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1.
《Engineering Geology》2001,59(1-2):1-49
Geologic concepts and scientific-technical guidance for the planning-design and construction of engineered works was recognized in Europe by the 1800s and by the early 1900s in North America. This early geologic knowledge and experience provided the rudimentary principles that guided practitioners of the 19th century in serving the emerging projects in western United States. Case studies review the scientific-technical lessons learned and the legacy of geologic principles established in the planning and construction of major civil, mining, and military engineered works in the western states. These contributions to GeoScience knowledge and engineering geology practice include:
- •Tunnels and aqueducts across active fault zones, beneath young volcanic features, groundwater-charged faults, and land subsidence mitigation.
- •Controversial foundation design, Folsom and Auburn dams, Golden Gate Bridge.
- •Protective underground construction chambers, safety dependent geologic setting.
- •Geologic mapping as database management leasing, maintenance railroad trackway.
- •Causeway Great Salt Lake, geo-risks calculated, mitigated ‘as-constructed’.
- •Nuclear powerplants seismic design.
- •Urban Land-Use, on-going processes, acceptable geo-risks.
- •Dwelling Insurance, insuree's responsibilities.
- •Selecting technique/method to mitigate risk, preferably based on extensive database, evaluation of characteristics and historical origin adverse features/conditions that constitute a geo-risk.
2.
《Tectonophysics》1987,138(1):45-53
In this paper, the seismic pattern in Northern China from 30 ° to 42 ° N latitude and 104 ° to 125 ° E longitude, and the characteristics of the epicentral distribution before large events are presented. The results suggest that:
- 1.(1) the earthquakes in the region are mainly located in the orthogonal curvilinear network formed by the seismic belts;
- 2.(2) the larger earthquakes (M ⩾6) occurred mainly in the nodal regions of this grid:
- 3.(3) the strike of the fracture planes of the earthquakes coincided with the directions of the seismic belts;
- 4.(4) the pattern of medium strong earthquakes (M ⩾ 4.7) prior to thirteen large earthquakes (M⩾ 7) are analysed to be of three types:
- 4.1.(a) mainly arranged along the two intersecting belts,
- 4.2.(b) randomly distributed,
- 4.3.(3) forming seismic gaps.
3.
《Applied Geochemistry》1999,14(7):861-871
To support and help hydrochemical evaluation a multivariate mathematical tool named M3 (Multivariate Mixing and Mass balance calculations) has been created within the Äspö Hard Rock Laboratory Research Programme. The computer code can be used to trace the origin of the groundwater and calculate the mixing portions and mass balances from ambiguous groundwater data. Groundwater composition data used traditionally to describe the reactions taking place in the bedrock can now be used to trace the effect from present and past groundwater flow with increased accuracy. The M3 model consists of the following 3 steps:
- •Multivariate analysis, called Principal Component Analysis (PCA) is used to summarise the information from the data set. The summarised information shown in the PCA plots is used for finding relationships, patterns, extreme waters and for further M3 modelling.
- •From the PCA plot mixing calculations are used to calculate the effect of the groundwater mixing on the obtained groundwater composition. This so-called ideal mixing model is used to calculate the mixing proportions given in %, for all the groundwater samples.
- •The final step in M3 calculations is the mass balance calculations. Deviations from the ideal mixing model are used to trace the sources and sinks of elements, given in mg/l, which can be due to mass balance reactions.
4.
The Karkonosze–Izera Massif is a large tectonic unit located in the northern periphery of the Bohemian Massif. It includes the Variscan Karkonosze Granite (about 328–304 Ma) surrounded by the following four older units:
- -Izera–Kowary (the Early Paleozoic continental crust of the Saxothuringian Basin),
- -Ještĕd (the Middle Devonian to Lower Viséan sedimentary succession deposited on the NE passive margin of the Saxothuringian Terrane), out of the present study area,
- -Southern Karkonosze (metamorphosed sediments and volcanics filling the Saxothuringian Basin), out of the present study area,
- -Leszczyniec (Early Ordovician, obducted fragment of Saxothuringian Basin sea floor).
- -formation of the Saxothuringian Basin and its passive continental margin (about 500–490 Ma)
- -Variscan thermal events:
- -regional metamorphism (360–340 Ma)
- -Karkonosze Granite intrusion (328–304 Ma)
- -Late Cretaceous and Neogene-to-Recent hypergenic processes.
5.
《Applied Geochemistry》2005,20(2):261-274
Very low concentrations of total S, mainly sedimentary sulphides, were quantitatively extracted from Quaternary sands of the Elbe Basin, using HNO3, Br2 and HCl, to distinguish 3 aquifer zones:
- •an upper aerobic section, containing low concentrations (only a few ppm) of non-sulphidic S compounds,
- •the central and lower part of the aquifer, dominated by 34S-depleted sedimentary Fe sulphides, formed by reduction of infiltrating SO4, derived from groundwater recharge, and
- •the lowest 5–10 m of the aquifer, containing high concentrations of 34S-enriched sulphides.
6.
《Organic Geochemistry》1987,11(5):371-377
Fluorescence microscopy is useful not only for identifying most of the oil-prone organic matter (macerals) in sedimentary rocks and coals but also for assessing their thermal maturities (ranks). This report introduces a violet-light excitation system which induces more than one order of magnitude stronger fluorescence intensity that the commonly used UV-light excitation system. The red/green quotient from violet-light excited fluorescence, Qv, of sporinite can be easily measured using this system. Several examples using coal and cuttings samples are presented to demonstrate the use of this technique for evaluating the thermal maturities of coals and sedimentary rocks.From the results of our studies we conclude that:
- 1.(1) Violet-light excited fluorescence from sporinites can be routinely measured to assess thermal maturity.
- 2.(2) Spectral (Quantitative) fluorescence technique is useful for evaluating thermal maturity when samples are poorly polished or deficient in vitrinite.
- 3.(3) Visual (Strew-mounted) kerogen slides can not be used for fluorescence measurements unless a non-fluorescent mounting medium is used.
7.
《Organic Geochemistry》1987,11(1):15-24
Models of kerogens belonging to the three classical Types have been represented at the following evolution stages:
- •-beginning of diagenesis (sensu-stricto),
- •-beginning of catagenesis,
- •-end of catagenesis.
8.
《Lithos》1987,20(2):153-168
The Thorsmörk ignimbrite, southern Iceland, contains a suite of granophyre xenoliths displaying magmatic or high-temperature sub-solidus mineral assemblages. These granophyres are consanguineous with the erupting comenditic magma. Four types of mineral assemblages are distinguished:
- 1.(A) oligoclase, edenitic hornblende, salitic pyroxene, magnesian biotite, magnetite and sphene;
- 2.(B) oligoclase, manganoan to sodic ferro-augite, fayalite, richterite, ilmenite and magnetite;
- 3.(C) anorthoclase, ferrohedenbergite to aegirine hedenbergite, ilmenite, magnetite and (riebeckite);
- 4.(D) cryptoperthite, aegirine hedenbergite to (aegirine), aenigmatite, arfvedsonite, ilmenite and magnetite.
9.
《Computers and Geotechnics》1987,4(2):61-83
Determination of critical buckling loads of columns in a medium which offers resistance to lateral deflections depend on:
- (a) Length of the pile, L.
- (b) Flexural stiffness of the pile, EI.
- (c) Stiffness of the soil, K, and
- (d) Boundary conditions of the pile, both at the top and the tip.
10.
《Geochimica et cosmochimica acta》1986,50(1):49-58
The coprecipitation of alkali metal ions (Li+, Na+, K+ and Rb+) with calcium carbonate has been studied experimentally and the following results have been obtained:
- 1.(1) Alkali metal ions are more easily coprecipitated with aragonite than with calcite.
- 2.(2) The relationship between the amounts of alkali metal ions coprecipitated with aragonite and their ionic radii shows a parabolic curve with a peak located at Na+ which has approximately the same ionic radius as Ca2+.
- 3.(3) However, the amounts of alkali metal ions coprecipitated with calcite decrease with increasing ionic radius of alkali metals.
- 4.(4) Our results support the hypothesis that
- 4.1.(a) alkali metals are in interstitial positions in the crystal structure of calcite and do not substitute for Ca2+ in the lattice, but
- 4.2.(b) in aragonite, alkali metals substitute for Ca2+ in the crystal structure.
- 5.(5) Magnesium ions in the parent solution increase the amounts of alkali metal ions (Li+, Na+, K+ and Rb+) coprecipitated with calcite but decrease those with aragonite.
- 6.(6) Sodium-bearing aragonite decreases the incorporation of other alkali metal ions (Li+, K+ and Rb+) into the aragonite.
11.
《Geochimica et cosmochimica acta》1986,50(8):1643-1653
Suspended sediments from the Indus River collected during 1981 through 1983 were analyzed for POC and its constituent fractions including amino acids, amino sugars and sugars. Percentage of POC decreased with increasing suspended matter concentrations, which suggested dilution of organic matter by mineral matter.The concentrations of amino acids, amino sugars and sugars varied, respectively, between 180 and 2000 μg/l, 5 and 125 μg/l, and 60 and 1100 μg/l. Their contributions to POC varied between 2 and 60% for amino acids and amino sugars, and between 2 and 15% for sugars. They were high during low sediment discharge (February to June), and low during high sediment discharge (August and September). Suspended sediments associated with high sediment discharge periods were characterized by low ratios of:
- 1.(i) aspartic acid:β-alanine
- 2.(ii) glutamic acid:γ-aminobutyric acid
- 3.(iii) amino acids:amino sugars
- 4.(iv) hexoses:pentoses. These and the relative distribution pattern of the monosaccharides such as galactose, arabinose, mannose and xylose indicated that, not only dilution, but also differences in the sources and processes affect the POC transport in the Indus River. These result in transport of biodegraded organic matter during high sediment discharge periods: this appears to be common to other major rivers of the region, with depositional centers in deep sea areas. These rivers, with their high sediment loads, could contribute up to 8 to 11% of the global annual organic carbon burial in marine sediments.
12.
《Comptes Rendus Geoscience》2019,351(5):355-365
Located in northern Niger, the NW–SE Téfidet trough is the western branch of the Ténéré rift megasystem.Here we present a tectono-sedimentary analysis of the Téfidet trough, based on the combined use of satellite imagery, field observations and measures, and available literature. We use these data to analyse the sedimentary facies and the tectonic deformations (faults, folds, basins) in the Téfidet trough, and derive their relative chronology. Doing so, we characterize synrift and postrift deformations and their interactions with sedimentation.Altogether our analyses suggest that the Téfidet trough was affected from the Cretaceous to the Paleogene by three major tectonic periods.
- •The first period was a rifting stage with extension and transtension during the Albian–Aptian times. The mean extension was ∼N60° and dominantly produced NW–SE-trending normal faults, a few strike-slip faults locally associated with small folds with sigmoidal axis and small reverse faults, and progressive unconformities.
- •the second period was also a rifting time, which prevailed during the Upper Cretaceous. The regime was marked by transtensional to extensional tectonics, under a ∼N130° shortening and a ∼N60° trending stretching. The end of this period saw the closure of the Téfidet trough.
- •the third period was a postrift stage. It was characterized by a ∼N70° extensional to transtensional regime during the Oligocene–Pliocene. It mainly produced post-sedimentary extensional faults and fractures and alkaline volcanism. We eventually discuss these deformation phases in relation with the Cretaceous Gondwana breakup and its related rifting events in West and North Africa, and with the subsequent Africa–Europe collision.
13.
《Tectonophysics》1987,142(1):99-109
Five hundred and fifty temperature values, initially measured as either bottom-hole temperatures (BHT) or drill-stem tests (DST), from 98 selected petroleum exploration wells form the basis of a geothermal gradient map of central Tunisia. A “global-statistical” method was employed to correct the BHT measurements, using the DST as references. The geothermal gradient ranges from 23° to 49°C/km. Comparison of the geothermal gradient with structural, gravimetric and petroleum data indicates that:
- 1.(1) the general trend of the geothermal gradient curves reflects the main structural directions of the region,
- 2.(2) zones of low and high geothermal gradient are correlated with zones of negative and positive Bouguer anomalies and
- 3.(3) the five most important oil fields of central Tunisia are located near the geothermal gradient curve of 40° C/km.
14.
《Tectonophysics》1987,138(1):79-92
Analysis of the space-time patterns of seismicity in the Himalaya plate boundary has established the existence of three seismic gaps:
- 1.(1) The “Kashmir gap” lying west of the 1905 Kangra earthquake;
- 2.(2) the “Central gap”, situated between the 1905 Kangra and the 1934 Bihar earthquakes;
- 3.(3) the “Assam gap” between the 1897 and 1950 Assam earthquakes.
15.
《Tectonophysics》1987,134(4):339-345
Downward continuation of temperature data from 73 wells extending to depths of 250 ft (76 m) provides constraints on the thermal regime of the Valles Caldera. Surface-temperature gradient data and bottom-hole temperatures were used as constraints in the downward continuation. Three factors were found to control the shallow thermal regime:
- 1.(1) heat associated with the main geothermal source;
- 2.(2) local topography; and
- 3.(3) west-southwest groundwater flow. Although the well density is relatively high, comparison with the topography shows that the wells are not randomly distributed and tend to be clustered in valleys. Many details in the thermal regime appear to be related to groundwater drainage in these valleys. Temperature gradients and temperatures generally increase in the same direction as the regional drainage of the caldera suggesting a long-wavelength, shallow component to this regional gradient trend. Inversion of gradient and temperature data show additional deep heat input in the west-southwest sector of the caldera which appears to be spatially associated to the youngest volcanism. A previously reported northeast displacement of the main heat source from the surface anomaly has not been confirmed.
16.
《Tectonophysics》1987,138(1):25-32
An earthquake (M = 5.9) occurred on November 7, 1983 in the Heze area, Shandong Province (35°17′ N, 115°17∃, H = 12 km). This earthquake belongs to the isolated type of earthquakes. There were no foreshocks; the aftershocks were few in number with their energy decreasing quickly.Within the area surrounding the main shock and up to about 200 km from the epicenter, several types of short-term and imminent anomalies were observed. The major characteristics of the anomalies are as follows:The short-term and imminent anomalies are relatively few in number. The maximum radius of the area where the anomalies occur is about 150–200 km from the epicenter. The time durations of what have been called short-term and imminent anomalies here are small, being
- 1.(1) from 10–20 days to 3–4 months and
- 2.(2) from 1–2 hours to 2–3 days, respectively. The premonitory information was scanty.
17.
Yiyang Zhao 《中国地球化学学报》1982,1(3):338-342
The following conclusions can be drawn from the work reported in this paper:
- Sixteen samples were determined for uranium by spectrophotometric method. The uranium content in the sea floor sediments of the Bohai Gulf ranges from 1.6 to 6.3 ppm, with an average of 4.3 ppm.
- Statistical data show close relationship between U concentration and grain size. Relatively larger amount of uranium was found accumulated in mud than in sand. The bulk of uranium is assumed to be derived from terrestrial detrital minerals.
- A positive correlation between U and Fe is recognized. Similar relation also can be seen between U and Al. The plot of U concentration vs. Fe is linear, and can be expressed by the linear regression equation:Y=?0.37+1.35X. The plot of U against Al gives an equation ofY=?2.48+1.01X.
- The average U/Corg. ratio for these sediments is 7×10?4, and the average ratios of U/P, U/Mn, and U/CaCO3 are 100×10?4, 50×10?4 and 2×10?4, respectively.
- Compared with the abundances of other shelf sediments, the average concentration of U in the area under consideration is close to that of sediments on the selves of Japan and the Gulf of Mexico, and the Black Sea. Uranium concentration in the Bohai Gulf sediments is comparable to that of the continental crust, but differs from that of deep-sea clay.
18.
《Tectonophysics》1987,143(4):337-342
The electrical (apparent) resistivities ρ were measured by means of the magnetotelluric effect at twenty sites in Greece and in two directions, E-W and N-S. In most of the sites, ρEW differs considerably from ρNS. These results allow the following three zones to be distinguished:
- 1.(1) an external zone along western Greece with ρEW >ρNS;
- 2.(2) an intermediate zone along the main mountain chain in continental Greece where ρNs >ρEW and
- 3.(3) an internal zone in the northern Aegean where ρEW >ρNS.
19.
《Geochimica et cosmochimica acta》1986,50(2):307-315
Bulk compositions were determined by broad-beam electron microprobe analysis for thirteen of the least aqueously altered chondrules in Murray (CM2). These and literature data reveal compositional differences between CM-CO and ordinary chondrite (OC) chondrules:
- 1.(a) CO chondrules are richer in refractory lithophiles and poorer in Cr, Mn and volatile lithophiles than OC chondrules; much lower refractory lithophile abundances in CM chondrules resulted from aqueous alteration,
- 2.(b) in CM-CO chondrites, abundances of refractory lithophiles are higher in nonporphyritic than porphyritic chondrules, whereas in H-L-LL3 chondrites the converse is true,
- 3.(c) Cr ranges are greater and Cr and Mn correlate more strongly in chondrules in CM-CO than in H-L-LL3 chondrites.
- 1.(1) pyroxene- and refractory-rich, FeO-poor;
- 2.(2) olivine-rich, refractory and FeO-poor.
20.
《Physics and Chemistry of the Earth, Part A: Solid Earth and Geodesy》1999,24(10):913-920
Climatic change in SE Europe can be characterized by the term aridification, which means increasing semi-aridity, manifested in an increase of mean annual temperature and at the same time in a decrease in the yearly precipitation.The paper deals with research results obtained within the framework of the MEDALUS II project (funded by the Commission of the European Communities). The project had the following objectives:
- 1.(i) Assessment of the impact of global change on the climate of the investigated area, including possible future climates.
- 2.(ii) Physical processes of aridification, including studies of groundwater level change, soil moisture profile dynamics, soil development, vegetation change and soil erosion.
- 3.(iii) Land use change, involving research on present land use and suggestions for the future.
- 1.(i) Statistical analysis of climatic oscillations and computer runs of climatic scenarios,
- 2.(ii) Analysis of ground water data, mapping and analysis of soils and vegetation, assessment of present and future soil, and
- 3.(iii) Land capability assessment through ranking environmental conditions according to the demands of the most widely grown arable crops in Hungary.