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1.
Principles of Probabilistic Regional Mineral Resource Estimation   总被引:1,自引:0,他引:1  
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.   相似文献   

2.
利用测井信息评价盐湖相烃源岩   总被引:1,自引:0,他引:1  
高阳 《沉积学报》2013,31(4):730-737
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。  相似文献   

3.
中国昆明地区岩溶洞穴洞口带苔藓植物研究   总被引:2,自引:1,他引:1  
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。   相似文献   

4.
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.  相似文献   

5.
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.  相似文献   

6.
Early Eocene hyperthermals are geologically short-lived global warming events and represent fundamental perturbations to the global carbon cycle and the Earth’s ecosystem due to massive additions of isotopically light carbon to the ocean-atmosphere system.They serve as ancient analogs for understanding how the oceanic carbonate system and surface-ocean ecosystem would respond to ongoing and future climate change.Here,we present a continuous carbonate record across the Eocene Thermal Maximum 2(ETM2 or H1,ca.54.1 Ma)and H2(ca.54 Ma)events from an expanded section at Ocean Drilling Program Site 1258 in tropical Atlantic.The abundant calcareous nannofossils and moderate carbonate content throughout the studied interval suggest this record was deposited above the calcite compensation depth(CCD),but below the lysocline and under the influence of terrestrial dilution.An Earth system model cGENIE is used to simulate the carbon cycle dynamics across the ETM2 and H2 to offer insights on the mechanism of the rapid warming and subsequent recovery in climate and ecosystem.The model suggests moderate changes in ocean pH(0.1–0.2 unit)for the two scenarios,biogenic methane from a rechargeable methane capacitor and organic matter oxidation from thawing of the permafrost.These pH changes are consistent with a recent independent pH estimate across the ETM2 using boron isotopes.The carbon emission flux during the ETM2 is at least an order of magnitude smaller than that during the Paleocene–Eocene Thermal Maximum(PETM)(0.015–0.05 Pg C yr-1vs.0.3–1.7 Pg C yr-1).The comparable pre-and post-event carbonate contents suggest the lysocline did not over deepen following the ETM2 at this tropical Atlantic site,indicating spatial heterogeneity in the carbonate system due to strong dilution influence from terrestrial weathering and riverine discharge at Site 1258.  相似文献   

7.
Late Mesoproterozoic igneous rocks in the SW Yangtze Block are important for understanding the role of it in reconstruction of the Rodinia supercontinent.In the present study,we report new geochronological,geochemical,and Nd-Hf isotopic data for the Cuoke plagioclase amphibolites and granites in the SW Yangtze Block.Geochronological results show that the plagioclase amphibolites and granites have similar late Mesoproterozoic zircon U-Pb ages of 1168-1162 Ma,constituting a bimodal igneous assemblage.The plagioclase amphibolites have high and variable TiO2 contents(1.15-4.30 wt.%)and Mg#(34-66)values,similar to the tholeiitic series.They are characterized by enrichment in LREEs and LILEs,and have OIB-like affinities with positive Nb and Ta anomalies.The plagioclase amphibolites have positive whole-rockεNd(t)(+3.2 to+4.3)and zirconεHf(t)(+4.3 to+10.7)values,indicating that they were derived from an OIB-like asthenospheric mantle source.The granites belong to the reduced peralkaline A-type series and have negativeεNd(t)value of-6.0 andεHf(t)values of-5.8 to-13.8,indicating a derivation from the partial melting of ancient mafic lower crust.In combination with the~1.05-1.02 Ga bimodal igneous assemblage in the SW Yangtze Block,we propose that the Cuoke 1168-1162 Ma igneous rocks were likely formed in a continental rift basin and argue against the existance of Grenvillian Orogen in the SW Yangtze Block during the late Mesoproterozoic.  相似文献   

8.
This paper is based on the analysis and research on the silver-lead-zinc polymetallic ore in New Ballyhoo Banner in southern Manzhouli of Inner Mongolia.Because metal mineralization brings rock formations,the geophysical features such as low resistivity,high polarization rate and uneven distribution of magnetization,the comprehensive geophysical methods are adopted including high-precision magnetic measurement,high-power induced polarization,IP field middle gradient and controlled source audio-frequency magnetotellurics.In the survey work of multi-metal ore deposits,from surface sweeping to single point measurement,and from single point to section going deeper layer by layer,the resolution of measurement is continuously improved,and various geophysical methods support and complement each other,so explorers can successfully predict the direction,scale and volume of the metallogenic belts in conjunction with geochemical exploration,geological survey and drilling.It has provided a strong basis for completing the exploration task of predicting the reserve volume of ore bodies.The research conclusions of this exploration case have thus a high reference value in the same type of exploration work.  相似文献   

9.
陈明  何门贵 《物探与化探》2008,32(2):196-198
在物探扫面工作中,有大量的剖面数据需要绘制成剖面平面图,要求寻找一个高效快速的制图方法.通过对Grapher 自动化功能的分析和实践,编制程序实现了快速绘制彩色渐变剖面平面图的需求,说明利用自动化脚本能够在获得精美图件的同时,可以极大地提高作图效率.  相似文献   

10.
冷生风化作用对边坡稳定性影响   总被引:1,自引:0,他引:1  
The experiment shows that considerable influence on density rock properties are subjected by nival weathering conditions. The main parameter defining the rock suitability for solution various engineering and geological problems is its firmness limit on single axis pressing. The firmness properties of sandstone being in absolutely dry condition for Kabakta suite at the beginning of investigation was 64.7 MPa, for Nerungri suite sandstones it was 48. 7 MPa. The investigations showed how much the nival conditions of cryohypergenesis of rock sandstones in Kabakta and Nerungri suites have destructive influence in comparison with aquale and more over aerale conditions. In the aerale conditions sedimentary rock firmness of Kabakta suite decreased to 23.2 MPa, in aquale conditions to 16.5, and in the nivale conditions to 8.9 MPa. In Nerungri suite sandstones are according to 17.7 MPa, 11.1 MPa, and 6 MPa after 300 freezing and thawing cycles. The common sandstone firmness decrease of Kabakta suite was 25 %,of Nerungri suite it was 23.8%. Marlstone samples after 400 FTC decrease to 62% in the nivale conditions and to 33 % in the aerale conditions. After 3~5 years of exploitation marlstone will destruct due to structural and textural inhomogenesis up to gruss, i.e. it will not meet the requirements of durability.Judging by the results of carried out experiment it should be concluded that by cryogenic weathering the sedimentary rocks (sandstones) and rocks with schistose lithogenic texture (marlstone) are subjected to disintegration. The primary rock samples firmness considerably influences on the disintegration rate.  相似文献   

11.
摩擦桩基桩土间极限摩阻力取值问题探讨   总被引:1,自引:0,他引:1  
陈银生 《世界地质》1999,18(1):54-59
通过对广珠东线高速公路横沥大桥的试桩及土体的工程地质条件分析,总结出影响摩擦桩基桩土间极限摩阻力取值的一般问题以及解决问题的方法和措施。  相似文献   

12.
从榴辉岩与围岩的关系论苏鲁榴辉岩的形成与折返   总被引:4,自引:1,他引:4       下载免费PDF全文
位于华北和扬子两板块碰撞带中的苏鲁榴辉岩形成的温压条件不但是超高压,而且是高温。榴辉岩的PTt轨迹表明其为陆-陆磁撞俯冲带的产物。榴辉岩的区域性围岩花岗质片麻岩为新元古代同碰撞期花岗岩,榴辉岩及其他直接围岩皆呈包体存在于其中,并见新元古代花岗岩呈脉状侵入榴辉岩包体中。区域性围岩新元古代花岗岩的锆石中发现有柯石英、绿辉石等包裹体,表明新元古代花岗岩的组成物质也经受过超高压变质作用,且榴辉岩与围岩新元古代花岗岩的锆石U-Pb体系同位素年龄基本相同。但新元古代花岗岩所记录的变质作用和变形作用期次(或阶段)却少于榴辉岩。椐上述可得如下推断:超高压榴辉岩与新元古代花岗岩岩浆是同时在碰撞带底部(俯冲板块前部)形成的;榴辉岩的第一折返阶段是由新元古代花岗岩岩浆携带上升的,其第二折返阶段是和新元古代花岗岩一起由逆冲及区域性隆起而上升,遭受剥蚀。  相似文献   

13.
In order to characterise the influence of the heavyrains on the observed landslides during the 1996–1997hydrological cycle, rainfall records for the last 100years are analysed from 104 stations in easternAndalusia. Regarding the amounts of rain recordedbetween October 1996 and March 1997 in the 104stations studied, 31 presented new all-time records;15 presented values that were 80–100% of thepre-1995 record; 49 stations, 80–50%; and 9stations, < 50%. A map has been devised of thesusceptibility of the materials through which thesouth-eastern Andalusian road network crosses,together with an inventory of the damage caused byinstability phenomena on banks and cuttings of theroad network during the winter of 1996–1997. Therelationships between the rainfall during the studyperiod, the damage caused to the road network and thesusceptibility of the materials affected are analysed.The results indicate that there is a clearcorrespondence between the rainfall recorded and thesusceptibility of the materials with the inventorieddamage. It is concluded that the widespread seriousdamage caused in early 1997 to the roads andsurrounding areas in the Alpujarra region and thecoast of the Province of Granada was mainly caused bythe extraordinarily heavy rains. However, considerablyless damage was observed where the susceptibility ofthe terrain is low, thus highlighting the extremeusefulness of terrain-susceptibility maps for riskprevention and territorial planning.  相似文献   

14.
某高速公路下伏煤矿采空区稳定性分析   总被引:10,自引:0,他引:10  
在论述某高速公路下伏砦脖煤矿采空区地质、采矿和工程地质特征的基础上, 进行了稳定性数值模拟分析, 定性与定量地分析与评价了该煤矿采空区的地表变形特征及稳定性。研究结果表明: 该煤矿采空区的变形尚未完成, 对拟建的高速公路将产生很大的危害, 必须采取相应的工程治理措施。   相似文献   

15.
混凝剂处理钻井废泥浆液的研究   总被引:4,自引:0,他引:4  
通过烧杯搅拌实验对混凝剂处理钻井废泥浆液进行研究,从混凝剂适应p H值范围、混凝效果、沉降速度三方面研究比较,找出一种较为理想的混凝剂,并分析了影响混凝剂性能的主要因素,确定了混凝剂的最佳投放剂量。   相似文献   

16.
黄河源区水环境变化及黄河出现冬季断流的原因   总被引:12,自引:0,他引:12  
自1954年有水文观测资料以来,黄河曾在青海省玛多县黄河沿水文站发生过3次断流。本文在分析黄河源区水环境特征及其影响因素的基础上指出,鄂陵湖、扎陵湖的环湖融区调节能力低,当遇到连续干旱、冬季其调节水量不足以维系黄河径流时便会发生断流,这是断流的主因。湖水位降低、开采沙金、过度放牧等自然和人为因素也会对黄河发生断流产生影响。鄂陵湖口附近黄河上修建的水电站开始蓄水,提高了两湖及环湖融区的调节能力,今后黄河冬季出现断流的可能性将大为降低。  相似文献   

17.
The Elder problem is an example of a density driven flow, motivated by experiments of a thermally driven convection in porous media. It is a mathematical benchmark problem used for code verification of density driven flow simulators and comparison of issues related to its numerical treatment. Its bifurcation diagram with respect to the Rayleigh number is investigated on a hierarchy of uniformly refined grids. Eleven stationary solutions are shown to exist for the Elder problem. Similar solutions can be found using the Boussinesq approximation. Despite this similarity the corresponding bifurcation diagrams are shown to be topologically not equivalent. This gives rise to serious doubts on the validity of Boussinesq approximation for this model problem. Grid convergence is investigated for the numerically obtained solutions.  相似文献   

18.
International unity is becoming ever stronger in this country owing to an increasing similarity in the development of the cultural environment. This comprises the provision of all the country's republics with a sufficient number of schools, theatres, and other institutions and cultural information media in accordance with the needs of the population. An important part is played by the rise in ‘the general educational level, as well as the level of professional qualifications and skills. Among all the Soviet nations and nationalities, this rise being more rapid among formerly backward peoples. Prominent among the factors of internationalization is the progressive development of the nationalities’ cultural resources, while professional culture is being increasingly brought within the reach of the masses.The implementation of the nationalities policy promotes the all-round development of all Soviet nations and nationalities, their drawing together, the upsurge of the individual capabilities of every Soviet citizen.  相似文献   

19.
正Artemia cysts are an extremely important component of aquaculture diets.It is well established that the cultivation of fish and shellfish derive substantial health and growth advantages when Artemia are included in the diets of the  相似文献   

20.
利用天山南坡科其喀尔冰川3号观测站2009年全年的气象观测资料,分析研究了科其喀尔冰川表碛区的小气候特征. 结果表明:总辐射和净辐射夏秋季较高、冬春季较低;反射辐射和地表反照率反之. 与其他地区不同,该区主要受积雪物理性质和下垫面状况的影响,冬春季地表反照率日变化表现为由大到小的变化过程,夏秋季表现为倒U型. 温度年变化表现为夏秋季高、冬春季低,最高月均值出现在8月,为9.4℃,最低月均值出现在1月,为-9.6℃. 受山谷风和冰川风的影响,全年的风向以西北风和西北偏西风为主,风向的日变化以11:00为界发生转向. 受降水和冰川消融等的影响,比湿夏秋季月均值较大,冬春季月均值较小.  相似文献   

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