刚果(金)马诺诺地区稀有金属矿床成矿地质特征与成矿规律          下载免费PDF全文

李继业  祝永平  柳长峰  祝艳  王纪昆  杨远东 《地质找矿论丛》2023,38(1):110-117

刚果(金)马诺诺地区地处基巴拉稀有金属成矿带,成矿地质条件优越。本文通过对该区稀有金属矿床成矿地质背景、典型矿床特征分析,总结了该区的成矿规律。结果表明,区域性断裂控制了该区的构造格局及矿产分布,具有明显的带状分布特征;岩浆活动强烈,其中尤以G4期岩浆侵入活动与稀有金属成矿关系密切;地层中的云母片岩类岩石提供良好的封闭条件,此3种要素的耦合有利于促使该区形成稀有金属矿床。  相似文献   

新疆东天山突出山铜铁矿床地球化学特征与地质意义          下载免费PDF全文

尚海军  张志欣  李卫东  张耀选  仇银江  刘锋  周可法  李强  王金林 《地质科学》2015,(4):1102-1119

突出山铜铁矿床是东天山雅满苏石炭纪弧前-岛弧带中代表性的铁多金属矿床, 矿体呈透镜状、脉状、似层状赋存于上石炭统底坎尔组下亚组火山岩中。矽卡岩阶段包裹体均一温度为151℃~>380℃, 盐度为1.91%~23.18% NaCl_eq, 密度为0.76~1.09 g/cm³, 热液硫化物阶段包裹体均一温度为101℃~280℃, 盐度为0.35%~23.05% NaCl_eq, 密度为0.74~1.13 g/cm³, 表明成矿流体属于中-高温、中-低盐度、中-低密度的NaCl-H₂O体系。(绿泥石)绿帘石矽卡岩、磁铁矿(镜铁矿)矿石、含磁铁矿灰岩的稀土配分模式均为轻稀土相对富集的右倾型(LREE/HREE=2.85~9.21), 以出现负铕异常(δEu=0.22~1.09)和铈异常不发育为特征, 与底坎尔组火山岩相似, 表明成矿物质来源于底坎尔组火山岩。矿区矽卡岩可能是火山热液交代碳酸盐岩形成的, 成矿条件为中-高温、较为宽广的氧化还原环境, 矿床成因属火山热液交代型。  相似文献   

扬子西南缘拉拉10CG矿床萤石稀土元素地球化学特征     

《矿物学报》2015,35(1)

以康滇地轴古元古代拉拉铁氧化物-铜-金(IOCG)矿床中不同期次萤石的稀土元素为研究对象,讨论其地球化学特征及指示意义.研究结果表明:拉拉IOCG矿床中有变质期和热液期2期萤石产出,变质期萤石分为早晚2个阶段,与铜钼矿化关系密切,形成温度较高,为同源不同阶段产物;热液期萤石与变质期不同源,为后期热事件产物.萤石整体表现出REE总量高的特征;从早期到晚期,萤石稀土总量呈逐渐减少趋势;变质期萤石是矿床中主要的REE载体之一.变质期成矿流体稀土含量较高,热液期成矿流体稀土含量较低.稀土配分模式呈LREE富集、HREE亏损的右倾型,轻重稀土分异明显,萤石的稀土配分模式受溶液体系中REE络合物稳定性的影响.变质期萤石继承了钠质火山岩的Ce、Eu异常特征,形成变质期萤石的高温变质流体具有负Ce异常且同时存在Eu2+和Eu3+;热液期萤石成矿流体具有温度低、氧逸度高的特征.Y的含量变化可能是引起本矿床萤石颜色变化的原因之一,其含量与颜色深浅呈负相关关系.  相似文献   

甲氨基阿维菌素苯甲酸盐对黑土区农田土壤动物群落的影响     

沙迪  翟清明  张雪萍  高梅香 《地理研究》2015,34(5)

甲维盐属高效半合成抗生素杀虫剂。在哈尔滨市典型黑土农田区,研究不同浓度甲维盐处理对土壤动物群落结构的影响。结果表明:甲维盐处理显著降低了土壤动物群落的个体密度和类群数量,且这种趋势随着甲维盐浓度的增加而增强;显著改变了群落的垂直分布格局,表聚性特征被削弱,使动物较多地聚集于5~15 cm土层;改变了群落多样性特征,其中螨类和跳虫对多样性的贡献相对较大;显著改变了表层土壤化学性质,但不同动物类群对土壤环境变化的响应规律不同,螨类和跳虫对甲维盐干扰具有较强的适应能力。甲维盐处理可以显著改变黑土区农田土壤动物群落结构,浓度是影响该过程的重要因素,施用杀虫剂时需慎重评价其生态后果。  相似文献   

Adaptation to climate change in desertified lands of the marginal regions in Egypt through sustainable crop and livestock diversification systems     

Hassan M. El Shaer 《寒旱区科学》2015,7(1):0016-0022

Environmental degradation resulting from current climate changes, including prolonged drought, land degradation, desertification, and loss of biodiversity, is presenting enormous challenges to achieve ...  相似文献   

CIRCULAR-ECONOMY MODELS OF ANIMAL HUSBANDRY INDUSTRY IN JILIN PROVINCE   总被引：1，自引：1，他引：0  

HAN Liang LI Bo SONG Tao TONG Lian-jun 《中国地理科学(英文版)》2006,16(2):148-153

1INTRODUCTION The circular-economyisan efficient resources metabolic process, based on principles of ecology and system engi- neering.Withcoupledstructure andthe complex ecolo- gical and economic evolution, it has the characteristics of overall integrity, coordination, and circulation (WANG, 2005). Compared with the traditionalecono- mic model, the circular-economy requires the technical model of production process to be changed from the opening flow pattern that is "resourcesconsumption…  相似文献   

一个动物识别专家系统在PROLOG下的实现   总被引：4，自引：0，他引：4  

夏明华 《成都信息工程学院学报》2003,18(4):371-375

首先扼要分析了专家系统的基本工作原理，然后用PROLOG语言实现了一个简单的动物识别专家系统。  相似文献   

黄河三角洲农牧业生产潜力   总被引：6，自引：0，他引：6  

许学工 《地理学报》1991,(2)

本文从对黄河三角洲的宜农地和宜牧地的分析入手,对该区农作物生产潜力、牧草及载畜量潜力进行了探讨。并针对目前农牧业生产水平和存在的问题,提出了相应的对策。  相似文献   

桂北动物物候气候变暖响应   总被引：4，自引：1，他引：3  

李世忠  谭宗琨  夏小曼  张印平  邹丽霞  唐广田 《气象科技》2010,38(3):377-382

对桂北地区1989~2007年青蛙、蟋蟀始鸣和终鸣以及气温等气候要素1975~2007年同步观测资料的对比分析结果表明,近10年来桂北地区青蛙和蟋蟀始鸣日期呈提前趋势,终鸣日期稳定,始终鸣间隔期及生长繁殖季显著延长;桂林雁山近34年来年平均气温呈显著上升趋势,特别是1997年以来增温显著,在增温过程中以春季增温为主,冬季和秋季增温次之,夏季呈弱降温趋势;2~4月平均气温和3月平均最高气温是影响青蛙和蟋蟀始鸣期和始终鸣间隔期的主要气候生态因子;动物物候变化是动物对气候变暖的响应。  相似文献   

Limiting hydrochemical factors for sustainability of water resources: The Cisjordanian experience     

Eliahu Rosenthal  Joseph Guttman  Peter Möller 《Chemie der Erde / Geochemistry》2009,69(3):191-222

In Cisjordan, surface- and groundwater flow are either towards the Jordan Valley-Dead Sea-Arava Valley (the Rift) or the Mediterranean Sea. Due to upstream exploitation by riparians to the Jordan River, the historical annual flow, which fluctuated between 250 and 1100 Mm³, has declined to a mere 100-200 Mm³. The remaining flow south of Lake Kinneret is highly polluted and heavily loaded with salts. Lake Kinneret (Sea of Galilee) is one of the major water resources in the area. Annually, between 200 and 700 Mm³ reach the Lake as surface and groundwater flow. The relatively high salinity of the Lake is caused by thermomineral water discharging from springs and seepages located onshore and on the bottom of the Lake. The main factors causing deterioration of the groundwater quality in the Rift are of geogenic character. These are different types of brines, whose outflow and penetration into freshwater aquifers was triggered by overpumpage. Contemporary encroachment of seawater caused by intensive water exploitation in the Coastal Plain is manageable and reversible. However, due to lack of hydrogeological evidence, no such statement can be made about the circulation of seawater beneath the Coastal Plain and into the deep-seated Yarkon-Taninim aquifer or the upflow of brines in the Rift.The flow regimes of the different brine bodies could not be elucidated. Whether each such brine-body flows by its particular hydrological regime or whether the movement of the different bodies is intradependent or interdependent with the regional movement of fresh groundwater, remain open questions. Therefore, sustainable development of groundwater resources is clearly dependent on the elucidation of the relationship between changes in the pressure of the brine with depth and its relationship to the overlying freshwater.The average total annual recharge of all water sources in Cisjordan is 1820 Mm³, which means that the total production of water must be managed within the limits of this annual volume. During drought years, total groundwater extraction exceeds the safe yield, causing drastic lowering of water levels and upflow of saline waters from greater depths.Because of the structural complexity of aquifers and hydrochemical variability of the numerous groundwater bodies, new hydrochemical methods have been developed for the identification of groundwater bodies and for the elucidation of their origins. These methods combine macrochemical, microchemical, and isotopic evidences. By combining distribution patterns of rare earths, yttrium and stable isotopes, a complete picture of catchment lithology and the altitude and latitude of precipitation could be obtained.The area west of the Jordan River is characterized by the occurrence of transboundary surface- and groundwater basins in which fresh and saline water and brines flow across political borders between Israel and the Palestinian Authority. It is very difficult to assess separately the annual safe yield of water resources for each of the two national entities. Neither country may dispose independently of its waters and is usually at the mercy of the other riparian. There is as yet no general multilateral international treaty in force allocating the water resources of international watercourses. At present there are two rules for the management of the waters of an international drainage basin—the rule of Equitable Distribution, and the obligation Not to Cause Significant Harm. The rules of equitable distribution have tended to focus on the issue of quantities of water rather than on quality of water, which is really relevant to the issue of equitable distribution. Future negotiations on the uses of the basin will need to deal with issues of characteristic salinities and geochemical features and on their impact on equitable sharing of water resources.  相似文献