Engineering Geological Map of the Sakha （Yakutia） Republic     

Vladimir B. Spektor  Yaroslav I. Torgovkin  Alena A. Shestakov  Valentin V. Spektor  Lena D. Ivanov  Boris M. Kozmin 《寒旱区科学》2014,6(5):0484-0493

The Engineering Geological Map of the Sakha（Yakutia） Republic covers about 3 million kilometers which is one-fifth of the territory of Russia.The map displays ground and geocryological conditions and active faults.Seismic intensity,schemes of zoning by factors of engineering geological conditions,and the general scheme of engineering geological zoning of the Sakha（Yakutia） Republic or the SR（Y）,are shown on the inset maps.The map is required to provide information for planning,construction and exploitation of engineering structures in the SR（Y）.A distinguishing feature of the map is the indication of almost blanket distribution of the frozen ground class.Types of the frozen ground class are separated by lithology,while ground varieties are separated by temperature.Fresh and ultra-fresh suprapermafrost water is predominant within the territory.The compiled map indicates parts of the Arctic-Asian and Baikalo-Stanovoi planetary seismic belts that make engineering geological conditions more complicated.  相似文献   

An unsustainable state: Contrasting food practices and state policies in the Czech Republic   总被引：1，自引：0，他引：1  

Petr Jehli?ka 《Geoforum》2011,42(3):362-372

This paper brings together consideration of food policies and practices and of post-socialist transition to raise neglected questions about means of nurturing more sustainable food systems in the developed world. The last three decades have been marked by the growing salience of food as a political and scholarly concern. While market-based alternative food systems have been heralded for their potential to promote environmental sustainability, the benefits of non-market practices such as household food self-provisioning and barter have been assumed rather than being the focus of research. In the western context, both types of food consumption have positive connotations. Although food self-provisioning in European post-socialist societies is a more wide-spread practice than in western societies, it has been on the periphery of research. The existing literature has conceptualised them as ‘coping strategies’ or as a legacy of irregular supply of goods in the state socialist era. Drawing on empirical research in the Czech Republic, we are proposing a novel approach to the phenomenon of household food production in post-socialist societies as a practice compliant with principles of sustainability. First, we highlight the large extent and social inclusivity of food self-provisioning in Czech society to demonstrate how post-socialist societies are a repository of a rich set of sustainability-promoting consumption practices in relation to food systems. Second, we show that international and domestic policy actors in these societies have ignored these alternative, socially inclusive and environmentally effective practices in favour of far less effective market-based sustainability oriented food policy initiatives. The paper promotes a more integrated view of non-market and market approaches in the pursuit of more sustainable food systems.  相似文献   

在时空框架中理解中国大学人文地理教学特色及其成因——以1912—1949年中国主要大学地理系为例     

周尚意  江道敏 《地理研究》2023,42(2):580-596

采用历史唯物主义史观,建立一个时空框架,分析民国时期中国大学人文地理教学特色及其成因。本文主要关注1912—1949年间,国立北平（北京）师范大学、国立中央大学、国立清华大学、国立中山大学的地理系的人文地理学教学特色。研究史料来自大学的教学档案、人物回忆文章、政府文件、中国学者编撰和翻译的教材和教参,同时参考了相关研究文献。借助时空框架,基于史料对比,得出结论：(1)只有在历史的时间脉络下,才能理解民国时期军事地理、国防地理和政治地理课程设置的必然性;(2)只有在世界格局的空间框架下,才能理解民国时期的“国耻地理”教育内容,以及“中体西用”主张的失败;(3)只有将时空框架进一步细化,才能深入理解民国时期大学人文地理教学中不同教师的能动性,如学术思想、教学风格、政治主张、教材编写和选用等。综上所述,只有站在开放的时空框架中,才能更为清醒地定位当前中国大学人文地理学教学。  相似文献   

面向地图集编制的地图可视化设计——以《中华人民共和国人口与环境变迁地图集》为例     

韩嘉福 《地球信息科学学报》2010,12(6):777-783

地图集的地图可视化设计与单幅地图不同,需要以地图集的总体设计思想为依据,在地图设计与表达时反映指标体系的科学完整性,体现地图集的总体协调性。本文以《中华人民共和国人口与环境变迁地图集》为例,详细介绍了以多指标、长时间序列为特征的人口与环境变迁地图的可视化设计与表达方法,包括:系列地图、结构及其数量变化、构成比例变化、数量变化及其对比关系、累积数量变化、多指标数量累积及其对比、相对某一时间基点变化、单指标多年统计特征的变化、单指标两个时期数据的对比等。该方法以对相关指标现状的表达为基础,重点强调制图对象变迁特征,表达指标体系之间的联系和区别。相关地图可视化设计方法可广泛应用于其他类似专题地图的设计过程中。  相似文献   

Isotopic composition of salt efflorescence from the sandstone castellated rocks of the Bohemian Cretaceous Basin (Czech Republic)   总被引：1，自引：0，他引：1  

Jana Schweigstillová  Richard P?ikryl  Miroslava Novotná 《Environmental Geology》2009,58(1):217-225

The origin of sulphates in sulphate-rich efflorescences on quartz sandstones with a clay matrix, exposed in rural areas of the Czech Republic is interpreted, based upon an isotopic study of S and O. Sulphates such as gypsum and/or alums exhibit δ³⁴S ranging from +1.3 to +6.1‰ and δ¹⁸O from +5.3 to +8.8‰. The low variability of S and O isotopes indicates a common source of the sulphur and a similar mode of sulphate formation. Atmospheric sulphates with a similar isotopic signature occur in the area, due to the combustion of sulphurous coal in power plants, located a few tens of kilometres from the sampling points. The sulphates crystallize from supersaturated pore waters that represent atmospheric precipitation, rich in sulphates, having percolated through the porous sandstone system. The previously proposed model of efflorescence growth (that it is due to the oxidation of pyrite) can be excluded, due to both the rare occurrence of pyrite and also to its different isotopic signature (δ³⁴S about −22‰). Although gypsum prevails in the central and eastern part of the studied area, the north and north-west of the Bohemian Cretaceous Basin (the most polluted region) exhibits a significant presence of alums (NH₄ ⁺ or K⁺−NH₄ ⁺-rich). Formation of alums can be explained by the partial dissolution of clay minerals or feldspars present in the sandstone matrix. Release of alumina from these phases is facilitated by the low pH of the precipitation (pH 4–4.5) and also locally by organic acids, traces of which were found in the studied efflorescences by the use of infrared spectroscopy.  相似文献   

Inversion of two-phase extensional basin systems during subduction of the Paleo-Pacific Plate in the SW Korean Peninsula:Implication for the Mesozoic “Laramide-style” orogeny along East Asian continental margin     

Seung-Ik Park  Jungrae Noh  Hee Jun Cheong  Sanghoon Kwon  Yungoo Song  Sung Won Kim  M.Santosh 《地学前缘(英文版)》2019,10(3):909-925

During subduction, continental margins experience shortening along with inversion of extensional sedimentary basins. Here we explore a tectonic scenario for the inversion of two-phase extensional basin systems, where the Early-Middle Jurassic intra-arc volcano-sedimentary Oseosan Volcanic Complex was developed on top of the Late Triassic-Early Jurassic post-collisional sequences, namely the Chungnam Basin. The basin shortening was accommodated mostly by contractional faults and related folds. In the basement, regional high-angle reverse faults as well as low-angle thrusts accommodate the overall shortening, and are compatible with those preserved in the cover. This suggests that their spatial and temporal development is strongly dependent on the initial basin geometry and inherited structures.Changes in transport direction observed along the basement-sedimentary cover interface is a characteristic structural feature, reflecting sequential kinematic evolution during basin inversion. Propagation of basement faults also enhanced shortening of the overlying sedimentary cover sequences. We constrain timing of the Late Jurassic-Early Cretaceous(ca. 158-110 Ma) inversion from altered K-feldspar 40 Ar/39 Ar ages in stacked thrust sheets and K-Ar illite ages of fault gouges, along with previously reported geochronological data from the area. This "non-magmatic phase" of the Daebo Orogeny is contemporaneous with the timing of magmatic quiescence across the Korean Peninsula. We propose the role of flat/low-angle subduction of the Paleo-Pacific Plate for the development of the "Laramide-style" basement-involved orogenic event along East Asian continental margin.  相似文献   

Zircon dating of North Bohemian granulites, Czech Republic: further evidence for the Lower Carboniferous high-pressure event in the Bohemian Massif     

J. Kotková  A. Kröner  W. Todt  J. Fiala 《International Journal of Earth Sciences》1996,85(1):154-161

U-Pb zircon and rutile multigrain ages and ²⁰⁷Pb/²⁰⁶Pb zircon evaporation ages are reported from high-pressure felsic and metapelitic granulites from northern Bohemia, Czech Republic. The granulites, in contrast to those from other occurrences in the Bohemian Massif, do not show evidence of successive HT/MPLP overprints. Multigrain size fractions of nearly spherical, multifaceted, metamorphic zircons from three samples are slightly discordant and yield a U-Pb Concordia intercept age of 348 ± 10 Ma, whereas single zircon evaporation of two samples resulted in ²⁰⁷Pb/²⁰⁶Pb ages of 339 ± 1.5 and 339 ± 1.4 Ma, respectively. A rutile fraction from one sample has a U-Pb Concordia intercept age of 346 ± 14 Ma. All ages are identical, within error, and a mean age of 342 ± 5 Ma was adopted to reflect the peak of HP metamorphism. Because rutile has a lower closing temperature for the U-Pb isotopic system than zircon, the results and the P-T data imply rapid uplift and cooling after peak metamorphism. The above age is identical to ages for high-grade metamorphism reported from the southern Bohemian Massif and the Granulite Massif in Saxony. It can be speculated that all these granulites were part of the same lower crustal unit in early Carboniferous, being separated later due to crustal stacking and subsequent late Variscan orogenic collapse.  相似文献   

Magnetostratigraphy of Cave Sediments: Application and Limits     

Bosák  Pavel  Pruner  Petr  Kadlec  Jaroslav 《Studia Geophysica et Geodaetica》2003,47(2):301-330

The application of the magnetostratigraphy for dating of clastic and chemogenic cave sediments has been limited by the complex conditions underground and the lack of age constraints on these deposits for correlation with geomagnetic polarity timescale (GPTS). Without age constraints any correlation of obtained results cannot be explicit. Additionally, the dynamic character of cave infilling, exhumation and fossilisation expressed by unconformities within preserved sedimentary profiles can hide a substantial part of the geological time. The detailed internal division of deposits (breaks in deposition and related processes) and scarcity of fossils make the correlation of obtained magnetostratigraphic log with geomagnetic polarity timescales sometimes problematic. The analytical results confirmed that the complete step/field procedure offered by demagnetisation methods must be applied. The application of complete analysis only to pilot samples and shortened, selected field/step approach, to other samples did not offer sufficient data set for reliable interpretation.  相似文献   

Vulnerability of groundwater to acid deposition, Jizerské Mountains, northern Czech Republic: construction and reliability of a GIS-based vulnerability map     

Zbynek Hrkal 《Hydrogeology Journal》2001,9(4):348-357

The area of the Jizerské Mountains in the northern part of the Czech Republic is known to have suffered from heavy acid atmospheric deposition which has led to mass extinction of the forest cover in apical parts of the mountains and to degradation of groundwater quality. A methodology for construction of groundwater vulnerability maps, using a Geographical Information System (GIS), has been developed as a tool for protecting the groundwater resources. The maps were constructed by using four subsidiary layers, each of which reflects a particular parameter that governs acidification. The factors that determine vulnerability are: (1) elevation above sea level, (2) morphology of the terrain, (3) areal extent and type of vegetation cover, and (4) lithology of the aquifer. A step-wise analysis and application of the data in each of the layers was accomplished to compare changes in the quality of groundwaters, and to obtain the best weighting factors for the individual parameters. Changes in alkalinity of the groundwater during the last 30 years were used as a test criterion. The vulnerability map should be a valuable tool to identify and outline areas most vulnerable to acidification and also areas considered for reforestation. Electronic Publication  相似文献   

The Cenomanian and Turonian in NortheasternCentral Asia     

Z.N. Pojarkova 《Cretaceous Research》1984,5(1):1-14

Northeastern Central Asia during the Albian and Early Cenomanianwas one of the peripheral basins of the Central Asian region. The similarity of their freshwater molluscs makes it possible to correlate isolated series in these two regions. Subsequently, a pulsating transgression of the Tadzhik Sea invaded northeastern Central Asia which became a part of the Central Asian Province of the Tethys. The complicated palaeogeography means that there are many different local biostratigraphic successions. The relations between these have been worked out from an integrated study of the biostratigraphy, palaeogeography, ecology and biogeography. Marked endemism amongst the molluscs, sometimes total, limits correlation with other regions of the Tethys; in particular, correlation of some of the local biozones (or “lones”) with western European zones is still uncertain.  相似文献