新疆包古图金矿四矿区L7号脉中的特殊矿物组合及其成矿意义

包古图金矿四矿区L7号脉由浅部的自然砷-石英脉型矿石和深部的辉锑矿-石英脉型矿石组成。矿脉中含罕见的As、Sb矿物,如paakkonenite（Sb₂AsS₂）、自然砷、自然锑、方锑金矿、硫锑金银矿（Au₃Ag₄Sb₁₀S₁₂）等。热液过程划分为5个阶段：黄铁矿-毒砂阶段（Ⅰ）,围岩中形成大量的毒砂和黄铁矿并伴随较强硅化;粗粒石英阶段（Ⅱ）,形成沿围岩壁或围岩角砾的梳状石英;Au-As-Sb矿化阶段（Ⅲ）,形成辉锑矿-自然锑-自然砷-paakkonenite-银金矿-自然金-方锑金矿-硫锑金银矿-辉锑银矿-银锌黝铜矿-斜方砷铁矿-硫铜锑矿-石英;晚期Sb矿化阶段（Ⅳ）,形成与粒状方解石共生的辉锑矿、自然锑和paakkonenite;方解石阶段（Ⅴ）,形成穿切矿体和围岩的方解石（-石英）细脉。辉锑矿和斜方砷铁矿交代毒砂,自然金、方锑金矿、paakkonenite和自然砷交代辉锑矿。辉锑矿的结晶主要受温度和还原S含量的控制,自然砷、自然锑的结晶主要受氧逸度和温度控制。As、Sb分别以自然砷、辉锑矿和自然锑形式存在,同时消耗大量H₂S,流体进入张性空间后也释放H₂S,导致硫逸度急剧降低,含Au络合物失稳而成矿。     

Isotopic Compositions of Sulfur in the Jinshachang Lead–Zinc Deposit, Yunnan, China, and its Implication on the Formation of Sulfur-Bearing Minerals

The Jinshachang lead–zinc deposit is mainly hosted in the Upper Neoproterozoic carbonate rocks of the Dengying Group and located in the Sichuan–Yunnan–Guizhou(SYG) Pb–Zn–Ag multimetal mineralization area in China.Sulfides minerals including sphalerite,galena and pyrite postdate or coprecipitate with gangue mainly consisting of fluorite,quartz,and barite,making this deposit distinct from most lead–zinc deposits in the SYG.This deposit is controlled by tectonic structures,and most mineralization is located along or near faults zones.Emeishan basalts near the ore district might have contributed to the formation of orebodies.The δ34S values of sphalerite,galena,pyrite and barite were estimated to be 3.6‰–13.4‰,3.7‰–9.0‰,6.4‰ to 29.2‰ and 32.1‰–34.7‰,respectively.In view of the similar δ34S values of barite and sulfates being from the Cambrian strata,the sulfur of barite was likely derived from the Cambrian strata.The homogenization temperatures(T ≈ 134–383°C) of fluid inclusions were not suitable for reducing bacteria,therefore,the bacterial sulfate reduction could not have been an efficient path to generate reduced sulfur in this district.Although thermochemical sulfate reduction process had contributed to the production of reduced sulfur,it was not the main mechanism.Considering other aspects,it can be suggested that sulfur of sulfides should have been derived from magmatic activities.The δ34S values of sphalerite were found to be higher than those of coexisting galena.The equilibrium temperatures calculated by using the sulfur isotopic composition of mineral pairs matched well with the homogenization temperature of fluid inclusions,suggesting that the sulfur isotopic composition in ore-forming fluids had reached a partial equilibrium.     

早子沟金矿黄铁矿标型特征及其地质意义

早子沟金矿位于西秦岭同仁—夏河—岷县金成矿带,矿区赋矿地层为三叠纪中统古浪堤组一段细碎屑岩,中性岩脉大量发育。矿体产于地层、脉岩及其接触带中,严格受断裂构造控制。本文通过对不同期次、不同矿石类型的黄铁矿进行分布、形态、矿物组合、元素组成以及硫同位素的研究,发现不同矿石类型的黄铁矿形成于不同的深度和地质环境;主成矿期黄铁矿以五角十二面体为主,常具碎裂结构;严重亏铁亏硫,ω(Au)/ω(Ag)=5.54,ω(Co)/ω(Ni)=4.2,类似于卡林型金矿特征,又兼有岩浆型矿床的特征;矿体中黄铁矿硫同位素δ34S‰变化范围-7.43‰～-8.62‰,与围岩黄铁矿硫同位素组成接近,说明硫主要来源于沉积地层,同时由于构造活动和岩浆侵入作用对硫同位素分馏产生了一定影响,使重硫有所富集。     

陕西韩城寒武系白云岩和石灰岩固硫试验

选用韩城7个分别采自于寒武系白云岩和石灰岩的样品,以10%和25%为基准,加入韩城的高硫煤中,进行固硫试验。研究表明:中、下寒武系白云岩固硫率为10%~15%,石灰岩的固硫率为15%~26%,上寒武统下部白云岩的固硫率为30%~47%。上寒武统中上部的白云岩固硫率为10%~20%。岩石中白云石和方解石的含量相当时,白云岩的固硫率高于石灰岩5~10个百分点。      

Diversity, distribution pattern and conservation status of the plants used in liver diseases/ailments in Indian Himalayan Region

Introduction The Indian Himalayan Region (IHR) is known for its unique, natural, representative biodiversity (Samant et al. 1998a). This biodiversity is being utilized by the inhabitants of the IHR in various forms, i.e., medicine, food (wild edibles), fuel, fodder, timber, making agricultural tools, fiber, religious and various other purposes (Samant and Dhar 1997, Samant et al. 1998b). In the remote areas of the IHR where primary health centers are located far from the villages, the in…     

表层底泥翻耕对太湖藻源性湖泛的预控作用

表层底泥已被证实是引发或诱发太湖湖泛发生的主要因素,但能否通过像控制湖泊内源污染的翻耕方式对湖泛形成预控,则有待与过程有关的实验研究.模拟研究太湖易发湖泛区底泥翻耕对藻源性湖泛的控制作用,跟踪监测不同翻耕深度和翻耕后时长,对照和处理组上覆水的视觉、嗅觉、营养盐和挥发性硫化物浓度,以及表层底泥理化性质的变化.结果表明,未翻耕的对照组在模拟实验中发生了湖泛,翻耕10 cm和翻耕20 cm差异不大,但翻耕后时长对湖泛发生影响较大.刚翻耕后(1 d)即进行藻源性湖泛模拟的处理组发生了湖泛,但在程度和持续时间上均低于对照组;翻耕180 d和540 d的处理组,10 cm和20 cm翻耕深度均未发生湖泛.合理选择翻耕的施工时间,可以有效预防和控制湖泛的发生.     

Diversity, distribution and prioritization of fodder species for conservation in Kullu District, Northwestern Himalaya, India

In the Indian Himalayan Region predominantly rural in character, livestock is one of the main sources of livelihood and integral part of the economy. Livestock mostly rely on fodder from wild. The diversity, distribution, utilization pattern, nativity, endemism, rarity, seasonality of availability, nutritive values, perceived economic values and pressure use index of livestock have not been studied. The present study attempts to enumerate 150 species of fodder representing trees (51 spp.), shrubs (54 spp.) and herbs (45 spp.). Poaceae (19 spp.) and Fabaceae (13 spp.) amongst families and Salix (6 spp.), Ficus, Clematis, and Desmodium (5 spp., each) amongst genera are rich in species. Maximum species were found in the 1801 ~ 2600 m zone, and the remaining two zones showed relatively low diversity. Out of the 150 species, 109 are used in summer, 5 winter and 36 throughout year. During rainy season, mostly grasses are used as fodder. Only 83 species are native to the Himalayan region, one species, Strobilanthus atropuroureus is endemic and 35 species are near endemic. The nutritive values of the fodder species were reviewed, and economic values and status of the species were also assessed. The pressure use index of the species was calculated on the basis of cumulative values of the utilization pattern, altitudinal distribution, availability, status, nativity and endemism. Amongst the species, Grewia oppositifoilia, Morus serrata, Indigofera heterantha, Quercus leucotrichphora, Ulmus villosa, U. wallichiana and Aesculus indica showed highest PUI indicating high preference and pressure. Season wise prioritization of the species for different altitudinal zones has been done. Appropriate strategy and action plan have been suggested for the conservation and management of fodder species.     

Deep scattering layers resolved by narrow‐beam echo sounder along 35°s in the south pacific

The narrow‐beam echo sounder (3.5° half angle, 20 kHz) is capable of resolving the configuration of deep scattering layers to 750 m and was used to study the ecology and population density of organisms that make up the layers. Several layers to 1,000 m depth were identified in the South Pacific Ocean, and the population densities calculated. Swimming speeds of possible predators are estimated at 0.2–0.3 m.sec‐¹. Among organisms calculated to range in length from 0.01 m to 0.07 m, the larger were interpreted as grazing on smaller organisms, after comparing results from two echo sounders of 12 kHz and 20 kHz frequencies respectively.     

赤道西太平洋部分海域上层水的海洋化学

主要研究了菲律宾东南海域（区域Ｉ）和伊里安岛东部的北部海域（区域Ⅱ）上层水（０～１５０ｍ）化学参数ｐＨ，Ｅｈ，Ｅｓ，∑Ｓ（－Ⅱ）和ａ＾２－ｓ等的分布特征和－２价硫的产生机制，结果表明，该海域表层南赤道逆流和次表层的赤道潜流是影响化学参数特别是ＤＯ和∑Ｓ（－Ⅱ）的主要因素，高生产力与高水温是赤道西太平洋上层水中－２价硫产生与保存的重要影响因素，区域Ⅱ中的ｐＨ，∑Ｓ（－Ⅱ）ａ＾２－ｓ，ＤＯ比区域Ｉ高而     

台湾岛东北部龟山岛附近海域自然硫烟囱体的基本特征研究

龟山岛热液活动区位于冲绳海槽向西延伸的部位，菲律宾海板块向欧亚板块下方俯冲在此隐没，热液活动的出现为研究该地区进一步的发展提供了契机．龟山岛热液活动产生的烟囱体高度富集自然硫，几乎没有其它矿物结晶形成，烟囱体本身呈现分层现象，自然硫的含量也是从烟囱体的外层到内层依次增高，与烟囱体颜色上表观的分层呈现良好的对应关系．我们根据这种分层现象探讨了烟囱体的成因机制和热液流体随时间的变化特征，同时根据等离子质谱（ICP-MS）和X射线衍射仪（XRF）的实验数据分析了自然硫烟囱体存在两种物质来源：热液活动区基底的安山岩和地幔，但是对于地幔物质以何种形式加入到热液流体中还需进一步研究．