Prospects of Carboniferous Shale Gas Exploitation in the Eastern Qaidam Basin

Shale gas is a resource of emerging importance in the energy field. Many countries in the world have been making big financial investments in this area. Carboniferous shale in the eastern Qaidam Basin shows good exploration prospects, but limited research and exploration work for shale oil and gas resources has been undertaken. Geochemical analyses were performed on shale derived from the Upper Carboniferous Hurleg Formation in the eastern Qaidam Basin, Qinghai Province, and secondary electron imaging capability of a Field Emission scanning electron microscope(FE-SEM) was used to characterize the microstructure of the shale. The reservoir and exploitation potential of the studied shale was assessed by comparison with research results obtained from the Barnett Formation shale in Fort Worth Basin, North America and the Basin shale of Sichuan province. The results indicate that the eastern Qaidam Basin Carboniferous shale is high-quality source rock. There are four major microstructural types in the study area: matrix intergranular pores, dissolution pores, intergranular pores, and micro-fractures. The size of the micropores varies from 6–633 nm, the majority of which is between 39–200 nm, with a relatively small number of micro-scale pores ranging from 0.13–1 μm. The pore characteristics of the studied shales are similar to the North American and Sichuanese shales, indicating that they have good reservoir potential. No micropores are present in the organic matter, which is induced by its composition; instead we found an important lamellar structure in the organic matter. These micropores and microfractures are abundant, and are connected to natural visible cracks that form the network pore system, which controls the storage and migration of shale gas. This connectivity is favorable for shale gas exploitation, providing great scientific potential and practical value.     

江西庐山牧马场剖面泥砾堆积物的成因分析及年代测定

庐山第四纪泥砾堆积物成因争论是庐山第四纪冰川争论的焦点之一。对新发现的庐山牧马场泥砾剖面进行了石英砂电镜扫描(SEM)和成因分析,并初步进行了电子自旋共振(ESR)年代测定。石英砂电镜扫描表明该剖面泥砾堆积物为冰川和流水共同作用形成,并在后期湿热化影响下导致部分化学特征明显;ESR测年数据表明该剖面形成于中更新世晚期(225.5±20)—(242.6±24)ka BP,与推测的时代(庐山冰期)基本一致。根据测试结果,作者认为庐山牧马场剖面具有第四纪冰川作用的痕迹,但其时代和规模尚有待探讨改进。     

胁迫时间和胁迫浓度对超积累植物印度芥菜细胞中镉分布的影响

超积累植物对重金属的区隔化作用能有效降低细胞质内金属离子的浓度,是对重金属重要的解毒机制之一,而细胞内各组织的区隔化作用大小并未取得一致性结论。本文研究了胁迫浓度和胁迫时间对超积累植物印度芥菜(Brassica juncea)细胞及亚细胞中镉分布的影响。印度芥菜幼苗分别用0.5、1.0、2.0、3.0、5.0mg/L镉胁迫1、5、7、10、14天后收获,采用电感耦合等离子体质谱法测定印度芥菜根系和叶片亚细胞中镉的含量。结果表明:镉在细胞壁中的比例占50%~64%,细胞液占22%~38%,细胞器占7%~17%,镉在细胞壁中所占比例显著高于细胞液和细胞器,证明细胞壁区隔化在镉的解毒机制中具有重要的作用。随着胁迫时间和胁迫浓度的增加,根系和叶片中亚细胞各组织中镉含量持续增加,超过7天,镉含量显著升高,说明镉对植物的危害是一个缓慢过程。印度芥菜对镉胁迫浓度的最大耐受量为1.0 mg/L,超过此浓度,植物细胞的破坏症状加重;细胞超微结构研究也表明,镉胁迫浓度超过1.0 mg/L后,细胞结构发生了不同程度的损坏,出现质壁分离、液泡增大甚至空泡化、质膜粗糙等现象,继而影响到细胞的正常功能。因此,在考察重金属对植物的危害时,要充分考虑时间和浓度梯度两个参数的协同作用。     

The geostatistics of the metal concentrations in sediments from the eastern Brazilian continental shelf in areas of gas and oil production

Geostatistical techniques were used to evaluate the differences in the geochemistry of metals in the marine sediments along the Eastern Brazilian continental margin along the states of Ceará and Rio Grande do Norte (Northeastern sector) and Espírito Santo (Southeastern sector). The concentrations of Al, Fe, Mn, Ba, Cd, Cu, Cr, Ni, Pb, V, Hg, and Zn were obtained from acid digestion and quantified using flame atomic absorption spectrometry (AAS), inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma atomic emission spectrometry (ICP-AES). The metals showed a similar order of concentration: Al > Fe > Ba > Mn > V > Ni > Pb > Cr > Zn > Cu, in both the Ceará; and Rio Grande do Norte shelf regions but different in the Espírito Santo shelf (Fe > Al > Mn > Ba > Zn > V > Cr > Ni > Pb > Cu. The concentrations of Hg and Cd were below the detection limit in all areas. A multivariate analysis revealed that the metals of siliciclastic origin on the continental shelf of Ceará are carried by Al. In addition, a large portion of metal deposits is connected to the iron and manganese oxides on the continental margin of Rio Grande do Norte. The metals from the continental supply on the coast of Espírito Santo (Cu, Ni, Ba, and Mn) are associated with Al; whereas Cr, Pb, V, and Zn are associated with iron in this southern area. Geochemical evaluations are needed to distinguish the origin and mineralogical differences of marine sediments within the regions. Scanning electron microscopy/energy dispersive spectrometry (SEM/EDS) applied to the sediments from the coast of Ceará showed the morphological diversity of sediment grains: biological fragments, multifaceted particles, aggregates, and crystals occurred in the three regions analyzed. Among these grains, calcite, Mg-calcite, and aragonite were predominant in the northeastern sector, whereas silicates and other minerals were predominant the southeastern sector. Mg, K, Ti, and Zr as well as the lanthanides La and Ce were identified using SEM/EDS and added to the geochemical analysis of the data.     

大平山铜矿毒砂单矿物扫描电镜分析

大平山铜矿床位于南京市江宁区横溪镇西侧,矿石中有用组分除铜以外,还伴生有As、Zn、Ag、Au、Co和Ni等元素,其中As元素质量分数较高,局部达0.2%～0.9%。通过显微观察和扫描电镜能谱分析,发现大平山铜矿矿石中As元素主要以硫化物形式,呈毒砂独立矿物以自形—半自形粒状、他形粒状赋存于矿石中。赋存方式主要为：以独立矿物呈稀疏浸染状分布于矿石中,局部呈条带状和中等稠密浸染状分布于矿石中;以交代方式与黄铁矿和黄铜矿共生于矿石中,但毒砂形成晚于黄铁矿和黄铜矿。     

In situ characterization of grain‐scale fluvial morphology using Terrestrial Laser Scanning

The grain‐scale morphology of fluvial sediments is an important control on the character and dynamics of river systems; however current understanding of its role is limited by the difficulties of robustly quantifying field surface morphology. Terrestrial Laser Scanning (TLS) offers a new methodology for the rapid acquisition of high‐resolution and high‐precision surface elevation data from in situ sediments. To date, most environmental and fluvial applications of TLS have focused on large‐scale systems, capturing macroscale morphologies. Application of this new technology at scales necessary to characterize the complexity of grain‐scale fluvial sediments therefore requires a robust assessment of the quality and sources of errors in close‐range TLS data. This paper describes both laboratory and field experiments designed to evaluate close‐range TLS for sedimentological applications and to develop protocols for data acquisition. In the former, controlled experiments comprising high‐resolution scans of white, grey and black planes and a sphere were used to quantify the magnitude and source of three‐dimensional (3D) point errors resulting from a combination of surface geometry, reflectivity effects and inherent instrument precision. Subsequently, a methodology for the collection and processing of grain‐scale TLS data is described through an application to a coarse grained gravel system, the River Feshie (D₅₀ 32 to 63 mm). This stepwise strategy incorporates averaging repeat scans and filtering scan artefact and non‐surface points using local 3D search algorithms. The sensitivity of the results to the filter parameter values are assessed by careful internal validation of Digital Terrain Models (DTMs) created from the resulting point cloud data. The transferability of this methodology is assessed through application to a second river, Bury Green Brook, dominated by finer gravel (D₅₀ 18 to 33 mm). The factor limiting the resolution of DTMs created from this second dataset was found to be the relative sizes of the laser footprint and smallest grains. Copyright © 2009 John Wiley & Sons, Ltd.     

郯庐断裂带南段加卸载响应比变化特征分析

本文对郯庐断裂带南段开展了分段加卸载响应比变化研究,总结了区域内显著地震前加卸载响应比时序曲线的变化特征。研究表明,加卸载响应比表征了地下介质的损伤程度,具有明确的物理意义,在实际应用中取得了较好的效果。在中小地震较为丰富的研究区域,加卸载响应比在显著地震前会出现短临高值异常; 而在中小地震活动水平不高的区域,加卸载响应比在震前更多地表现为长期的背景高值异常。     

CT扫描技术在微观驱替实验及剩余油分析中的应用

CT扫描技术不仅可以重建不同驱替液在不同驱替时刻的微观剩余油分布图像,而且通过X射线衰减系数换算成CT值,还可以计算岩心的孔隙度和含油饱和度参数,从而对实验岩心的非均质性和每一驱替过程不同驱替时刻的微观剩余油进行定量分析。分析认为实验岩心在不同驱替阶段微观剩余油类型之间存在量的转化。      

From experimental plots to experimental landscapes: topography,erosion and deposition in sub‐humid badlands from Structure‐from‐Motion photogrammetry

In the last decade advances in surveying technology have opened up the possibility of representing topography and monitoring surface changes over experimental plots (<10 m²) in high resolution (~10³ points m^‐1). Yet the representativeness of these small plots is limited. With ‘Structure‐from‐Motion’ (SfM) and ‘Multi‐View Stereo’ (MVS) techniques now becoming part of the geomorphologist's toolkit, there is potential to expand further the scale at which we characterise topography and monitor geomorphic change morphometrically. Moving beyond previous plot‐scale work using Terrestrial Laser Scanning (TLS) surveys, this paper validates robustly a number of SfM‐MVS surveys against total station and extensive TLS data at three nested scales: plots (<30 m²) within a small catchment (4710 m²) within an eroding marl badland landscape (~1 km²). SfM surveys from a number of platforms are evaluated based on: (i) topography; (ii) sub‐grid roughness; and (iii) change‐detection capabilities at an annual scale. Oblique ground‐based images can provide a high‐quality surface equivalent to TLS at the plot scale, but become unreliable over larger areas of complex terrain. Degradation of surface quality with range is observed clearly for SfM models derived from aerial imagery. Recently modelled ‘doming’ effects from the use of vertical imagery are proven empirically as a piloted gyrocopter survey at 50m altitude with convergent off‐nadir imagery provided higher quality data than an Unmanned Aerial Vehicle (UAV) flying at the same height and collecting vertical imagery. For soil erosion monitoring, SfM can provide data comparable with TLS only from small survey ranges (~5 m) and is best limited to survey ranges ~10–20 m. Synthesis of these results with existing validation studies shows a clear degradation of root‐mean squared error (RMSE) with survey range, with a median ratio between RMSE and survey range of 1:639, and highlights the effect of the validation method (e.g. point‐cloud or raster‐based) on the estimated quality. Copyright © 2015 John Wiley & Sons, Ltd.     

Atmospheric inorganic aerosol of a non-industrial city in the centre of an industrial region of the North of Spain,and its possible influence on the climate on a regional scale

Mineral particles could have influenced on the climate of Oviedo, a non-industrial city situated in the centre of an industrial zone of the North of Spain, increasing the temperature and the precipitations, in spite of the fact that “greenhouse gases” concentrations have diminished in this city in recent years. The directive (1999/30/EC) of the European Commission began to be applied in Oviedo in the year 2003. In agreement with this norm, our first aim was the identification of the inorganic particulate matter of the PM10 and PM2.5 fractions sampled in this city. X-ray diffraction and scanning electron microscopy coupled with X-ray dispersive energy spectrometry were used. The percentages of the different mineral phases of the PM were obtained by a Rietveld refinement of powder X-ray diffraction data. The compositions of the PM10 and PM2.5 fractions of this city are similar. Sulphates are the most abundant particles in the both fractions. Most sulphates, nitrates and sal-ammoniac would have formed by reaction between solid, liquid and/or gas particles and they could be associated with the power stations near to the city and traffic. Wüstite and haematites come from the iron and steel industries of Gijón and Avilés. The main natural sources of halite and carbonates and silicates are sea spray and soil resuspension by the wind, respectively.