Hydrogeological conditions for the forming and quality of mineral waters in Serbia

In the past researches conducted on the territory of Serbia, 5 regional geotectonic units have been distinguished with registered occurrences of 230 mineral springs. Recent analyses of the bottled mineral waters quality have not included systematic examinations of micro-components present in these waters. Based on the analyses of the bottled mineral waters (EuroGeoSurveys Geochemistry Expert Group), it has been observed that the water quality is greatly influenced by the chemical composition of igneous intrusions, regardless of the fact that the analyzed waters have been taken from different aquifers (Neogene sediments, limestone, flysch, schist).     

新疆谢米斯台地区中段火山岩岩石学、地球化学及其含矿性研究

新疆西准噶尔谢米斯台山地区位于西伯利亚板块与准噶尔板块之间的古生代萨吾尔—阿尔曼太复合岛弧内。该地区的火山岩以安山岩—英安岩—流纹岩组合为主,有少量的粗面岩产出。在地球化学特征上,火山岩SiO_2含量变化范围较大(53.91～75.71 wt%),K_2O/Na_2O比值为0.45～1.89,Al_2O_3含量较高(10.81～17.94 wt%),铁含量低(1.20～7.26 wt%),TiO_2含量低(0.19～1.78 wt%),大离子亲石元素及轻稀土元素富集,微量元素具岛弧火山岩特征;地球化学的特征以及在该地区发现的大量铜矿化,预示着该地区将是一个有利的成矿远景区。     

The relationship between seismic velocity and radioactive heat production in crustal rocks: An exponential law

In crystalline rocks seismic velocityV _p and densityp increase, whereas radioactive heat productionA decreases from acidic to basic compositions. From the velocity-density systematics for crustal rocks at different pressures an empiricalA(V _p) relationship has been derived for the range 5.0–8.0 km/sec which follows the exponential law:A(V _p )=a exp (-bV _p ), where the numerical factorsa andb depend onin situ pressure. A graph is given by means of which the heat production distributionA(z) can be obtained for any givenV _p (z) structure.Contribution No. 207, Institute of Geophysics, ETH Zurich.     

硅质大火成岩省的形成机制及其与资源环境的关系

硅质大火成岩省是以流纹质熔结凝灰岩为主体的( 80vol.%),覆盖面积大于105km2、体积大于2.5×105km3的巨型岩浆岩建造,多呈条带状产出在大陆边缘,可能与大陆裂解和相邻镁铁质大火成岩省密切相关;其形成时间相对镁铁质大火成岩省较长,可达～40Myr。岩石中有黑云母、角闪石等含水斑晶,多为钙碱性系列,具有从I型向A型花岗质岩石过渡的地球化学特征。本文在前人工作的基础上,整理了五个主要硅质大火成岩省的样品数据,综合研究认为其形成是玄武质岩浆底侵(或地幔柱上升),使得前期由于俯冲形成的富水下地壳重熔后经历不同程度分离结晶的结果。硅质大火成岩省的形成暗示深部有"隐伏的镁铁质大火成岩省",因为上部硅质岩浆的阻碍和富水地壳不易形成岩浆运移通道所以未能喷出,但这些镁铁质岩浆向上输送了大量的SO_2气体。大规模的硅质岩浆活动一方面能够将这些SO_2气溶胶送入平流层吸收太阳辐射,另一方面能够使海洋富铁后通过光合作用吸收大气中的CO_2,从而导致全球降温。此外,硅质大火成岩省还是一个大型的热液成矿系统,形成大量的低硫化型贵金属浅成低温热液矿床,具有重要的经济意义。     

Volcanic features of the North Rockall Trough: application of visualisation techniques on 3D seismic reflection data

Understanding the volcanic processes operating during continental break-up is hampered by the subsequent burial of the majority of the volcanic pile beneath thick sedimentary sequences currently located in bathymetrically deep offshore regions. Although portions of these volcanic systems are currently exposed on land, a full understanding of the volcanic structure, the eruptive styles and their evolution is not possible as these localities have been partially eroded. Furthermore, as the onshore exposure represents a volumetrically minor part of the entire system, the documented eruptive styles may not be representative. The increasing availability of 3D seismic reflection data has the potential to significantly enhance our understanding of break-up related volcanism, as it allows direct access to detailed information from the buried volcanic succession. However, conventional seismic interpretation methodologies cannot determine lava flow morphologies, and as a result, eruptive styles and their evolution are still largely based on extrapolation from the accessible onshore outcrop data. New 3D seismic volume visualisation techniques allow the buried basalt morphologies to be examined for the first time in a manner similar to outcrop, aerial photographic or satellite-based observations. Applying this new approach for 3D seismic data to the North Rockall Trough, U.K. Atlantic margin, demonstrates that a range of volcanic features indicative of eruptive style can be determined. The data reveal a complex terrain containing lava flows originating from discrete volcanic centres, contemporaneous normal faults, linear fissures a few kilometres long, radial fissures and inflation ridges. Lava flow morphologies that are indicative of tube-fed inflated sheetflows, intracanyon flows and elongate subaerial flows that enter water downslope to produce a large hyaloclastite delta are observed.Electronic Supplementary Material Supplementary material is available in the online version of this article at .Editorial responsibility: J. Stix     

Contact zone permeability at intrusion boundaries: new results from hydraulic testing and geophysical logging in the Newark Rift Basin, New York, USA

Hydraulic tests and geophysical logging performed in the Palisades sill and the underlying sedimentary rocks in the NE part of the Newark Rift Basin, New York, USA, confirm that the particular transmissive zones are localized within the dolerite-sedimentary rock contact zone and within a narrow interval below this contact zone that is characterized by the occurrence of small layers of chilled dolerite. Transmissivity values determined from fluid injection, aquifer testing, and flowmeter measurements generally fall in the range of 8.1E-08 to 9.95E-06 m²/s and correspond to various scales of investigation. The analysis of acoustic and optical BHTV images reveals two primary fracture sets within the dolerite and the sedimentary rocks—subhorizontal fractures, intersected by subvertical ones. Despite being highly fractured either with subhorizontal, subvertical or both fracture populations, the dolerite above and the sedimentary rocks below the contact zone and the zone with the layers of chilled dolerite are significantly less conductive. The distribution of the particular conductive intervals is not a function of the two dominant fracture populations or their density but rather of the intrusion path of the sill. The intrusion caused thermal fracturing and cracking of both formations, resulting in higher permeability along the contact zone.     

Liquid immiscibility and its role at the magmatic–hydrothermal transition: a summary of experimental studies

Several types of fluid immiscibility may affect the evolution of volatile-rich magmatic systems at the magmatic–hydrothermal transition. The topology of silicate–salt–H₂O systems implies that three-fluid immiscibility (silicate melt+hydrosaline melt+vapour) should be stable in a broad range of compositions and P–T conditions. The most important factor controlling the immiscibility appears to be the Coulombic properties (electric charges Z and ionic radii r) of the main network-modifying cations and the capacity for immiscibility appears to decrease in the following sequence: Mg>Ca>Sr>Ba>Li>Na>K. Liquid immiscibility is enhanced in peralkaline compositions and in the presence of nonsilicate anions such as F⁻, Cl⁻, CO₃²⁻ and BO₃³⁻. In volatile-rich magmatic systems, the H₂O is likely to react with the chloride, fluoride, borate and carbonate species and the chemical effects of high-temperature hydrolysis may be greatly enhanced by phase separation in systems with multiple immiscible fluid phases. Natural granitic magmas can thus exsolve a range of chemically and physically diverse hydrosaline liquids and the role of these fluid phases is likely to be especially significant in pegmatites and Li–F rare-metal granites.     

基于GIS的石油勘探图形库系统分析和设计

首先讨论目前我国石油勘探工程图形图像的标准化研究，提出相应的图形图像分类、分层标准和编码规范；然后基于信息流分析提出多层的C／S系统体系结构；利用GIS技术对系统体系结构进行功能分配以实现系统的制图功能、济览查询功能、图件输入输出等管理和操作功能、异构图形库的转换功能、图形分析应用功能和图形发布功能。最后讨论了系统研发中的两个难点，一是石油勘探工程中图形图像的标准化研究程度；二是对各油田前期投入开发的各种异构图形库系统的兼容和转换处理。