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In the present study the origin of clay deposits occurring in an inland platform, in central Portugal, was investigated by their mineralogical and chemical composition. The clay deposits, exploited for ceramic industry are composed of silt-clay facies, the Monteira Member and the Arroça Member, which are assigned to the Coja Formation (Paleogene) and the Campelo Formation (Miocene), respectively. These clayey facies show almost compositional homogeneity, especially concerning texture. The mineralogical composition of the Monteira Member displays slightly higher content in smectite and interstratified clay minerals, which is supported by the chemical composition of samples analyzed. Both members present similar REE patterns, displaying an intense weathering record and little variation in the source area composition. Minor element geochemistry suggests low content in heavy minerals and transition metals. REE patterns and ratios of geochemical parameters support the dominant metasedimentary provenance, with a granite source contribution and also mature recycled sediments of continental origin. The study results’ suggest that the clays of these two members have the same source in terms of lithology and recycled sediments from the Hesperian massif. During the deposition of the Arroça Member, a major remobilization of the Monteira Member is suggested, explaining the geochemical similarity of both facies.  相似文献   

3.
煤矸石—水相互作用的溶解动力学及其环境地球化学效应研究党志(中国科学院地球化学研究所,贵阳550002)关键词水—岩作用煤矸石地球化学动力学采煤矿区复垦环境效应收稿日期:1997-3-10作者简介:党志男1962年生博士生环境地球化学煤矸石以其量多、...  相似文献   

4.
西宁煤田尔麻粘土矿为侏罗纪含煤地层的共生矿产,通过对尔麻粘土矿主矿层的矿床地质、矿石矿物、物化特征及显微结构的测定分析,评价了该地的矿石质量,指出尔麻粘土矿依其低—低中铁、少硫、硅铝比值适中、可塑性强、表面活性大等特征,可作为生产化工产品、耐火材料及器皿的原料。  相似文献   

5.
Four outcrops of Lower Cretaceous (Barremian) karst bauxites located in Teruel (NE Spain) were analysed to determine their mineral associations and genesis related to climatic palaeoweathering events and late superimposed kaolinization processes. The materials comprise metric‐sized pisolitic blocks embedded in a clay‐rich red groundmass. Fourteen samples were examined by X‐ray diffraction, optical microscopy, scanning and transmission electron microscopy and the major elements were analysed by inductively‐coupled plasma mass spectroscopy (ICPMS). The samples are composed of kaolinite, gibbsite, goethite, and hematite as the main phases, with diaspore, boehmite, anatase, and rutile as accessory minerals. The results show a complex sequence of mineralogical and geochemical processes that transformed the parent rock into the current bauxite materials. The clay‐rich groundmass constitutes the lateritic parent material of the pisolitic bauxites. In the parent material authigenic kaolinite (e.g. vermicular kaolinite and kaolinite between cleavage sheets of pre‐existing mica) has been observed; Fe oxides formed subsequent to kaolinite. In the pisolitic bauxites, mineralogical and textural evidence indicates that bauxitization took place at the expense of previous kaolinite, with gibbsite post‐dating the other Al hydroxides. The pisolitic bauxites also show a more homogeneous chemical composition and a relative Ti, Al and Zr enrichment. The data are consistent with an intense palaeoweathering event during the Lower Cretaceous (Barremian) under tropical climatic conditions (warm and humid). Several stages probably took place during the bauxitization process, suggesting variations in water saturation conditions. Subsequent karst reactivation stages and related collapses were responsible for the present lithostructure of the deposits and allowed late kaolinization not related to climate to take place. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   

6.
This paper presents an analytical study of LateBronze andIronAge ceramics and natural clay deposits from the archaeological site ofPuig deSa Morisca in southwestMallorca,Spain. In our study, we combine petrographic, micropaleontological, mineralogical (X‐ray powder diffraction) and textural (laser particle size) analyses of sherds and local clays that may have been used as raw material in ceramic production. This approach allowed us to compare the ceramics’ formal characteristics with those observed in nearby plastic clays and assess raw clay procurement and paste preparation. The results indicate the use of local (<500 m distance) calcareous clays throughout theLateBronze andIron ages. This raw material was mixed with other coarser clays or crushed calcite, as well as other calcareous tempers, such as breccias or calcarenites, located close to the site. The results demonstrate that the same clay deposit was used to make ceramic vessels following different technological choices and recipes. Thus, local communities established a strong connection with the same raw materials through time that were located within the potters’ preferential range of exploitation.  相似文献   

7.
Spongillite from João Pinheiro, Minas Gerais, Brazil is mainly known for its use in brick production and in the refractory industry. Very few studies have focused on its geological context. Spongillite-rich deposits occur in shallow ponds on a karstic planation surface developed on rocks of the Neoproterozoic São Francisco Supergroup. Cenozoic siliciclastic sediments are related to this surface. A field study of these deposits and analysis of multispectral images showed a SE–NW preferential drainage system at SE, suggesting that Mesozoic Areado Group sandstones were the source area of the spongillite-hosting sediments. Mineralogical and textural characterization by optical microscopic analysis, X-ray diffraction (XRD), differential and gravimetric thermal analysis (DTA-GTA), infrared spectroscopy (IR) and scanning electron microscopy (SEM) of seven open-pit spongillite-rich deposits (Avião, Carvoeiro, Vânio, Preguiça, Divisa, Severino, Feijão) showed a sedimentological similarity between the deposits. They are lens-shaped and are characterized at the bottom by sand facies, in the middle by spicules-rich muddy-sand facies and at the top by organic matter-rich muddy-sand facies.Petrographically, the spongillite-hosting sediments and the siliclastic sediments of the Areado Group show detrital phases with similar mineralogical and textural features, such as the presence of well-sorted quartz grains and surface features of abrasion typical of aeolian reworking that occurred in the depositional environment in which the sandstones of the Areado Group were formed. Detrital heavy minerals, such as staurolite, zircon, tourmaline, and clay minerals, such as kaolinite, low amounts of illite, scarce chlorite and mixed-layer chlorite/smectite and illite/smectite occur in the spongillite-hosting sediments and in sandstones from the Areado Group. In both formations, staurolite has similar chemical composition. These mineralogical and textural features show that the sediments of the Areado Group constitute the main source of the pond sediments that host spongillite.  相似文献   

8.
宁夏鸳鸯湖矿区煤的可选性特征   总被引:1,自引:0,他引:1  
鸳鸯湖矿区以不粘煤为主,长焰煤次之,是良好的煤化工和动力用煤。从煤岩特征,煤的筛分、浮沉、煤及矸石的泥化程度试验等方面,对矿区及各井田煤的可选性特征进行了研究,研究表明:清水营井田煤中粘土类矿物较多,可选性较差,其它井田可选性相对较好;矿区煤中粘土矿物多呈细胞充填状,惰质组含量较高,难选出灰分很低的煤;当浮煤灰分控制在6.00%~11.00%,浮煤产率大于80%,煤为中等可选-易选;煤遇水易泥化,矸石为高泥化程度。研究结果可为煤的洗选工艺设计提供依据。  相似文献   

9.
烧变矿床及烧变岩系煤自燃的产物。从宏观及微观上搞清其产状、分带性、物质组分及其形成机理。开拓地质科学的新领域,填补岩石矿物学及矿床学中的空白。并作为找煤的有效标志及增加耐火材料、建材、陶瓷原料的新类型和基地。  相似文献   

10.
矿山尾砂表生地球化学过程实验研究   总被引:5,自引:0,他引:5  
在对石菉铜锡矿和河台金矿层砂矿物物相及化学组成研究基础上,利用自行设计的大口径淋滤柱开展了淋滤实验和静置浸泡(溶解)实验。研究结果表明,矿山层矿排放水不一定是酸性,它取决于矿床脉石矿物、赋矿的岩石及其次生蚀变矿物的酸缓冲能力。矿山排放水的组成是地表或地下水与矿山层砂中矿物和氢氧化物及非品态物质相互作用的结果,元素的赋存状态对其被淋滤的程度有很大影响。优先流能使重金属大量带出,因此要尽量防止优先流的形成。研究结果可为矿山综合整治和修复提供重要依据。  相似文献   

11.
论高岭石粘土和铝土矿研究的新进展   总被引:4,自引:0,他引:4  
刘长龄 《沉积学报》2005,23(3):467-474
过去我国地质界向前苏联学习,把球粘土(Ballclay)作为高岭土或耐火粘土的一个变种,使我们找矿走入误区,以致后来从美国进口球粘土。其实球粘土的结晶性质这个内在因素与高岭土或耐火粘土常不相同,则派生的性能更不一样,应成为独立的矿种,还可与国际接轨。又过去国内外学者认为高岭石高度有序为热液型的,而沉积型的为无序高岭石。但笔者等的研究,我国高岭石高度有序而规模大且均匀稳定的,应算沉积型的紫矸(古生代高岭石软质粘土),可以作流动性好的造纸涂料。又我国硬水铝石岩溶铝土矿,应属于生物有机质成矿作用的沉积型铝土矿。  相似文献   

12.
Based on the mineral and chemical compositions of spoils taken from the Shilu Cu-Mo deposit and Hetai gold deposit, the leaching and batch experiments were made on spoils taken from these two deposits using the leaching column designed by the authors. The experimental results showed that it is not always true that the mine drainage is acidic. Its acidity depends on acid-buffering capacity of gangue, host rock and its alteration mineral assemblage. The composition of the drainage water is related with the interaction between superficial or underground water and solid materials in the spoils, including minerals, hydroxides and amorphous substances. The leaching extent of the element is related with its occurrence form in the deposit. The preferential flow results in leaching-out of heavy metals in large amounts. So it is important to prevent the generating of preferential flow in the system. The results will provide very important grounds for the comprehensive management of land and ecological rehabilitation of the mine site.  相似文献   

13.
Based on the mineral and chemical compositions of spoils taken from the Shilu Cu-Mo deposit and Hetai gold deposit ,the leaching and batch experiments were made on spoils taken from these two deposits using the leaching column designed by the authors.The experimental results showed that it is not always true that the imine drainage is acidic.Its acidity depends on acid-buffering capacity of gangue,host rock and its alteration mineral assemblage.The composi-tion of the drainage water is related with the interaction between superficial or underground water and solid materials in the spoils,including minerals,hydroxides and amorphous substances.The leaching extent of the element is related with its occurrence form in the deposit.The prefer-ential flow results in leaching-out of heavy metals in large amounts.So it is important to prevent the generating of preferential flow in the system.The results will provide very important grounds for the comprehensive management of land and ecological rehabilitation of the mine site.  相似文献   

14.
The elemental composition of high temperature ash (750°C) and forms of S were studied in 25 coal seams from the Escucha Formation (Middle Albian) in the Teruel Mining District, northeast Spain. The principal analytical method was ICP-MS, but ICP-ES was also used in the determination of some trace elements. The analytical data show wide ranges of trace element cotnents among the coal seams studied, even in the vertical profile of a single coal seam. These wide ranges of the trace element concentrations are attributed to both syngenetic and epigenetic processes.When a comparison was made between the average trace element contents of the Teruel Mining District coals, and those of the average content in worldwide coals, the Teruel coals show slightly higher concentrations of Be and U, and lower concentrations of Ba, Cd, Mn, Pb, Sr and Zr. Further, three main groups of trace elements were differentiated on the basis of the inorganic/organic association: (1) trace elements with inorganic affinity; Ba, Ce, Co, Cr, La, Mn, Ni, Rb and Zr. Between these, Ba, Ce, Cr and Rb show a well defined correlation with the clay mineral content, and Co and Ni with pyritic-S content; (2) trace elements with an intermediate (mixed) affinity; As, Cd, Cu, Dy, Er, Eu, Gd, Ge, Ho, Lu, Mo, Nd, Pb, Pr, Sb, Sm, Sr, Tb, Th, Tm, U, Yb and Zn. In this group, As, Cd, Cu, Ge, Mo, Th, U and Zn show a weak trend associated with the mineral matter and Sr with the organic matter; and (3) Be shows an organic affinity. The high mineral matter content (21.3% HTA) of the Teruel coals may account for the great number of elements with inorganic affinity. This classification represents a general trend, but the results show that the affinities of some trace elements (e.g. As, Sb and Zn) may vary from one coal seam to another in the Teruel Mining District.  相似文献   

15.
Chemical analyses of high-temperature coal ashes were used to establish the distribution, association and relationship between major inorganic elements such as Si, Al, Ti, Fe, Mn, Mg, Ca, Na, K, P, S and CO2 in a number of New South Wales economic coal seams and to study the composition and character of mineral matter in these coals. The methods used for the evaluation of the data were statistical analysis (univariate and bivariate), ratios, normative mineral composition and variation diagrams.The distribution of major and minor inorganic elements in coal appears to be related to the amount of mineral matter occurring in coal (determined as ash yield) and its mineralogical composition. The quantitative variations in levels of these elements can be classified as in-seam and inter-seam variations. In-seam variations are largely ash yield dependent, i.e. the levels of an element (wt.%) in coal increase along with the increase of its ash content (wt.%). The inter-seam variations are more complex and are related to both ash yield and to the mineralogical composition of mineral matter.The principal components of New South Wales coal ashes are silicon and aluminium. Silicon may be present as silica or combined with aluminium in different proportions to form clay minerals, such as kaolinite, illite, mixed-layer clay minerals, and smectite. Thus, the concentration levels of aluminium in relation to silicon in coal may give an indication about the character of clay minerals present in coal.Ratios and correlation coefficients of element pairs such as Al and Ti, Na and K, and Na and Al were used to determine differences in the chemical composition of high-temperature coal ashes of seams from various stratigraphic positions and provinces. In some seams the nature of associations of these elements is more significant than in others. This is interpreted as being a product of specific environmental conditions controlling the deposition of these seams.The nature of clay mineral content in coal is believed to be a major reason for chemical dissimilarities found between seams of various stratigraphic levels and geographic areas. For example, in some seams kaolinite, in others expandable clay minerals are dominant. The vertical distribution of these minerals has a stratigraphic significance. Within the Upper Permian Newcastle Coal Measures a trend from kaolinite-rich through to expandable minerals-rich and to kaolinite-rich assemblages can be observed from the bottom to the top. These changes are noticeably gradual.All significant variations in the clay mineral assemblages could relate to the long-term changes in the provenance of sedimentary material, weathering conditions in the source area and the rate of subsidence in the place of deposition. These changes are associated with major tectonic events controlling the history of sedimentation within the paralic Sydney and Gunnedah Basins during the Permian.  相似文献   

16.
中国伊利石粘土矿概述   总被引:1,自引:0,他引:1  
伊利石粘土具有良好的物化性能,在陶瓷、化肥、造纸及化工等行业及环境保护领域中有广泛的用途,是开发前景广阔的粘土矿物。中国伊利石粘土矿主要分布于浙江、吉林、河南等省,多产于中生代的环太平洋地壳运动较强烈地带,一般与火山活动密切相关,常赋存于流纹质火山碎屑岩夹少量陆相沉积的一套晶屑玻屑凝灰岩、含砾凝灰岩等火山岩组成的地层中,一般呈脉状、似层状、透镜状产出。可划分出热液蚀变型、沉积型和风化型三种成因类型。研究表明,具有工业价值的伊利石粘土矿床形成于中生代晚期与火山岩有关的地层中。  相似文献   

17.
张永康 《江苏地质》1996,20(3):129-136
江苏优质矿产主要有五大类:即粘土类矿产,建材类矿产,化工原料矿产,冶金辅助原料矿产,特种用途矿产。江苏矿产资源的开发应注重开源,开优,开新和开外相结合的原则。适当加大地质工作投入,实施好全省矿产资源勘查工程,力争实现矿产资源的重大突破。大力开发优势矿产资源,提高全省非金属矿开发利用水平,形成一批非金属矿产原材料基地。依靠科技进步,开发新产品,新矿种,振兴矿业经济。  相似文献   

18.
Clay-bearing Upper Pliocene red clastics and Quaternary alluvial deposits occupy the Ankara basin. The clayey levels of the Upper Pliocene deposits, referred to as Ankara clay, is considered as a source for compacted clay liners due to their low coefficients of permeability and widespread distributions throughout Ankara. This study investigates the geological, geotechnical and mineralogical properties of the founding clayey soils at two sites of the Ankara region. The geotechnical index properties along with the hydraulic conductivities of the clayey soil samples collected from these sites were determined. A mathematical relation between the clay mineralogical content and hydraulic conductivity was established. The results of this investigation show that, from a geotechnical point of view, Ankara clay may be regarded as a highly suitable material for a compacted clay landfill liner given that its mineralogical compatibility with leachate is confirmed.  相似文献   

19.
[研究目的]湖南省矿产资源丰富,矿种及成因类型繁多,但对各类矿产形成的时代和构造背景尚缺乏系统归纳和总结.[研究方法]本文在既有区域矿产资料基础上,结合近些年区域构造演化、成岩成矿年龄、矿床成因机制等研究成果,对湖南省成矿地质事件及各期成矿事件的构造背景、矿床成因、矿产发育和分布特征等进行了系统探讨和总结.[研究结果]...  相似文献   

20.
The potters' quarter of the ancient city of Sagalassos, southwest Turkey, was one of the largest and most enduring ceramic‐producing manufactories in the eastern Mediterranean. The objective of our study was to determine environmental circumstances that favored development of different clay resources in the territory of Sagalassos and to assess utilization of these resources in the local pottery manufactory. The potters' quarter was established where, owing to favorable geological circumstances, a large clay body had developed. The bedrock in the potters' quarter, a tectonized ophiolite sequence, has synclinal structure; hence, surface runoff and groundwater tend to accumulate in its center. The weathering of the basic rock formed a smectite‐rich clay with vertic properties. This clay was mined in antiquity, and mineralogical and chemical analyses indicate that it was used for the production of local ceramics from Hellenistic to Byzantine times. It is likely that colluvium on top of the ophiolitic clay at the potters' quarter is related to deforestation and slope processes after the potters' quarter was abandoned. In sum, environmental circumstances determined the location of the artisanal quarter of Sagalassos, with its clay quarrying operation and ceramic manufactory. However, for the local mass‐produced Sagalassos red slip ware, the results of our chemical and mineralogical analyses indicate that a different, more suitable clay was used: detrital lake sediments, rich in chlorite and chlorite/smectite mixed layers, located about 8 km from the original artisanal quarter. The choice for this clay was determined both by the presence of a suitable clay deposit, as well as socio‐economic circumstances such as land ownership. The site of Sagalassos yielded unique evidence of mining of clay at a ceramic production site, as well as import of nearby clays. The local and imported clays were used side‐by‐side, but one for the production of common wares and building ceramics, and the other for the manufacturing of luxury fine tablewares. © 2003 Wiley Periodicals, Inc.  相似文献   

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