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Comparative analysis of taxonomic diversity dynamics of condontophorids from Boreal (Arctic regions of Russia) and Tethyan (Northwest Pacific) paleobasins showed that they had most favorable habitat environments in tropical seas. In the Boreal realm, condontophorids went through three stages of evolution comprising probably four substages and four phases, whereas three stages with six substages and twelve phases are distinguished in the Tethyan realm. The most important abiotic factors that controlled development of conodontophorids are paleotemperature of seawater and paleogeographic settings. Renewals in taxonomic composition conodontophorids and diversification of their assemblages have been confined to moments of paleotemperature and/or sea level rise. The comparative analysis of stages in evolution of conodontophorid and bivalve assemblages has been carried out. As is established, the peak taxonomic diversity of bivalves in Boreal seas was in the Late Triassic after the diversity minimum of the Early Triassic time. In contrast, conodontophorids were most diverse in the Olenekian Age.  相似文献   
3.
城市热岛效应监测方法研究进展   总被引:16,自引:0,他引:16  
城市热岛效应是一种由于城市建筑及人们活动导致的热量在城区空间范围内聚集的现象,是城市气候最明显的特征之一.由于城市热岛影响因素以及相互关系的复杂性,为了精确细致地描述其时空分布,人们采用了多种方法来研究城市热岛现象,主要归纳为:气象站法、定点观测法、运动样带法、遥感测定法以及模拟预测等.最后,认为各种测定方法都存在一定的缺陷,建议多种测定方法综合运用.  相似文献   
4.
Loess and loess-like deposits were much studied in the Soviet Union, and are currently under investigation in Russia and surrounding countries. There is a vast literature in Russian, which touches on all aspects of loess science and technology. In particular, the studies of the origin of collapsibility are almost totally in Russian, and of course studies on the various regions of Russia and the countries of the Former Soviet Union FSU appear in Russian. This review looks at the literature in Russian and attempts to pick out key contributors, major topics and works and to identify the critical regions and zones of investigation. Because so many regions of the FSU had people living on loess ground, there is a vast literature on engineering geology and ground engineering topics, and this tends to dominate all the literature on loess in Russian. Following Russian practice, the fine-grained deposits under consideration are divided into loess and loess-like deposits. Three main topics are recognised across the whole spectrum of loess research: formation and distribution of loess deposits; stratigraphy, cyclicity and palaeoclimatology; and engineering topics, in particular hydrocollapse and subsidence, and we concentrate on the engineering geology topics. An attempt is made, based on the map of Abelev and Abelev [Abelev, Yu.M., Abelev, M.Yu., 1968. Fundamentals of design and construction on collapsible macroporous soils, 2nd ed. Stroiizdat, Moscow, 431 pp. (in Russian)] of collapsing loess deposits, to define seven loess regions within the geographical limits of the old USSR. The seven regions are those where geotechnical problems might be expected.  相似文献   
5.
俄罗斯远东金属矿床形成条件的古地球动力学分析   总被引:1,自引:0,他引:1  
根据本区地质构造的新资料,提出了区域板块构造模型。研究了从俯冲到加利福尼亚型转换和由后者又到俯冲的古地球动力学环境更替的意义。这种更替发生在对本区最重要的中—新生代历史时期,对区域成矿带整体乃至一些金属矿床的形成具有重要影响。论证了一些地体性质,尤其是俯冲-增生杂岩对矿床形成的重要意义。  相似文献   
6.
TK-350 stereo-scenes of the Zonguldak testfield in the north-west of Turkey have been analysed. The imagery had a base-to-height ratio of 0·52 and covered an area of 200 km × 300 km, with each pixel representing 10 m on the ground. Control points digitised from 1:25 000 scale topographic maps were used in the test. A bundle orientation was executed using the University of Hanover program BLUH and PCI Geomatica OrthoEngine AE software packages. Tests revealed that TK-350 stereo-images can yield 3D geopositioning to an accuracy of about 10 m in planimetry and 17 m in height. A 40 m resolution digital elevation model (DEM) was generated by the PCI system and compared against a reference DEM, which was derived from digitised contour lines provided by 1:25 000 scale topographic maps. This comparison showed that accuracy depends mainly on the surface structure and the slope of the local terrain. Root mean square errors in height were found to be about 27 and 39 m outside and inside forested areas, respectively. The matched DEM demonstrated a systematic shift against the reference DEM visible as an asymmetric shift in the frequency distribution. This is perhaps caused by the presence of vegetation and buildings.  相似文献   
7.
Socalledfreeeconomicregionisaspecialregionwithoutjurisdictionofcustoms,delimitedbyonecountry.Inthisregionvariouspreferentialpoliciesofreducingorremittingtaxationareimplemented.Itcanprovidemanyconvenientconditionsforfreeflowofinternationalcommodity…  相似文献   
8.
The work is aimed at litho-, bio- and magnetostratigraphic subdivision of the Middle-Upper Jurassic sedimentary succession in the northeast of the Ul’yanovsk-Saratov depression (the East Russian plate). Problems of regional and interregional correlation of distinguished subdivisions are considered. As is shown, the ammonite biostratigraphy is most effective method for solving problems of chronostratigraphy.  相似文献   
9.
This paper is a brief explanation of the diagrams of the Cretaceous transgressions and regressions on the Russian Platform, in the Crimea (Figures 1–3) and some regions of central Asia—the western flanks of the Tien Shan mountains, the Fergana basin, the Zeravshan-Gissar and Alaj mountains, and the Northern Pamirs (Figures 5–7).Internationally recognized stages are employed. They are interpreted by Sasonova (1967) for the Lower Cretaceous (K1) of the Russian Platform, by Naidin (1977) for the Upper Cretaceous (K2) of the Platform and the Crimea, by Djalilov (1971) and Pojarkova (1976) for the Upper Cretaceous of central Asia. General data on the stratigraphy of the Cretaceous of central Asia may be found in Anon 1977.  相似文献   
10.
New pollen and radiocarbon data from an 8.6-m coastal section, Cape Shpindler (69°43′N; 62°48′E), Yugorski Peninsula, document the latest Pleistocene and Holocene environmental history of this low Arctic region. Twelve AMS 14C dates indicate that the deposits accumulated since about 13,000 until 2000 radiocarbon years BP. A thermokarst lake formed ca. 13,000–12,800 years BP, when scarce arctic tundra vegetation dominated the area. By 12,500 years BP, a shallow lake existed at the site, and Arctic tundra with Poaceae, Cyperaceae, Salix, Saxifraga, and Artemisia dominated nearby vegetation. Climate was colder than today. Betula nana became dominant during the Early Preboreal period about 9500 years BP, responding to a warm event, which was one of the warmest during the Holocene. Decline in B. nana and Salix after 9500 years BP reflects a brief event of Preboreal cooling. A subsequent increase in Betula and Alnus fruticosa pollen percentages reflects amelioration of environmental conditions at the end of Preboreal period (ca. 9300 years BP). A decline in arboreal taxa later, with a dramatic increase in herb taxa, reflects a short cold event at about 9200 years BP. The pollen data reflect a northward movement of tree birch, peaking at the middle Boreal period, around 8500 years BP. Open Betula forest existed on the Kara Sea coast of the Yugorski Peninsula during the Atlantic period (8000–4500 years BP), indicating that climate was significantly warmer than today. Deteriorating climate around the Atlantic–Subboreal boundary (ca. 4500 years BP) is recorded by a decline in Betula percentages. Sedimentation slowed at the site, and processes of denudation and/or soil formation started at the beginning of the Subatlantic period, when vegetation cover on Yugorski Peninsula shifted to near-modern assemblages.  相似文献   
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