基于MCR模型和DO指数的九江滨水城市生态安全网络构建   总被引：1，自引：1，他引：0  

戴璐  刘耀彬  黄开忠 《地理学报》2020,75(11):2459-2474

兼顾生态保护和经济增长的生态安全网络对引导滨水城市走可持续发展道路具有重要指导意义。本文以九江市为例,采用景观生态数据集和产业信息数据集,结合最小累积阻力模型（MCR）和连续空间的产业集聚测度指数（DO）构建了综合评价方法,分别对景观生态格局和经济生产空间进行分析,诊断二者的空间冲突确定战略节点并构建生态安全网络。结果表明：① 研究区包含重要生态源地29个,总面积为7323 km²;生态安全阻力高值区面积占39.69%,位于城市中部和东部连片区域,低值区则处于外围,且连通过渡区域较少,呈现空间上两极分化的“中心—外围”景观生态格局;② 经济生产空间临近水资源分布,呈现为小尺度集聚、大尺度分散的空间格局;主要产业集聚区的平均长度和数量均显示出重度污染行业>轻度污染行业>中度污染行业的空间关系;③ 识别出景观生态廊道总长685.57 km,选取了25个生态—经济战略节点,规划了18条总长424.53 km的重要绿带和26条总长662.46 km的一般绿带,共同构成了“蜂巢状”九江市生态安全网络格局。本文采用自然和经济条件相结合的综合分析视角,为生态安全格局的构建提供了多样化的实现途径。  相似文献   

九江市网纹红土标准贯入击数与力学参数关系分析          下载免费PDF全文

蒋兵 《探矿工程》2020,47(10):89-92

针对九江市网纹红土层标准贯入试验实测锤击数与试验孔深、土的压缩模量、抗剪强度关系之间进行了相关性分析。结果表明：网纹红土标准贯入击数与试验孔深为正显著线性相关关系，与土的压缩模量为正弱线性相关关系，与抗剪强度为正弱线性相关关系。分析成果对在九江市开展岩土工程勘察活动具有很好的指导和借鉴意义。  相似文献   

江西南城小竺萤石矿成矿作用及找矿方向          下载免费PDF全文

占岗乐  吴火星 《华东地质》2021,(3):302-309

矿区位于武夷山成矿带之北部Cu-Pb-Zn-Ag-萤石成矿亚带,成矿条件优越。该文通过地质测量、槽探工程和钻探工程相结合的工作方法,结合已有的坑道工程,总结矿体的空间分布、赋存状态及控矿因素,开展成矿规律和成矿作用研究工作;通过对成矿地质体及成矿构造的综合研究,判断成矿时代,探讨成矿机理。研究表明:该矿床类型为中低温热液充填型萤石矿床,印支晚期的斑状黑云母花岗岩体为成矿提供物质来源,NE向主断裂及次生的压扭性断裂是矿区的主要导矿、贮矿构造。运用研究成果探明该萤石矿床资源储量达中型规模,扩大了萤石矿床的资源前景,并指明了找矿方向。  相似文献   

Intra-oceanic island arc origin for Iratsu eclogites of the Sanbagawa belt,central Shikoku,southwest Japan     

Atsushi Utsunomiya  Bor-ming Jahn  Kazuaki Okamoto  Tsutomu Ota  Hironao Shinjoe 《Chemical Geology》2011,280(1-2):97-114

New geochemical and Sr–Nd isotopic data for the Iratsu eclogite and surrounding metamorphic rocks of the Sanbagawa belt, Japan, show that, while the protoliths of the metamorphic rocks formed in a variety of tectonic settings, the Iratsu body represents a deeply subducted and accreted island arc. The igneous protoliths of eclogites and garnet amphibolites were probably generated from a mantle source that had components of both a depleted mantle modified by slab-released fluid (as seen in a negative Nb anomaly) and an enriched mantle, similar to that of ocean island basalts (OIB). Fractional crystallization modeling indicates that the protoliths of some garnet clinopyroxenites from the Iratsu body are cumulates from a basaltic magma that crystallized under high O₂ and H₂O fugacities in the middle to lower crust. The source characteristics and crystallization conditions suggest that the protoliths of the Iratsu rocks formed in an oceanic island arc. Quartz eclogites from the marginal zone of the Iratsu body have geochemical signatures similar to turbidites from the Izu–Bonin island arc (as seen in a negative Nb anomaly and a concave REE pattern). The protoliths might be volcaniclastic turbidites that formed in a setting proximal to the oceanic island arc. Geochemical and isotopic signatures of the surrounding mafic schists are similar to normal (N-) and enriched (E-) mid-ocean-ridge basalt (MORB), and distinct from the rocks from the Iratsu body. The protoliths of the mafic schists likely formed in a plume-influenced mid-ocean ridge or back-arc basin. Pelitic schists from the surrounding rocks and pelitic gneisses from the marginal zone of the Iratsu body have evolved, continental geochemical signatures (as seen in a negative ε_Nd(t) value (~?5)), consistent with their origin as continent-derived trench-fill turbidites.  相似文献   

江西德兴斑岩铜矿石英闪长玢岩成因及成矿学意义          下载免费PDF全文

鲍波  姜军胜  于玉帅  秦拯纬  郑忠超  柳潇  陕亮  董宜勇  李福林 《岩石矿物学杂志》2023,42(4):483-501

为探究石英闪长玢岩成因及幔源基性岩浆对斑岩铜矿的贡献,本文选取德兴矿床石英闪长玢岩开展了锆石U-Pb定年、Hf同位素和全岩地球化学研究。获得石英闪长玢岩LA-ICP-MS锆石U-Pb年龄为169 Ma,与成矿花岗闪长斑岩侵位时间一致,岩体为中侏罗世岩浆活动的产物。石英闪长玢岩具有低的SiO₂(58.41%~63.12%)和K₂O(1.68%~2.94%)含量及A/CNK值(0.85~1.04),富集大离子亲石元素和轻稀土元素,亏损高场强元素Nb、Ta、Ti和重稀土元素,属于钙碱性到高钾钙碱性系列岩石。具有相对亏损的锆石Hf同位素组成,εHf(t)=2.20~7.93(最大值7.93),指示其源区为岩石圈地幔。锆石稀土元素配分模式图显示出明显的正Ce异常,岩浆氧逸度(lg f_O2)为-20.05~-6.66,达到磁铁矿-赤铁矿氧逸度等级,指示石英闪长玢岩结晶自高氧逸度岩浆。全岩地球化学特征显示,德兴石英闪长玢岩与成矿花岗闪长斑岩及其暗色包体符合岩浆混合的演化趋势,说明成矿花岗闪长斑岩可能是中侏罗世幔源基性岩浆和地壳酸性岩浆大规模混合作用的产物,并且石英闪长玢岩代表了岩浆混合过程中的幔源基性端员。结合前人研究成果,认为在中侏罗世伸展构造背景下,软流圈物质上涌导致新元古代受交代的岩石圈地幔部分熔融形成幔源基性岩浆,基性岩浆的底侵作用诱发下地壳物质熔融并与之发生一定程度的岩浆混合作用,形成了花岗闪长斑岩的母岩浆。高氧逸度幔源岩浆的加入可抑制斑岩体系硫化物的过早饱和,同时为德兴矿床注入了成矿所需的部分挥发分和金属元素。  相似文献   

Geochronology,geochemistry, and mineralization of the granodiorite porphyry hosting the Matou Cu–Mo (±W) deposit,Lower Yangtze River metallogenic belt,eastern China     

《Journal of Asian Earth Sciences》2014

Porphyry and skarn Cu–Fe–Au–Mo deposits are widespread in the Middle and Lower Yangtze River metallogenic belt (MLYMB), eastern China. The Matou deposit has long been regarded as a typical Cu–Mo porphyry deposit within Lower Yangtze part of the belt. Recently, we identified scheelite and wolframite in quartz veins in the Matou deposit, which is uncommon in other porphyry and skarn deposits in the MLYMB. We carried out detailed zircon U–Pb dating and geochemical and Sr–Nd–Hf isotopic studies of the granodiorite porphyry at Matou to define any differences from other ore-related granitoids. The porphyry shows a SiO₂ content ranging from 61.85 wt.% to 65.74 wt.%, K₂O from 1.99 wt.% to 3.74 wt.%, and MgO from 1.74 wt.% to 2.19 wt.% (Mg^# value ranging from 45 to 55). It is enriched in light rare earth elements and large ion lithophile elements, but relatively depleted in Nb, Ta, Y, Yb and compatible trace elements (such as Cr, Ni, and V), with slight negative Eu anomalies (Eu/Eu^* = 0.88–0.98) and almost no negative Sr anomalies. Results of electron microprobe analysis of rock-forming silicate minerals indicate that the Matou porphyry has been altered by an oxidized fluid that is rich in Mg, Cl, and K. The samples show relatively low ε_Nd(t) values from −7.4 to −7.1, slightly high initial ⁸⁷Sr/⁸⁶Sr values from 0.708223 to 0.709088, and low ε_Hf(t) values of zircon from −9.0 to −6.5, when compared with the other Cu–Mo porphyry deposits in the MLYMB. Zircon U–Pb dating suggests the Matou granodiorite porphyry was emplaced at 139.5 ± 1.5 Ma (MSWD = 1.8, n = 15), which is within the age range of the other porphyries in the MLYMB. Although geochemical characteristics of the Matou and other porphyries in the MLYMB are similar and all adakitic, the detrital zircons in the samples from Matou suggest that Archean lower crust (2543 ± 29 Ma, MSWD = 0.25, n = 5) was involved with the generation of Matou magma, which is different from the other porphyries in the belt. Our study suggests that the Matou granodiorite porphyry originated from partial melting of thickened lower crust that was delaminated into the mantle, similar to the other porphyries in the MLYMB, but it has a higher proportion of lower crustal material, including Archean rocks, which contributed to the formation of the porphyry and related W-rich magmatic-hydrothermal system.  相似文献   

基于污染足迹模型的湖州市农业污染评估     

李静  焦雯珺  闵庆文  李文华  赵军凯 《资源与生态学报(英文版)》2022,13(1):93-99

太湖流域的水环境质量呈现严重恶化趋势,农业污染物的排放是太湖流域水体环境恶化的主要原因之一。农业污染物主要来源于种植业、畜禽养殖业和水产养殖业的生产过程,不同于以往分开论述三者对水环境的影响,本文基于全国第一次污染普查数据,运用污染足迹模型定量分析了湖州市农业面源(种植业、畜禽养殖业和水产养殖业)对水环境的影响。研究结果表明:(1)农业生产产生的污染物对水环境的影响排序为:磷>氮>有机物;(2)各农业生产类型对水环境的影响排序为:水产养殖业>种植业>畜禽养殖业;(3)湖州市各区县对水环境的影响也存在着明显的空间差异。通过对湖州市农业污染足迹评估,可以明确地提出哪种污染物类型、农业生产类型和区域是湖州市农业面源污染治理的重点。研究结果可以为太湖流域农业的可持续发展和水资源的可持续利用提供一定的参考价值。  相似文献   

浅论赣北九瑞铜金矿集区的资源潜力   总被引：1，自引：0，他引：1  

陈波  占岗乐 《地质与勘探》2007,43(3):46-50

九瑞矿集区是长江中下游铜金成矿带的重要组成部分.数十年来,几代地质和矿山工作者为探明其矿产资源,作出了不懈的努力,取得了巨大成果.但近年来,随着勘探难度的加大,该区矿床勘查和研究处于"半停滞"状态.文章运用前人的科研资料,结合近期的工作成果,用"铜金矿集区"的概念和观点,阐述了矿集区的特征,总结了其控矿因素和成矿规律,分析了九瑞铜金矿集区的成矿系统和资源潜力.  相似文献   

武宁县煤矿矿山地质灾害发育现状及防治措施     

孙国庆 《化工矿产地质》2007,29(1):15-19

江西省武宁县煤矿多属小型矿山,但小煤矿的开采同样会引起诸多矿山地质灾害问题,如废石乱堆乱放,诱发泥石流;不规范开采,造成区域地下水位下降,引起地面沉降、塌陷和矿井冒顶、突水、瓦斯爆炸等,这些问题需要评估和解决。对上述问题进行成因分析、危害性探讨,并针对每项矿山地质灾害问题提出相应的防治措施,可使该区地质灾害得到有效的控制。  相似文献   

江西黄连坑锰矿成矿特征及成因探讨     

左全狮  黄修保 《华东地质学院学报》2007,30(2):119-124

江西省武宁县境内分布了众多的小型铁、锰矿床(点),前人称之为“武宁式”铁矿。通过对黄连坑锰矿区地层的含矿性、控矿构造及容矿构造、矿体特征、矿石类型等地质特征的论述,认为震旦系地层是“初始矿源层”,滑脱构造对成矿物质起迁移、富集及容矿作用。并与萍—乐断陷盆地内的沉积加热液叠改型乐华锰矿床进行了对比分析,二者在矿体规模、矿石类型、锰品位等方面存在显著差别,应属不同成因类型的矿床。初步认为黄连坑锰矿床属构造控矿、风化淋滤成因。  相似文献