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781.
A. B. Yavuz 《Environmental Geology》2006,51(2):211-227
?zmir is the third largest city in Turkey and has being the centre of art, culture, tourism and trade activities throughout the 5,000 years of its history. Natural stones brought from different parts of the world have been widely used for construction of the prestigious buildings, monuments and roads etc., in the past in the city. Renovation of the street pavements and public gathering areas in the city centre has been undertaken by the Metropolitan Municipality in 2000 and continued through the year of 2001. These renovation activities have mainly been carried out in the streets running parallel to the sea shore. Volcanic rocks brought from the Central Anatolia Ankara-Gölba?? (andesites) and Kayseri-?ncesu (tuffs) have been used in the renovation works. These rocks have shown extensive deteriorations within 4 years of their usage between 2001 and 2005 under the influence of different environmental factors. In this study, the deteriorations developed in the recently placed volcanic rocks used as kerb and pavement stones in the city centre of ?zmir in the light of their mineralogical, chemical, physical and mechanical properties, used locations and the environmental factors are presented. 相似文献
782.
B. N. Ryzhenko 《Geochemistry International》2006,44(8):835-840
783.
V. I. Vinogradov G. A. Belenitskaya M. I. Bujakaite V. N. Kuleshov M. A. Minaeva B. G. Pokrovskii 《Lithology and Mineral Resources》2006,41(1):85-97
New isotope data on Lower Cambrian rocks of the Irkutsk amphitheater are reported in three communications. The first communication
is devoted to the sulfur isotopic composition, which is most sensitive to ostsedimentary geochemical transformations of sulfate
rocks in saliferous formations. It is shown that δ34S values in Bel’sk and Zhigalovo boreholes are within 22–35‰ The lowest values are close to the sulfur isotopic composition
of a halogenic basin, while the highest values are related to epigenetic sulfate reduction. This process was responsible for
the elimination of 100 m of anhydrites from the Lower Cambrian section. 相似文献
784.
A. M. Larin E. B. Sal’nikova A. B. Kotov L. B. Makar’ev S. Z. Yakovleva V. P. Kovach 《Stratigraphy and Geological Correlation》2006,14(5):463-474
Early Proterozoic granitoids are of a limited occurrence in the Baikal fold area being confined here exclusively to an arcuate belt delineating the outer contour of Baikalides, where rocks of the Early Precambrian basement are exposed. Geochronological and geochemical study of the Kevakta granite massif and Nichatka complex showed that their origin was related with different stages of geological evolution of the Baikal fold area that progressed in diverse geodynamic environments. The Nichatka complex of syncollision granites was emplaced 1908 ± 5 Ma ago, when the Aldan-Olekma microplate collided with the Nechera terrane. Granites of the Kevakta massif (1846 ± 8 Ma) belong to the South Siberian postcollision magmatic belt that developed since ~1.9 Ga during successive accretion of microplates, continental blocks and island arcs to the Siberian craton. In age and other characteristics, these granites sharply differ from granitoids of the Chuya complex they have been formerly attributed to. Accordingly, it is suggested to divide the former association of granitoids into the Chuya complex proper of diorite-granodiorite association ~2.02 Ga old (Neymark et al., 1998) with geochemical characteristics of island-arc granitoids and the Chuya-Kodar complex of postcollision S-type granitoids 1.85 Ga old. The Early Proterozoic evolution of the Baikal fold area and junction zone with Aldan shield lasted about 170 m.y. that is comparable with development periods of analogous structures in other regions of the world. 相似文献
785.
786.
UKAEGBU V. U. EKWUEME B. N. 《中国地球化学学报》2006,25(2):122-131
1 IntroductionThe study area is part of the Obudu Plateau,which forms part of the Precambrian Pan-African tec-tonothermal belt, lying between the West African Cra-ton and the Gabon-Congo Craton ( Fig. 1). It isbounded by the Benue Trough, in the NE-SW axi… 相似文献
787.
B. Tapley J. Ries S. Bettadpur D. Chambers M. Cheng F. Condi B. Gunter Z. Kang P. Nagel R. Pastor T. Pekker S. Poole F. Wang 《Journal of Geodesy》2005,79(8):467-478
A new generation of Earth gravity field models called GGM02 are derived using approximately 14 months of data spanning from
April 2002 to December 2003 from the Gravity Recovery And Climate Experiment (GRACE). Relative to the preceding generation,
GGM01, there have been improvements to the data products, the gravity estimation methods and the background models. Based
on the calibrated covariances, GGM02 (both the GRACE-only model GGM02S and the combination model GGM02C) represents an improvement
greater than a factor of two over the previous GGM01 models. Error estimates indicate a cumulative error less than 1 cm geoid
height to spherical harmonic degree 70, which can be said to have met the GRACE minimum mission goals.
Electronic Supplementary Material Supplementary material is available in the online version of this article at 相似文献
788.
Analysis of geophysical networks derived from multiscale digital elevation models: a morphological approach 总被引:1,自引:0,他引:1
Tay L.T. Sagar B.S.D. Hean Teik Chuah 《Geoscience and Remote Sensing Letters, IEEE》2005,2(4):399-403
We provide a simple and elegant framework based on morphological transformations to generate multiscale digital elevation models (DEMs) and to extract topologically significant multiscale geophysical networks. These terrain features at multiple scales are collectively useful in deriving scaling laws, which exhibit several significant terrain characteristics. We present results derived from a part of Cameron Highlands DEM. 相似文献
789.
S. M. Moorthi Nitant Dube D. Dhar B. Kartikeyan R. Ramakrishnan 《Journal of the Indian Society of Remote Sensing》2005,33(2):277-283
Remote sensing data products need to meet stringent geodetic and geometric accuracy specifications irrespective of intended
user applications. Georeferencing is the basic processing step towards achieving this goal. Having known the imaging geometry
and mechanism, the mathematical models built with the use of orbit and attitude information of the spacecraft can correct
the remote sensing data for its geometric degradations only up to system level accuracy (IRS-P6 DP Team, 2000). The uncertainties
in the orbit and attitude information will not allow the geometric correction model to generate products of accuracy that
can meet user requirements unless Ground Control Points (GCP) are used as reference geo-location landmarks. IRS-P6 data processing
team has been entrusted with developing a software system to generate data products that will have desired geodetic and geometric
accuracies with known limitations. The intended software system is called the Value Added Data Products System (VADS). Precision
corrected, Template Registered, Merged and Ortho Rectified products are the value added products planned with VADS. 相似文献
790.
B. K. Bhattacharya V. K. Dadhwal 《Journal of the Indian Society of Remote Sensing》2005,33(2):331-338
The retrieval of land (soil-vegetation complex) surface temperature (LST) was carried out over semi-arid mixed agriculture
landscape of Gujarat using thermal bands (channel 4 and 5) and ground emissivity from atmospherically corrected NDVI of NOAA
AVHRR LAC images. The atmospheric correction of Visible and NIR band reflectance was done using SMAC model. The LST computed
from split-window method and subsequently corrected with fractional vegetation cover were then compared with near synchronous
ground observations of soil and air temperatures made during 13–17 January and April, 1997 at five Land Surface Processes
Experiment (LASPEX) sites of Anand, Sanand, Derol, Arnej and Khandha covering 100 km x 100 km. The fractional vegetation cover
corrected LST at noon hrs. varied from 301.6 – 311.9K in January and from 315.8 – 325.6K in April. The LSTcorr were found to lie in the mid way between AT and ST during January. But in April, LST were found to be more close to ST which
may be due to relatively poor vegetation growth as indicated by lower NDVI values in April indicating more contribution to
LST from exposed soil surface. 相似文献