新疆喀拉通克铜镍矿田成矿条件、岩浆通道与成矿潜力分析   总被引：3，自引：0，他引：3       下载免费PDF全文

秦克章田 野姚卓森  王勇 毛亚晶  王斌 薛胜超  唐冬梅康 珍 《中国地质》2014,41(3):912-935

位于中亚造山带北缘的喀拉通克早二叠世铜镍硫化物矿区是新疆规模最大的铜镍矿山,包含13个岩体,相当部分为隐伏岩体,其中1号、2号、3号、9号矿床为主力矿床,经过30余年持续开发,最大开采深度已达740 m,已面临后备资源不足的危机。已知矿体主要产于辉长岩、苏长岩、辉长苏长岩以及橄榄苏长岩中,甚至角闪辉长岩局部也含矿,未见超镁铁岩产出,具有显著的磁性(200 nT)、重力(0.29×10~(-5)m/s~2)、激化率异常,以镁铁岩含矿、岩体规模小且成群成带、分异演化程度高、富铜(Cu/Ni约3:2)、PGE较高、块状硫化物贯入矿体普遍发育为特色。其围岩为含炭质板岩、片岩和凝灰岩,变形强烈,常规电法受到炭质层的干扰。依据岩石学、地球化学研究,岩浆源于软流圈地幔,基于与东天山同期铜镍矿床含矿岩相及其比例和剩余重力异常的比较,推断其应发育有相当比例的超镁铁岩,因而深部出现超基性岩的可能性很高,且含矿性应更好。这一推断得到坑道钻探的证实,2013年矿区在Y2岩体东段650~740 m深度和Y2岩体西段400~500 m深度发现隐伏超镁铁岩且含矿,局部见贯入块状矿体。橄榄辉石岩、辉石橄榄岩系矿区首次发现,粒度很细,发育强烈的蛇纹石化、纤闪石化,推测只是隐伏超基性岩的头部。结合控岩控矿构造的追溯及南、北岩带的侧伏和倾伏方向判断,硫化物珠滴构造的发现与系统观测统计,围岩烘烤边和角岩化的研究分析,提出南岩带主岩浆通道位于Y2与Y3岩体之间,而不是原普遍认为的岩浆通道位于Y1与Y2岩体之间。结合矿区的现状,提出采用高分辨率浅层地震、CSAMT和瞬变电磁地-井测量,结合传统的高精度重力勘探、磁法勘探和激发极化法来勘探和预测南岩带深部隐伏含矿超镁铁岩的空间位置和产状,圈定岩浆通道和隐伏铜镍矿体,进而推动北岩带和外围G21、22号岩体的深部探矿工作。  相似文献   

红柳沟北镁铁-超镁铁质岩体矿物学特征及矿石成因分析     

周伟  姜常义  杜玮  宋艳芳  凌锦兰  夏明哲  王梦玺  赵彦锋 《岩石矿物学杂志》2014,33(4):671-680

红柳沟北镁铁-超镁铁质岩体位于柴达木陆块北部的欧龙布鲁克微陆块东北缘,呈岩墙状,出露面积约0.1km~2,由方辉橄榄岩、橄榄二辉岩、含长单辉橄榄岩、橄榄辉长苏长岩、暗色橄榄辉长岩、苏长岩、辉长岩等组成,各岩相带在空间上呈渐变过渡关系。电子探针分析结果显示,岩体的主要造岩矿物为贵橄榄石、古铜辉石、普通辉石和斜长石,并且各矿物的结晶温度为1 307~1 122℃。岩体钛铁矿化明显,主要金属矿物为钛铁矿、钛磁铁矿和磁铁矿。利用橄榄石Fo最高值反演出原生岩浆MgO含量为8.49%,FeO含量为10.03%,TiO_2含量为1.63%,为普通玄武质岩浆。通过综合研究各矿物形成的温度和氧逸度条件,认为岩浆从橄榄石结晶到普通辉石结晶,其氧逸度是缓慢升高的,并且氧逸度是控制红柳沟北岩体Ti-Fe氧化物结晶的主要因素。  相似文献   

Geochemistry of mafic rocks and melt inclusions and their implications for the heat source of the 14.0°S hydrothermal field,South Mid-Atlantic Ridge     

Bing Li  Xuefa Shi  Yaomin Yang  Jun Ye  Jingjing Gao  Wenqin Zheng 《中国地球化学学报》2014,33(4):325-335

Fresh rocks sampled from the 14.0°S hydrothermal field of the South Atlantic Ridge can be divided into two categories： olivine-gabbro and basalt. The olivine-gabbro is composed mainly of three types of minerals： olivine, clinopyroxene and plagioclase, while a multitude of melt inclusions occur in the plagioclase phenocrysts of the basalts. We analyzed the whole-rock, major and trace elements contents of the basaks, the mineral chemistry of phenocrysts and melt inclusions in the basalts, and the mineral chemistry of olivine-clinopyroxene-plagioclase in the olivine-gabbro, then simulated magma evolution within the crust using the COMAGMAT program. The whole-rock geochemistry shows that all the basalts exhibit typical N-MORB characteristics. In addition, the mineral chemistry characteristics of the olivine-gabbro （low-Fo olivine, low-Mg# clinopyroxene, high-TiO2 clinopyroxene, low-An plagioclase）, show that strong magma differentiation occurred within the crust. Nevertheless, significant discrepancies between those minerals and phenocrysts in the basalts （high-Fo olivine, high-An plagioclase） reflect the heterogeneity of magma differentiation. High Mg# （-~0.72） melt inclusions isobaric partial crystallization simulations suggest that the magma differentiation occurred at the depth shallower than 13.03 km below the seafloor, and both the vertical differentiation column shows distinct discrepancies from that of a steady-state magma chamber. Instead, a series of independent magma intrusions probably occurred within the crust, and their corresponding crystallized bodies, as the primary high-temperature thermal anomalies within the off-axis crust, probably act as the heat source for the development of the 14.0°S hydrothermal system.  相似文献   

潍坊北部海咸水入侵特征及现状评价   总被引：1，自引：0，他引：1       下载免费PDF全文

蒙永辉  傅建  王志成  于爱丽 《山东国土资源》2014,30(6)

潍坊北部是我国典型的海咸水入侵区,通过资料收集、海咸水入侵专项调查、地质环境监测与实验、样品分析测试和室内综合分析研究,基本查清了海咸水入侵发展及演化历史。工作区海咸水入侵发展过程可划分为发生和发展、快速发展、慢速发展和稳定发展4个阶段,目前处于稳定发展期。利用2012年水质测试结果,选取Cl-、矿化度、SO2-4,rHCO-3/rCl-,K+等指标作为评价因子,运用模糊数学的方法,对潍坊北部海(咸)水入侵区入侵程度的现状做出综合评价;结合工作区海咸水入侵的特征和现状,针对性地提出了今后的防治重点和对策。  相似文献   

The impact of highly permeable layer on hydraulic system in a coastal aquifer     

Kue‐Young Kim  Weon Shik Han  Eungyu Park 《水文研究》2013,27(22):3128-3138

This study is aimed to understand the hydraulic mechanism of coastal aquifer systems that include highly permeable layers (HPLs). These hydrologic conditions can be found in many volcanic islands that are composed of a series of lava flows discharged into sea or other standing body of water. In the first part, we developed a numerical model based on the geologic and hydrologic data obtained from the eastern Jeju Island, Korea, of which the aquifer contains clinker and hyaloclastite layers. The simulation results reproduced spatial location of fresh‐saline water interface, especially the abrupt decline of interface at the inland part and the thickness variation of transition zone along the cross‐section observed at the eastern Jeju coastal aquifer. We were able to find out that these phenomena are strongly related to the presence of the HPL. In the second part, quantitative analyses were conducted with the use of hypothetical models in order to understand the dynamic characteristics of coastal system that includes HPLs. A series of sensitivity studies were conducted to assess the effect of the horizontal length and vertical depth of HPL on the spatial location of the interface toe and the configuration of transition zone. Various case studies have shown that the seawater intruded into the inland more as the horizontal length of HPL was increased and its vertical depth was decreased. In other simulations including two HPLs, the vertical distance between these two HPLs primarily controlled the flow regime, flux variations, and the configuration of the transition zone. Finally, we performed simulations to evaluate the effect of a rising sea‐level. This study provides more understanding of how the presence of HPL controls the seawater intrusion processes, and the spatial configurations of fresh‐saline water interface at coastal aquifers. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

Modelling river water temperature using deterministic,empirical, and hybrid formulations in a Mediterranean stream     

Rafael Marcé  Joan Armengol 《水文研究》2008,22(17):3418-3430

River water temperature is a common target of water quality models at the watershed scale, owing to its principal role in shaping biogeochemical processes and in stream ecology. Usually, models include physically‐based, deterministic formulations to calculate water temperatures from detailed meteorological information, which usually comes from meteorological stations located far from the river reaches. However, alternative empirical approaches have been proposed, that usually depend on air temperature as master variable. This study explored the performance of a semidistributed water quality application modelling river water temperature in a Mediterranean watershed, using three different approaches. First, a deterministic approach was used accounting for the different heat exchange components usually considered in water temperature models. Second, an empirical approximation was applied using the equilibrium temperature concept, assuming a linear relationship with air temperature. And third, a hybrid approach was constructed, in which the temperature equilibrium concept and the deterministic approach were combined. Results showed that the hybrid approach gave the best results, followed by the empirical approximation. The deterministic formulation gave the worst results. The hybrid approach not only fitted daily river water temperatures, but also adequately modelled the daily temperature range (maximum–minimum daily temperature). Other river water features directly dependent on water temperature, such as river intrusion depth in lentic systems (i.e. the depth at which the river inflow plunges to equilibrate density differences with lake water), were also correctly modelled even at hourly time steps. However, results for the different heat fluxes between river and atmosphere were very unrealistic. Although direct evidence of discrepancies between meteorological drivers measured at the meteorological stations and the actual river microclimate was not found, the use of models including empirical or hybrid formulations depending mainly on air temperature is recommended if only meteorological data from locations far from the river reaches are available. Copyright © 2008 John Wiley & Sons, Ltd.  相似文献   

基于智能体的自适应入侵检测系统   总被引：1，自引：0，他引：1  

李平  黄迪明 《成都信息工程学院学报》2004,19(4):535-540

提出了一种基于智能体技术的自适应入侵检测系统体系结构,将智能体技术和自适应模型生成技术应用于入侵检测系统中.智能体技术的应用解决了传统的集中式入侵检测系统的弊病,将任务处理和数据分布到网络各个结点上,通过各种智能体来协作完成入侵检测任务,充分利用网络和主机资源.而智能体与自适应模型生成技术相结合,采用遗传算法建立准确的数据模型,使得入侵检测系统能够自动配置和更新不同环境下的入侵检测模型,能够通过自我学习、自我改进来提高系统的入侵检测能力和适应能力.  相似文献   

THE CHARACTERISTIC AND CAUSE OF SEA WATER INTRUSION AND POLLUTION IN SOUTH LIAODONG PENINSULA     

刘庆书  许劲松  张万忠 《中国地理科学(英文版)》1993,3(4):334-347

Based on various patterns of groundwater and their abundance characters in south Liaodong Peninsula, the distribution, stage, pattern and characters of sea water intrusion in the serious sea water intrusion areas are analysed. The reasons to cause sea water intrusion are uneven precipitation, limited recharge of surface water, artificial overpumping, lithology and geological structure. It can provide scientific basis for reasonable utilization of limited water resource in line with the local conditions.  相似文献   

Mathematical modelling of sea water intrusion,Nauru Island     

F. Ghassemi  A. J. Jakeman  G. Jacobson 《水文研究》1990,4(3):269-281

A two-dimensional finite element model for density dependent groundwater flow was calibrated to simulate sea water intrusion in Nauru Island in the Central Pacific Ocean. Nauru Island occupies an area of 22 km² and supports a population of 8500. The island has been mined for its phosphate deposits and current reserves indicate that the mine has about eight years life remaining. The water supply of the island is about one third dependent on imported water which is also used as ballast on the phosphate ships. Imported water will not be available in the future, and a hydrogeological investigation shows that the island is underlain by a fresh water layer, less than 5 m thick. The freshwater layer overlies a thick transition zone of brackish water which in turn overlies sea water. Simulation of several management options shows that it is possible to substitute current importation of fresh water by careful extraction from the groundwater resources of the island.  相似文献   

Changes in the abundance and composition of picophytoplankton in relation to the occurrence of a Kyucho and a bottom intrusion in the Bungo Channel,Japan     

Miho Hirose  Toshiya Katano  Yuichi Hayami  Atsushi Kaneda  Takeshi Kohama  Hidetaka Takeoka  Shin-ichi Nakano 《Estuarine, Coastal and Shelf Science》2008

The Bungo Channel in southwestern Japan receives both warm, called Kyucho, and cold deep-water intrusions (bottom intrusion) from the Pacific Ocean. Abundances of Prochlorococcus, Synechococcus, and eukaryotic picophytoplankton were monitored from 18 July to 17 August 2001 to clarify whether advected picophytoplankton from the Pacific Ocean can grow in the channel or not. Synechococcus cells were further discriminated into low- and high-PUB types according to their fluorescence property in flow cytometry. From 18 to 25 July, the water temperature decreased by 3 °C at a 5-m depth at all stations, indicating the occurrence of a bottom intrusion. From 25 July to 4 August, a Kyucho occurred and the water temperature rapidly increased. From 4 to 17 August, a bottom intrusion and a Kyucho both occurred twice, although the intensities were smaller than those occurring until 4 August. From 18 to 30 July, the abundance of both Prochlorococcus and a high-PUB type of Synechococcus drastically decreased because of a bottom intrusion; however, the abundances rapidly increased due to the advection by a Kyucho. These advected cells increased from 4 to 17 August in the channel and Kitanada Bay. Changes in the abundance of low-PUB type of Synechococcus and eukaryotic picophytoplankton were less noticeable than those in the abundance of Prochlorococcus and high-PUB type. The present study demonstrated that oceanic picophytoplankton advected by the Kyucho could grow in the channel. However, abundances of low-PUB type and eukaryotic picophytoplankton increased higher than those of Prochlorococcus and high-PUB type did. Thus, these oceanic phytoplankters will be excluded when Kyucho does not occur for a long time. The co-occurrence of various types of picophytoplankton found in the channel is probably achieved by both Kyucho event and their growth capability in the channel.  相似文献