高分遥感技术在西昆仑大红柳滩-俘虏沟地区地质找矿中的应用          下载免费PDF全文

王辉  秦绪文  范玉海  杨金中  金谋顺  张少鹏  廖友运  杨晨  崔胜  贺小龙  匡经水  郭鹏程 《中国地质》2018,45(6):1289-1301

在西昆仑大红柳滩-俘虏沟地区,以WorldView-2高空间分辨率数据为主要信息源,在标准影像图制作基础上,针对性地进行图像增强处理,突出相关控矿要素和矿化信息,开展地质矿产遥感解译;利用ASTER数据开展矿化蚀变有关的遥感异常信息提取,配合适量的野外调查验证,发现了4种极具找矿前景的矿化带类型：①大红柳滩（含稀有金属）花岗伟晶岩带1处;②大红柳滩层控型铁多金属矿化带1处;③俘虏沟燕山期花岗岩有关热液脉型铁、铅、银、铜矿化区1处;④俘虏沟层控型含铜铅锌银的菱铁-赤铁矿矿化带4处;通过遥感综合分析,圈定遥感找矿靶区11处,其中A级遥感找矿靶区5处、B级遥感找矿靶区3处、C级遥感找矿靶区3处,为后续区域地质矿产调查项目规划部署和矿产资源勘查评价提供依据。因此,高分遥感技术在西昆仑地区矿产地质综合调查中作用显著,可实现找矿工作的快速突破,值得在相同或类似区域进一步推广应用。  相似文献   

安哥拉罗安达湿陷性砂的载荷试验研究     

唐国艺  唐立军  刘智  刘争宏  于永堂  乔虎 《水文地质工程地质》2018,(5):108-108

安哥拉罗安达广泛分布的湿陷性砂（Quelo砂）,是一种对水十分敏感的特殊砂土,具有浸水后强度降低,并产生湿陷变形的特殊性质,由于缺乏相应的资料和工程经验,其湿陷程度和承载特性是评价的难点。本文通过天然和浸水饱和条件下的载荷试验,实测和研究了罗安达Quelo砂的湿陷变形特点和不同条件下的承载力特征。试验研究结果显示,罗安达Quelo砂是一种湿陷程度为轻微—中等的湿陷性土;Quelo砂的承载力对水分异常敏感,地基土含水率的微小变化即可导致承载力数倍的降低,且饱和后的承载力较小,试验场地浸水饱和后的地基承载力深度修正系数可取1.07。试验表明,在工程实践中考虑地基土含水率变化对地基承载力的影响,不采用消除地基全部湿陷量或部分湿陷量的方法,而将红砂地基当做一般地基进行设计是可行的。  相似文献   

桂东南永安岩体锆石U-Pb测年、Hf同位素特征及其地质意义     

袁永盛  刘胜  南争路  詹华思 《岩石矿物学杂志》2018,37(6):869-883

永安岩体位于钦杭结合带南部,属桂东南十万大山-大容山复式岩体的一部分,其岩石类型为斑状堇青黑云花岗闪长岩。对永安岩体斑状堇青黑云花岗闪长岩进行了LA-ICPMS锆石U-Pb测年,获得其年龄为252. 8±3. 3Ma,为晚二叠世花岗岩。对永安岩体花岗岩进行的全岩地球化学分析结果表明,岩石富Al、高K,铝饱和指数A/CNK均大于1. 1,标准矿物分子刚玉均大于1%;岩石富集轻稀土元素,亏损重稀土元素,轻重稀土元素分馏明显,稀土元素的球粒陨石标准化配分曲线为轻稀土元素富集的右倾型,具弱负铕异常;岩石富集大离子亲石元素(Rb、Ba、K、Sr),亏损高场强元素(Nb、P、Ti、Ta)和Ba、Sr。花岗岩的锆石εHf(t)=-14～-8,tDM2=2. 3～1. 8 Ga。通过本文工作,结合前人关于永安岩体矿物学、全岩地球化学、Hf同位素和锆石微量元素的分析资料,认为永安岩体岩石为强过铝质S型壳源花岗岩,地幔组分没有提供成岩物质,但地幔底侵作用为成岩提供了热能,花岗岩形成于后碰撞阶段的拉张环境中。  相似文献   

Assessment of trace metals contamination in stream sediments and soils in Abuja leather mining,southwestern Nigeria     

Abiola Oyebamiji  Adegbola Odebunmi  Hu Ruizhong  Atta Rasool 《中国地球化学学报》2018,37(4):592-613

This study is aimed at determining the level of environmental degradation as well as the concentration of trace elements in soil and stream sediments in order to evaluate the environmental impact of the mining operation. Twenty-five (25) soils and ten (10) stream sediment samples were collected from the study area. The physicochemical parameters were determined using appropriate instrumentation with the aid of a digital pH meter (Milwaukee meter) to measure the pH and electrical conductivity, total dissolved solids, moisture content and loss on ignition of the soil and stream sediment samples. The pH of the soil sample ranged from (6.10 to 7.19); Electrical conductivity ranged from (21.3 to 279.4 µS/cm), moisture content varied from (0.60% to 7.20%), and the LOI ranged from (2.03% to 18.62%). The results of the analysis showed that the concentrations of the trace elements in the soils and stream sediment samples were slightly higher than the background values. Plots of the trace elements in stream sediment samples show moderate, consistent decrease downstream except at points where there was mine water discharge into the main river. The pollution levels of heavy metals were examined in stream sediment and soil samples using different assessable indices, such as the enrichment factor, which showed significant-moderate enrichment for Cr, Th, Nb, Zn, Pb, Y and Zr and the geo-accumulation index, which showed practically moderate contamination with Cr, Ni and Sr based on regional background reference values. Geo-accumulation index and contamination index for soils and stream sediment revealed uncontaminated to moderate contamination. Likewise, elements with moderate contamination were Cr, Ni and Sr. The Pearson correlation showed that there were significant positive associations among selected metals in soil and stream sediment samples.  相似文献   

Effects of a proline solution cover on the geochemical and mineralogical characteristics of high-sulfur coal gangue     

Youfa Luo  Yonggui Wu  Tianling Fu  Hu Wang  Rongrong Xing  Zhilin Zheng 《中国地球化学学报》2018,37(5):701-714

Batch experiments were conducted to comparatively evaluate the inhibition effects and mechanisms of a low-concentration (1%) proline solution cover on the release of pollutants from high-sulfur coal gangue. High-sulfur coal gangue was continuously immersed in a proline solution and in deionized water (as a control treatment) for 540 days. The results showed that the coal gangue in the control treatment was oxidized and generated leachate with poor water qualities, i.e., the leachate exhibited lower pH values, higher redox potential values, higher pollutant concentrations (SO₄^2?, Fe, Mn, Cu, and Zn), and high levels of acidophilic sulfur-oxidizing bacteria. However, compared to the control treatment, the addition of the proline solution (1%) significantly improved the water quality of the leachate by significantly reducing the Eh values, the pollutant concentrations (SO₄^2?, Fe²⁺, Fe, Mn, Cu, and Zn), and the activity of acidophilic sulfur-oxidizing bacteria and by significantly increasing the pH value to neutral. The proline treatment significantly inhibited the oxidation of coal gangue and the release of pollutants, mainly by inhibiting the activity of acidophilic sulfur-oxidizing bacteria and by altering the heavy metal fractions and the mineralogical characteristics. Therefore, in engineering practice, workers should consider using an environmental friendly aqueous proline solution cover to achieve the in-situ control of pollutant releases from coal gangue dumps.  相似文献   

Geochemistry and geochronology of Late Jurassic and Early Cretaceous intrusions related to some Au (Sb) deposits in southern Anhui: a case study and review     

Qing Hu  Huangling Gu  Xiaoyong Yang  Yisu Ren  Ergen Gao  Zhangxing Nie 《中国地球化学学报》2018,37(3):360-383

Some Au deposits in southern Anhui Province have recently been found to be closely associated with Late Mesozoic intrusions. Typical examples include the Huashan Au (Sb) deposit and Au deposits at Zhaojialing, Wuxi, and Liaojia. In order to understand the mechanisms that led the formation of these Au deposits, we make detailed reviews on the geological characteristics of these Au deposits. Specifically, we present new LA-ICP-MS zircon U–Pb dating, along with elemental and Hf isotopic data from the Huashan Au (Sb) deposit. Our data suggests that the Huashan ore-related intrusions were emplaced during the Late Jurassic and Early Cretaceous periods (144–148 Ma). They are characterized by arc-magma features and high oxygen fugacity and are rich in inherited zircons. Zircon U–Pb ages and Lu–Hf isotopes from intrusions suggest that Proterozoic juvenile lithosphere is the main source of these intrusions. The regional geological history implies that lithosphere beneath southern Anhui was produced during a Proterozoic subduction and was fertilized with Au (Cu) in the process. Integrated with the results of previous studies, we inferred that Late Mesozoic intrusions formed by the remelting of the lithosphere could provide the metal endowment for the Au-rich deposits in southern Anhui.  相似文献   

Spatio-temporal Distribution of Three Kinds of Flash Droughts over Agricultural Land in China from 1983 to 2015   总被引：1，自引：0，他引：1  

Xiang Zhang  Nengcheng Chen  Chuli Hu  Xiaoting Peng 《地球科学进展》2018,33(10):1048-1057

At present, flash drought occurs globally and regionally and causes a lot of socio-economic loss in a very short time. Therefore, flash drought has been regarded as one of the hottest issues in drought research. However, flash drought monitoring, prediction and decision-making have encountered a lot of challenges due to its multiple driven factors and complex spatio-temporal process. Aiming at this problem, this paper focused on the agricultural land in China, and analyzed the spatio-temporal distribution of three kinds of flash droughts (i.e., precipitation-deficit, high-temperature, and composite flash droughts) from 1983 to 2015. We studied the occurrences, duration, spatial distribution, temporal distribution, and trend of all three kinds of flash droughts. Our results demonstrated that, the occurrences of flash drought agricultural land in China increased year by year, among which high-temperature flash drought increased dramatically; duration of flash droughts had different trends, but the variations were relatively smooth; Northeast China was identified as a vulnerable area of flash drought, indicating more flash drought events and longer duration; flash droughts in China were found to concentrate in spring (high-temperature drought) and summer seasons (precipitation-deficit drought). This study is helpful for building new flash drought monitoring method and system, and it is also valuable for flash drought preparedness on regional scale.  相似文献   

华蓥山中段地区地下水资源量评价   总被引：1，自引：1，他引：0  

康小兵  罗声  许模  刘宏 《中国岩溶》2018,37(4):527-534

四川华蓥山中段地区水流失比较严重,供需矛盾突出,水环境持续恶化,不但影响到居民正常的生产和生活,而且严重影响了该地区国民经济的建设和发展。通过野外调查和综合分析现场收集的资料,总结出华蓥山中段地区地下水资源量流失情况:该区每年流失的水资源量约为0.914 4亿m3,且华蓥山褶皱西翼水流失总量大于东翼,而西翼北端是区内水流失量最严重的区域,其水资源量流失的影响因素主要为气候、社会发展及人类活动等。   相似文献   

Study of late-Mesozoic magmatic rocks and their related copper-gold-polymetallic deposits in the Guichi ore-cluster district,Lower Yangtze River Metallogenic Belt,East China     

Huangling Gu  Zhangxing Nie  Jianghong Deng  Liuan Duan  Qing Hu 《International Geology Review》2018,60(11-14):1404-1434

ABSTRACT

The Guichi ore-cluster district in the Lower Yangtze River Metallogenic Belt hosts extensive Cu–Au–Mo polymetallic deposits including the Tongshan Cu–Mo, Paodaoling Au, Matou Cu–Mo, Anzishan Cu–Mo, Guilinzheng Mo and Zhaceqiao Au deposits, mostly associated with the late Mesozoic magmatic rocks, which has been drawn to attention of study and exploration. However, the metallogenic relationship between magmatic rocks and the Cu–Au-polymetallic deposits is not well constrained. In this study, we report new zircon U–Pb ages, Hf isotopic, and geochemical data for the ore-bearing intrusions of Guichi region. LA-ICP-MS U–Pb ages for the Anzishan quartz diorite porphyrite is 143.9 ± 1.0 Ma. Integrated with previous geochronological data, these late Mesozoic magmatic rocks can be subdivided into two stages of magmatic activities. The first stage (150–132 Ma) is characterized by high-K calc-alkaline intrusions closely associated with Cu–Au polymetallic ore deposits. Whereas, the second stage (130–125 Ma) produced granites and syenites and is mainly characterized by shoshonite series that are related to Mo–Cu mineralization. The first stage of magmatic rocks is considered to be formed by partial melting of subducted Palaeo-Pacific Plate, assimilated with Yangtze lower crust and remelting Meso-Neoproterozoic crust/sediments. The second stage of magmatism is originated from partial melting of Mesoproterozoic-Neoproterozoic crust, mixed with juvenile crustal materials. The depression cross to the uplift zone of the Jiangnan Ancient Continent forms a gradual transition relation, and the hydrothermal mineralization composite with two stages have certain characteristics along the regional fault (Gaotan Fault). Guichi region results from two episodes of magmatism probably related to tectonic transition from subduction of Palaeo-Pacific Plate to back-arc extensional setting between 150 and 125 Ma, which lead to the Mesozoic large-scale polymetallic mineralization events in southeast China.  相似文献   

Evaluating climate change adaptation efforts on the US 50 states’ hazard mitigation plans     

Qiao Hu  Zhenghong Tang  Lei Zhang  Yuanyuan Xu  Xiaolin Wu  Ligang Zhang 《Natural Hazards》2018,92(2):783-804

Climate change brings uncertain risks of climate-related natural hazards. The US Federal Emergency Management Agency (FEMA in Climate change: long-term trends and their implications for emergency management, 2011. https://www.fema.gov/pdf/about/programs/oppa/climate_change_paper.pdf) has issued a policy directive to integrate climate change adaptation actions into hazard mitigation programs, policies, and plans. However, to date there has been no comprehensive empirical study to examine the extent to which climate change issues are integrated into state hazard mitigation plans (SHMPs). This study develops 18 indicators to examine the extent of climate change considerations in the 50 SHMPs. The results demonstrate that these SHMPs treat climate change issues in an uneven fashion, with large variations present among the 50 states. The overall plan quality for climate change considerations was sustained at an intermediate level with regard to climate change-related awareness, analysis, and actions. The findings confirm that climate change concepts and historic extreme events have been well recognized by the majority of SHMPs. Even though they are not specific to climate change, mitigation and adaptation strategies that can help reduce climate change risks have been adopted in these plans. However, the plans still lack a detailed assessment of climate change and more incentives for collaboration strategies beyond working with emergency management agencies.  相似文献