The role of karst in the genesis of sulfur deposits, Pre-Carpathian region, Ukraine

 Most of exogeneous epigenetic sulfur deposits are clearly associated with intensely karstified carbonate and sulfate rocks. This paper demonstrates, using the Pre-Carpathian region as an example, that karstification is one of the most important processes controlling the formation of sulfur deposits. This is determined by a coincidence of some major prerequisites of these two processes. In the Podol'sky and Bukovinsky regions the Miocene aquifer system is well drained by erosion valleys; the giant network caves known here in gypsum formed under past artesian conditions. In the region of sulfur deposits, associated with the same karstified gypsum strata, true artesian conditions still prevail. Hydrogeologic data show that abundant cavities detected in the vicinity of sulfur deposits can be interpreted as having the same origin as the fossil caves of the Podol'sky and Bukovinsky regions. The current widespread belief that the gypsum/anhydrite stratum in the region is aquifuge separating the Miocene aguifers is inadequate. This belief caused much controversy with regard to the genetic interpretations of sulfur deposits in the region. Caves formed by the upward water flow through the gypsum/anhydrite stratum govern the water exchange between the aquifers within the aquifer system. A new karst model for the formation of sulfur deposits is suggested. It agrees well with the hydrogeological features of the Miocene sequence and with biogeochemical mechanisms of sulfur origin in low-temperature diagenetic environments. Received: 16 February 1995 · Accepted: 4 June 1996     

地缘战略交汇区地理环境的介质属性及其地缘环境效应——以乌克兰为例

文章将理论建构与案例分析相结合,首先提出地缘介质概念,论证了地理环境的介质属性及其传导权力的效率差异,并阐明不同地缘介质的地缘功能,然后以乌克兰为案例,揭示地缘行为体挖掘并利用地理环境的介质属性进行权力施动的空间实践及其产生的地缘环境效应。结果表明：1）地处地缘战略交汇区的乌克兰,其地理环境的介质属性显著,这为地缘行为体在乌克兰进行权力施动提供了空间中介。2）乌克兰地理环境中各介质要素的地缘功能及其对地缘行为体权力传导的效率差异明显。地理位置和地形地貌具有地缘安全功能,自然资源的地缘经济功能强大,政党和民族的地缘政治功能较强,语言和宗教的地缘文化功能较为凸显。自然资源、政党、民族、宗教的介质属性较强,地理位置、地形地貌的介质属性在逐渐减弱。3）不同地缘行为体（利益集团）争相利用地理环境的介质属性进行权力的空间施动,使其在乌克兰的地缘位势此消彼长,致使乌克兰地缘环境激烈震荡。从地缘介质的视角探索权力施动的空间实践及其效应,对提升中国在周边的地缘影响力具有一定启示意义。     

Magmagenesis in a subduction-related post-collisional volcanic arc segment: the Ukrainian Carpathians

Calc-alkaline magmatism in the south-west Ukraine occurred between 13.8 and 9.1 Ma and formed an integral part of the Neogene subduction-related post-collisional Carpathian volcanic arc. Eruptions occurred contemporaneously in two parallel arcs (here termed Outer Arc and Inner Arc) in the Ukrainian part of the Carpathians. Outer Arc rocks, mainly andesites, are characterized by LILE enrichment (e.g. K and Pb), Nb depletion, low compatible trace element abundances, high ⁸⁷Sr/⁸⁶Sr, high δ¹⁸O and low ¹⁴³Nd/¹⁴⁴Nd isotopic ratios (0.7085–0.7095, 7.01–8.53, 0.51230–0.51245, respectively). Inner Arc rocks are mostly dacites and rhyolites with some basaltic and andesitic lavas. They also show low compatible element abundances but have lower ⁸⁷Sr/⁸⁶Sr, δ¹⁸O and higher ¹⁴³Nd/¹⁴⁴Nd ratios (0.7060–0.7085, 6.15–6.64, 0.5125–0.5126, respectively) than Outer Arc rocks. Both high-Nb and low-Nb lithologies are present in the Inner Arc. Based on the LILE enrichment (especially Pb), a higher fluid flux is suggested for the Outer Arc magmas compared with those of the Inner Arc.

Combined trace element and Sr–Nd–O isotopic modelling suggests that the factors which controlled the generation and evolution of magmas were complex. Compositional differences between the Inner and Outer Arcs were produced by introduction of variable proportions of slab-derived sediments and fluids into a heterogeneous mantle wedge, and by different extents of upper crustal contamination. Degrees of magmatic fractionation also differed between the two arcs. The most primitive magmas belong to the Inner Arc. Isotopic modelling shows that they can be produced by adding 3–8% subducted terrigenous flysch sediments to the local mantle wedge source. Up to 5% upper crustal contamination has been modelled for fractionated products of the Inner Arc. The geochemical features of Outer Arc rocks suggest that they were generated from mantle wedge melts similar to the Inner Arc primitive magmas, but were strongly affected by both source enrichment and upper crustal contamination. Assimilation of 10–20% bulk upper crust is required in the AFC modelling, assuming an Inner Arc parental magma. We suggest that magmagenesis is closely related to the complex geotectonic evolution of the Carpathian area. Several tectonic and kinematic factors are significant: (1) hydration of the asthenosphere during subduction and plate rollback directly related to collisional processes; (2) thermal disturbance caused by ascent of hot asthenospheric mantle during the back-arc opening of the Pannonian Basin; (3) clockwise translational movements of the Intracarpathian terranes, which facilitated eruption of the magmas.     

Hydrochemistry and solution rates in gypsum karst: case study from the Western Ukraine

The gypsum karst in the Western Ukraine spreads through a large territory covering more than 20,000 km² and is represented by a range of stages (evolutionary types), from deep-seated through subjacent to entrenched. Correspondingly, hydrogeological settings of karst development, circulation patterns and chemical characteristics of groundwaters differ substantially between the respective areas. Based on 1,800 analyses, this paper summarises hydrochemistry of the gypsum-hosting Miocene aquifer. The majority of sampling has been performed in conjunction with a study regime of gypsum solution rates by means of standard tablets. In this study, which included 53 tablet stations representing varying conditions of water-rock interaction, 644 weight-loss measurements were made over the period 1984–1992. The highest rates are characteristic of entrenched karst although active dissolution is localised along well-defined sinking streams with short underground courses, rare vertical percolation paths and the water table. Lower but still quite substantial rates are characteristic of subjacent and deep-seated (confined) karst. However, the overall dissolution removal is greater due to higher flow through the gypsum and the larger area of rock-solvent contact. The results are generalised in order to derive the approximate solution rates characterising major situations and to be suitable for modeling purposes.     

Catching air? Climate change policy in Russia, Ukraine and Kazakhstan

Russia, Ukraine and Kazakhstan have each participated actively in the UN Framework Convention on Climate Change (UNFCCC) Conferences of the Parties, and each is developing domestic rules and institutions to address UN obligations under the treaties. Russia and Ukraine are each Annex I/Annex B countries. Kazakhstan will become Annex I upon ratification of the Kyoto Protocol, but has not yet established itself as Annex B. Each state has evolved a distinct set of policies and priorities in the domestic and the international arena. Drawing largely on interviews in each country, this article presents brief histories of the evolution of climate policy, focusing on each state’s behavior in the international arena, the sources of domestic policy leadership, and the forces that led to change in each national approach. Current policies and practices are evaluated with an eye towards learning from the successes and failures in each state.     

地缘战略交汇区地缘环境演变评估模型构建及其应用——以乌克兰为例

地缘环境研究是当前国内政治地理研究的重点和热点,在概念、内涵、分析框架、空间分异、系统模拟等领域已取得较大进展,但对于地缘战略交汇区这一特殊地缘政治区域的地缘环境研究鲜有涉及。论文基于地缘战略的空间和权力属性,融合政治地理学的地缘环境、地缘位势,国际关系学的现实主义、自由主义和建构主义等理论,兼顾主体间性的哲学思想,构建了地缘战略交汇区地缘环境的评价模型,并以乌克兰为例进行了实证研究以验证模型的可靠性。结果表明：① 整体上,乌克兰的地缘环境演变态势趋好,但波动剧烈,未来其地缘环境还会出现间歇式动荡;② 受历史文化渊源、军事物质权力、战略投入意愿、经济相互依赖、地理空间距离等因素的影响,俄罗斯在乌克兰一直保持较大的地缘位势优势;③ 德国在乌克兰的地缘位势年际起伏较大,近年来主要受地缘经济因素的影响呈升高的趋势。法国和美国在乌克兰的地缘位势一直低于俄罗斯和德国,未来法国地缘位势会小幅升高,美国将会降低。论文提出的地缘战略交汇区地缘环境评价模型,经历史验证,评估结果与乌克兰国内政局演变态势拟合度较高,模型可靠性好,可为其他地缘战略交汇区的地缘环境评价提供参考。     

Phenolics occurrence in surface water of the Dniester river basin (West Ukraine): natural background and industrial pollution

Phenolics’ occurrence in surface water of the Dniester river basin (West Ukraine) with the definition of the natural background is studied. The main attention is given to the Upper Dniester basin and its tributary Stryj as the parts of the Sub-Carpathian oil- and gas province with the numerous objects of oil industry. The total amount of phenolics in water is studied. Phenolics’ concentrations from the first micrograms to the first milligrams per litre have been found in the surface water of the region. The natural background is defined as 0.012 mg l⁻¹ for the areas out of the industrial influence. The anthropogenic part of phenolics is caused mainly by oil industry. The oil-producing objects provide the main phenolics’ releases in the region, due to the low protection level of mechanical facilities as well as to breach of technological norms on the oil-extracting objects. A man-made pollution of the basin water has a regional character and the natural self-purification processes seem to be insufficient for its neutralisation on the plains in particular.     

乌克兰的几种新型解卡震击器

国家经济的高速增长推动了对矿产能源的需求,使钻探工作量逐年增加。面对深孔复杂地层,钻探过程中卡钻事故时常发生。震击器是解决卡钻事故的有效措施,但油气钻井中常用的震击器在小口径的地质钻探中使用效果并不理想,因此设计适用于地质岩心钻探的新型震击器十分必要。介绍了乌克兰针对比较严重的卡钻事故而设计的带弹簧加压式阀门的液动震击器,在保证其工作可靠性的同时,利用其高频的冲击功可以大大提高解卡工作的效率;针对比较容易发生卡钻地区而设计的随钻式机械震击器,可以在卡钻发生后第一时间进行解卡工作,避免了卡钻事故的进一步恶化,有效的节省了处理卡钻事故的时间。这种解决地质钻探中卡钻事故的有效技术工具,引进、推广应用前景广泛。