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1.
《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.
2.
《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.
3.
《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.
4.
《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.
5.
《Journal of Structural Geology》1988,10(6):593-605
Similar fold interferences are examined in two different ways.
- 1.(1) We show the importance of taking into account the original position of the stratification with respect to the orientations of two interfering fold phases. Basin and dome cases correspond to particular orientations of the interfering phases with respect to each other. In all other cases, coaxiality may be achieved for particular positions of the original stratification.
- 2.(2) We have achieved a computer-aided modelling which allows the visualization by means of sections and block-diagrams of any two or three similar fold interferences. The program allows us to define the stratification, orientations of the various phases and their profiles (sinusoidal or drawn by hand), and orientations and dimensions of the selected section or block diagram. Faults may also be represented.This modelling method is a powerful research tool that we hope to apply in future to detailed studies of fold interferences, to achieve quantitative field models of multiply folded and faulted terranes.
6.
《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.
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.
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.
10.
《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.
11.
Prof. Jean -Claude Vicente 《International Journal of Earth Sciences》1975,64(1):343-394
Hercynian absolute ages obtained from many plutonites and metamorphites of the Sierras Pampeanas compel to consider this polymetamorphic domain rather as an intermediate hinterland and axis of divergent symmetry between the two elementary geosyncline ranges (Cuyanides and Bolivianides) of the south america hercynian orogen. Attempt of Cuyanides paleogeographic organization indice to define during the geosyncline period (Cambrian to Devonian): the Pampean zone which consist of:
- an internal sub-zone (eastern) or pampean s. st. with hinterland significance
- a more external sub-zone (western) or transpampean or Umango sub-zone with intermediate features between eugeanticlinal ridge and eugeosynclinal furrow;
- the Calingasta zone as a typical eugeosynclinal furrow with pelagic-terrigenous ordovician sedimentation and ophiolitic magmatism followed by early silurian than devonian Flyschs;
- the Zonda zone as an external ridge with neritic cambro-ordovician facies and devonian flyschs.
12.
《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.
13.
Most of the Cu (± Mo,Au) porphyry and porphyry-related deposits of the Urals are located in the Tagil-Magnitogorsk, East-Uralian Volcanic and Trans-Uralian volcanic arc megaterranes. They are related to subduction zones of different ages:
- (1)Silurian westward subduction: Cu-porphyry deposits of the Birgilda-Tomino ore cluster (Birgilda, Tomino, and Kalinovskoe) and the Zeleny Dol Cu-porphyry deposit;
- (2)Devonian Magnitogorsk eastward subduction and the subsequent collision with the East European plate: deposits and occurrences are located in the Tagil (skarn-porphyry Gumeshevskoe etc.) and Magnitogorsk terranes (Cu-porphyry Salavat and Voznesenskoe, Mo-porphyry Verkhne-Uralskoe, Au-porphyry Yubileinoe etc.), and probably in the Alapaevsk-Techa terrane (occurrences of the Alapayevsk-Sukhoy Log cluster);
- (3)Late-Devonian to Carboniferous subduction: deposits located in the Trans-Uralian megaterrane. This includes Late-Devonian to Early Carboniferous Mikheevskoe Cu-porphyry and Tarutino Cu skarn-porphyry, Carboniferous deposits of the Alexandrov volcanic arc terrane (Bataly, Varvarinskoe) and Early Carboniferous deposits formed dew to eastward subduction under the Kazakh continent (Benkala, etc.).
- (4)Continent-continent collision in Late Carboniferous produced the Talitsa Mo-porphyry deposit located in the East Uralian megaterrane.
14.
《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.
15.
《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.
16.
Compositions and textures of relic forsterite in carbonaceous and unequilibrated ordinary chondrites
《Geochimica et cosmochimica acta》1986,50(7):1379-1395
Several percent of the olivine in the C2, C3 and unequilibrated ordinary chondrites (UOC) can be distinguished by blue cathodoluminescence (CL) and an unusual composition for forsterite. This olivine has the following textural features:
- 1.(1) forms cores in single olivine grains;
- 2.(2) shows subhedral to euhedral boundaries against rim olivine;
- 3.(3) rarely contains inclusions;
- 4.(4) has embayments containing olivine like that of the rim;
- 5.(5) occurs within chondrules especially in UOC meteorites.
17.
《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.
18.
《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.
19.
Dr. G. Wessely 《International Journal of Earth Sciences》1990,79(2):513-520
The exploration for hydrocarbons in the deepest tectonic »floor« underneath the Vienna basin with depths of 6.5–8.5 km, was undertaken between 1977 and 1985 and based on several important conditions: -The assumption that an autochthonous sedimentary cover lies upon the Crystalline Basement (Bohemian massif) below the Neogene basin infill and the Alpine-Carpathian nappes. -Expressed high zones exist within the Vienna basin with exploration targets at depths reachable by drilling. -The significant accumulation of oil- and gasfields m shallower position over the area of interest. As a result of the 4 deep wells drilled for the abovementioned targets more information has been acquired concerning the stratigraphy, facies distribution and depth positions of the autochthonous Jurassic, Upper Cretaceous and Tertiary Molasse along the Eastern flank of the Crystalline basement spur of the Bohemian Massif. The allochthonous, Waschberg- und Flyschzone, both Alpine-Carpathian units underneath the Vienna basin, have been penetrated by these wells for the first time and the overthrust of the Calcareous Alps over the Flysch nappes has been proven (well Aderklaa UT1). Additional information about Neogene sedimentation and faulting was obtained. Drilling results made it possible to get a more comprehensive picture of the 3 tectonic »floors« of the Vienna basin, m detail represented by the Zistersdorf and Aderklaa profiles. Thick basin marls of the Upper Jurassic represent a large source potential for hydrocarbons. The favourable reservoir layers, detected in the Mesozoic sections of the foreland area have not been encountered here till now. A high supply of free hydrocarbons within the deepest floor must be assumed on the basis of many oil and gas shows, a major gas kick in Zistersdorf ÜTla and a limited oil production from a fractured zone along a thrustline in the Maustrenk ÜTla well, both occurring in an overpressured environment. 相似文献
20.
Prof. Dr. G. Haase Dr. L. Händel Dr. Chr. Nagel Dr. Chr. Opp Dr. R. Zierath 《GeoJournal》1990,22(2):153-165
Problems of landscape and resource protection resulting from the intensification of land-use can be mastered only by intersectoral planning and a land management considering (landscape-)ecological principles right from the beginning. In the district of Leipzig ecological studies in the '80ies have focussed on:
- Determination of the regional pattern of atmospheric immissions;
- Registration of heavy metals in soil and vegetation;
- Soil compaction, soil erosion;
- Study of stress indicators in the aeration zone and in the top-most aquifer in order to examine barrier effects in the percolation process.