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广东四会优质沙糖桔产地生态地球化学特征 总被引：1，自引：0，他引：1
四会地区是中国重要的沙糖桔产区,重点对威整和地豆两处沙糖桔园进行了生态地球化学调查。采集了沙糖桔园表层至底层土壤、出露的代表性基岩、沙糖桔叶和果实样品,实测了营养、有益和有害元素以及土壤营养元素有效态的含量。通过分析得出:(1)优质沙糖桔产区植物营养、有益元素含量适宜,重金属元素中Cd、Cr、Hg等的含量符合无公害水果产地环境要求;(2)在土壤—沙糖桔生态系统中,大多数有益、营养元素从深部到表层的变化规律具有相似性;(3)沙糖桔各器官(叶、果皮、果实)中,元素大多在叶中较为富集,有害元素在果实中富集较小,大多数营养元素在果皮中较果肉中富集;(4)成土母质以砂岩及花岗岩发育而成的赤红壤较适宜,尤以砂岩为母质的土壤更好。 相似文献
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福建省是中国杨梅重要产地,其中龙海市浮宫杨梅因其独特品质而名扬海外,是当地的名特优农产品。以龙海杨梅产地为研究区,系统采集了35套岩石-土壤-杨梅果实样品,测定了主量组分、植物营养有益元素、有害元素以及土壤部分营养元素有效态含量。研究表明：受地质背景影响,浮宫镇及其周边杨梅产地土壤中植物营养有益元素的有效度及其有效量普遍高于东泗镇,而有害元素含量较低,为浮宫杨梅的优质高产、富硒杨梅产出提供了地质地球化学条件;土壤中植物营养元素P、Mn、Cu、Zn、S有效态含量与其全量显著正相关;研究区岩石、土壤Se含量均远高于全国平均水平,采集的35件杨梅果实样品富硒率高达74.3%;植物营养有益元素的富集系数明显高于有害元素,显示出杨梅对营养有益元素的选择性吸收以及对有害元素的阻遏作用。 相似文献
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在《江西省鄱阳湖及周边经济区1∶25万多目标地球化学调查》成果的基础上,依据地球化学特征(包括土壤酸碱度、营养元素、有益元素丰缺、有机质含量、重金属污染情况等)和环境质量情况(包括地貌类型分区和光、热、水影响条件),将全区划分为优质农业区、中等农业区、低级农业区等3种类型。其中,优质农业区农业营养元素Mg比较丰富,Mn、Cu、Zn及Mo等有益元素出现高背景分布,As、Cd、Pb和Hg含量呈正常分布,土壤重金属元素综合污染指数属无污染等级;中等农业区营养元素Mg在背景值及高含量分布范围,Mn等有益元素含量在低背景和高含量范围内,表层土壤重金属As等综合污染指数为轻度污染;低级农业区营养元素Mg含量属中等和缺乏,Mn等有益元素在背景值和低含量分布,属缺乏的元素含量,As等有害元素为轻度污染和中度污染。 相似文献
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莆田枇杷产区土壤-枇杷生态系统的主要影响因素 总被引：1，自引：0，他引：1
通过对福建莆田枇杷产区地球化学特征的研究,对影响土壤-枇杷生态系统的主要因素进行了探讨,认为光照、温度、湿度、地势等等,对枇杷的长势起着重要的作用.除此以外,土壤的母岩类型、枇杷的不同品种以及土壤理化性质(包括pH值、有机质、交换性盐基离子等)等因素都对土壤-枇杷生态系统有着不同程度的影响. 相似文献
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以土壤中有毒有害元素含量为依据,以元素污染叠加程度为准则,提出了土壤污染等级标准的确定方法。长江三角洲、福建沿海地区的试验研究表明,表、深层土壤成土母质具有同源性,元素含量具有较好的相关性,深层土壤基本不受人类活动的影响,基于深层土壤元素含量确定的地球化学基准值是土壤污染等级划分的基础依据,据此建立了长江三角洲地区土壤污染等级标准,取得了该地区土壤污染等级划分结果。根据土壤污染成因及其生态环境意义,厘定了不同土壤污染等级的内涵。研究认为土壤污染等级区的生态效应需综合各种因素进行分析。 相似文献
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海南省胡椒种植基地土壤中重金属元素污染评价 总被引：8，自引：5，他引：8
在对海南省胡椒主要种植区--文昌区和琼海区胡椒种植地土壤中重金属元素含量进行调查的基础上,运用单项污染指数法和内梅罗综合污染指数法,结合绿色食品产地环境技术条件及土壤环境质量二级标准,对其含量现状进行了评价.结果表明,文昌区中仅有东阁镇种植地区符合绿色食品产地环境技术条件要求,玄武岩风化的铁质砖红壤区及花岗岩风化的黄色砖红壤区的重金属元素污染因子主要为Cr、Ni,其次为Cu;琼海区只有长坡花岗岩及变质岩风化区两种植地土壤中Pb、As超标,其他母质类型的土壤均符合绿色食品产地环境技术条件要求.整体看,研究区胡椒种植地土壤中重金属元素含量受人为活动因素影响较小,母岩母质类型是造成土壤重金属含量高的重要原因. 相似文献
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在现有几种锚杆数值分析方法的基础上,对考虑了浆体切向受力性态的三维锚杆单元理论及其应用进行了研究,编制了三维锚杆有限元计算程序,并结合例子对浆体锚杆的变形、应力规律进行了分析。计算结果显示了模型的可靠性和实用性。 相似文献
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Geochemistry and origin of elements in some UK coals 总被引：3，自引：0，他引：3
Twenty-four UK coals ranging in rank with 4.6%–37.6% volatile matter were analysed for 46 major and trace elements. The samples were obtained from the UK Coal Bank and are representative of the major UK coal fields. The major element distributions are interpreted in terms of the mineralogical variations—quartz and kaolinite are largely responsible for the Si and Al, carbonates for Ca and Mg and pyrite for Fe. Also exerting an influence in some samples are siderite, Al-phosphate minerals and illite. Based on statistical relationships with the major elements, Rb, Cr, Th, Ce, Zr, Y, Ga, La, Ta, Nb and V are thought to be mainly present in the clay minerals, and As, Mo, Sb, Tl, Se and Bi and Pb are probably present in pyrite. Strontium and Ba are concentrated in a restricted number of samples related to the phosphate minerals. Germanium is the only element for which a major organic association can be demonstrated. Elements with an indirect association with the organic matter are Na, Cl, and Br in porefluids and possibly Te. The ash content is controlled mainly by the detrital input and the trace elements related to the ash content are therefore those elements associated with the clay minerals. Variations with rank would appear to be mainly related to the moisture content (porefluids). The trace elements associated with the quartz and clay minerals are thought to be dominantly detrital in origin. The non-detrital elements, essentially those contained in pyrite, are thought to have been incorporated in the depositional environment from waters with enhanced salinities through seawater ingress, hence there are positive relationships between S and trace element concentrations. 相似文献
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G. J. Chakrapani 《Environmental Geology》2005,48(2):189-201
Chemical weathering and resulting water compositions in the upper Ganga river in the Himalayas were studied. For the first time, temporal and spatial sampling for a 1 year period (monthly intervals) was carried out and analyzed for dissolved major elements, trace elements, Rare Earth Elements (REE), and strontium isotopic compositions. Amounts of physical and chemical loads show large seasonal variations and the overall physical load dominates over chemical load by a factor of more than three. The dominant physical weathering is also reflected in high quartz and illite/mica contents in suspended sediments. Large seasonal variations also occur in major elemental concentrations. The water type is categorized as HCO3––SO42––Ca2+ dominant, which constitute >60% of the total water composition. On an average, only about 5–12% of HCO3– is derived from silicate lithology, indicating the predominance of carbonate lithology in water chemistry in the head waters of the Ganga river. More than 80% Na+ and K+ are derived from silicate lithology. The silicate lithology is responsible for the release of low Sr with extremely radiogenic Sr (87Sr/86 Sr>0.75) in Bhagirathi at Devprayag. However, there is evidence for other end-member lithologies for Sr other than carbonate and silicate lithology. Trace elements concentrations do not indicate any pollution, although presence of arsenic could be a cause for concern. High uranium mobilization from silicate rocks is also observed. The REE is much less compared to other major world rivers such as the Amazon, perhaps because in the present study, only samples filtered through <0.2 m were analysed. Negative Eu anomalies in suspended sediments is due to the excess carbonate rock weathering in the source area. 相似文献
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Chemical Analysis of Iron Meteorites by Inductively Coupled Plasma-Mass Spectrometry 总被引：2，自引：0，他引：2
Iron meteorites were analysed for nineteen siderophile and chalcophile elements by conventional inductively coupled plasma-mass spectrometry with the specific aim of demonstrating that this technique is an effective alternative to the more routine, yet complex, methodologies adopted in this field such as instrumental or radiochemical neutron activation analysis. Two aliquots of each meteorite sample, in the form of small shavings, were dissolved, one in 6 mol l-1 HNO3 and the other in aqua regia , and diluted to a final concentration of 1 mg sample per 1 ml of solution, without pre-concentrating the analytes. Nitric acid solutions were used for the determination of the elements Cr, Co, Ni, Cu, Ga, Ge and As; aqua regia solutions were analysed for the elements Mo, Ru, Rh, Pd, In, Sn, Sb, W, Re, Ir, Pt and Au. Samples were analysed by external calibration, carried out using synthetic multi-elemental solutions, and internal standardisation (with Be, Rb and Bi selected as internal standards). The results obtained from the analyses of nine geochemically well-characterized iron meteorites (Canyon Diablo, Odessa, Toluca, Coahuila, Sikhote-Alin, Buenaventura, Tambo Quemado, Gibeon, NWA 859) with widely variable chemical compositions are in good agreement with literature values for most elements. Detection limits were generally below the lowest concentration observed in iron meteorites. The most notable exception is for Ge, which cannot be successfully determined in the low-Ge meteorites of groups IVA, IVB and IIIF and a number of ungrouped irons. A test of the overall reproducibility of the adopted method, undertaken by repeatedly analysing the same Odessa IAB meteorite specimen, yielded relative standard deviations (1 s ) of between 1 and 6% for all elements except Cr (40%). 相似文献
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ICP-AES法测定岩石、土壤和水系沉积物中22种元素 总被引：9，自引：0，他引：9
用盐酸、硝酸、氢氟酸和高氯酸溶解,ICP-AES法测定岩石、土壤及水系沉积物中22种 常量、次量和微量元素的分析方法。研究了不同的溶矿方法和条件:选择了最佳的分析谱线、观测 高度、背景扣除位置等条件。方法具有检出限低、精密度高及准确度好等特点,符合多目标区域地 球化学样品测试的要求,经国家一级岩石、土壤及水系沉积物标准物质分析验证,结果满意。 相似文献
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浙江花岗岩类地球化学与地壳演化——Ⅱ.元古宙花岗岩类 总被引：13，自引：0，他引：13
浙江元古宙花岗岩类包括神功期（1．8－1．9Ga）和晋宁晚期（0．6—0．9Ga）。研究了浙江元古宙花岗岩类的主元素、微量元素、稀土元素和Rb、Sr同位素组成特征及岩石成因，探讨了浙江地壳的演化。浙江地壳形成于太古亩和元古宙，地壳增生的时期为2．6－2．7、0．8-1．1和0.1－0.12Ga。随时间演化浙江地壳组成有变化，但分异演化不明显。沿江-绍断裂分布的晋宁晚期慢源和壳幔混合中酸性岩是普宁期俯冲碰撞的证据。加里乐和印支期是两次规模不大的构造运动。 相似文献
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北淮阳晓天火山岩盆地片麻状花岗岩成岩年代学及地球化学特征 总被引：1，自引：0，他引：1
岩石的锆石U-Pb定年和主量、微量、稀土元素分析是研究侵入岩成岩时代、岩石成因的主要研究手段。本文在野外地质调查工作的基础上，采用X射线荧光光谱、电感耦合等离子体发射光谱、电感耦合等离子体质谱和LA-ICP-MS等技术对晓天火山岩盆地内杨三寨附近发现的片麻状钾长花岗岩进行相关地球化学分析。结果表明：该岩体主量元素以高硅、钾和钠，低铁镁钙磷为特征，其中SiO2含量为65.86%~78.29%，Al2O3为10.89%~16.02%，MgO为0.17%~1.17%，K2O为1.37%~6.44%，Na2O为0.53%~6.50%，属于高钾钙碱性系列。微量元素方面，样品以亏损Nb、Sr、P和Ti，富集La、Ce、Nd和Zr为特征。稀土元素方面，含有较高的稀土元素（ΣREE=152.70~650.88μg/g），轻稀土富集重稀土亏损（LREE/HREE=6.77~20.64），多数具有较弱的负铕异常（δEu=0.29~1.15），铈异常不明显；稀土元素标准化曲线以右倾为特征。30个锆石点的206Pb/238U年龄分布于720~828Ma之间，加权平均年龄为776±11Ma （MSWD=2.1）。研究认为，盆地内新元古代片麻状钾长花岗岩的发现表明晓天盆地中心存在隆起，并不是之前研究认为的"斗"形的两边浅中间厚的盆地形态，这对该盆地的构造形态认识和进一步找矿具有重要的指导意义。 相似文献
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卡拉盖雷铜钴金矿是那拉提构造带内发现的首例以Cu为主,伴生Mo,Co,Au,Pb,Zn的火山岩型热液矿床.矿区内出露的地层主要为石炭系下统大哈拉军山组火山岩地层,矿区岩浆岩主要有花岗闪长岩、闪长岩和辉绿岩脉.通过火山岩地层和侵入岩样品的地球化学分析,认为区内大哈拉军山组是一套由玄武岩、安山岩、英安岩、流纹岩组成的连续亚碱性的火山岩系列,且以钙碱性系列为主;矿区钾长花岗岩属于准铝质—过铝质岩类,碱性系列,花岗闪长岩和闪长岩属于准铝质—过铝质岩类,钙碱性—碱性系列,基性侵入岩属于弱碱性—碱性系列.稀土元素特征显示中酸性侵入岩可能属于地壳重熔型花岗岩;基性侵入岩与基性火山岩来源一致. 相似文献