新疆东准噶尔卡拉麦里造山型金成矿系统与区域构造演化     

顾雪祥  章永梅  葛战林  陈伟志  徐劲驰  黄岗  陶威 《地学前缘》2020,27(2):254-275

新疆东准噶尔卡拉麦里地区以金水泉、双泉、南明水、苏吉泉东等为代表的金矿床,构成了一套与晚古生代碰撞造山有关的金成矿系统。矿床夹持于区域性的卡拉麦里深大断裂和清水—苏吉泉大断裂之间,矿化受次级脆-韧性断层控制,以中等至陡倾斜的含金石英脉和破碎蚀变岩的形式产于晚古生代浅变质火山沉积岩中。流体包裹体、H-O-S-Pb同位素和热液锆石U-Pb年代学研究表明,成矿流体具中高温(集中于240~330 ℃)、低盐度(<6% NaCl_eq)、富CO₂的变质流体特征,成矿物质来自赋矿的火山沉积岩系,流体不混溶(相分离)和水-岩反应(围岩硫化作用)是导致金沉淀的主要机制,成矿深度变化于7~15 km之间,成矿时代约为314 Ma。晚石炭世至早二叠世,研究区的构造体制由挤压向走滑或走滑伸展转换,构造应力的释放导致深部变质脱水形成的低盐度CO₂-H₂O-NaCl±CH₄含金流体,沿走向NW至近EW向的走滑剪切断裂向地壳浅部流动,并在脆-韧性过渡带或脆性变形带的次级断裂中形成含金石英脉及蚀变岩型金矿石。  相似文献   

布格改正和地形改正的误差——关于区域重力测量中地形改正最大半径的讨论     

杨学祥 《大地测量与地球动力学》1992,(2)

在布格改正中,我们假定地壳为无限大水平板。事实上,地球表面是球面而不是平面。当地壳充分小类似于平面时,它不可能同时为无穷大;当地壳充分大时,它又不是一个平面。因此,布格改正势必造成相当大的误差。本文提出几种计算球壳重力的精确公式,用以减少布格改正和地形改正中的计算误差。  相似文献   

新疆地区强震前地磁低点位移异常的特点及其与构造活动的联系   总被引：3，自引：0，他引：3       下载免费PDF全文

黄雪香  丁鉴海  张淑兰 《地震工程学报》1998,20(2):22-28

对地磁垂直分量日变低点位移异常与１９８５年以来新疆ＭＳ≥５．０地震相对应的震例进行了分析研究．结果表明,该区的地震活动和地磁低点位移异常都有其独特之处,并与其孕震的内、外环境因素有着密切联系．  相似文献   

利用岩石地球化学特征判断西秦岭寒武系含矿硅岩建造的沉积环境   总被引：10，自引：0，他引：10  

刘家军  刘建明 《沉积学报》1998,16(4):42-49

西秦岭寒武系硅岩建造是拉尔玛、邛莫金矿床和牙相金矿点的赋矿岩系。其主要由炭质硅岩和炭质板岩组成。其中的含矿硅岩构造十分丰富,有块状、条带状、层纹状、多孔状和同生角砾状等。硅岩单层厚度一般为30～200 m。其主要成分除SiO₂( 平均含量 95. 30%) 外,其它氧化物含量能达1% 者仅有 FeO 、Fe₂O₃和 P₂O₅,且 FeO/Fe₂O₃比值大于 1, 而 Sr/Ba 比值小于 1 。硅岩建造中有机炭含量相当高,一般为(0.12～8.14) %,高者达 22 %。硅岩中稀土以总量低(3.29×10-6～100×10-6)、铈亏损为特征。硅岩建造中沉积黄铁矿的δ34S值变化在-10‰～ +46.9‰之 间。 硅岩的δ300Si值主要变化在+0.4 ‰～+0.8‰之间。硅岩建造的上述特点反映其主要是在深海-半深海环境下形成的。  相似文献   

基于VB与MO的GPS网形成图模块的实现     

赵勇  余学祥  贾小敏  鄢继选 《测绘信息与工程》2009,34(4):19-21

分析了在GPS数据处理过程中，对GPS网形图中各个属性的显示要求，利用MO图形绘制及图层管理等功能和VB语言进行有效结合，实现了GPS控制网图形的绘制输出和相应空间数据及属性数据信息的查询功能，为进一步的GPS数据处理和闭合差的计算求解奠定了基础。  相似文献   

降水预报在水库汛限水位动态控制中的可用性研究     

吴彬贵  姚学祥  廉铁辉  王本德 《气象科技》2007,35(5):708-713

利用降水短期预报和实况资料,分析预报某一量级降水条件下实况降水量级的概率分布。从防洪安全角度出发,重点分析某一量级降水预报条件下漏报各量级降水的可能性。并采用适线法,求解与经验点据拟合最优的水文频率曲线统计参数,估算各量级降水预报条件下实况降水的概率分布。分析结果显示,不同量级降水预报的可信度不同,各量级降水预报均表现出漏报率小、空报率大的特征;结合水文频率曲线,讨论了在汛限水位动态控制中如何应用各量级降水预报的问题。  相似文献   

Water requirements and stability of oasis ecosystem in arid region,China   总被引：4，自引：0，他引：4  

Bing Liu  Wenzhi Zhao  Xuexiang Chang  Shoubo Li  Zhihui Zhang  Mingwu Du 《Environmental Earth Sciences》2010,59(6):1235-1244

This research was conducted to determine the water requirements of oasis ecosystem with crop evapotranspiration method, and to analyse the water balance between the supply and requirement using water balance model, and then assess the stability of oasis ecosystem in the middle of Heihe River basin, China. The results indicated that the summations of the water supply and requirement approximated to 82.54 and 110.13 Mm³ years⁻¹ in 2007, and the water deficit was 27.59 Mm³ years⁻¹. The farmland was the largest water consumer with a consumption of 57.07 Mm³ years⁻¹ and accounted for 51.82% of the total water requirements. It was followed by the water area 38.83 Mm³ years⁻¹, forestland 12.13 Mm³ years⁻¹ and domestic and industrial 2.10 Mm³ years⁻¹, and accounted for 35.26, 11.01 and 1.92%, respectively. The stability index was 0.74, which implies that the oasis ecosystem have already started degenerating in sub-stability state. However, the water requirement of unit area was 1243.70 mm years⁻¹ and larger than other oases in arid region of China, which implies that the water resource scarcity do not exist in the middle basin where the excessive waste of the flood irrigation method has broken the balance between the water supply and requirement in the basin scale.  相似文献   

Geopulsation, Volcanism and Astronomical Periods     

Yang Xuexiang  Chen Dianyou  Yang Xiaoying  Yang Shuchen 《世界地质(英文版)》2000,3(1)

Volcanism is mainly controlled by the intermittent release of energy in the earth. As far as the differential rotation of the earth's inner core is concerned, the Galactic Year may change the gravitational constant G, the solar radiative quantity and the moving speed of the solar system and affect the exchange of angular momentum between core and mantle as well as the energy exchange between crust and mantle. As a result, this leads to eruptions of superplumes and magma, and controls the energy flow from core - mantle boundary (CMB) to crust. When the earth' s speed decreases, it will release a huge amount of energy. They are the reason of the correspondence of the volcanic cycles one by one with the astronomical periods one by one. According to the astronomical periods, volcanic eruptions may possibly be predicted in the future.  相似文献   

New Views on Global Change     

Yang Xiaoying  Yang Xuexiang  Du Xinwei 《世界地质(英文版)》2000,3(2)

Many cosmic facts , such as the earth orbit, the activity of the sun, the moon and the planet orbits and so on,may effect on geological processes on the earth including precipitation. It is a serious problem that the human being is facing with water deficiency. Global cooling and tectonic activity are the major factors of desertification and human action aggravates this process. It is time to do something to prevent the acceleration in the mature and artificial hazards. We must keep the balance of nature for sustainable development.  相似文献   

"Smashing the Moon" Accelerating Global Warming     

Xuexiang Yang  Dianyou Chen 《世界地质(英文版)》2003,6(2)

The existence of the lunar has its advantages as well as disadvantages. Many dynamic phenomena are related to the lunar due to the rate of masses of the earth and the lunar is maximum. That is probably the reason for the life existence on the earth. The tide resulted from the moon gravitational force is the root of some disasters. However, it can also reduce the green house effect and regulate the temperature. It is proved that the moon is the thermostat of the earth. The greenhouse effect would be out of control without the moon, and the tendency for the global warming up would be critical. It is a risk to smash the moon without understanding clearly the advantage and disadvantage.  相似文献