Principles of Probabilistic Regional Mineral Resource Estimation

Five principal sources of uncertainty in quantitative mineral resource estimation are listed and illustrated by means of a simple example (mosaic model) and a case history study for large copper deposits in the Abitibi area of the Canadian Shield. Abitibi copper potential originally was estimated on the basis of 1968 estimates of production and reserves totalling 3.12 Mt Cu. This prognostication now could be evaluated on the basis of 2008 copper production and reserves totalling 9.50 Mt Cu. An earlier hindsight study performed on the basis of 1977 data (totalling 5.23 Mt Cu) showed seven new discoveries occurring either in the immediate vicinities of known deposits or on broad regional copper anomalies predicted from the 1968 inputs. By 1977, the global geographic distribution pattern of large copper deposits in the Abitibi area had stabilized. During the next 30 years, new copper was essentially found close to existing deposits, much of it deeper down in the Earth's crust. In this paper, uncertainties associated with copper ore tonnage are analyzed by comparison of 2008 data with 1968 data using (a) log-log plots of size versus rank, and (b) lognormal QQ-plots. Straight lines fitted by least squares on these plots show that 1968 slopes provide good estimates of 2008 slopes but 1968 intercepts are much less than 2008 intercepts. In each linear log-weight versus log-rank plot, the slope is related to fractal dimension of a Pareto frequency distribution, and in a lognormal QQ-plot it is determined by logarithmic variance. The difference between 2008 and 1968 intercepts represents the increase in copper ore production and reserves from 1968 to 2008. The Pareto model fits actual copper and massive sulphides increase over the past 40 years better than the lognormal frequency distribution model for 10 km×10 km cells on favorable environments in the Abitibi area.      

利用测井信息评价盐湖相烃源岩

盐湖相烃源岩富含膏、盐质成分,使其测井响应特征发生极大改变,给测井评价烃源岩带来困难。基于实测数据,分析了盐湖相烃源岩中普遍发育的纯泥岩、含膏(盐)泥岩和膏(盐)质泥岩有机碳含量的测井响应模式,发现纯泥岩和含膏(盐)泥岩TOC与AC和LogRt呈正比,与DEN呈反比,膏(盐)质泥岩TOC与DEN呈正比,与LogRt呈反比,并基于此建立了盐湖相烃源岩测井评价方法,即首先利用ΔGR区分岩性,再针对不同岩性建立TOC评价模型,最后根据实测S₁+S₂和TOC建立相关关系,就可以求取烃源岩的TOC和S₁+S₂。利用该方法对东营凹陷沙四下亚段烃源岩性质和展布进行分析,发现预测TOC与实测TOC吻合程度高,具有一定推广价值。     

中国昆明地区岩溶洞穴洞口带苔藓植物研究

为了研究中国西南岩溶洞穴植物区系与生物多样性特征, 作者曾两次对云南昆明地区12个岩溶洞穴进行了野外考察和苔藓植物标本采集工作。其中含昆明市石灰岩洞穴1个, 石林县石灰岩洞穴5个和宜良县白云岩洞穴6个。根据采自12个岩溶洞穴洞口带的164件苔藓植物标本研究, 本文首次报道昆明地区洞穴苔藓植物10科18属25种。昆明地区洞穴中分布较多的苔藓植物科有丛藓科( Po ttiaceae) 5属8种,凤尾藓科( Fi ssidentaceae ) 1属4种,柳叶藓科( Amblystegiaceae ) 3 属3 种和青藓(Brachytheciaceae ) 2属3种。溶洞中较常见的4种苔藓植物种类是萤光苔类植物光苔Cyathodiumcavernarum Kunze ( 见于6个溶洞中) , 小凤尾藓Fissidens bryoides Hedw ( 见于4个溶洞中) , 橙色净口藓Gymnostonum calcareum Nees et Ho rsch (见于3 个溶洞中)和长叶扭口藓Tortella tortuosa( Hedw ) Limp ( 见于3个溶洞中)。野外观察表明,受洞穴弱光环境生态因子的限制, 昆明地区洞穴苔藓植物主要生长于洞穴洞口0～ 26m带范围内; 2种丛集型藓类植物, 橙色净口藓Gymnostonumcalcareum Nees et Horsch, 和钩喙净口藓G.recurvirost re Hedw 参与洞口带钟乳石或石笋钙华沉积。      

Analysis on the deployment of mining research supported by the grant program of Deep Resources Exploration and Mining

The Deep Resources Exploration and Mining(DREAM) grant program, within the framework of The National Key Research and Development Program grants, is a pillar to implement China's science and technology strategy in the area of deep resources exploitation. To tackle the insufficient of theories and technologies for the 1000-meter-deep mining, a section of mining, covering the research of basic theories, general technologies and application demonstration, was arranged in the layout of DREAM under the principle of "whole chain design, integrated implementation". In the aspect of basic research, DREAM mainly focused on the deep rock mechanics and mining theory, such as the in-situ mechanical behavior of deep rock, deep high stress induction and energy regulation theory. For the general and key technologies, DREAM supported the research on the mine construction and hoisting, excavation, rock breaking, mining methods and mining safety according to the characteristics of coal and metal mines. For the demonstration application, taking green, safe and efficient as the starting point, DREAM aimed at the green, safe and high efficiency mining, and the demonstration and leading role projects such as the low-waste and high-efficiency back fill mining. Since 2016, 10 RD projects have been funded, and 122 institutional participants with a total budget of RMB 235 million from the central government and RMB 480 million from enterprises as well as local governments have been involved. It is expected that the mining section of DREAM would contribute to establishing the theory and technology system in the area of deep mining and promoting the ability of deep resource exploitation in China.     

Geology and mineralization of the Tiegelongnan supergiant porphyry-epithermal Cu (Au,Ag) deposit (10 Mt) in western Tibet,China: A review

The Tiegelongnan Cu(Au,Ag)deposit in central Tibet contains more than 10 Mt of copper ranking 29 th in the world.It is characterized by typical porphyry-epithermal alteration and mineralization.In order to improve the understanding of porphyry-epithermal copper deposit in Tibet,new zircon U-Pb age and sulfur isotope data along with published data in the Tiegelongnan are presented to investigate the formation and preservation mechanism.Ore-related intrusive rocks in the Tiegelongnan including Early Cretaceous(about 120 Ma)granodiorite porphyry and diorite porphyry are closely related to the northward subduction of Bangongco-Nujiang ocean.Sulfur mainly comes from deep magma,and ore-forming fluid is affected by both magmatic and meteoric water.The metallogenic setting of Tiegelongnan is consistent with those of Andean porphyry copper deposits in South America.The cover of the Meiriqiecuo Formation volcanic rocks,Lhasa-Qiangtang collision and India-Eurasian collision have significance in the preservation and uplift of the deposit.The formation,preservation and discovery of Tiegelongnan play an important role in exploration of ancient porphyry-epithermal deposits in Tibet.     

Application of 3D Static Modelling in Reservoir Characterization: A Case Study from the Qishn Formation in Sharyoof Oil Field, Masila Basin, Yemen

Three-dimensional(3 D)static modelling techniques are applied to the characterization of the Qishn Formation(Fm.)in the Sharyoof oil field locating within the Masila basin,southeastern Yemen.The present study was initiated by the seismic structural interpretation,followed by building a 3 D structural framework,in addition to analysing well log data and from these,3 D facies and petrophysical models are constructed.In the Sharyoof oil field,the Qishn Fm.exhibits depth values within the range of 400-780 m below sea level,with a general increase towards the SSE.A set of high dip angle normal faults with a general ENE-WSW trend dissect the rocks.The strata are also folded as a main anticline with an axis that is parallel to the fault trend,formed as a result of basement uplift.According to the facies models,the Qishn Fm.comprises 43.83% limestone,21.53% shale,21.26% sandstone,13.21% siltstone and 0.17% dolomite.The Qishn Carbonates Member has low porosity values making it a potential seal for the underlying reservoirs whereas the Upper Qishn Clastics SI A and C have good reservoir quality and SIB has fair reservoir quality.The Upper Qishn Clastics S2 and S3 also have fair reservoir quality,while the Lower Qishn Clastics zone has good reservoir quality.The water saturation decreases towards the west and east and increases towards north and south.The total original oil in-place(OOIP)of the Upper Qishn clastics is 106 million STB within the SI A,SIC and S2 zones.Drilling of development wells is recommended in the eastern study area,where good trapping configuration is exhibited in addition to the presence of a potential seal(Upper Qishn Carbonates Member)and reservoir(Qishn Clastics Member)with high porosity and low water saturation.     

印度共和国地质构造与区域成矿

印度共和国位于南亚次大陆中部,陆地面积297.32万km2(不包括印控克什米尔地区与锡金),北部为喜马拉雅高山区,海拔平均为5500m;中部是印度河-恒河-布拉马普特河(在中国境内称雅鲁藏布江)平原,平均海拔100~200m,是印度经济最发达、人口最稠密地区;南部是印度半岛高原区,西高东低,     

多年冻土环境对寒区天然气管线稳定性的影响

Field investigations of several gas mains in different geosystems were carried out in Noviy Urengoy region (Eastern Siberia) in September, 2003. There were on ground pipelines covered with peat or sand. In case of small rivers pipelines were elevated by pile support on the shores. Because pipelines were applied in cryolithozone that means special secure methods used in pipeline systems functioning and operating. There are multiple sites of natural landscapes destructed or totally destroyed during building and exploiting of the pipelines. That causes negative cryogenic processes development. The most dangerous one is the heaving, that reaches up to several meters in humid landscapes. The complex thermoerosion, thermokarst and heaving occur very often at one site. The heaving of piles leads to pipe deformations and the emergency situations to occur. It is possible to predict negative cryogenic processes development and so far to reduce an emergency risk.     

Water in coesite: Incorporation mechanism and operation condition,solubility and P-T dependence,and contribution to water transport and coesite preservation

A series of coesite,coexisting with or without a liquid phase,was synthesized in the nominal system SiO2-H2O at800-1450℃and 5 GPa.Micro-Raman spectroscopy was used to identity the crystalline phase,electron microprobe and LA-ICP-MS were employed to quantity some major and trace elements,and unpolarized FTIR spectroscopy was applied to probe the different types of hydrogen defects,explore water-incorporation mechanisms and quantify water contents.Trace amounts of A1 and B were detected in the coesite.Combining our results with the results in the literatures,we have found no positive correlation between the Al contents and the"Al"-based hydrogen concentrations,suggesting that previously proposed hydrogen-incorporation mechanism H^++Al^3+■Si^4+does not function in coesite.In contrast,we have confirmed the positive correlation between the B contents and the B-based hydrogen concentrations.The hydrogen-incorporation mechanism H^++B3^+■Si^4+readily takes place in coesite at different P-T conditions,and significantly increases the water content at both liquid-saturated and liquid-undersaturated conditions.For the SiO2-H2O system,we have found that type-Ⅰhydrogarnet substitution plays a dictating role in incorporating water into coesite at liquid-saturated condition,type-II hydrogarnet substitution contributes significantly at nearly dry condition,and both operate at conditions in between.The water solubility of coesite,as dictated by the type-Ⅰhydrogarnet substitution,positively correlates with both P and T,cH2O=-105(30)+5.2(32)×P+0.112(26)×T,with cH2O in wt ppm,P in GPa and T in℃.Due to its low water solubility and small fraction in subducted slabs,coesite may contribute insignificantly to the vertical water transport in subduction zones.Furthermore,the water solubility of any coesite in exhuming ultra-high pressure metamorphic rocks should be virtually zero as coesite becomes metastable.With an adequately fast waterdiffusion rate,this metastable coesite should be completely dry,which may have been the key factor to the partial preservation of most natural Coe.As a byproduct,a new IR experimental protocol for accurate water determination in optically anisotropic nominally anhydrous minerals has been found.Aided with the empirical method of Paterson(1982)it employs multiple unpolarized IR spectra,collected from randomly-orientated mineral grains,to approximate both total integrated absorbance and total integrated molar absorption coefficient.Its success relies on a high-level orientation randomness in the IR analyses.     

Magmatic and hydrothermal zircon growth during multiple orogenic cycles in an evolving mantle wedge

The Hongseong area of the Hongseong-Imjingang Belt in the central-western Korean Peninsula forms part of a subduction-collision system that is correlated with the Qinling-Dabie-Sulu Belt in China. Several serpentinized ultramafic bodies carrying blocks of metamorphosed mafic rocks occur in this area. Here we investigate zircon grains in serpentinites from Bibong(BB) and Wonnojeon(WNJ), and high-pressure(HP) mafic granulite from Baekdong(BD) localities based on U-Pb, REE and Lu-Hf analyses. The zircons from BD HP mafic granulite show distinct age peaks at 838 Ma, 617 Ma and 410 Ma, with minor peaks at1867 Ma, 1326 Ma and 167 Ma. The Neoproterozoic age peaks in these rocks as well as in the serpentinites suggest subduction-related melt-fluid interaction in the mantle wedge at this time. The older zircon grains ranging in age from the Early to Middle Paleoproterozoic might represent detrital grains from the basement rocks transferred to the wedge mantle through sediment subduction. The BD HP mafic granulite shows a Middle Paleozoic age peak(Devonian; 410 Ma). The 242-245 Ma age peaks in the compiled age data of zircon grains serpentinites from BB and WNJ correspond to a major Triassic event that further added melts and fluids into the ancient mantle wedge to crystallize new zircons. In the chondrite normalized rare earth element diagram, the magmatic zircon grains from the studied rocks show LREE depletion and HREE enrichment with sharply negative Eu and Pr anomalies and positive Ce and Sm anomalies. The REE patterns of hydrothermal zircons show LREE enrichment, and relatively flat patterns with negative Eu anomaly. Zircon Hf signature from the WNJ serpentinite show negative εHf(t)(-18.5 and-23.5) values indicating an enriched mantle source with TDM in the range of 1614 Ma and1862 Ma. Zircons from the BD HP mafic granulite also show slightly negative εHf(t)(average-4.3) and TDM in the range of 1365-1935 Ma. Our study provides evidence for multiple zircon growth in an evolving mantle wedge that witnessed melt and fluid interaction during different orogenic cycles.     

福建省长乐—南澳断裂带,平潭—东山褶皱带基本特征的研究

闽东南沿海变质带实际上是由平潭—东山褶皱带和长乐—南澳断裂带所组成,前者是复杂的基底褶皱带,后者是大型的脆-韧性剪切带,它大体上是前者的西界。褶皱带的褶皱样式反映岩石在变质与变形时处于强塑性压扁及流变的机制。微观构造研究进一步获得变质构造岩在固态流变中的运动学和动力学特征。区域变质作用的温度为540—600℃,压力2400—3600Mpa。变质作用的高峰期约距今170Ma。     

钦-杭接合带之构造特征

华南大陆壳由扬子地块和华夏地块两个主要的地质构造单元组成,其间发育一条板块碰撞拼接带——钦-杭接合带,依据地层组成、构造变形差异,进一步划分为鄣公山构造混杂岩带、绍兴-江山对接带,前者叠加发育在扬子地块南部陆缘江南古岛弧之上,后者代表两地块间消减了的大洋及边缘海混杂体,经历了晋宁-加里东多期碰撞拼贴：晋宁期华夏陆块向扬子陆块俯冲、碰撞、走滑,形成了透镜-网结状韧性剪切系统争三期褶皱变形;加里东运动,华夏陆块再次与扬子陆块碰撞、仰冲,导致华南加里东造山带逆冲推覆在晋宁期造山带之上。至此,两者最终焊接成一体,形成了统一的晚古生代沉积盖层。     

复杂曲流带识别标志及其内部点坝叠加接触模式

以现代沉积为指导,通过岩芯、测井地质、地震沉积学分析研究复杂曲流带边界砂体类型及其内部结构特征,提出了识别地下复杂曲流带的典型标志,即曲流带边界处废弃河道的长度与曲流带边界的长度比值大于65%,尤其在曲流带凹岸一侧此比值超过85%。通过对比分析正演模型、测井地质剖面及分频后地震反射轴的波形及振幅,识别并总结出研究区曲流带内部主要发育点坝主体-初期点坝-初期河道边缘、点坝伊始-废弃河道、点坝伊始-点坝伊始、废弃河道-废弃河道、废弃河道-点坝伊始、末期河道-点坝等点坝间边界叠加类型,并在此基础上建立了研究区曲流带内部结构模式。     

Tectonic Evolution of the Himalayan Collision Belt

This paper discusses the tectonic divisions of the Himalayan collision belt anddeals with the tectonic evolution of the collision belt in the context of crustal accretion in thefront of the collision belt, deep diapirism and thermal-uplift extension and deep material flow-ing of the lithosphere-backflowing. Finally it proposes a model of the tectonic evolution-progressive intracontinental deformation model-of the Himalayan belt.     

后坪-大洛韧性剪切带初步研究

位于政和-大埔断裂带中北段的后坪-大洛韧性剪切带，规模较大，由一系列北北东向平行状、网结状的糜棱岩带组成。是由加里东期和印支期四套运动学性质各不相同的韧性剪切系统构成，是不同期次、不同形变叠加变形的产物，是造山带中浅层位复杂构造运动的产物。     

Remnants of a Neoproterozoic Collisional Orogenic Belt in the Core of the Phanerozoic Qinling Orogenic Belt (China)

NW-SE trending paleotectonics are recognized from the WNW-ESE trending Qinling complex in the core of the Qinling belt. They consist of trending stratum, boundary shear zones, deformed linear plutons and ophiolite. The field relationships and ages of the deformation, magmatism and metamorphism suggest that the paleotectonics formed in Neoproterozoic. The ages of deformed and undeformed plutons approximately constrain the peak deformation during 958-889 Ma. Both the two trending tectonics constitute an orogen-scale tectonic replacement by S2 (Phanerozoic WNW-ESE tectonics) of S1 (NNW-SSE trending Neoproterozoic), similar to structural replacement in outcrop. The strong contractional deformation, (high-pressure) metamorphism, and granitic magmatism that evolved from syn-collisional (S-type), to post-collisional (I-type) and to post-collisional (A-type), as well as regional extension at 885-700 Ma in Qinling, display a cycle of a collisional orogeny. Thus, the NW-SE trending paleotectonics could be remnants of a collisional orogenic belt. The belt originally could trend NNW-SSE, if reworking and modification of Paleozoic and/or Mesozoic NNE-SSW contractional deformation are eliminated. Accordingly, assemblage and breakup of some continental blocks occurred in Neoproterozoic in Qinling, which seems to correspond to assemblage and breakup of Rodinia supercontinent in the world. This study provides new insight into the evolution of the Qinling orogenic belt and the reconstruction of Proterozoic supercontinent of China, and also presents a case study of recognition of an old orogen from a young orogen.     

Chert in the Iberian Pyrite Belt

Since lenses of chert are common within the volcano-sedimentary succession hosting the massive sulphide deposits of the Iberian Pyrite Belt (Spain and Portugal), we examined numerous chert occurrences, both petrographically and geochemically, to test their possible value for massive sulphide exploration. The chert is found at two main lithostratigraphic levels (upper and lower) that are also interpreted as massive-sulphide bearing. In both cases the chert is located at the top of acidic volcanic sequences or in the associated sediments; we have not been able to observe the relationships between massive sulphides and chert, but some of the large orebodies of the Province (Lousal, La Zarza, Tharsis, Planes-San Antonio body of Rio Tinto, Neves) are described as being locally capped by chert facies. Four main types are recognized among the chert and associated facies: (1) red hematitic chert?±?magnetite; (2) radiolarian and/or sedimentary-textured (conglomeratic) chert with hematite and/or Mn oxides; (3) pale sulphidic chert; (4) rhodonite and/or Mn carbonate?±?magnetite facies. In the Spanish part of the Province the radiolarian chert is confined to the upper level; the distribution of the other types appears to be haphazard. The hydrothermal origin of the South Iberian chert is shown by its high Fe-Mn and low Co-Ni-Cu contents. The presence of small positive Ce anomalies indicates a shallow marine environment (shelf or epicontinental sea), which is consistent with the volcanological and sedimentological data. The chert was emplaced below the sea floor through chemical precipitation and/or through alteration and replacement of the country rock, residual traces of which are ghost phenocrysts and high Al, Ti and rare earth contents. Macro- and microscopic relationships indicate that the oxide facies (hematite?±?magnetite) formed first, probably providing a protective insulating cover against the marine environment and enabling an evolution towards sulphide facies; a phase of Mn?carbonate and silicate + quartz?±?chlorite + sulphides appears to be even later. It was not possible, through discrimination, to isolate a chert that could be considered as representing a lateral marker of massive sulphides; moreover, both field observations and geochemical data seem to indicate a relative independence of this siliceous sulphide hydrothermal activity from the hydrothermal activity giving rise to the massive sulphides. Such is also indicated by the lead isotopic signature of the chert, which is appreciably more radiogenic than that of the massive sulphides; the lead enrichment in the sulphidic chert facies indicates the participation of a different source (sediments, sea water) from that of the massive sulphides. The hypothesis of an independent hydrothermal “chert” event can thus be envisaged, wherein the chert reflects submarine low-temperature hydrothermal activity that is most apparent during a “break” within the volcano-sedimentary succession and which may locally have competed with the high-temperature hydrothermal activity giving rise to the massive sulphides. The interest of the chert thus rests in its palaeodynamic significance, as a marker of periods of volcanic quiescence, and in its possible role as a protective insulating cap favourable to the deposition of massive sulphides.     

秦岭洛栾断裂带糜棱岩的变形特征及形成环境分析

洛栾断裂带是华北板块南缘与秦岭北缘的分界线,其变形作用细节可以恢复板块碰撞过程中板缘的变形作用。洛栾断裂带走向为290°,倾向NNE,倾角多为67°~80°,由多条近平行的韧性剪切带组成,单个剪切带宽度由几米至上百米不等,西部较窄,东部较宽。洛栾断裂带主要构造活动有四期,第二期强烈的塑性变形形成了大规模的糜棱岩。糜棱岩中的线理倾伏向、矿物σ、δ残斑和石英脉形态等运动学特征均指示断裂带具有由南向北俯冲兼有左行平移的运动学特征。糜棱岩的变形特征显示洛栾断裂带东部的变形机制为晶质塑性变形,西部为低温扩散蠕变、颗粒边界滑移以及晶质塑性变形机制。糜棱岩中的矿物塑性变形序列为:方解石黑云母石英斜长石钾长石。洛栾断裂带长英质糜棱岩的变形相自东向西依次为二长石变形相、石英斜长石变形相和石英变形相。糜棱岩的形成温度为300~550℃,其中东部的温度高于西部。角闪石全铝压力计获得的压力为:0.75~0.95GPa,多硅白云母压力计得出的压力为0.27~0.87 GPa。差异应力为0.32~0.41GPa,应变速率值为3.92917×10~(-11)~3.17713×10~(-16)。雪茄状应变椭球体和大于0.75的涡度显示断裂带为强烈剪切拉伸变形,且西段强于东段。上述特征显示洛栾断裂带是发育于中-中深层次的韧性变形,糜棱岩的变形条件总体属于中温、中压环境下的中等应变条件,但东部温度高于西部,西部差异应力大于东部。相当于东部位于中地壳偏深环境,西部位于上地壳下部-中地壳上部环境,说明洛栾断裂带在后期的抬升过程中东部高于西部。这期糜棱岩的变形是对洛栾断裂带第二期构造活动的响应,真实地反映了洛栾断裂带这期构造活动的构造物理作用过程和形成环境,对解读洛栾断裂带的形成环境有着重要意义。     

秦岭造山带中段重磁异常与成矿带的关系

成矿带的展布受地质构造的控制,而地质构造在重磁异常上有明显反映。为了研究秦岭造山带中段重磁异常与成矿 带的关系,该文系统整理、处理了秦岭造山带中段已获得的重磁力测量资料,分析研究了重磁异常的展布特征、推断了研 究区的断裂构造,讨论了结晶基底的起伏特征,并结合区域地质资料及矿床分布资料讨论了重磁场特征及其与地质构造、 成矿带的关系。结果表明,秦岭造山带中段成矿带均分布在重、磁异常梯度带上或几组不同方向异常的交汇部位,尤其在 局部重力高异常范围内及其边部梯度带上矿体富集。这一结果为研究秦岭造山带的地质演化、地质构造（尤其是深部构 造）、断裂分布及下一步的成矿有利区预测提供重要的参考信息。