妥拉海河石墨矿床是在青海省发现的首个超大型大鳞片晶质石墨矿.该矿床位于柴达木盆地南缘、东昆仑中段,矿体呈层状、似层状赋存于下元古界金水口岩群下岩组的片麻岩、钙质片麻岩、石英片岩和大理岩中,属于典型的片麻岩型石墨矿床.为探讨其矿床成因,本文对含矿地层开展了详细的岩相学、全岩地球化学和同位素地球化学研究.研究结果表明:含矿的石墨片麻岩、石墨石英片岩稀土元素总量为82.95×10-6～154.86×10-6,轻稀土富集,具有明显的Eu负异常和Ce弱负异常,显示了原岩形成于大陆边缘浅海缺氧沉积环境.赋矿的变质岩原岩为富含有机质的砂质岩、杂砂岩和钙硅酸盐岩,物质来源主要是陆源碎屑,少量为浅海的碳酸盐岩.矿石中石墨片麻岩和大理岩的δ13C同位素组成指示石墨的碳质来源于生物有机碳,而大理岩的碳质来源为无机碳.妥拉海河石墨矿床是形成于古元古代的区域变质型矿床.

青海石灰岩矿资源较为丰富,分布相对集中,且品质好.在总结青海省内石灰岩资源特征、分析国内石灰岩深加工产业现状的基础上,提出了石灰岩资源优质优用的梯级开发利用建议:一是开展石灰岩分级高值利用、产业布局研究;二是加强政策引导和支持力度,坚持绿色发展与开发,实现经济高质量发展.

本文对比分析了青海柴达木盆地北缘典型脉石英矿床地质特征,在此基础上初步探讨了成矿规律,认为该区脉石英为加里东晚期酸性花岗岩岩浆演化期后热液沿区内主要断裂、裂隙充填而形成的热液型矿床.

夏乌日塔多金属矿床是赛坝沟金矿田内近年找矿勘查中新发现的以铅锌金为主的多金属矿床类型,本文较全面地总结了矿床地质地球化学特征及找矿标志,以期为矿床成因研究及区域多金属矿的勘查提供实践经验及理论依据.

We often have to get coordinates on the map during daily geological work.This paper has discussed two methods to massively export coordinates on the map based on MAPGIS software.One way to export coordinates is to use the "graph manipulation/document transition" subsystem of MAPGIS software,and the other is to use "utility service/projection transformation"subsystem.We have concluded that the second method is favorable to export property values of points on the map such as coordinates by comparassion.

Good prospecting effect is gained by stream sediment survey in black shales area in Chengkou region of Northeast Chongqing,which consists of Upper Sinian to Lower Cambrian rocks such as black carbonaceous aleurolite,carbonaceous silty slate,and carbonaceous siliceous rocks.Focusing on the study of black shales and based on comprehensive analysis,this paper has pointed out that manganese,vanadium,silver,and barium are the main ore-forming elements,while manganese mainly enriches in Dengying and Doushantuo formations,vanadium and silver in Lujiaping Formation,and barium in Bashan Formation.The paper has also established a geochemical anomaly model for black shales and shown a clear direction for prospecting.

The black rock series of Lower Cambrian are well developed in Chengkou district,Chongqing.ICP-MS techniques was used to analyze trace element contents in Lower Cambrian black rock series,including cherts,black siltstones and multi-elements concentrated layers.Compared to northern Guizhou and northwestern Hunan,the REE in these rocks is very low with the value ranging from 111.41×10-6 to 184.13×10-6,averaging 138.83×10-6.LREE/HREE ratios vary from 2.49 to 3.44,indicating that LREE is relative abundant.δCe values range from 0.39 to 0.46,showing almost negative anomaly,and the δEu shows unconspicuous anomaly,with the value between 0.84 and 1.10.The indicators of δCe,δU,V/Cr,Ni/Cr and V/(V+Ni) demonstrated that these black rock series formed in the anoxic environment.REE geochemical characteristics and their diagrams,high enrichments of Cr,Sb,As,Bi and U/Th ratios indicated that black rock series mainly formed by hydrothermal deposition.Meanwhile,the petrogenesis of black rock series was associated with volcanism,which provided the composition and dynamics to the hydrothermal activity.

The quartz-molybdenite vein,discovered newly in the Beishan ore block of Xiaoxinancha copper-gold mine,is parallel to adjacent copper-gold ore bodies,indicating that they are commonly controlled by the same structure system. The metal minerals in molybdenum ore is dominated by molybdenite obviously cutting by later pyrite and chalcopyrite. The lode molybdenum mineralization shows the similar minerals assemble as early metallogenic stage of the major copper-gold mineralization. Primary inclusions in quartz minerals from the vein include gas,aqueous two-phase and daughter-mineral inclusions. The ore-forming fluid is of high temperature ( 300 to 380 ℃) ,high salinity ( 12. 99 % to 47. 36 % NaCleqv) and belongs to the NaCl-H2O fluid system. The fact that different types of inclusions are coexistent,together with their approximate homogeneous temperature,confirms that the fluid underwent the process of boiling as early-stage fluid of the major copper-gold mineralization in the deposit. Comparing with data on the Xiaoxinancha deposit,it can be concluded that the quartz-molybdenite vein is formed in the early metallogentic stage of copper-gold mineralization. The conclusion in this paper can supply basic data for isotopic dating and metallogenetic mechanism.

Sanjiazi deposit is one of the scheelite deposits in Northeastern China found in recent years.In order to discuss the metallogenesis,their geological and geochemical characteristics of the deposit is studied,including the composition of REE and trace elements in metallogenic granitic rocks,marble wall rock as well as in skarn ores.These granitic rocks containing scheelite mineralization,has similar geochemical features with those of the I-type granites, such as aluminium super-saturation,variable alkaline composition,K_2ONa_2O and low ratio of Rb/Sr.Moreover,the facts of low content of REE,negative δEu anomalies,unobvious δCe anomalies and right-declining chondrite-normalized REE patters demonstrate that tungsten-bearing granitic rocks was derived from deep crust or upper mantle.Together with geological features of the deposit,contents of trace elements and sulfur isotope in different rocks and ores,a conclusion can be drawn that the ore-forming materials,including W element,may come from the Mengjialing intrusion.The Sanjiazi scheelite deposit belongs to the skarn deposit and is related to the NW subduction of the Pacific plate underneath Eurasia plate in the Early Yanshanian period.

为确定杨金沟大型钨矿的成矿物质来源,本文运用白钨矿单矿物的微量元素、稀土元素特征加以示踪.ICP-AES测定结果显示:白钨矿亏损Mo,Bi,Sn,Nb,Ta等,具有很低的Rb/Sr,Nb/Ta和Zr/Hf值,指示其成矿物质具有壳源特征,而并非主要来自深源岩浆的结晶分异作用;不同白钨矿样品的REE组成基本一致,Eu元素出现明显的正Eu异常(δEu 2.21～4.43),墓本未见Ce元素异常(δCe为0.92～1.08),表明白钨矿与流体之间稀土元素发生了强烈分异;白钨矿与赋矿围岩的REE球粒陨石标准化配分曲线形态相似,进一步显示五道沟群浅变质岩对杨金沟钨矿成矿物质的贡献.综合分析认为,杨金沟钨矿的成矿流体为源自上地慢的富含CO_2的中高温流体,沿构造上升并与五道沟群浅变质岩发生交代作用引起黑云母等含钾矿物分解产生N_2,最终形成富含W等成矿物质的NaCl-H2O-CO2-N2流体体系.随着构造减压作用,CO2不断逸出,破坏了矿液内物理化学体系的平衡,导致WO4~(2-)与Ca~(2+)在适当物理化学条件下形成白钨矿.

The mineralizing process of the Yangjingou large scheelite deposit can be listed such four metallogenetic stages as pyrite-arsenopyrite, quart-coarse scheelite, quartz-sulphides-fine scheelite as well as carbonates stage. In order to analyze the source, features and evolution of ore-forming fluid, fluid inclusions in quartz minerals formed in the major metallogenetic stage are studied. Types of fluid inclusions include gas-rich (Ⅰ),gas-liquid (Ⅱ), pure-CO2 (Ⅲ) and CO2-bearing three phase (Ⅳ). The gas phase of typeⅠinclusions is proved to be mainly composed of CO2, CH4 and N2, their homogenization temperatures vary from 278.5 to 336.4℃, with salinities (NaCl) from 3.53% to 7.72%. TypeⅡ inclusions, with ratios of gas to liquid in change from 10% to 45%, are homogenized to liquid during heating, their homogenization temperatures vary from 144.7 to 345.9℃, mainly from 190 to 220℃, salinities(NaCl) from 3.05% to 9.34%. Type Ⅲ is dominated by CO2 with minor CH4. Type Ⅳ fluid inclusions are composed of three phases (VCO2+LCO2+LH2O), homogenization temperatures change from 301.6 to as 305.1℃.Comprehensive study on ore-forming condition,geological features of the deposit, compositional and microthermometric analysis of fluid inclusions leads to the conclusion that the ore-forming fluid of the Yangjingou deposit belongs to the NaCl-H2O-CO2(-N2) hydrothermal system with medium-high temperature, low salinity. It is derived from deep crust to upper mantle and mixed by ore-forming materials from the Paleozoic metamorphic strata of the Wudaogou Group which hosts scheelite-quartz veins. The immiscibility of ore-forming fluid played an important role in the metallogenetic process of Yangjingou scheelite deposit.

In order to trace the ore-forming material of Yangjingou large scheelite deposit, trace elements and rare earth elements (REE) compositions of the scheelite mineral were determined by ICP-AES. The results show that the scheelite is depleted with Mo, Bi, Sn, Nb and Ta, and with very low ratios of Rb/Sr, Nb/Ta and Zr/Hf, indicating that primitive ore-forming materials of the Yangjingou deposit mainly came from the crust instead of the deep magmatic crystallization and differentiation. The scheelites picked from different samples possess very similar REE composition, obviously positive Eu anomalies ( δEu 2. 21 ∼ 4.43 ) and little Ce anomalies (δCe 0. 92 ∼ 1. 08) , suggesting that intensive REE differentiation occurred between the scheelites and the ore-forming fluid. Moreover, both the scheelite and wall-rocks of the Wudaogou Group have similar dextral-inclined chondrite-normalied patterns, indicating low-grade metamorphic rocks of the Wudaogou Group supplied major ore-forming materiaL The conclusion may be drawn in this paper that the primitive ore-forming fluid derived predominantly from the upper mantle, and rich in CO 2. The wall rock alteration resulted in decomposing of potassic minerals (i. e. biotite) and forming of N 2. The NaCl-H 2O-CO 2-N 2 fluid system rich in such oreforming main rial as tungsten, with the ascending of the fluid, decompressed rapidly and caused the escaping of CO 2 from the fluid. The breaking of physical-chemical balance of mineralizing fluid gave birth to the scheelite in Yangjingou deposit.

The Mengjialing intrusion in Siping area is one of tungsten-bearing granitic intrusions discovered recently in Northeastern China.In order to study its petrogenesis and relationship with scheelite mineralization,composition of trace elements and REE in two samples from the intrusion were tested.Different granitic rocks in Mengjialing intrusion were enriched in such metalligenic elements as W,Sn,Mo,Cu,Pb,As,Sb,Bi.They had similar ratios of Rb/Sr as the I-type granites,rich in light rare-earth elements(LREEs) and with low negative Eu anomalies.These data,together with composition of major elements,indicated that Mengjialing intrusion was derived from deep crust or upper mantle and was the major source of scheelite mineralization in this area.LA-ICP-MS zircon U-Pb dating demonstrated that the 206Pb/238U ages of zircons from porphyritic biotite adamellite(associated with Sanjiazi scheelite deposit) ranged from 165 Ma～181 Ma,yielding a weighted mean age of 172.4 Ma±1.8 Ma(n=18).It was considered that the Mengjialing granitic intrusion and associated scheelite mineralization took place under the tectonic background of the Pacific plate subduction to the Eurasia plate in the early Yanshanian period.The tungsten mineralization should be treated as an important member of the Yanshanian endogenic metallogenic series in this area.

作为一种先验模型,地质-地球化学找矿模型强调已知矿床的成矿地质背景、控矿条件、矿床地质特征及找矿标志等研究,以地球化学测量为主要手段,提取综合预测信息,进行有机的关联和置信提取.