganoconcha and Waagenoperna?Yananoconcha assemblages are present in the middle and upper members of the Badaowan Formation. The sedimentary succession is interpreted as terrestrial with two mainly lake deposit intervals within Haojiagou and Badaowan formations, yielding fresh water algae and bivalves. However, the presence of brackish water algae Tasmanites and the marine?littoral facies bivalve Waagenoperna from the Badaowan Formation indicate that the Junggar Basin was influenced by sea water caused by transgressions from the northern Tethys, during the Sinemurian.  相似文献   

Regional Distribution and Prospects of Potash in China   总被引：4，自引：0，他引：4  

ZHENG Mianping  an  ZHENG Mianping  YUAN Heran  LIU Xifang  CHEN Wenxi  LI Jinsuo 《《地质学报》英文版》2011,85(1):17-50

China was formed by amalgamation of several small continental blocks (cratons), micro, blocks and orogenic belts in different paleoclimatic settings. It may be correlated with other continental blocks but has its own specific characteristics; therefore the tectonic environments of China’s marine and continental saline basins and salt, and potash, forming environment have some specific characteristics: multiple phases of salt formation, difference in salt, forming ages, migration and concentration of salt, forming processes and diversity of component materials, as well as small sizes of marine saline basins and great changes of saline basins in the late stage and occurrence of abundant liquid mineral resources. The nature of the tectonic basement exerted a key controlling effect on the formation of potash basins. The stable tectonic region was favorable for potash concentration in a quasi, stable region, and quasi, and the quasi-stable region was favorable for salt concentration and potash formation in a local stable tectonic region. Most China’s major ancient saline basins occur in “quasi, cratons (continental block)”; especially all the marine saline basins occur in continental blocks with the Precambrian basement. These regions are the key ones for potash search. Most relatively large, scale soluble salt deposits are developed in relatively stable continental nuclei. According to the characteristics of the tectonic domains where China’s salt, forming basins are located, the North China, Yangtze and Tarim, Qaidam salt minerogenetic domains and the northern Qiangtang, western Yunnan salt minerogenetic belt may be distinguished. Their salt and potash prospects will be discussed separately.  相似文献   

2010上海世博会上欧泊营销的启示     

余芳  包德清 《地质科学译丛》2011,(1):43-46

欧泊是一种具有特殊光学效应的宝石,其变幻莫测的色彩令人着迷。但在国内珠宝市场上欧泊的销售份额很小,有关其有效营销方法研究方面的参考资料基本处于空白状态。借助2010年上海世博会的契机,结合笔者在澳大利亚馆销售欧泊产品4个月的经历,着重从多角度吸引顾客、留住顾客、销售攻心术、灵活引导及创新推广活动等方面分析了澳大利亚AODC公司的营销策略,从中总结出几点建议,旨在对国内珠宝营销有所启发。  相似文献   

宁镇中段夕卡岩型铜多金属矿床多元信息成矿预测初步研究          下载免费PDF全文

张术根  余旭辉  徐莺 《地质找矿论丛》2011,26(2):167-175

宁镇中段铜多金属矿床主要为接触交代型矿床.文章以地质环境和成矿规律研究为基础,采用逻辑信息法综合提取地质、遥感、地球物理和地球化学多层次成矿预测信息,构建逻辑信息法成矿预测要素组合.并以此为指导,按照地质成矿条件有利程度、物化探异常强度与规模、环形构造发育程度、遥感解译蚀变显现强度与规模,进行综合判别确定成矿有利位置,...  相似文献   

基于RAGA的PPC模型在化探异常分析中的应用——以凤太矿集区为例          下载免费PDF全文

廖时理  张均  张利亚  姚涛 《地质找矿论丛》2011,26(1):90-95

化探数据处理的核心内容是地球化学背景与地球化学异常的合理区分,找矿信息提取将直接影响到成矿预测的结果.文章采用基于RAGA的PPC模型对凤太矿集区1:5万水系沉积物化探数据进行处理,初步探讨了投影寻踪聚类方法在地球化学异常识别与元素共生组合方面的应用,以及投影方向值所代表的地质意义.结果表明,PPC模型的化探异常识别效...  相似文献   

山西灵丘支家地铅锌银矿矿石微观组构及地球化学特征对成矿期次的指示意义     

覃娴瑟  吴堑虹  于洪立 《大地构造与成矿学》2011,35(1):118-127

山西灵丘支家地铅锌银矿床为中生代隐爆角砾岩型多金属热液矿床。通过显微镜、扫描电镜对矿石进行观察,发现矿石发育显示不同成矿阶段的矿物组合,矿物溶蚀结构、硫化物角砾、脉状、环带等结构构造,并分析了这些结构构造对成矿期次的指示意义;黄铁矿、闪锌矿、方铅矿等硫化物的S、Fe、Cu、Zn、Pb、Ag、In、Sn、Sb元素含量分布显示早期成矿阶段形成的硫化物较晚期的富Ag、In、Sn、Sb;不同成矿阶段的方铅矿Pb同位素组成没有明显差别。矿石的微观结构构造、硫化物元素组成特征说明该矿区发育两次成矿作用,而且二者间存在构造及热液蚀变的间断,Pb同位素特征则说明两次成矿发生于同一大地构造背景,该认识为该矿成矿模型的建立及找矿工作提供了新思路。  相似文献   

复杂形态岩体接触带成矿耦合动力学三维数值模拟:以安庆铜矿为例   总被引：4，自引：1，他引：3  

赵义来  刘亮明 《大地构造与成矿学》2011,35(1):128-136

安庆铜矿是长江中下游成矿带中重要的矽卡岩矿床,其矿体绝大部分产在形态复杂的岩体接触带上,对于这种矿体定位特点,本文采用数值模拟的方法探讨了其动力学机制和主要的控矿因素。首先以AutoCAD和GO-CAD为平台构建安庆铜矿岩体及围岩的三维实体模型,并通过C++编程实现到模拟软件的模型格式转换,然后以FLAC3D为平台进行安庆铜矿热液成矿过程的力-热-流耦合数值模拟。结果显示,受控于拉张应力场,岩体大部分位置表现为正的体应变;月山岩体东枝南接触带是扩容最为明显的区域,部分岩石单元的大扩容角对扩容区出现有一定的贡献,岩石物理性质的差异及接触带的复杂形态则是其主要原因;岩石扩容部位成为流体汇集的有利场所,汇流部位与明显扩容区及主矿体产出位置相一致,推断矿体的定位是力-热-流共同作用的结果;运算结果亦指示现有矿体深部存在新的有利找矿靶区。  相似文献   

宁夏月亮山西麓找矿远景预测中的重磁资料应用研究   总被引：1，自引：0，他引：1  

程建华  尹秉喜 《物探化探计算技术》2011,33(1):45-50,119

这里对月亮山西麓重磁资料进行了处理解释,研究了磁异常、重力异常和地球化学组合的异常特征。通过对成矿地质背景条件的分析,解释了研究区磁异常很可能是隐伏的中基性潜火山岩,或是与其相关的铁-铜多金属所为,同时还预测了车路湾南、赵家佬、泉儿湾、王民北磁异常为研究区重要的找矿远景靶区。  相似文献