共查询到20条相似文献，搜索用时 78 毫秒
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《中国勘察设计》2014,(2)
正苏州市市政工程设计院有限责任公司成立于1983年,从事工程设计、规划、咨询、勘察等服务,是拥有市政(给水、排水、道路、桥梁、城市隧道、燃气、环境工程)、水利、公路、轨道交通、地下空间开发、规划、建筑、城市景观、照明、雕塑、咨询、岩土、测量、勘察等专业的大型综合类甲级设计企业。下设"市政交通设计院、建筑规划设计院、景观园林设计院、勘察及岩土工程设计院"四大专业设计院,并在全国各地设立众多分支机构开展勘察设计业务。该公司专注于城市建设的设计咨询服务;不断追求专业素养、文化内涵和服务品质有机融合,公司业务涵盖众多专业领域,拥有先进、齐全的技术装备和大量高素质专业技术人才,拥有较强的技术优势和骄人业绩。近几年来,该公司抓住机遇,不断开拓,完成了大量高水准的市政工程、公路交通工程、建筑工程、景观工程勘察设计及咨询任务。 相似文献
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本刊讯记者王艺静报道近日,中国勘察设计协会公布了勘察设计行业从事工程项目管理和工程总承包企业完成合同额2014年排序名单。在公布的4项排名中,中铁第四勘察设计院集团有限公司、中铁第一勘察设计院集团有限公司等企业入选工程项目管理完成合同额87强,中国寰球工程公司、中国中材国际工程股份有限公司等企业入选工程总承包完成合同额144强,中国中元国际工程有限公司、中冶京诚工程技术有限公司等企业入选专项承包完成合同额8强,中国建筑西南勘察设计研究院有限公司、中冶集团武汉勘察研究院有限公司等企业入选岩土工程治理完成合同额28强。 相似文献
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我国勘察设计行业是与新中国同步成长发展起来的产物。在我国解放初期，为了满足国家恢复经济的需要，我国沿用了前苏联计划经济的建设体制模式，各部委成立了相应的设计院(所)，如：建设部设计院、邮电部设计院、机械工业部设计院、纺织部设计院等，各省(市)也成立了相应的设计院(所)。这些院(所)的成立，集中了当时的许多优秀的技术人才，为我国解放初期经济发展做出了巨大贡献，为我国基础设施、基础工业项目的建设提供了保障。 相似文献
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A. M. S. Clark 《Mineralium Deposita》1979,14(1):119-122
It is proposed that the Adola placer gold was derived, ultimately, from the ultrabasic rocks which are now represented by serpentinites and talc-schists. During the process of serpentinisation the ultrabasic rocks expelled abundant silica and available gold, which were deposited as gold-quartz veins in the overlying brittle basalts. Erosion of these basalts, now amphibolites has resulted in concentration of the gold as placers in the overlying conglomerates and soils. 相似文献
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The distribution and size of the barnacle Balanus subalbidus were studies along salinity gradients in coastal Louisiana and Mississippi. It was common in gradient estuaries occurring in salinities ranging from near fresh water to 16 ppt. It was the dominant barnacle species in the oligohaline zone, but at salinities above 6 ppt its relative abundance decreased and it was replaced by B. improvicus and B. eburneus. Its low-salinity limit corresponded to the boundary between the oligohaline and fresh water estuarine salinity zones and there was a high negative correlation between size (basal rostral-carinal diameter) and salinity. Its size and distribution could be used to determine prevailing salinity at a site because of its abundance and uniform distribution in oligohaline areas. 相似文献
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《Journal of Geochemical Exploration》2004,84(1):3-20
The Chinkuashih is a group of dacite-related hydrothermal enargite-gold deposits of the Quaternary age, which produced 94 tons of gold and 119,101 tons of copper from 1895 to 1987. It has remaining reserves of 656 tons of gold with an average grade range of 1.5–3.5 g/ton of Au for all orebodies discovered.Mercury content in different media such as stream sediments, heavy minerals in stream sediments, soils, rocks/ores, and pyrite samples was analyzed by a gold–film mercury detector to evaluate whether mercury is a good pathfinder for these types of deposits at Chinkuashih. The gold film technique is more rapid and cheaper than the traditional fire assay or fire assay/ICP-MS gold and trace element analyses.Mercury in stream sediments and soils indicated the border zone of gold mineralization 12 km away from the center of mineralization at Chinkuashih. Mercury in heavy minerals of the stream sediments distinguished the intermediate zone with gold veins and gold/gold–copper breccia pipes from the core or inner zone with the gold–copper zone. It has been found that contours of 1000 or 500 ppb Hg of soil samples can delineate the outcropping gold orebodies. The gold ores generally contain 1000 ppb or more Hg. 相似文献
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A possible mechanism of the ascent of material within the Earth’s crust and mantle is the mechanism of hydroextrusion, i.e.,
the effect of squeezing of material under excess pressure. The major factors that predetermine the high plasticity of the
material and its ability to produce hydroextrusions are high lithostatic pressures and temperatures. The phenomenon of hydroextrusion
can be most clearly illustrated by the example of the origin of salt diapirs. The driving force of hydroextrusions of material
in the crust and mantle is excess pressure, which can result from lateral differences between the densities of rocks (as is
the case during the development of salt diapirs) and phase transitions associated with a volume increase. When the material
of the upper mantle undergoes partial melting with the derivation of basaltic melts at depths of 60–100 km, excess pressures
reach 80 MPa, whereas the plasticity limit of 20% melted rocks is no higher than 5 MPa. As a result, the partially molten
material is forced from the melting region toward zones with lower lithostatic pressures. A local temperature increase in
the transitional zones in the Earth’s mantle at positive dP/dT values of the phase transitions also gives rise to excess pressures, whose values can range from 100 to 800 MPa at a 0.5–3.0%
volume change and which can be the driving force during the origin of mantle plumes.
Original Russian Text ? V.N. Anfilogov, Yu.V. Khachai, 2006, published in Geokhimiya, 2006, No. 8, pp. 873–878. 相似文献
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Groundwater as a geologic agent: An overview of the causes, processes, and manifestations 总被引：29，自引：4，他引：25
József Tóth 《Hydrogeology Journal》1999,7(1):1-14
The objective of the present paper is to show that groundwater is a general geologic agent. This perception could not, and
did not, evolve until the system nature of basinal groundwater flow and its properties, geometries, and controlling factors
became recognized and understood through the 1960s and 1970s.
The two fundamental causes for groundwater's active role in nature are its ability to interact with the ambient environment
and the systematized spatial distribution of its flow. Interaction and flow occur simultaneously at all scales of space and
time, although at correspondingly varying rates and intensities. Thus, effects of groundwater flow are created from the land
surface to the greatest depths of the porous parts of the Earth's crust, and from a day's length through geologic times. Three
main types of interaction between groundwater and environment are identified in this paper, with several special processes
for each one, namely: (1) Chemical interaction, with processes of dissolution, hydration, hydrolysis, oxidation-reduction,
attack by acids, chemical precipitation, base exchange, sulfate reduction, concentration, and ultrafiltration or osmosis;
(2) Physical interaction, with processes of lubrication and pore-pressure modification; and (3) Kinetic interaction, with
the transport processes of water, aqueous and nonaqueous matter, and heat. Owing to the transporting ability and spatial patterns
of basinal flow, the effects of interaction are cumulative and distributed according to the geometries of the flow systems.
The number and diversity of natural phenomena that are generated by groundwater flow are almost unlimited, due to the fact
that the relatively few basic types are modified by some or all of the three components of the hydrogeologic environment:
topography, geology, and climate. The six basic groups into which manifestations of groundwater flow have been divided are:
(1) Hydrology and hydraulics; (2) Chemistry and mineralogy; (3) Vegetation; (4) Soil and rock mechanics; (5) Geomorphology;
and (6) Transport and accumulation. Based on such a diversity of effects and manifestations, it is concluded that groundwater
is a general geologic agent.
Received, December 1998 · Revised, January 1999 · Accepted, January 1999 相似文献
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An academic geophysical research as a regional gravity survey was made during 1994 in the Western White Nile to infer the shallow crustal structures in the area. The result of the survey was compiled as a Bouguer anomaly map with a contour interval of 2 ×10-5m/s2. It is found that the negative residual anomalies are related to the Upper Cretaceous sediments (Nubian Sandstone Formation) filling all depressions in the Basement complex surface while the positive residual anomalies are attributed to the relatively shallow or outcropping Basement rocks and the steep gravity gradients are resulting from the sharp contacts between the sedimentary infill and the Basement rocks. To define the geological structures in the area, 9 profiles were studied. For each of the profiles, measured and computed Bouguer gravity anomalies, crustal density model, subsurface geology evaluation were performed. A G-model computer program was applied in the gravity modeling, which is based on the line-integral method of gravity computation. A geological/structural map was proposed showing inferred sedimentary basins, faulting troughs and uplifted Basement block and tectonic trends. The basins are believed to be fault-controlled which developed by extensional tectonics (pull-apart mechanism). As for the mechanism and cause of faulting, the area is considered as a part of the Central Sudan rift system which had been subjected to several tectonic events since Early Cambrian to Tertiary times which resulted in the formation of several fracture systems associated with block subsidence, rifting and basin formation. 相似文献
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Julia Semprich Nina S. C. Simon Yuri Yu. Podladchikov 《International Journal of Earth Sciences》2010,99(7):1487-1510
Constraints on density as a function of pressure, temperature, and composition are crucial to understand isostatic movements
during geodynamic processes. Here, we provide a systematic series of density diagrams extracted from thermodynamic calculations
for a variety of crustal compositions within a wide P–T range. We quantify systematic density changes in collisional settings for relevant compositional variations and attempt to
simplify the density–composition relationships. Rock densities depend strongly on pressure, temperature, and composition.
Densities at some selected pressure–temperature conditions increase linearly with increasing Al2O3 as well as MgO/FeO contents in pelitic rocks. Al- and Fe-rich pelites yield the highest densities, which is mostly due to
the formation of garnet but also depends on other minerals and changes of reactions. The effect of loading on densities is
investigated, and we show that for deep burial, a meta-pelite rich in Fe and Mg yields much larger density changes than a
dry basalt and that the burial of such a rock with a composition close to typical lower crust may result in significant negative
buoyancy. Metamorphism of hydrous lower crust due to pressurization and heating thus leads to densification of thickened lower
crust, while heating of dry crust leads to a decrease in density. Hence, water-loaded isostatic subsidence due to metamorphism
of water-saturated lower crust is substantial and increases with the thickness and depth of the reacting layer, while dry
compositions show much less or only transient densification and subsidence. The density change due to thermal expansion, an
extensively used concept in geodynamic models, predicts uplift under the same P–T conditions and is an order of magnitude smaller than the density variation calculated from petrologically consistent diagrams. 相似文献
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A. A. Nikonov 《Natural Hazards》1992,6(1):1-10
This paper relates some facts about abnormal animal behaviour prior to several Armenian earthquakes. The catastrophic Spitak, northern Armenia, earthquake of 7 December 1988, M = 7, I
0 = X, was preceded by extensive occurrences of abnormal animal behaviour. Proof was established by questioning residents in the area and by distributing specially prepared questionnaires shortly after the event. Approximately 200 reports from 50 sites were examined. The raw data recorded included lists of different types and locations of species that have shown abnormal responses to an impending earthquake, distribution of anomalous occurrences over the area, and precursor times. It is concluded that specially conducted observations of animal behaviour as a possible premonitory phenomenon is both useful and necessary. 相似文献
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《Quaternary Science Reviews》2007,26(15-16):1965-1974
Environmental changes, occurring during the Weichselian Lateglacial to Early Holocene transition, are supposed to be caused by rapid climate changes. Vegetation changes that occurred during the Early Holocene show a pattern of increased boreal forest development with dominance of birch (Friesland phase) to a more open vegetation with an increase of predominantly grasses (Rammelbeek phase), subsequently followed by renewed birch and, later on, pine forest development. Based on palynological evidence and botanical macrofossils, the Rammelbeek phase is supposed to have been caused by a change to dry, rather than cold climate. Detailed 14C-dating, using a wiggle-matched AMS-14C chronology, is used to place the vegetation changes in a time-stratigraphic framework. The Rammelbeek phase can be placed to around 11.3 ka cal BP. A direct correlation to the 11.2 ka event, as recorded in the Greenland ice-cores, is tempting. In this paper we propose an alternative approach by using a common proxy registered in both ice-core and terrestrial records. Based on oxygen isotopes, a Preboreal oscillation (PBO) appears to be present in many Early Holocene lacustrine carbonate-rich records. We used the δ18O signal of calcareous lake deposits (Kingbeekdal, Southern Netherlands), in which biostratigraphically a Rammelbeek phase is present. The signal in the stable isotopes seems to correlate to the Greenland ice-core records. This exercise shows that the PBO as recorded in the oxygen isotopes occurs not during the palynologically defined Rammelbeek phase but early in the Friesland phase. Moreover, the palynological record of the Kingbeekdal sequence shows, at the level of the δ18O reversal, a distinct opening of the birch forest and a temporary disappearance of thermophilous taxa, while the light requiring juniper increases. This implies a more complex pattern of climate response registered by the different proxies as previously thought. 相似文献