基于Sufer软件的安徽巢湖马家凹地区土壤化探测量的数据处理方法

通过各项地质工作,完成面积约7.47 km2的土壤化探测量,采集样品1 353个,根据统计分析结果,确定了区内Au元素与Cu、Pb、Zn及Ag的关系较之Co、Ni密切,反映了区内金的成矿与老地层有一定的成因联系。通过异常等级的确定,圈定金化探异常9个。并利用地球化学块体方法对区内金的资源潜力进行了评估。初步认为区内金在构造、地层有利地段是最佳的最找矿地段。     

山东省招远市后仓地区金矿成矿地质特征

山东省招远市后仓地区位于胶东半岛的北部,其大地构造处于华北地台胶东台隆之胶北隆起区,区内构造活动和岩浆活动强烈,岩石蚀变及矿化现象比较普遍,已经发现2条矿体,具有较好的成矿条件和找矿前景。     

西秦岭岷-礼成矿带岩浆活动与金矿成矿模式探讨

岷-礼成矿带发现较多大型金矿,同时在岩体内发现斑岩型钼矿。金矿床矿石中除有低温矿物外,还有黄铜矿、白钨矿等中-高温矿物,白钨矿在寨上金矿中是载金矿物之一;钼矿中也有黄铜矿、白钨矿矿物;金、钼、钨矿化分带有一定空间关系;金矿床地球化学、稳定同位素、放射性同位素和流体包裹体的研究表明成矿物质,成矿流体有深源特征;中川岩体群的岩石学、年代学、岩石化学、微量元素、稀土元素特征表明岩体为复式岩体,具有壳幔混源特征;据此建立成矿带内受印支-燕山期岩浆活动控制的金矿成矿模式。     

西藏丁青县扎格拉金矿床地质特征、流体包裹体特征及成因

扎格拉金矿位于班公湖-怒江结合带东段及冈底斯-念青唐古拉板片北缘的腾冲-班戈岩浆弧带上;受被动陆缘深海复理石建造、 脆-韧性剪切带和深成岩浆活动控制。流体包裹体类型以单相和A型两相盐水溶液包裹体为主;次为B型两相盐水溶液包裹体、 富CO2两相包裹体和含CO2三相包裹体;成矿流体属中低温和中低盐度H2O-NaCl-CO2体系。氢、 氧同位素和相对富含K+、 Na+、Ca2+、 Mg2+、Cl-、SO2-4 的包裹体液相成分;显示成矿流体主要来自长期封存于沉积岩的深循环热（卤）水中;矿床成因类型为浅成中低温地下热（卤）水溶滤型金矿床。其成矿特征和流体性质与穆龙套型金矿床具有诸多相似性;研究该区域对西藏“沙丁板岩系”分布区金铜多金属找矿具有重要意义。     

甘肃礼县中川地区金矿成岩和成矿年龄的SHRIMP厘定

甘肃省礼县中川地区属于礼（县）岷（县）金矿带的东段,成矿作用与中川花岗杂岩体有密切的关系。运用高分辨率和高灵敏度离子探针（SHRIMP）测试技术,获得了中川花岗杂岩体形成的精确年龄,主侵入时代为210～160 Ma（可信度95%,MSWD=1.4）,该花岗岩体属于燕山早期-印支期造山运动的产物;3颗锆石（4个测点）的SHRIMP测试结果表明,中川地区金成矿的年龄为197～162 Ma,证实礼县中川地区金成矿于中川花岗岩体形成及稍后的时间段。年龄测试和地质剖面测量资料都证实,中川花岗岩体南部地层应该划在中石炭统地层中。与中川花岗杂岩体地质情况类似的碌础坝、 柏家庄、 闾井、 教场坝、 温泉等岩体外接触带仍然有很大的找矿前景。     

The Moreira Gomes deposit of the Cuiú-Cuiú goldfield: Fluid inclusions and stable isotope constraints and implications for the genesis of granite-hosted gold mineralization in the Tapajós Gold Province,Brazil

Moreira Gomes is a recently discovered deposit (21.7 t Au) of the Cuiú-Cuiú goldfield, Tapajós Gold Province, Amazonian Craton. The mineralized zone is about 1200 m long, 30–50 m wide, and at least 400 m in depth. The zone is controlled by a subvertical, east–west-trending structure that is related to a left lateral strike-slip fault system. The host rocks are predominantly tonalites of the Creporizão Intrusive Suite (1997 ± 2 Ma) of uncertain tectonic setting (magmatic arc or post-collision). Hydrothermal alteration and mineralization are predominantly of the fissure-filling type and locally pervasive. Sericitization, chloritization, sulfidation, silicification, carbonatization and epidotization are the observed alteration types. Pyrite is the predominant sulfide mineral and bears inclusions of chalcopyrite, galena, sphalerite and minor hessite and bismuthinite. Gold occurs predominantly as inclusions in pyrite and subordinately in the free-milling state in quartz veins. Ag, Pb and Bi have been detected by semi-quantitative EDS analysis.Three types of fluid inclusions, hosted in quartz veins and veinlets, have been identified. (1) one- and two-phase CO₂ inclusions; (2) two- and three-phase H₂O–CO₂-salt inclusions, and (3) two-phase H₂O-salt inclusions. The CO₂-bearing types are interpreted as the product of phase separation of an immiscible fluid. This fluid presents low to moderate density, low to moderate salinity (1.6–11.8 wt.% NaCl equivalent) and was trapped at 280° to 350 °C. The chemical system of the aqueous inclusions may contain CaCl₂ and/or MgCl₂, salinity varies from zero to 10.1 wt.% NaCl equivalent. Only locally salinities up to 25% have been recorded. This fluid was trapped between 120° and 220 °C and is interpreted as resulting from mixing of a hotter and more saline aqueous fluid (in part derived from phase separation of the H₂O–CO₂ fluid) with a cooler and dilute aqueous fluid.The δ³⁴S values of pyrite (−0.3‰ to 3.9‰) are probably related to magmatic sulfur. The isotopic composition of inclusion fluids and of the fluid in equilibrium with hydrothermal minerals (quartz, chlorite, and calcite) show δ¹⁸O and δD values that range from +0.5 to +9.8‰, and from −49 to −8‰, respectively. Mineral pairs show equilibrium isotopic temperatures that are compatible with the fluid inclusion homogenization temperatures and with textural relationships of the hydrothermal minerals.Isotopic results combined with mineralogical and fluid inclusion data are interpreted to reflect a magmatic-hydrothermal system that evolved in at least three stages. (1) Exsolution of a CO₂-bearing magmatic fluid between 400 °C and 320–350 °C and up to 2.1 kbar (6 km in depth) followed by phase separation and main precipitation of the hydrothermal assemblage composed of chlorite–sericite–pyrite–quartz-gold. (2) Cooling and continuous exsolution of CO₂ produced a CO₂-depleted and slightly more saline aqueous fluid that was trapped mainly at 250°–280 °C. The predominant hydrothermal assemblage of stage 1 continued to form, but epidote is the main phase at this stage. (3) Mixing of the stage 2 aqueous fluid with a cooler and dilute aqueous fluid of meteoric origin, which was responsible for the main carbonatization phase. The mineralizing fluid was neutral to slightly alkaline and relatively reduced. H₂S (and/or HS^-) might have been the main sulfur species in the fluid and Au(HS)^2- was probably the gold transporting complex. Gold deposition occurred as a consequence of a combination of mechanisms, such as phase separation, mixing and fluid-rock interaction.The Moreira Gomes is a granite-hosted gold deposit that is interpreted to be a product of a magmatic-hydrothermal gold system. The age of ore formation (∼1.86 Ga) is consistent with the final stages of evolution of the widespread high-K, calc-alkaline Parauari Intrusive Suite, although the transitional to predominantly alkaline Maloquinha Intrusive Suite cannot be ruled out. Notwithstanding, the deposit does not show the classic features of (oxidized or reduced) intrusion-related gold deposits of Phanerozoic magmatic arcs.     

贵州省贞丰县雄黄岩金矿床地质特征及找矿方向

雄黄岩金矿床位于黔西南灰家堡矿田东段,矿床受灰家堡背斜控制,矿床位于灰家堡背斜东段枢纽产状由缓变陡地段,主要矿体赋存于中上二叠统茅口组与龙潭组岩溶不整合面构造蚀变体中,矿体分布于背斜核部800 m,矿体规模大;其次赋存于龙潭组中上部不纯碳酸盐岩中,矿体分布于背斜核部300～500 m.构造蚀变体普遍具金矿化,能否形成工业矿体受卷入地层厚度、岩性组合、蚀变强弱及古岩溶地貌等因素控制.通过对该矿床地质特征的研究,特别是构造蚀变体矿化研究和深部地球探测,认为在该区沿灰家堡背斜轴线向东延伸段、两翼构造蚀变体及北翼F101断层带中仍有矿体存在,具有较好的找矿远景.     

利用MorPAS对上黑龙江成矿带进行金成矿预测

上黑龙江成矿带主要由早-中侏罗世河流-湖泊-洪积相含煤碎屑岩组成,目前已发现多个中小型矿床,在该区进行成矿预测意义重大。文章利用MORPAS成矿预测系统,采用证据权重法进行了成矿预测工作,在充分研究区内已知矿床的成矿规律基础上,以1：257Y地质图为背景,物化探异常分析子系统对1：20万区域化探数据进行C—A分形确定异常下限,综合现有的找矿标志,提取有利的成矿要素,进行针对处理,制成上黑龙江成矿带MORPAS金成矿预测分析图,提供成矿靶区,为森林高覆盖区提供找矿有利单元。     

山东金青顶金矿床Ⅱ号矿体成矿特征

金青顶金矿床Ⅱ号矿体位于胶东隆起南缘,牟平乳山金成矿带中部,是目前该成矿带上最大的石英脉型金矿床。单个矿体延深之大,厚度、品位变化之稳定,且易采易选,这在胶东东部地区乃至全国尤为罕见。     

矿物热电系数及其在地质找矿中的应用

作者的研究表明,在非本征激发区,矿物热电系数随着活化温度的增高而增大;在本征激发区,随活化温度的增高而减小。矿物晶体中所含杂质的种类和含量多少决定矿物的导电类型。矿物热电系数可广泛应用于地质找矿和矿床评价中,以黄铁矿为例,在同一水平面上的含金矿脉,矿脉中黄铁矿热电系数正值高时,其矿石含金量也高。应用黄铁矿热电系数的正高值、混合型和负值可确定矿体和矿体的剥蚀深度。