兰坪金顶铅锌硫化物成矿中硫化氢成因

滇西北兰坪金顶超大型铅锌矿床是目前中国最大的铅锌矿床,也是世界上形成时代最新且唯一的陆相沉积岩容矿的超大型铅锌矿床。为探讨金顶铅锌矿所需大量硫化氢的形成机理,对矿区含有机质包裹体均一温度、硫同位素、碳同位素进行了测试、整理和分析。研究表明：金顶矿区广泛分布的石膏、硬石膏和丰富的有机物质为生成大量硫化氢提供了重要条件;在早期成岩-矿化阶段,温度相对较低,以生物还原作用产生硫化氢为主;在主成矿期,伴随着深部幔源流体的上涌,温度升高,油气的高温热化学还原作用产生大量硫化氢。     

云南金顶铅锌矿床成矿物质来源及有机成矿作用

分析了金顶铅锌矿床同位素及生物标志化合物特征,探讨了矿床成矿物质来源及有机成矿作用.结果表明,矿石铅主要来自上地幔,成矿流体主要为地幔流体和盆地卤水.矿区有机质的母质来源以低等水生生源的海藻类为主,同时伴随有一定量的陆源高等植物组分的输入,有机质来源于三叠纪三合洞组碳酸盐岩地层.有机质在成矿作用中可能起到的作用有:还原硫酸盐提供成矿所需的硫源;形成有机金属络合物,活化运移成矿金属元素;改变成矿物理化学环境对成矿物质的还原沉淀作用.     

兰坪坳陷上三叠统原油地球化学及有机成矿意义

兰坪坳陷金顶矿区下含矿层产有多层稠油,储层主要为上三叠统三合洞组的灰岩和角砾状灰岩.原油地球化学特征表明有机母质是多源性的,并以低等水生藻类贡献为主,沉积水体介质以还原性占优势,具有较高盐度,有机质热演化处于成熟-高成熟阶段,生物降解改造较为强烈.铅锌金属与稠油的共生、金属硫化物的有机生物硫特征、有机质富集地区矿化强烈等均表明有机质参与了金属成矿.按照不同世代有机质与金属成矿作用机理,本区有机成矿主要以配合作用及吸附、还原作用为主.     

兰坪坳陷上三叠统原油地球化学及有机成矿意义

兰坪坳陷金顶矿区下含矿层产有多层稠油，储层主要为上三叠统三合洞组的灰岩和角砾状灰岩。原油地球化学特征表明有机母质是多源性的，并以低等水生藻类贡献为主，沉积水体介质以还原性占优势，具有较高盐度，有机质热演化处于成熟一高成熟阶段，生物降解改造较为强烈。铅锌金属与稠油的共生、金属硫化物的有机生物硫特征、有机质富集地区矿化强烈等均表明有机质参与了金属成矿。按照不同世代有机质与金属成矿作用机理，本区有机成矿主要以配合作用及吸附、还原作用为主。     

木里冻土区天然气水合物成藏特征

为探讨木里冻土区天然气水合物的烃类来源及成藏特征,应用地球化学反演方法,根据碳同位素和成熟度的关系,分析烃类的成因和来源,结合水合物赋存特征、地层埋藏史等研究水合物成藏特征。结果表明:木里冻土地区天然气水合物的烃类气体以油型气为主,浅部混有少量煤成气;前者主要来源于石炭统和下二叠统烃源岩,侏罗系烃源岩贡献较小。水合物成藏空间分布非均质性较强,纵向上不同层段的气体来源和充注特征具有较大差异,上部层段烃类成熟度较低,来源于早期常规油气藏破坏后逸散气体,混有少量水合物分解甲烷;中部层段甲烷具有"多阶"充注特征,有原油裂解气贡献,底部发育油气优势运移路径;下部层段烃类主要来源于深部烃源岩层(早二叠系和石炭系),具有"多阶"充注特征。水合物形成前的常规油气藏演化和水合物形成后的保存条件,是研究区天然气水合物成藏和展布的主控因素。     

塔西地区富烃类还原性盆地流体与砂砾岩型铜铅锌-铀矿床成矿机制

塔西地区萨热克大型砂砾岩型铜矿床和乌拉根铅锌矿床进入矿山开发期,今后找矿潜力大但成矿机制不明,制约了成矿与找矿预测。基于构造岩相学和地球化学岩相学,以西南天山造山带为核心,塔西地区前陆盆地、山间盆地和后陆盆地对于砂砾岩型铜矿床、铅锌矿床和铀矿床有不同控制作用:1在西南天山造山带北侧的托云中—新生代后陆盆地系统中,其次级盆地(萨热克巴依中生代山间拉分断陷盆地)上侏罗统库孜贡苏组上段为萨热克式砂砾岩型铜矿赋存层位;2在西南天山造山带南侧的前陆盆地系统中,乌拉根砂砾岩型铅锌矿赋存在下白垩统克孜勒苏群顶部与古近系底部,巴什布拉克大型砂岩型铀矿床赋存在伽师前陆盆地克孜勒苏群中;3在前陆盆地系统中,古近系顶部和新近系渐新统—中新统为砂岩型铜矿床赋存层位。富烃类还原性盆地流体识别构造岩相学标志为沥青化蚀变相、沥青化—褪色化蚀变带、碎裂岩化相和沥青化蚀变相多重耦合结构;地球化学岩相学标志包括富含有机碳,矿物包裹体中含有含烃盐水、气态烃-液态烃-气液态烃、轻质油和沥青等有机质类包裹体,低盐度和中盐度成矿流体,Cu-Ag-Mo同体共生矿体,氧化相铜、硫化相铜和钼硫化物等。砂砾岩型铜铅锌-铀矿床成矿机制主要包括:1同生断裂带由走滑拉分断陷发生构造反转后,转变为挤压收缩体制,即烃源岩大规模生烃-排烃机制;2反转构造带、区域性不整合面、滑脱构造带、高孔隙度和渗透率砾岩等构造岩相带为富烃类还原性盆地流体大规模运移构造通道;3高孔隙度和渗透率砾岩类下部低渗透率泥质粉砂岩和上部含膏泥岩为岩相岩性圈闭构造岩相学标志;4大规模富烃类还原性盆地流体与含铜紫红色铁质杂砾岩(氧化相铜)有多相流体多重耦合结构,可能是砂砾岩型铜矿床大规模富集成矿机制,低温卤水沉积叠加富烃类还原性盆地流体成矿可能是形成砂砾岩型铅锌矿床机制,富烃类还原性盆地流体多期次混合与氧化相铀被还原可能是砂岩型铀矿富集成矿机制。     

新疆彩霞山铅锌矿床地质及同位素地球化学特征

对彩霞山铅锌矿床矿石矿物和围岩的硫、铅同位素及脉石矿物的氢、氧同位素地球化学特征进行了研究。分析结果显示,成矿物质来源于地壳和地幔的混合;硫来源主要为同化了海水硫酸盐的岩浆硫,并有少量生物还原硫参与。氢、氧同位素指示成矿流体早期可能有岩浆热液,主成矿期主要是地层中的建造水参与成矿。     

太行山连巴岭铅锌矿床地质特征及成矿物质来源

连巴岭铅锌矿区位于太行山北段涞源花岗岩体北侧与阜平变质核杂岩北西缘,产于乌龙沟—上黄旗深断裂带的次级平行断裂带中。分析了连巴岭铅锌矿床成矿地质背景、矿相学特征以及控矿构造,对比研究了矿石S-Pb同位素组成,探讨了成矿物质来源,建立了成矿模式。结果表明:金属硫化物样品(黄铁矿、闪锌矿、黄铜矿、方铅矿)的硫同位素组成为(-2.7~6.9)×10-3,多数集中在(-1~3)×10-3,平均值为1.1×10-3,与地幔硫接近;硫同位素组成频率直方图呈塔式分布,表明其深源岩浆硫的特点;矿石铅同位素组成稳定,花岗岩是主要的成矿母岩,成矿物质具有壳幔混合特点,并来源于上地幔—下地壳物质部分熔融形成的岩浆。连巴岭铅锌矿床成矿模式为:岩层因受到多种构造应力的影响而发生变形和破裂;中生代燕山运动引起次一级的褶曲断裂和节理,使地壳变得更加虚弱;基底的王安镇岩体发生断裂,花岗岩体乘机侵入;然后酸性、中性、基性岩脉侵入,由于颗粒细小,近于致密,渗透性差的中性岩脉起到屏蔽、遮挡作用,使得含矿热液与白云岩发生交代作用而聚集堆积形成矿体。     

鄂尔多斯盆地姬塬油田延长组原油性质与来源分析

通过原油与油田水物理性质、原油与烃源岩族组成、饱和烃气相色谱以及萜烷与甾烷等生物标志化合物特征的多项地球化学指标对比,表明鄂尔多斯盆地姬塬油田延长组长8、长6、长4+5等油层组原油性质较为复杂,其成熟度、母源氧化-还原环境及母质类型等方面存在显著差异。烃源岩评价也显示长9、长8、长7、长6、长4+5段的暗色泥岩有机质质量和类型有所差别,但均具备生排烃能力。油源对比结果进一步证明:成藏过程存在多套油源混源供油的成藏效应,其中长8油层组原油主要来源于长7—长8段烃源岩;长6油层组原油主要来源于长7—长6段烃源岩;长4+5油层组原油存在长7、长6及长4+5段多源烃源岩的贡献。     

陕西凤太矿集区东塘子铅锌矿床地质-地球化学特征与成因

东塘子铅锌矿床位于南秦岭凤太矿集区南部,铅锌矿体产于中泥盆统古道岭组灰岩与上泥盆统星红铺组千枚岩接触界面,受背斜构造与硅钙岩性界面控制。热液成矿作用过程可划分为脉状硫化物-铁碳酸盐-石英(Ⅰ)、块状硫化物-碳酸盐(Ⅱ)、方解石石英脉-贫硫化物(Ⅲ)、厚大石英碳酸盐脉-贫硫化物(Ⅳ)4个阶段,其中,Ⅰ、Ⅱ阶段为主成矿阶段。东塘子乃至整个凤太矿集区内铅锌矿床成因认识的分歧主要集中在沉积成因和热液成因之争,进一步研究矿床成因是凤太矿集区深部找矿预测的基础。通过矿石的结构构造、黄铁矿成分、H-O同位素组成、微量元素地球化学特征等研究,对东塘子铅锌矿床成因进行探讨。结果表明:东塘子铅锌矿床脉状与块状矿石中的黄铁矿w(Co)/w(Ni)平均值分别为18.70与8.56,为热液成因;矿石δDV-SMOW值为-94.9‰~-83.3‰,平均值为-87.0‰,δ18OH2O值为8.0‰~11.1‰,平均值为9.8‰,成矿流体早期主要来源于岩浆水,晚期有地层水与大气降水混入。综合矿床地质、地球化学、H-O同位素等特征,认为东塘子铅锌矿床属于受中泥盆统古道岭组灰岩与上泥盆统星红铺组千枚岩之间"硅钙面"控制的岩浆热液型矿床,矿床深部可能存在隐伏岩体与成矿作用中心,深部找矿潜力较大。     

Strategy of photo-protection in phytoplankton assemblages in the Kongsfjorden,Svalbard, Arctic

Photo-protective functions were investigated in phytoplankton assemblages at Kongsfjorden, Svalbard in spring, using their UV-absorbing compounds (mycosporine-like amino acids (MAAs)), xanthophyll pigments (diadinoxanthin (DD) and diatoxanthin (DT)) and < beta >- dimethylsulphoniopropionate (< beta >_-DMSP). The dominant phytoplankton species in the inner bay were dominated by Phaeocystis spp. and nanoflagellates, while the offshore waters were dominated by Thalassiosira spp. In the inner bay, UVabsorbing compounds and xanthophyll pigments exhibited higher ratios of MAA to chlorophyll a (MAA:chl a ratio), and both DD and DT to chlorophyll a (DD:chl a ratio and DT:chl a ratio), respectively. Thus, the photoprotective-pigments such as DD and DT appear to complement MAAs in the natural phytoplankton assemblage. However, the ratio of < beta >_-DMSP to chlorophyll a (< beta >_-DMSP:chl a ratio) did not show a distinct spatial distribution according to environmental factors or interspecies differences. In this study, we found that photoprotective compounds occurred in a manner dependent on the phytoplankton species composition in Kongsfjorden Bay, where Phaeocystis is the dominant species.     

Glacier change in the Tanggula Mountains,Tibetan Plateau,in 1969-2015

To improve our knowledge of glacier change in the Tanggula Mountains located in the northeast of the Tibetan Plateau, we delineated outlines of the glaciers in 1991 and 2015 using Landsat TM/OLI images and compared them with the reported glacier data in the First Chinese Glacier Inventory in 1969 and the Second Chinese Glacier Inventory in 2007. These comparisons showed that the glacier area and ice volume decreased by 524.8 km~2 and 37 km~3, respectively. The majority of the glacier area loss was concentrated in the area class of 1-5 km~2, between 5300 m and 5500 m in elevation, on north and east facing slopes and in the Dam Qu River basin. These glacier changes exhibited spatial and temporal differences. The glacier retreat rategradually increased from 1969 to 2015, and the rate in the east was higher than that in the west. From 1969 to 2015, the warming rate in the Tanggula Mountains was 0.38°C/10 a, while the annual precipitation only increased by 0.4%. The slight increase in the amount of precipitation made a limited contribution to glacier change, while the change in temperature led to noticeable shrinkage of the glaciers. Contrary to the retreat or stagnation of most glaciers in the study area,there were 10 glaciers that experienced clear advance in 1986-2015 with noticeable increases in both area and length. Whether or not these 10 glaciers are surge glaciers requires further study.     

Vegetation geo-climatic zonation in the rocky mountains,Northern Utah,USA

We developed a vegetation geo-climatic zonation incorporating the zonal concept, gradient and discriminant analysis in Wasatch Range, northern Utah, USA. Mountainous forest ecosystems were sampled and described by vegetation, physiographic features and soil properties. The Snowpack Telemetry and National Weather Service Cooperative Observer Program weather station networks were used to approximate the climate of sample plots. We analysed vegetation and environmental data using clustering, ordination, classification, and ANOVA techniques to reveal environmental gradients affecting a broad vegetation pattern and discriminate these gradients. The specific objective was to assess and classify the response of the complex vegetation to those environmental factors operating at a coarse-scale climatic level. Ordination revealed the dominant role of regional, altitude-based climate in the area. Based on vegetation physiognomy, represented by five tree species, climatic data and taxonomic classification of zonal soils, we identified two vegetation geo-climatic zones： （1） a montane zone, with Rocky Mountain juniper and Douglas-fir; and （2） a subalpine zone, with Engelmann spruce and subalpine fir as climatic climax species. Aspen was excluded from the zonation due to its great ecological amplitude. We found significant differences between the zones in regional climate and landformgeomorphology/soils. Regional climate was represented by elevation, precipitation, and air and soil temperatures; and geomorphology by soil types. This coarsescale vegetation geo-climatic zonation provides a framework for a comprehensive ecosystem survey, which is missing in the central Rocky Mountains of the United States. The vegetationgeoclimatic zonation represents a conceptual improvement on earlier classifications. This framework explicitly accounts for the influence of the physical environment on the distribution of vegetation within a complex landscape typical of the central Rocky Mountains and in mountain ranges elsewhere.     

Characteristics of the microzooplankton community in Jiaozhou Bay,Qingdao, China

The species composition and abundance of microzooplankton at 10 marine and five coastal stations(Hongdao,Daguhe,Haibohe,Huangdao and Hangxiao) in the Jiaozhou Bay(Qingdao,China) were studied in 2001.The microzooplankton community was found to be dominated by Tintinnopsis beroidea,Tintinnopsis urnula,Tintinnopsis brevicollis and Codonellopsis sp.The average abundance of microzooplankton was highly variable among stations.Specifically,the abundance of microzooplankton was higher at inshore stations and lower ...     

Controlling mechanisms for the trace metals, (Cu,Zn, Cd,Fe, Co and Ni) in anoxic sea water in Saanich Inlet,British Columbia,Canada

A study was conducted on Cu, Zn, Cd, Fe, Co and Ni levels in Saanich Inlet anoxic seawater. Data on the concentration of these trace metals and H₂S, and other oceanographic parameters were obtained in four cruises. Equilibrium models are presented together with in situ data. The results strongly support the assumption that the solubilities of Cu, Zn, Cd, Fe, Co and Ni are controlled by bisulfide and/or polysulfide complexes. The species of Cu, Zn, Cd and Ni are shown to be Cu(S₄) ₂ ³⁻ and Cu(Sn₄S₅)³⁻, Zn(HS) ₂ ⁰ and ZnHS ₂ ⁻ , Cd(HS) ₂ ⁰ and Ni(HS) ₂ ⁰ , respectively. The solid species controlling Fe²⁺ and Co²⁺ are respectively the pyrohotites FeS and CoS. The data illustrates that thermodynamic equilibrium has been established in the H₂S-controlled seawater of Saanich Inlet, and that equilibrium has not been established in the H₂S−O₂-coexisted seawater of Saanich Inlet. The lack of equilibrium in the H₂S−O₂-coexisted seawater is a result of the flushing or mixing of oxygenated seawater with anoxic water. The new species of trace metals are still in the processes of reduction and precipitation. Contribution No. 1428 from Institute of Oceanology, Academia Sinica     

Seasonal Variations in Phytoplankton Community Structure in the Sanggou,Ailian, and Lidao Bays

The seasonal variations in phytoplankton community structure were investigated for the Sanggou Bay （SGB） and the adjacent Ailian Bay （ALB） and Lidao Bay （LDB） in Shandong Peninsula,eastern China.The species composition and cell abundance of phytoplankton in the bay waters in spring （April 2011）,summer （August 2011）,autumn （October 2011）,and winter （January 2012） were examined using the Uterm6hl method.A total of 80 taxa of phytoplankton that belong to 39 genera of 3 phyla were identified.These included 64 species of 30 genera in the Phylum Bacillariophyta,13 species of 8 genera in the Phylum Dinophyta,and 3 species of 1 genus in the Phylum Chrysophyta.During the four seasons,the number of phytoplankton species （43） was the highest in spring,followed by summer and autumn （40）,and the lowest number ofphytoplankton species （35） was found in winter.Diatoms,especially Paralia sulcata （Ehrenberg） Cleve and Coscinodiscus oculus-iridis Ehrenberg,were predominant in the phytoplankton community throughout the study period,whereas the dominance of dinoflagellate appeared in summer only.The maximum cell abundance of phytoplankton was detected in summer （average 8.08 × 103 cells L-1） whereas their minimum abundance was found in autumn （average 2.60 x 103 cellsL-1）.The phytoplankton abundance was generally higher in the outer bay than in the inner bay in spring and autumn.In summer,the phytoplankton cells were mainly concentrated in the south of inner SGB,with peak abundance observed along the western coast.In winter,the distribution of phytoplankton cells showed 3 patches,with peak abundance along the western coast as well.On seasonal average,the Shannon-Wiener diversity indices of phytoplankton community ranged from 1.17 to 1.78 （autumn 〉 summer 〉 spring 〉 winter）,and the Pielou＇s evenness indices of phytoplankton ranged from 0.45 to 0.65 （autumn 〉 spring 〉 summer〉 winter）.According to the results of canonical correspondence analysis,phosphate level w     

准噶尔盆地玛湖凹陷下三叠统百口泉组扇三角洲沉积特征

准噶尔盆地玛湖凹陷下三叠统百口泉组的沉积背景分析表明,研究区存在东西2个方向的6个分支物源,古凸起及沟槽对水系具有分隔控制作用,控制砂体沉积。通过岩心观察,归纳总结出9种岩相,结合录井、测井资料分析,认为玛湖凹陷下三叠统百口泉组沉积相类型主要为扇三角洲相,并详述了7种微相的沉积特征。利用地质地震资料综合分析,确定出玛湖凹陷百口泉平面沉积特征,凹陷内发育6个受物源控制明显的扇体,相邻扇体在平原相带被凸起带分隔,在前缘相带内相互交汇叠置。      

东营凹陷博兴洼陷深洼区古近系沙河街组三段中亚段沉积特征

利用岩心、测井、录井、地震等资料,应用层序地层学与沉积学理论,建立博兴洼陷深洼区古近系沙河街组三段中亚段层序地层格架,识别沉积相类型,揭示研究区沙河街组三段中亚段湖底扇砂体的充填期次和规律.结果表明:沙河街组三段中亚段地层划分为2个三级层序,层序内部细分为6个体系域;识别湖底扇中扇、湖底扇外扇、深湖3种沉积亚相,以及辫状水道、水道间、席状浊积岩、远源浊积岩和深湖泥5种沉积微相;总结各沉积微相在岩心、测井、地震上的识别特征;在层序格架内识别各体系域沉积相平面展布规律.此研究对该区下一步油气资源的勘探开发具有指导意义.     

云南昌宁柯街断裂带温泉水化学特征

通过对柯街断裂带上2个温泉(梁园温泉和大地温泉)水样的阴阳离子分析,正确划分了温泉水的水化学类型;同位素
数据表明,2个样品的δD和δ18O值均在大气降水线附近,且未显示δ18O值向右漂移现象,说明该区地下热水具有现代大气降水
的氢氧同位素组成特征,推断温泉形成与火山、岩浆型热源没有直接关系。大气降水的同位素组成与海拔高程之间的耦合关系,
证明了地下热水补给源区位于西部山区;通过采用SiO₂ 温标计算得出了温泉的热储温度和热水循环深度。梁园温泉热储温度为
100.1℃,热水循环深度是1643.3m,大地温泉热储温度为79.8℃,热水循环深度是1237.2m。柯街断裂带的构造特征及岩性特
征与地下热水的水化学组成、深循环机制和冷热水的混合机制有着本质的联系。