深埋藏条件下鲕粒灰岩的热水交代实验研究

在相对静岩压力40 MPa、地温150℃(大体相当于4 000 m深埋条件)、用时15 d的条件下,对灰色中厚层状鲕粒灰岩进行深埋藏热水交代白云化实验研究。结果表明:反应前后岩石的结构发生了轻微变化,尾液中的主要化学成分Ca2+浓度从0 mg/L增加到337 mg/L,Mg2+浓度从过饱和溶液降低到2 830 mg/L。电子探针分析结果表明,固体样CaO含量由61.000%降为60.830%,而MgO则由0.296%升到0.350%。可见,参与实验的固、液样品反应前后主量元素Ca、Mg有一定的变化。但根据样品的宏观观察、镜下鉴定、扫描电镜及X衍射图谱的综合对比,认为在该实验条件下,尚未产生明显的白云化现象。     

Petrographical and geochemical characterization of Comblanchien limestone (Bourgogne,France): A fingerprint of the building stone provenance

The Comblanchien limestone is a well-known building stone that deserves a quantitative characterization in order to be able to certify its origin. We compare petrographical and geochemical characteristics of limestones commercialized under the name of Comblanchien to those of one of their competitors (VATC, a Portuguese coated grain-bearing limestone). From macroscopic and microscopic observations, the distinction is somehow difficult but the coated grain-bearing Comblanchien samples have δ¹³C values (from +1.75 to +2.25‰) different from those of the VATC sample (negative δ¹³C value). As an example of application of these results, three samples from a building site near Paris are also studied in order to verify their provenance. We conclude that they do not come from quarries from the Comblanchien area, but likely from Portugal. The study shows that a detailed analysis of building limestones may provide a robust tool for discriminating between currently mined stones of different provenances, and thus open the possibility to attach to a given limestone a fingerprint, an identity card, and if required a commercial label.     

The typology of ancient quarries within the Paleocene limestone of Álava in northern Spain

Paleocene limestone and dolomitized limestone of Álava, Spain, were used as building materials from the Neolithic age until the Neoclassical, predominantly in the production of headstones, sculpture, and stonework during the Roman era (1st to 4th centuries) and Romanic and Gothic periods (10th to 15th centuries). The quarrying methods employed are related to topographic relief. Five types of ancient quarry have been identified: escarpment, dip‐slope (ascending and descending), edge, and trench. The oldest quarries (1st to 4th centuries) are the trench‐cut stone pits of “Raso de Cezama.” Later, from the Romanic period (10th to 15th centuries), descending dip‐slope, escarpment, and edge‐based quarries were worked, such as those at Achuri, Ajarte, and Santa Elena. Finally, an ascending dip‐slope quarry was developed at Marquínez during the Neoclassical period (18th century). © 2009 Wiley Periodicals, Inc.     

Geological and environmental implications in the reclamation of limestone quarries in Sierra de Callosa (Alicante,Spain)

Sierra de Callosa have an area of 8 km² and a maximum altitude of 566 masl. Geologically, it is found to be primarily comprised of carbonated rocks. Mine spoils coming from limestone quarries extraction are often used in the working reclamation process. These materials could be actually employed profitably once conveniently amended with organic matter. A study on the temporary evolution of nutrients and several physical–chemical parameters in a mineral waste amended with municipal solid waste (MSW) compost has been carried out. The effect of incorporating such waste to mine spoils in an arid gravel quarry has been studied, quantifying the temporal evolution of nutrients and several physical–chemical parameters in the mixture. Three plots have been prepared with mine spoils proceeding from a limestone quarry located in the south of the province of Alicante (municipality of Redován). These plots have been amended with 3 kg/m² of MSW compost. Texture, pH, electrical conductivity, oxidizable organic matter, N-Kjeldahl, available P, Na, K, Ca, Mg, Fe, Mn, Cu and Zn were analysed. The results reflected the contribution of nutrients to the substrate after the MSW addition. The variability of the information indicated the heterogeneity of the MSW composition, as well as the difficulty of obtaining a homogeneous MSW mixture–mineral waste.     

辉石中结构羟基变温行为的红外光谱初步研究

运用显微傅立叶变换红外光谱(Micro-FTIR)技术观察了辉石(单斜辉石和斜方辉石)中结构OH在原位连续加热、降温和阶段加热过程中的行为,从而更清楚地了解了缺陷氢在晶体结构中的位置及其结合机制。样品为安徽女山新生代玄武岩中的普通辉石巨晶和橄榄岩包体中的斜方辉石。温度从室温升到500℃,间隔100℃。实验结果表明,单斜辉石和斜方辉石的红外谱图随温度变化的趋势相同,即:OH的伸缩振动峰位都是随温度升高而向低波数移动,而且这种变化是可逆的;峰位的移动主要受H所取代的阳离子的位置或晶格空隙的热膨胀的影响。     

Environmental risk evaluation of the use of mine spoils and treated sewage sludge in the ecological restoration of limestone quarries

The ecologic restoration criteria in areas degraded from extraction activities require making use of their mine spoils. These materials do not meet fertility conditions to guarantee restoration success and therefore, need the incorporation of organic amendments to obtain efficient substratum. Reducing the deficiencies in the organic material and restoration material nutrients with the contribution of treated sewage sludge is proposed in this work. This experiment was based on a controlled study using columns. The work was conducted with two mine spoils, both very rich in calcium carbonate. The first mineral, of poor quality, came from the formation of aggregates of crushed limestone (Z). The other residual material examined originated in limestone extraction, formed by the levels of interspersed non-limestone materials and the remains of stripped soils (D). Two treatments were undertaken (30,000 and 90,000 kg/ha of sewage sludge), in addition to a control treatment. The water contribution was carried out with a device that simulated either short-duration rain or a flooding irrigation system in order to cover the surface and then percolate through the soil. The collection of leached water took place 24 h after the applications. Different parameters of the leached water were determined, including pH, electrical conductivity, nitrate anions, ammonium, phosphates, sulphates and chlorides. The values obtained for each irrigation application are discussed, and the nitrate values obtained were very elevated.     

Chinese neolithic jade: A preliminary geoarchaeological study

This study deals with a geoarchaeological examination of the jade artifacts unearthed from the major sites of jade-using cultures over Neolithic China. The earliest examples of true jade—tremolite-actinolite nephrite—were jade artifacts from the Chahai site at Fuxin in Liaoning, dating back to the 6th millennium B.C., approximately contemporaneous with the beginning of the Neolithic age. The expansion of jade-using culture during the Neolithic period was gradually from east through west China. The jade-using culture thrived especially in both the lower Yangtze River and Liao River valleys, and came to a climax during the late Neolithic period when not only could nephrite be discerned from jadelike and other minerals and rocks, but also nephrite of various grades could apparently be deliberately used to make jades of different types according to their importance in social life. It may be suggested that the raw nephrite used to make jades during the Neolithic age was derived from unknown ancient deposits that might be within China proper rather than at Kunlun Mountain.     

柴达木盆地北缘构造带早古生代造山后作用初探：泥盆纪沉积物物源示踪

柴达木盆地北缘(柴北缘)泥盆系牦牛山组以发育冲积扇沉积体系的粗碎屑岩和中酸性火山岩的岩石组合为特征,记录了柴北缘构造带从碰撞造山进入造山后阶段的核部岩石剥露过程。尕海南山牦牛山组地层顶部和底部的凝灰岩锆石LA-ICP-MS U-Pb加权平均年龄分别为396.6±2.4 Ma(MSWD=0.39,n=14)和396.9±2.5 Ma(MSWD=0.052,n=14),指示了牦牛山组沉积时代大致为早泥盆世末期。不同出露点牦牛山组砂岩碎屑锆石LA-ICP-MS U-Pb年龄谱具有不同的峰值特征：尕海南山调查点A,样品20QH-19具有532～505 Ma、935～891 Ma、1136～1064 Ma和3110～1309 Ma多峰特征;尕海南山调查点B,样品20QH-21具有537～443 Ma、1073～798 Ma和2463～1785 Ma多峰及20QH-22以明显的单一峰值～420 Ma为特征;牦牛山调查点C,20QH-26以明显的～418 Ma单峰为特征。多样的年龄组分指示了牦牛山组沉积物质主要来源于柴北缘志留纪—泥盆纪同造山岩浆岩、寒武系—奥陶系滩间山群、沙柳河群及欧龙布鲁克地块。...     

Controlled blasting in a limestone mine using electronic detonators: A case study

Except for very deep-seated deposits, open cast mining method has been recognized as the safest and most productive mode for mining minerals. Ever growing demand in minerals and coal has compelled the mine operators to increase the size of mine, which has resulted in an increasing trend towards large capacity open cast projects. Explosives and blasting techniques play a significant role in efficient opencast mining operations. There have been constant technological developments towards safer, faster, economical and more efficient blasting systems. Further, globally increased competitiveness has necessitated to carryout blasts in such a way that the desired degree of fragmentation is achieved in the primary blast, with minimum undesired side effects such as ground vibration, air blast/noise, flyrock, generation of oversize boulders, formation of toe, and over break or back break. Hence, the ultimate objective of the blasting engineer is to ensure that the blasts are carried out in an eco-friendly manner. This paper presents a case study of limestone mine where a controlled blasting was conducted near a green structure of wagon tippler (at 2 m) being constructed for foundation work of belt conveyor as the mine management wants to double the existing production. This paper deals with controlled blast design and its implementation using electronic detonators with signature hole technique.     

Chert provenance analysis at the Mack Canyon Site,Sherman County,Oregon: An evaluative study

Chert is the most frequent lithic raw material in the Columbia Plateau, but archaeologists have made few attempts to link chert artifacts to their quarries in this area. The Mack Canyon Site in north-central Oregon is near a chert source, providing an opportunity to compare provenance analysis techniques. Macroscopic and microscopic visual attributes and element concentrations were determined for 26 samples from six sources in the Columbia Plateau. Additional concentration data from two other sources were included for comparison. Four artifacts were selected from the Mack Canyon Site for comparison to the nearby outcrop. Although all of the artifacts were macroscopically indistinguishable from the local material, microscopic attributes and element concentrations indicate that only one of the artifacts came from the outcrop. Linking chert artifacts and quarries through statistical analysis of element concentrations holds promise for the Columbia Plateau. © 1996 John Wiley & Sons, Inc.     

Compositional multivariate statistical analysis of thermal groundwater provenance: A hydrogeochemical case study from Ireland

Thermal groundwater is currently being exploited for district-scale heating in many locations world-wide. The chemical compositions of these thermal waters reflect the provenance and circulation patterns of the groundwater, which are controlled by recharge, rock type and geological structure. Exploring the provenance of these waters using multivariate statistical analysis (MSA) techniques increases our understanding of the hydrothermal circulation systems, and provides a reliable tool for assessing these resources.Hydrochemical data from thermal springs situated in the Carboniferous Dublin Basin in east-central Ireland were explored using MSA, including hierarchical cluster analysis (HCA) and principal component analysis (PCA), to investigate the source aquifers of the thermal groundwaters. To take into account the compositional nature of the hydrochemical data, compositional data analysis (CoDa) techniques were used to process the data prior to the MSA.The results of the MSA were examined alongside detailed time-lapse temperature measurements from several of the springs, and indicate the influence of three important hydrogeological processes on the hydrochemistry of the thermal waters: 1) salinity and increased water-rock interaction; 2) dissolution of carbonates; and 3) dissolution of sulfides, sulfates and oxides associated with mineral deposits. The use of MSA within the CoDa framework identified subtle temporal variations in the hydrochemistry of the thermal springs, which could not be identified with more traditional graphing methods, or with a standard statistical approach. The MSA was successful in distinguishing different geological settings and different annual behaviours within the group of springs. This study demonstrates the usefulness of the application of MSA within the CoDa framework in order to better understand the underlying controlling processes governing the hydrochemistry of a group of thermal springs in a low-enthalpy setting.     

High-resolution records of location and stratigraphic provenance from the rare earth element composition of fossil bones

Bone apatite acts as a natural, timed sampling device, scavenging trace elements from local pore waters over timescales of ca. 1-50 ka. The rare earth element (REE) and U/Th composition of fossil bones reflects associated pore water compositions during the period of recrystallisation. The REE composition of fossil bones is controlled by partitioning of REE between pore waters and particle surfaces, and the REE composition of fossil bones reflects the REE composition of pore waters which vary spatially and temporally. Light REE are preferentially sorped onto particle surfaces, thus the high La/Yb values seen in many bones from coastal marine and aeolian environments are best explained by release of REE from light REE-enriched particles to local pore waters and subsequent immobilisation in recrystallising bones. The REE compositions of bones recovered from pedogenically altered diatomite sediments of the Olorgesailie Formation of southern Kenya vary over spatial scales of less than 10 m. Location accounts for 48% of the observed variation in bone chemistry and bones recovered from eight discrete excavations within the same time-equivalent stratigraphic layer can be assigned to their excavation location with >70% accuracy based on a discriminant analysis of REE, U, and Th composition. Despite this within-layer variation, bones recovered from different stratigraphic horizons within the Olorgesailie Formation can also be distinguished on the basis of their trace element composition. Bones recovered from four stratigraphic horizons spanning ca. 0.5 million years were assigned to their correct stratigraphic layer with >90% accuracy. Where sedimentological conditions are favourable, the trace element composition of fossil bone may be used to test stratigraphic provenance and burial location in excavated bone with a temporal resolution of <10 ka and a spatial resolution of <10 m. The trace element composition of fossil bone may also be used to investigate the accumulation history of vertebrate assemblages and to reconstruct pore water variability across land surfaces.     

A karst of thousands: Jamaica's limestone scenery

About two-thirds of the surface-rock outcrop of Jamaica consists of Cretaceous and Cenozoic, particularly mid-Tertiary, limestones. The island has been subaerially exposed for less than 10 million years. During this time, a combination of high tropical temperatures and high seasonal rainfall, coupled with widespread jointing and faulting related to the island's position within the North Caribbean Plate Boundary Zone, has led to the development of an impressive karst topography over much of Jamaica.     

高温状态下加载速率对石灰岩力学效应研究

采用美国MTS810电液伺服材料试验机,对200 ℃高温状态下的石灰岩试件进行了5级不同加载速率下的单轴压缩试验,考察了石灰岩的全应力-应变曲线,给出了其峰值强度、峰值应变、弹性模量E随加载速率的变化特征。研究结果表明,(1) 石灰岩的峰值强度、弹性模量在加载速率v = 0.000 5～0.005 mm/s内,随加载速率增大呈急剧上升现象;当v = 0.005 0～0.5 mm/s内,随加载速率增大呈下降趋势;当v >0.5 mm/s后,呈现上升趋势。(2) 石灰岩的峰值应变在v = 0.000 5～0.005 mm/s内,随加载速率增大呈下降趋势;在v = 0.005～5.0 mm/s加载速率区段,峰值应变呈现缓慢上升现象。研究结果可为相关岩体的爆破效应及评价岩石工程的稳定性提供参考。     

重塑黏土的高压次固结特性初探

利用自行研制的高压固结试验系统,对重塑黏土试样进行了竖向压力从0.25 MPa到12.00 MPa的一维固结试验;并利用三轴设备对该土样进行了0.3～2.5 MPa的等向固结试验。试验结果表明：一维固结试验获得的各级压力固结曲线均有明显的次固结阶段,重塑黏土的次固结系数随竖向压力增大而非线性变化;具体而言,当固结压力小于2 MPa,次固结系数随竖向压力增大而显著减小,当固结压力大于2 MPa后,次固结系数则几乎不变;等向固结试验获得的次固结系数则远小于一维固结试验获得的相应值,其随固结压力的变化规律也与一维固结不同。此外,从微观角度对试验结果进行的分析表明,高压下黏土次固结变形的物理机制不同于低压。即低压下黏土次固结变形的主因是颗粒间的相对滑移,而高压下则是结合水膜的蠕变;而且低压下偏应力对次固结变形有控制性影响,但高压下其影响很小。     

Katol meteorite shower, Maharashtra: A preliminary study

A meteorite shower occurred in Katol (21° 15′ 30″ N; 78° 35′ 00″ E; at an elevation of 415 m above msl), Nagpur district of Maharashtra state, India on May 22, 2012 between 14:00 to 14:30 hrs (Indian Standard Time) with a presently observed strewn field of ～5.0 sq km area. The event was experienced by the hundreds of inhabitants with a loud noise and fire ball between Akola in the west to Nagpur in the east. The Geological Survey of India has so far collected 27 meteorite pieces with a total weight of 3500 gm. The locations, size, shape and surface features of the individual meteorite pieces have been recorded. Based on their physical properties, mineralogy, mineral chemical mapping and REE chemistry, the Katol meteorites have been classified as olivine-rich H5 type differentiated stony meteorite with reconstituted chondrules. The preliminary evidence suggests the presence of pre-solar grains in Katol meteorite.     

Single-layer folding in marble and limestone: An experimental study

Folding experiments have been carried out on single-layers of Carrara marble and Solnhofen limestone at a confining pressure of 275 bars, temperature of 400°C, and strain rates of 5.5×10⁻⁷ to 8.2×10⁻⁷. The marble and limestone layers were embedded in a rock-salt matrix and in a matrix of a mixture of 60% fine-grained halite and 40% fine-grained calcite, respectively, and deformed to different percentages of bulk shortening. Aspect ratios of the layers varied between 11.25 and 15. The stress-strain relationship reveals that strain increased with a very small increment in compressive stresses, once folding was initiated.With progressive deformation the bulk strain is compensated by folding along one fold hinge. The resulting folds are concentric and a combination of class 1a, 1b and 3 type. The changes in the arc length, layer thickness, limb dip and wavelength with progressive folding in marble layers, are discussed.The microstructure and texture of the folded marble and limestone layers have been investigated optically and by means of an X-ray texture goniometer. The inner fold arc exhibits a strong preferred orientation, whereas in the outer fold are the preferred orientation is poorly developed. Differences in the fabric in medium-grained marble and fine-grained limestone layers have been attributed to the difference in mechanism of deformation.     

基于沉积物物质来源的地下水化学特征分析:以北京市平原区为例

沉积物物质来源不同,其沉积环境和沉积特征不同,其地球化学特征、水动力体系和地下水循环响应不同。文中以北京市平原区为例,通过沉积物物质来源分析,研究浅层地下水化学分布特征。首先根据地下水系统分区进行取样和实验,采用矿物组合、风化强度及相关分析等多种方法综合分析北京市平原区沉积物的物质来源及其组合特征,多种方法分析结论一致,即北京平原区的主要物质来源:一是流经燕山山地花岗岩变质岩区的潮白河系统,一是流经西山山地石灰岩区的永定河系统;而两系统中、下部是多期物源多层交叠、纵横交错沉积形成的。其次在物源分析基础上通过水质分析研究两系统剖面上地下水水化学特征,即两系统剖面地下水化学类型主要为HCO3--Ca.Mg型水;但永定河系统的溶解性总固体、阴阳离子浓度均大于潮白河系统,这与两剖面所在系统物源分析的结果相吻合,即分析结果表明物源的沉积环境及沉积组合特征决定了系统的地下水化学特征。