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991.
Hani N. Khoury 《Arabian Journal of Geosciences》2018,11(4):72
The Azraq basin (the Badia region in NE-Jordan) is rich in its industrial rocks and minerals. Most of the commodities are concentrated in one area, which is the Azraq depression (El-Qa’). The climatic changes (wet and dry) of Azraq closed lake contributed in the formation of industrial rocks and minerals in the El-Qa’. Basalt, pyroclastics, zeolites, diatomaceous earth, bentonite, palgorskite, porcelanite, saline brines, chalk, limestone, and gypsum are the potential industrial commodities. The basaltic rocks are of high alkalis content and good homogeneity and are of good potential use in constructions and cast basalt. The scoriaceous pyroclastic material proved to be of excellent properties for use as lightweight aggregates, cultivation purposes, and for the production of pozzolanic cement. Smectite-rich beds (bentonite) from Ein El Badia could be used as binder, absorbent, and additives for feeding farm animals. Palygorskite is potential for use in drilling mud, paint, pharmaceuticals, and as a filtering medium. The diatomaceous earth deposits are Moler type and could be used as filter aid and absorbent. Zeolites are efficient for agricultural purposes, animal waste, and wastewater treatment plants. Saline brine is exploited in the Azraq mudflat area for table salt. Porcelanite could be used as an absorbent of hazardous elements, abrasive, and filler. The softness and high purity of chalk enable its use as filler and in the lime production. The large limestone concretions are of high quality for use as a building stone. Gypsum (gypcrete) could be used after the removal of the undesired chert impurities. The Badia region is a highly potential area for future exploration and mining industry in a manner that achieves the required outcomes and minimizes impacts on ecosystems. 相似文献
992.
In Europe, the Wide Wheel abrasion (WWA) test and the B?hme abrasion (BA) test are among the most widely used standard test
methods for determining abrasion resistance of natural stones, the former being the reference test method in EN 14157 Standard.
However, it is stated in the Annex-A (Informative) of EN 14157 Standard that very limited data are available to provide correlations
between these two test methods. To be able to fill this gap, in this study, 25 different natural stones belonging to sedimentary,
metamorphic and igneous groups were tested for their abrasion resistance as well as physico-mechanical properties. Also, for
a better interpretation of abrasion resistance characteristics of the tested stone materials, relationships between abrasion
resistance and physico-mechanical properties were statistically examined. A statistically significant linear correlation (R
2 = 0.85; P value = 0.000) was established between the WWA test and the BA test, which could be used in practice for converting the measured
abrasion resistance values from one testing method to another. It was also found that the correlation between these two test
methods improved significantly (R
2 = 0.93; P value = 0.001) when relatively high-porosity stone materials (porosity ≥1%) were separately evaluated. Both methods of abrasion
resistance employed in the present study showed statistically significant linear correlations with uniaxial compressive strength
and Brazilian tensile strength, the former proving to be a more influencing parameter on resistance to abrasion. Also, from
the point view of representing actual abrasion mechanism of stone materials in practice, the necessity of simulating multi-directional
foot traffic in abrasion testing methods was discussed. In this respect, the reference test method in the EN 14157 Standard
was criticized for not fully meeting this requirement. It was also pointed out that the reference method could have some drawbacks
when applied to coarse-grained granitic rocks having cleavable minerals such as plagioclase and orthoclase feldspars. 相似文献
993.
Uppermost Tortonian to lower Messinian temperate carbonates crop out in the Agua Amarga Basin (SE Spain). They consist of four units. The lower three units can be tentatively assigned to the lowstand systems tract of a fourth-order sequence, constituting in turn the lowstand (‘megatrough unit’), transgressive (‘breccia unit’) and highstand (‘bedded unit’) stages of a higher-order cycle. All these materials were deposited in a small pull-apart basin related to the sinistral Carboneras strike-slip fault system. The best represented is the bedded unit (up to 25 m thick), which consists of bioclastic, bryozoan/bivalve-dominated calcarenites/calcirudites with abundant fragments of echinoids, barnacles, benthic foraminifers, coralline algae, brachiopods and solitary corals. Facies trends within this unit are roughly arranged in an E-W direction, with the coastline to the north of the basin. The depositional model is that of a gentle ramp with prograding beaches and shoals in its higher parts. Seaward of the shoals was the ‘factory area’, where most organisms lived and maximum carbonate production took place. From this area some of the skeletons were washed landwards by waves and/or currents during storms and incorporated into the shoals and beaches, and others moved downslope along the ramp as mass-flows, accumulating to form the ‘fan-bedded zone’. The factory-area and fan-bedded sediments intercalate five well-defined, thick beds of calcarenites/fine-grained calcirudites. They show bar morphologies (single or amalgamated), or make up sand-waves with very consistent tabular cross-bedding pointing landwards. These beds formed in a very shallow, wave/current-influenced, coastal environment. The bars and sand waves in the fan-bedded zone developed during lowstands, while those located higher up in the ramp interbedded with the factory facies are related to transgressive stages. Prograding beaches, shoals, factory facies and fan-bedded layers developed during the highstands. Net skeletal production occurred mainly during the highstands. Sediment-accretion values of these sediments are similar to those of present and ancient shallow-marine, temperate carbonates considering that the whole bedded unit was deposited in a 100 000-year interval (equivalent to the short eccentricity cycle). The five cycles inside the bedded unit would therefore correspond to the c. 20 000-year precession cycles of the Milankovitch band. 相似文献
994.
S. Lafuerza N. Sultan M. Canals J. Frigola S. Berné G. Jouet M. Galavazi F. J. Sierro 《International Journal of Earth Sciences》2009,98(4):751-768
Data from in situ piezocone tests (CPTU) and laboratory analyses are utilized for the interpretation of the stress history
of Quaternary sedimentary sequences in the upper continental slope of the Gulf of Lion, northwestern Mediterranean Sea. A
CPTU based preconsolidation pressure profile referenced to the current effective stress indicates that the deposit is underconsolidated
from 12 meters below the seafloor (mbsf) down to at least 150 mbsf. Excess pore pressure below 12 mbsf is further supported
by results from oedometer and dissipation tests. Subseafloor pockmarks and indications of free gas in seismic reflection profiles
reveal four main overpressure sources (SI–SIV) with overpressure ratios >0.3 at subseafloor depths coinciding with levels
where the dominantly silty-clayey sediment contains increased proportions of sand. We relate the excess pore pressure related
to free gas due to gas exsolution processes and sea level variations driven by Pleistocene sea level changes. 相似文献
995.
Dr. K. Shuto Dr. N. Tsuchiya Dr. S. Tamura Dr. H. Kagami 《Mineralogy and Petrology》1991,44(3-4):213-234
Summary Shiribeshi Seamount is located to the east of the Okushiri Ridge, in the northeast Japan Sea. Whole rock K-Ar age of olivine-augite andesite dredged from the Seamount was determined to be 0.9 ± 0.2 Ma (Tsuchiya et al., 1989), indicating that Shiribeshi Seamount is a Quaternary volcano in the back-arc region off the junction of the Northeast Japan and Kurile arcs. Shiribeshi volcano is composed of basalt to rhyolite, which show a typical island arc calc-alkaline nature on the basis of petrographical characteristics of 95 samples dredged from four sites. Abundances of incompatible elements including K, Rb, Sr, Nb, P, Ti, Y and Zr in 16 representative rocks are discussed, together with those in the Quaternary volcanic rocks from the NE Japan and Kurile arcs in terms of compositional variation across the arcs. The estimated composition of the primary magma of Shiribeshi volcano is characterized by higher incompatible element contents and a higher Zr/Y ratio than primary magmas in the volcanic front side. Based on HFS element concentrations the degree of partial melting for three primary magmas of Oshima-Oshima, Shiribeshi and Rishiri volcanoes in the northeast Japan Sea may decrease gradually with increasing distance from the volcanic front. However, LIL element contents, especially K and Rb are lower in the primary magma of Rishiri volcano located far from the volcanic front than in the remaining two primary magmas, which would imply that LIL/HFS ratios (or degree of contribution of LIL elements originating from the subducted oceanic crust) become minimal at Rishiri volcano. One basalt and three andesites from Shiribeshi volcano have the restricted range of low87Sr/86Sr ratios of 0.70297–0.70300, which indicates that the magma source for Shiribeshi volcano may be slightly more enriched in Sr isotopic compositions than theN-type MORB source.
With 7 Figures 相似文献
Geochemie des neuentdeckten quartären submarinen Vulkans Shiribeshi im Nordöstlichen Japanischen Meer
Zusammenfassung Der Shiribeshi Seamount liegt östlich des Okushiri Rückens im nordöstlichen Japanischen Meer. Gesamtgesteins K-Ar Alter von Olivin-Augit-Andesiten von diesem Seamount ergeben Werte von 0,9 ± 0,2 Ma (Tsuchiya et al., 1989), und weisen darauf hin, daß Shiribeshi ein quartärer Vulkan im back-arc Bereich nahe dem Kreuzungspunkt des nordostjapanischen und des Kurilen-Inselbogens ist. Er besteht aus Gesteinen, deren Zusammensetzung von Basalt bis Rhyolit reicht. Petrographische Daten von 25 Proben, die von vier submarinen Lokationen durch Dredging aufgesammelt wurden, weisen auf eine typische kalk-alkalische Inselbogenzusammensetzung hin. Die Verbreitung von inkompatiblen Elementen, die unter anderem K, Rb, Sr, Nb, P, Ti, Y und Zr umfassen, in 16 representativen Proben wird zusammen mit denen von quartären vulkanischen Gesteinen aus dem nordöstlichen Japanischen und den Kurilen-Inselbogen diskutiert; dabei wird Variationen der Zusammensetzung über die Bögen hinweg besondere Beachtung geschenkt. Die so ermittelte Zusammensetzung des primären Magmas des Shiribeshi Vulkans wird durch höhere inkompatible Elementgehalte und höhere Zr/Y Verhältnisse charakterisiert, wenn man sie mit primären Magmen an der vulkanischen Stirn des Inselbogens vergleicht. HFS Element-Konzentrationen lassen erkennen, daß der Grad teilweiser Aufschmelzung für drei primäre Magmen von Oshima-Oshima, Shiribeshi und Rishiri im nordöstlichen Japanischen Meer graduell mit zunehmender Entfernung von der vulkanischen Stirm abnimmt. Die Gehalte an LIL Elementen und besonders an K und Rb sind in dem primären Magma des Rishiri Vulkans, der weit von der vulkanischen Front entfernt liegt, höher als in den zwei anderen primären Magmen. Dies weist darauf hin, daß LIL/HFS Verhältnisse (oder der Beitrag von LIL Elementen, die aus subduzierter ozeanischer Kruste stammen) am Rishiri Vulkan ein Minimum erreichen. Ein Basalt und drei Andesite von Shiribeshi zeigen87Sr/86Sr Verhältnisse von 0,70297 bis 0,70300; dies läßt erkennen, daß die Quelle des Magmas für Shiribeshi etwas mehr an87Sr angereichert war, als dieN-Typ Quelle.
With 7 Figures 相似文献
996.
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
997.
998.
Results of numerical simulations using the WRF-ARW nonhydrostatic model are presented for eight episodes of intense convection over European Russia in the summer of 2007. The calculations were performed on four nested grids with horizontal grid meshes of 27, 9, 3, and 1 km. Convection was parametrized on the first two grids and explicitly resolved on the other two. It has been found that simulations on finer grids with explicit calculation of convective flows make it possible to reproduce heavy rainfalls and strong-wind zones in the areas of intense convection. A preliminary verification of the short-range predictions of convective systems shows that the maximum 12-h precipitation totals and the maximum winds at 10 m are close, in the order of magnitude, to the observed values. Prediction of convection centers is the weakest point. Difficulties in the model verification associated with the absence of data with high space-time resolution are discussed. 相似文献
999.
Pranab K. Roy Chowdhury Jeanette E. Weaver Eric M. Weber Dalton Lunga St. Thomas M. LeDoux Amy N. Rose 《International Journal of Digital Earth》2020,13(1):119-135
ABSTRACTUrban areas presently consume around 75% of global primary energy supply, which is expected to significantly increase in the future due to urban growth. Having sustainable, universal energy access is a pressing challenge for most parts of the globe. Understanding urban energy consumption patterns may help to address the challenges to urban sustainability and energy security. However, urban energy analyses are severely limited by the lack of urban energy data. Such datasets are virtually non-existent for the developing countries. As per current projections, most of the new urban growth is bound to occur in these data-starved regions. Hence, there is an urgent need of research methods for monitoring and quantifying urban energy utilization patterns. Here, we apply a data-driven approach to characterize urban settlements based on their formality, which is then used to assess intra-urban urban energy consumption in Johannesburg, South Africa; Sana’a, Yemen; and Ndola, Zambia. Electricity is the fastest growing energy fuel. By analyzing the relationship between the settlement types and the corresponding nighttime light emission, a proxy of electricity consumption, we assess the differential electricity consumption patterns. Our study presents a simple and scalable solution to fill the present data void to understand intra-city electricity consumption patterns. 相似文献
1000.
A. M. Zvyagintsev N. S. Ivanova I. N. Kuznetsova V. A. Lapchenko 《Russian Meteorology and Hydrology》2017,42(5):353-356
The review is based on the results of the operation of the total ozone (TO) monitoring system in the CIS countries. The system is functioning in the operational regime at the Central Aerological Observatory (CAO) and uses the data from the national network equipped with M-124 filter ozonometers being under the methodological supervision of the Main Geophysical Observatory. The quality of the entire system functioning is under operational control based on the observations obtained from neighboring countries and the OMI satellite equipment (NASA, USA). Basic TO observation data are generalized for each month of the first quarter of 2017 and for the first quarter. Data on surface ozone values in the Moscow region and Crimea are also provided. 相似文献