粤宋桂地区新发现5处多金属矿点     

《山西地质》2014,(4):22-22

由广东省佛山地质局承担的“广东宋桂地区矿产远景调查”项目目前顺利通过验收。项目组在区内新发现金银多金属矿点5处,新发现矿化体或矿化线索多处。据该项目负责人介绍,“广东宋桂地区矿产远景调查”项目成果突出,共圈定地球化学异常100处,划出找矿远景区5处,从大量的地物化遥信息中优选出找矿靶区10处,新发现金银多金属矿点5处,新发现矿化体或矿化线索多处,其中“德庆县老王坑银多金属矿”和“郁南县黄金顶金矿”获得了探矿权。  相似文献   

Geochemistry of mafic rocks and melt inclusions and their implications for the heat source of the 14.0°S hydrothermal field,South Mid-Atlantic Ridge     

Bing Li  Xuefa Shi  Yaomin Yang  Jun Ye  Jingjing Gao  Wenqin Zheng 《中国地球化学学报》2014,33(4):325-335

Fresh rocks sampled from the 14.0°S hydrothermal field of the South Atlantic Ridge can be divided into two categories： olivine-gabbro and basalt. The olivine-gabbro is composed mainly of three types of minerals： olivine, clinopyroxene and plagioclase, while a multitude of melt inclusions occur in the plagioclase phenocrysts of the basalts. We analyzed the whole-rock, major and trace elements contents of the basaks, the mineral chemistry of phenocrysts and melt inclusions in the basalts, and the mineral chemistry of olivine-clinopyroxene-plagioclase in the olivine-gabbro, then simulated magma evolution within the crust using the COMAGMAT program. The whole-rock geochemistry shows that all the basalts exhibit typical N-MORB characteristics. In addition, the mineral chemistry characteristics of the olivine-gabbro （low-Fo olivine, low-Mg# clinopyroxene, high-TiO2 clinopyroxene, low-An plagioclase）, show that strong magma differentiation occurred within the crust. Nevertheless, significant discrepancies between those minerals and phenocrysts in the basalts （high-Fo olivine, high-An plagioclase） reflect the heterogeneity of magma differentiation. High Mg# （-~0.72） melt inclusions isobaric partial crystallization simulations suggest that the magma differentiation occurred at the depth shallower than 13.03 km below the seafloor, and both the vertical differentiation column shows distinct discrepancies from that of a steady-state magma chamber. Instead, a series of independent magma intrusions probably occurred within the crust, and their corresponding crystallized bodies, as the primary high-temperature thermal anomalies within the off-axis crust, probably act as the heat source for the development of the 14.0°S hydrothermal system.  相似文献   

东川-易门式铜矿床成矿作用研究的几个问题     

冉崇英  吴鹏 《大地构造与成矿学》2014,(4)

从宏观基础地质入手,按矿床学的一些基本概念,针对东川-易门铜矿床地质地球化学特征,探讨了一些存在争议的重要问题。研究认为:狮山段是绿汁江组下部独立存在的地层层位;东川-易门式铜矿床属沉积-改造成因,其中的层状铜矿属沉积成岩成因,不是"热液成矿";所谓东川-易门式矿床(稀矿山除外)为"喷流沉积成矿"或"岩浆叠加",尚依据不足;刺穿体是构造作用产物,对成矿有利,是良好的找矿标志,其中的角砾岩主要是沉积角砾岩与构造角砾岩,或沉积-构造角砾岩,不足以冠名"隐爆角砾岩(筒)"。  相似文献   

椭球体的视电阻率特征     

张超  汤井田  强建科 《物探化探计算技术》2014,(2):158-163

椭球体是最具代表性的典型三维地电体之一,它三个轴的长短经过变化后可以和多种形状的地电体相似。因此,实现了椭球体电阻率的求解,就可以模拟绝大多数三维地电体的电阻率曲线。从拉普拉斯方程的求解出发,得到了均匀空间中存在的水平椭球体异常表达式,并用简单加倍的方法得到了均匀半空间中水平椭球体的视电阻率公式,结合倾斜旋转椭球体的视电阻率公式的规律,得到了倾斜椭球体的视电阻率公式,再进行一系列简化得到板状体。最后分析对比了均匀电场中旋转椭球体和板状体的视电阻率曲线的形态和规律。结论表明:旋转椭球体与板状体的视电阻率曲线的走向大体相似,且板状体的曲线相比旋转椭球体较缓和。对于低阻情况,在异常体顶部附近的视电阻率异常为零,异常体的倾向一侧有极小值,反倾向一侧有极大值,曲线随倾角α的增大而逐渐变陡。对于高阻情况,视电阻率的极大值出现在异常体顶部附近,两侧有极小值,倾向一侧的曲线较缓和而反倾向一侧的曲线较陡峭,随着倾角α的增大,视电阻率异常变大。  相似文献   

河北省遵化—迁西地区超基性岩生成时代的探讨     

李树朋  刘小滨  王京隆  赵文浩 《吉林地质》2014,(2):20-25

冀东地区已蛇纹石化及未蚀变的超基性岩绝大多数在新太古代变质深成岩中呈包体存在,不少专家把这些超基性岩归属太古宙。笔者认为该区未变质及已蛇纹石化超基性岩应是显生宙的产物,而不是太古宙变质深成岩的"捕掳体"。同时对遵化—迁西地区蛇纹岩生成时代进行探讨。  相似文献   

崩塌体水力输移与塌岸淤床交互影响试验          下载免费PDF全文

余明辉  郭晓 《水科学进展》2014,25(5):677-683

以二元结构河岸崩塌模式为研究背景,在弯道水槽中展开系列试验,研究凹岸坡脚处成型崩塌体在水力作用下输移过程及其对岸坡稳定性与河床冲淤的交互影响。试验成果表明,崩塌体经水力分解破碎呈块状、片状或颗粒状起动,部分随水流带至凸岸或下游,堆积在坡脚附近的崩塌体残留量随水力作用大小及土体特性不同而变化。崩塌体临水面周围尤其上下游端水流紊动强烈易形成较大剪切力区,临坡面上下游端附近剪切力较无崩塌体时减小;崩塌体体积越大,对剪切力区特征的改变也越明显。崩塌体的存在虽不能制止附近岸坡的再次崩塌,但可能抑制崩岸发展及附近河床淤积的程度,崩塌体的粘性或体积越大,这种抑制作用越显著;相同崩塌体抑制附近河床淤积的程度较抑制岸坡崩塌的程度大。  相似文献   

我国主要内生铁矿碱交代机理探讨     

张光耀 《地球化学》1985,(1):58-66

Alkali-metasomatism and/or alkali-metasomatites are commonly recognized in different types of endogenic iron deposit,especially in the contact-metasomatic and porphyrite types in China.Alkali-metasomatites occur at the bottom of the mineralized alteration zone,in the marginal facies of the metallogenetic magmatic masses adiacent to iron ore bodies.They are approximately consistent with the attitudes of the ore bodies.As a result of alkali-metasomatism,great changes have taken place in the source rocks,producing distinet alteration zones with the color becoming lighter and lighter upwards and outwards.The alkali-metesomatic solntion is a kind of pneumato-hydrothermal solution rich in Cl,Si and alkalis.Its main components are alkalis and volatiles(dominantly H2O and Cl).The alkalis are closely related to magmatie source and its subsequent differentiation,while H2O is derived mainly from meteoric waters absorbed by the magma and Cl mainly from magma-mesitized gypsum-salt strata(including ground brines).In essence,alkali-metasomatism is the continuation of magmatic evolution and also an auto-metamorphism within the metallogenetic masses,i.e.,a complex ion-exchange reaction under certain physico-chemical conditions.The whole process of alkali-metasomatism can generally be divided into the Na^ -,Ca^2 -and Na^ -replacement stages.In the Ca^2 -replacement stage iron was largely separated from the source rocks.Alkali-metasomatism and the formation of iron ore deposits are two different forms of expression with respect to the same magmatic process,and both are controlled by and genetically related to magmatism,as is indicated by the facts that some of the oreforming materials are products of the de-iron process during alkali-metasomatism and that alkalis and volatiles have played an active role in the formation of iron and differential fusion of silicate melt.  相似文献   

双基地激光测风雷达回波信号仿真研究          下载免费PDF全文

李绍辉  孙学金  邵连军  易欣  张传亮 《气象科学》2023,43(4):523-533

本文针对传统的体散射模型并未考虑大气不均匀性对信号传输的影响等问题,通过引入垂直非均匀的大气参数改进了模型,并利用其建立了体目标的双基地激光测风雷达方程,仿真了侧向散射回波信号,并与单基地雷达进行了对比分析。研究表明:水平方向上,双基地激光测风雷达的回波信号分布特征与单基地雷达差异较大,其回波信号等值线在近地面为卵形线,随着探测高度的增加,回波信号等值线逐渐变为以主、被动雷达为焦点的椭圆形,并最终趋近于圆形;垂直方向上,双基地激光测风雷达的回波信号随高度衰减剧烈,近地面的回波能量约为10^-10 J,4 km高度的回波能量约为10^-15J,在中低层大气(0~10 km),回波信号中气溶胶散射占比大,在高层大气(10 km以上),分子散射占比大。  相似文献   

惊天一声响 窑体夷平地     

王继宏  杨西潭  霍海涛 《河南国土资源》2006,(11):34

10月18日,南阳市宛城区黄岗镇大夫庄村。“三、二、一、起爆!”“轰隆!”伴随着震聋发聩的爆破声,又一座40余米高的砖瓦窑烟囱应声坍塌,溘然消失。这是宛城区一日之内爆破拆除的第8座非法砖瓦窑厂,同时标志着南阳市2006年度粘土砖瓦窑厂治理整顿任务几近完成。砖瓦窑厂实现的是个别人的一时之利,损害的是子孙后代的长远生计,拆得好!”在现场,围观群众对拆除行动叫好不绝。是日上午10时许,由宛城区分管领导带领,区国土资源局、区砖瓦窑厂治理办、区城建土地综合执法大队等单位,在南阳市公安局宛城分局和黄岗镇有关部门的配合下,在大夫庄村宛…  相似文献   

GIS中的坐标系定义与转换     

单宝强  毛永强 《黑龙江国土资源》2005,(11):38-39

GIS中的坐标系定义是GIS系统的基础，正确定义GIS系统的坐标系非常重要。GIS中的坐标系定义由基准面和地图投影两组参数确定，而基准面的定义则由特定椭球体及其对应的转换参数确定，因此欲正确定义GIS系统坐标系，首先必须弄清地球椭球体（Ellipsoid）、大地基准面（Datum）及地图投影（Projection）三者的基本概念及它们之间的关系。  相似文献