西藏冈底斯多金属成矿带斑岩铜矿定位预测与资源潜力评价   总被引：3，自引：1，他引：2  

佘宏全  李光明  董英君  潘桂棠  李进文  张德全  丰成友 《矿床地质》2009,28(6):803-814

自1999年开展地质大调查以来,冈底斯成矿带斑岩铜矿研究取得了重大进展.本文在全面收集冈底斯成矿带地质、矿产和物化探资料基础上,建立了本区GIS平台上的资源预测评价系统.采用数理统计分析,确定了冈底斯成矿带斑岩铜矿定位预测的定量化标志35个,认为对斑岩铜矿预测影响比较重要的地质变量(因素权重>0.2)为花岗岩体(不限时代)、Cu、Mo、W、Au、Ag、Bi化探异常、Cu-Mo、Cu-Mo-Au、Cu-Au-Ag组合化探异常、矿床规模、重力场中低负异常场等.在此基础上,开展了工作区斑岩铜矿的定位预测,圈定了斑岩铜矿成矿远景区33处,计算结果与实际矿产分布和地质理论分析相吻合.采用面金属量法对冈底斯成矿带斑岩铜矿的资源潜力进行了估算,结果表明,冈底斯地区仍具有良好的斑岩铜矿找矿远景,1 000 m以浅的潜在铜资源量可达1亿吨以上.其中,驱龙-甲马-拉抗俄、松多雄、白容-冲江、松多握、吉如、达布、汤不拉、龙卡朗、崩不弄金矿、洞嘎、雄村、麦热-仁钦则、蒙哑啊东北、吹败子、岗达、沙让-亚贵拉、青龙-龙马拉、冲木达、洛麦南、拉屋找矿潜力较大.  相似文献   

Is Comet C/1853 E1 (Secchi) extrasolar?     

R.L. Branham 《Astronomische Nachrichten》2012,333(2):118-124

Comet C/1853 E1 (Secchi) has a hyperbolic orbit with eccentricity 1.01060 and perihelion outside of the Earth's orbit. Integrating the orbit with barycentric coordinates backwards to 50000 AU, the approximate edge of the Oort cloud, shows that the orbit remains hyperbolic. This is still true even if plutoids additional to Pluto are included in the integration. Nor does including Galactic tidal and disc effects and possible nongravitational forces change the orbit to a high eccentricity ellipse. Although certain factors, such as unknown massive plutoids, gravitational effects by interstellar gas clouds, or unmodelled nongravitational forces operating on the comet, could change this situation, the tentative conclusion that the origin of this comet is extrasolar remains the one most consistent with the observations (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)  相似文献   

基于双差定位法的鄂尔多斯块体西北缘地震精定位研究     

郭伟  刘甜甜  范玲玲  李贵明 《山西地震》2021,(1):10-14,19

针对鄂尔多斯块体西北缘地震活动的复杂性及目前台网定位方法存在偏差的问题,采用双差定位法对2009—2019年发生在鄂尔多斯块体西北缘的地震事件进行重新定位。经研究表明,双差定位之后地震分布更集中,鄂尔多斯块体西缘的地震沿银川吉兰泰断陷带分布,北缘的地震沿河套断陷带分布,地震定位精度明显提高,这与块体周缘复杂的地质构造背景和动力学过程密切相关。定位结果可为进一步研究该区域的地震活动性等提供参考。  相似文献   

张家口—渤海地震带中小地震应力降分布特征     

贾炯  赵英萍  王亚玲  蔡玲玲  王莉婵  王宁 《地震地磁观测与研究》2021,42(1):20-25

采用河北测震台网资料,分析了张家口—渤海地震带2008—2018年1220条M_L≥2.0地震的应力降。结果表明,应力降可能与应力有关,并且随震级的增加而出现不同尺度的变化,该区域应力降优势分布为0.70—3.00 MPa。  相似文献   

塔北、塔中地区碳酸盐岩及其原油中的二苯并噻吩类化合物   总被引：4，自引：0，他引：4  

李景贵  郑建京  刘文汇  陈国俊  孟自芳 《沉积学报》2004,22(2):348-353

塔里木盆地塔北、塔中地区四口井(库南1井,轮南46井,塔中12井和塔参1井)寒武-奥陶系12个碳酸盐岩烃源岩(泥灰岩,泥质灰岩和云岩)岩芯样品抽提物芳烃组分中的二苯并噻吩类化合物组成和丰度变化特征可分为三种类型:Ⅰ二苯并噻吩、甲基二苯并噻吩型;Ⅱ二苯并噻吩、甲基二苯并噻吩、二甲基二苯并噻吩+三甲基芴混合物型;Ⅲ二苯并噻吩、甲基二苯并噻吩、二甲基二苯并噻吩和三甲基二苯并噻吩型。研究的塔北、塔中隆起11个海相油二苯并噻吩类化合物分布类型均为二苯并噻吩、甲基二苯并噻吩、二甲基二苯并噻吩和三甲基二苯并噻吩型,和海相烃源岩二苯并噻吩类化合物第Ⅲ种分布类型完全相同。据此推断:塔北隆起8个海相油可能主要来源于塔北轮南地区下奥陶统;塔中隆起3个海相油可能来源于塔中地区中-上奥陶统。  相似文献   

北淮阳带东段变质构造地层早期构造变形及其区域地质意义   总被引：1，自引：0，他引：1  

王果胜  宋鸿林  马文璞  刘文灿 《地学前缘》2004,11(3):83-90

北淮阳构造带位于大别造山带北缘 ,其中东段安徽境内变质构造地层佛子岭岩群对北淮阳带区域构造研究至关重要。研究表明 ,以原黄龙岗岩组为界 ,佛子岭岩群上、下部早期构造变形明显不同。佛子岭岩群下部郑堂子岩组、仙人冲岩组、祥云寨岩组发育以固态流变为特征的褶叠层构造 ,形成于地壳伸展构造体制下 ,是横向构造置换作用的产物。佛子岭岩群上部诸佛庵岩组、八道尖岩组、潘家岭岩组表现为纵弯褶皱变形 ,构造置换不彻底 ,局部保留有原生沉积结构构造 ,形成于地壳收缩构造体制下 ,是纵向构造置换作用的产物。因此 ,文中将原佛子岭岩群解体为下部卢镇关构造混杂岩带和上部诸佛庵岩群 ,原黄龙岗岩组构造片岩为两者之间的近水平的韧性剪切拆离滑脱带  相似文献   

Earthquake-controlling Processes of Detachment Zones in Eastern North China     

SUN Aiqun  NIU Shuyin  SHAO Ji''an  HOU Quanlin  ZHANG Jianzhen Shijiazhuang College of Economics  Shijiazhuang  Hebei  School of Earth  Space Sciences  Peking University  Beijing Institute of Geology  Geophysics  Chinese Academy of Sciences  Beijing 《《地质学报》英文版》2004,78(1):283-290

The basin-and-range area in eastern North China is known for frequent occurrence of earthquakes, their great magnitudes and heavy losses thereby incurred. Seismic studies in the past usually emphasized the intersections, inflexions and branches of the faults. However, the intensities of many great earthquakes in this area do not show linear distribution, and the epicenters are horizontally dispersed at certain depths instead of along the strike of faults. Based on the sub-mantle plume studies made by authors in the past decade, it is thought that there exists an uplifted sub-mantle plume under the fault depression area in North China. The uplifting and intrusion of mantle materials caused the upper crust to be faulted, while low-velocity and high-velocity layers are alternatively distributed in the middle crust under the influence of the mantle and the lower crust. The middle and lower crust materials were detached from the top of the sub-mantle plume to the surroundings while the sub-mantle plume materi  相似文献   

Evidence of N₂-ice on the surface of the icy dwarf Planet 136472 (2005 FY9)     

S.C. Tegler  W.M. Grundy  F. Vilas  W. Romanishin  D.M. Cornelison 《Icarus》2008,195(2):844-850

We present high signal precision optical reflectance spectra of 2005 FY9 taken with the Red Channel Spectrograph and the 6.5-m MMT telescope on 2006 March 4 UT (5000-9500 Å; 6.33 Å pixel⁻¹) and 2007 February 12 UT (6600-8500 Å; 1.93 Å pixel⁻¹). From cross-correlation experiments between the 2006 March 4 spectrum and a pure CH₄-ice Hapke model, we find the CH₄-ice bands in the MMT spectrum are blueshifted by 3 ± 4 Å relative to bands in the pure CH₄-ice Hapke spectrum. The higher resolution MMT spectrum of 2007 February 12 UT enabled us to measure shifts of individual CH₄-ice bands. We find the 7296, 7862, and 7993 Å CH₄-ice bands are blueshifted by 4 ± 2, 4 ± 4, and 6 ± 5 Å. From four measurements we report here and one of our previously published measurements, we find the CH₄-ice bands are shifted by 4 ± 1 Å. This small shift is important because it suggest the presence of another ice component on the surface of 2005 FY9. Laboratory experiments show that CH₄-ice bands in spectra of CH₄ mixed with other ices are blueshifted relative to bands in spectra of pure CH₄-ice. A likely candidate for the other component is N₂-ice because its weak 2.15 μm band and blueshifted CH₄ bands are seen in spectra of Triton and Pluto. Assuming the shift is due to the presence of N₂, spectra taken on two consecutive nights show no difference in CH₄/N₂. In addition, we find no measurable difference in CH₄/N₂ at different depths into the surface of 2005 FY9.  相似文献   

湖南九嶷山复式花岗岩体SHRIMP锆石定年及其地质意义   总被引：53，自引：11，他引：42  

付建明  马昌前  谢才富  张业明  彭松柏 《大地构造与成矿学》2004,28(4):370-378

应用SHRIMP锆石U-Pb法获得九嶷山复式花岗岩中的主要岩体形成年龄为:雪花顶花岗岩(432±21)Ma、金鸡岭花岗岩(156±2)Ma、砂子岭花岗岩(157±1)Ma和西山火山-侵入杂岩(156±2)Ma。结果显示砂子岭岩体属燕山早期而非印支期;西山火山-侵入杂岩属燕山早期而非燕山晚期。花岗岩中继承锆石复杂,其形成时代为1579Ma、2108Ma和2669Ma,提供了九嶷山地区存在古-中元古代,甚至太古代基底的年龄信息。新元古代(912Ma)锆石的大量出现为扬子陆块和华夏陆块碰撞带通过本区的认识提供了一个间接证据。  相似文献   

Mesozoic to Cenozoic retroarc basin evolution during changes in tectonic regime,southern Central Andes (31–33°S): Insights from zircon U-Pb geochronology     

《Journal of South American Earth Sciences》2019

The southern Central Andes of Argentina and Chile (27–40°S) are the product of deformation, arc magmatism, and basin evolution above a long-lived subduction system. With sufficient timing and provenance constraints, Andean stratigraphic and structural records enable delineation of Mesozoic-Cenozoic variations in subsidence and tectonic regime. For the La Ramada Basin in the High Andes at ∼31–33°S, new assessments of provenance and depositional age provided by detrital zircon U-Pb geochronology help resolve deformational patterns and subsidence mechanisms over the past ∼200 Myr. Marine and nonmarine clastic deposits recorded the unroofing of basin margins and sediment contributions from the Andean magmatic arc during Late Triassic to Early Cretaceous extension, thermal subsidence, and possible slab rollback. Subsequent sediment delivery from the Coastal Cordillera corresponded with initial flexural accommodation in the La Ramada Basin during Andean shortening of late Early Cretaceous to Late Cretaceous age. The architecture of the foreland basin was influenced by the distribution of precursor extensional depocenters, suggesting that inherited basin geometries provided important controls on later flexural subsidence and basin evolution. Following latest Cretaceous to early Paleogene tectonic quiescence and a depositional hiatus, newly dated deposits in the western La Ramada Basin provide evidence for a late Paleogene episode of intra-arc and proximal retroarc extension (development of the Abanico Basin, principally in Chile, at ∼28–44°S). Inversion of this late Paleogene extensional basin system during Neogene compression indicates the southern Central Andes were produced by at least two punctuated episodes of shortening and uplift of Late Cretaceous and Neogene age.  相似文献