北祁连东段冷龙岭—毛毛山地区 金矿化地质特征及找矿方向

冷龙岭—毛毛山地区位于北祁连东段。为揭示这一地区金成矿规律和控矿因素,从大地构造背景、含矿建造以及成矿构造等几个方面讨论了青分岭金矿床的成矿条件。通过对该区区域地质和构造特征以及金地球化学异常特征分析,提出了进一步找矿方向。     

滇东北渔户村组内的富铅锌矿床成矿地质特征及成因

渔户村组为滇东北富铅锌矿床的重要产出层位。通过茂粗、金沙厂、五星、乐红、大海等矿床，总结了滇东北渔户村组内的富铅锌矿床的地质特征及成因，认为其与喷流沉积成矿作用和后期改造作用有关，为海底火山喷流沉积－改造成因。     

咸阳市城区地下水超采问题及对策

咸阳市是陕西的第三大城市,城市用水严重依赖地下水,地下水起采问题相当严重,已形成了三个区域性地下水降落漏斗.本文通过地下水水位现潮资料,对成阳地下水起采区现状和成因进行了初步分析,并提出解决和缓解这一局面的对策.     

辽宁红旗营子铅锌多金属矿地质特征及岩体与脉岩同源性探讨

红旗营子铅锌多金属矿位于华北地台北缘辽东古元古代裂谷的辽东-吉南成矿带上.矿区地层为古元古界辽河群盖县组,断裂控制着矿床的分布.中生代岩浆岩活动频繁,与成矿关系密切.基于对红旗营子铅锌多金属矿地质特征的系统分析,研究了区内脉岩与矿体的时空关系,探讨了岩体与脉岩的同源性问题,认为区内脉岩与铅锌矿体在空间上密切共生,并且直...     

新疆昭苏卡拉盖雷铜金矿床地质地球化学特征及成因探讨

卡拉盖雷铜金矿床位于新疆西天山那拉提构造带境内西段,为近年在该成矿带内发现的首例以Cu为主,伴生Au、Co等的火山岩型热液矿床。δD、δ18O分析结果表明,成矿流体在早—中阶段以岩浆热液为主,晚阶段有大气降水加入。δ34S分析结果表明,硫源主要来自深部地壳或上地幔,并有地层硫混入。铅同位素分析表明,矿区铅源为壳、幔混合俯冲带铅。辉钼矿的Re-Os同位素模式年龄为(259.6±9.7)Ma,说明矿床早阶段的成矿年龄为早二叠世末期。笔者进一步探讨了矿床成因,认为大哈拉军山组火山岩为早期矿源层;在晚石炭世后碰撞伸展阶段,来自地壳深部的含矿岩浆热液沿区域深大断裂、火山通道及浅部断裂系统运移并萃取早期矿质元素,于有利构造部位形成矿体。     

Decomposition and Evolution of Intracontinental Strike-Slip Faults in Eastern Tibetan Plateau

Little attention had been paid to the intracontinental strike-slip faults of the Tibetan Plateau. Since the discovery of the Longriba fault using re-measured GPS data in 2003, an increasing amount of attention has been paid to this neglected fault. The local relief and transverse swath profile show that the Longriba fault is the boundary line that separates the high and flat tomography of the Tibet plateau from the high and precipitous tomography of Orogen. In addition, GPS data shows that the Longriba fault is the boundary line where the migratory direction of the Bayan Har block changed from eastward to southeastward. The GPS data shows that the Longriba fault is the boundary fault of the sub-blocks of the eastern Bayan Har block. We built three-dimensional models containing the Longriba fault and the middle segment of the Longmenshan fault, across the Bayan Har block and the Sichuan Basin. A nonlinear finite element method was used to simulate the fault behavior and the block deformation of the Eastern Tibetan Plateau. The results show that the low resistivity and low velocity layer acts as a detachment layer, which causes the overlying blocks to move southeastward. The detachment layer also controls the vertical and horizontal deformation of the rigid Bayan Har block and leads to accumulation strain on the edge of the layer where the Longmenshan thrust is located. After a sufficient amount of strain has been accumulated on the Longmenshan fault, a large earthquake occurs, such as the 2008 Wenchuan earthquake. The strike slip activity of the Longriba fault, which is above the low resistivity and low velocity layer, partitions the lateral displacements of the Bayan Har block and adjusts the direction of motion of the Bayan Har block, from the eastward moving Ahba sub-block in the west to southeastward moving Longmenshan sub-block in the east.     

天山乌鲁木齐河流域山区降水δ18O和δD 特征及水汽来源分析

依据乌鲁木齐河流域山区3个站点实测次降水δ18O和δD数据以及气象观测资料,结合临近GNIP(Global Network of Isotopes in Precipitation)站点数据,对其降水δ18O和δD特征及水汽来源进行了分析。结果表明,大气降水中δ18O值波动范围大,但呈现明显的季节性变化:冬季降水δ18O较低,夏季降水δ18O较高。受流域山区气候和地理条件影响,从上游到下游各站点大气降水线截距和斜率均呈现逐渐减小趋势。大气降水中δ18O和δD与日均气温存在密切正相关关系,且温度与δ18O之间的相关性优于δD。降水中d-excess值也表现出季节性变化,冬季降水d-excess值高于夏季降水。利用HYSPLIT 4.0气团轨迹模型,得出夏季水汽主要来源西风环流输送,冬季受西风环流和极地气团共同影响。