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Francisco González-Sánchez Antoni Camprubí Eduardo González-Partida Rafael Puente-Solís Carles Canet Elena Centeno-García Viorel Atudorei 《Mineralium Deposita》2009,44(3):343-361
Northeastern Mexico hosts numerous epigenetic stratabound carbonate-hosted low-temperature hydrothermal deposits of celestine,
fluorite, barite and zinc-lead, which formed by replacement of Mesozoic evaporites or carbonate rocks. Such deposits can be
permissively catalogued as Mississippi Valley-type (MVT) deposits. The deposits studied in the state of Coahuila are associated
with granitic and metasedimentary basement highs (horsts) marginal or central to the Mesozoic Sabinas Basin. These horsts
controlled the stratigraphy of the Mesozoic basins and subsequently influenced the Laramide structural pattern. The Sabinas
Basin consists of ~6,000-m-thick Jurassic to Cretaceous siliciclastic, carbonate and evaporitic series. The MVT deposits are
mostly in Barremian and in Aptian-Albian to Cenomanian formations and likely formed from basinal brines that were mobilized
during the Laramide orogeny, although earlier diagenetic replacement of evaporite layers (barite and celestine deposits) and
lining of paleokarstic cavities in reef carbonates (Zn–Pb deposits) is observed. Fluid inclusion microthermometry and isotopic
studies suggest ore formation due to mixing of basinal brines and meteoric water. Homogenization temperatures of fluid inclusions
range from 45°C to 210°C; salinities range from 0 to 26 wt.% NaCl equiv., and some inclusions contain hydrocarbons or bitumen.
Sulfur isotope data suggest that most of the sulfur in barite and celestine is derived from Barremian to Cenomanian evaporites.
Regional geology and a compilation of metallogenic features define the new MVT province of northeastern Mexico, which comprises
most of the state of Coahuila and portions of the neighboring states of Nuevo León, Durango and, perhaps extends into Zacatecas
and southern Texas. This province exhibits a regional metal zonation, with celestine deposits to the south, fluorite deposits
to the north and barite and Zn–Pb deposits mostly in the central part. 相似文献
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Roelof D. Schuiling Viorel Badescu Richard B. Cathcart Piet. A. L. C. Van Overveld 《Marine Georesources & Geotechnology》2013,31(1-2):25-37
ABSTRACT Ocean gulfs offer a means of artificially creating a depression, which can be used for a regionally significant hydroelectric macroproject. We examine here the case for a dam at the Strait of Hormuz that blocks a large gulf situated in an arid region. A 35 m evaporation of this concentration basin will reduce its watery surface area by ～53% and allow generation of ～2.050 MW (or possibly ～2.500 MW) of electricity. Our conclusion is that the proposed Electricity Development Infrastructure Node (EDIN) is a feasible and desirable macroproject. If the macroproject starts in the near-term future, it would require a significant change in the logistics of oil and gas transport from this region. Alternatively, it can be considered as an attractive future solution for the energy requirements of the region after exhaustion of its oil and gas reserves. 相似文献
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This paper focuses on different ways of characterizing the solar radiative regime of a day and the stability of this regime. The days may be stratified in classes of cloud shade, observed total cloud cover amount, daily averaged clearness index, and fractal dimension of the solar global irradiance signal. A new Boolean parameter related to solar irradiance fluctuation is defined, namely the sunshine stability number. The time averaged value of the sunshine stability number is used for the characterization of the radiative regime stability during a given time interval. Ranking the days from the view-point of the stability of their radiative regime is performed by using the daily average value of the sunshine stability number and appropriately defined values of disorder and complexity, respectively. Measurements performed in the Romanian town of Timisoara (latitude 45°46?? N, longitude 21°25?? E and 85?m altitude above mean sea level) are used here. They refer to time series of global and diffuse solar irradiance recorded at 15-s time interval between sunrise and sunset during all the days in 2009. 相似文献
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Roelof Dirk Schuiling Richard B. Cathcart Viorel Badescu Dragos Isvoranu Efim Pelinovsky 《Natural Hazards》2007,40(2):327-338
Normally the consequences of an impact of an asteroid in a water body are discussed in terms of the beach run up of impact-generated
waves. If even a small asteroid would hit the Black Sea, however, the potential emissions of toxic and flammable gases could
be more disastrous to the region (comprised of Romania, Ukraine, Russia, Georgia, Turkey and Bulgaria) than the tsunami caused
by the impact. 相似文献
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Two new Boolean parameters are defined: the sunshine number (related to the state of the sky) and the sunshine stability number (which is as a measure of the fluctuation of the radiative regime). Elementary statistical and sequential properties of both parameters are presented in this paper. Actinometric and meteorological data measured at 15?s lag during 2009 in Timisoara (Romania, southeastern Europe) are used. The yearly series of daily averaged sunshine number has negative skewness and kurtosis. The series of daily averaged sunshine stability number has positive skewness and kurtosis. The series of daily averaged values of sunshine number are best described by an ARIMA(0,1,2) model. ARIMA(0,1,0) and ARIMA(0,2,0) models (associated with an appropriately defined white noise) may be used for synthesis of the sunshine number time series. The first model is to be preferred for practical reasons. The series of daily averaged values of sunshine stability number are best described by an ARIMA(2,2,1) model. The ARIMA(0,0,0) model is recommended to be used for generating time series of sunshine stability number. This model may be used for any particular day during the year and the only parameter depending on the day is the white noise standard deviation. A relationship between the white noise standard deviation and the daily averaged sunshine stability number is proposed. 相似文献
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Two-dimensional (2D) and one-dimensional (1D) shallow-water models are used to evaluate the seashore effects of the tsunami
generated by an asteroid impacting the western regions of the Black Sea about 208 km from the coast. The tsunami’s speed and
the effects on the coastal regions depend on many factors, among which the most important is asteroid size. The tsunami generated
by a 250-m asteroid reaches the nearest land location in 24 min and needs about 2 h to arrive at all Black Sea coast. The
run-up value is about 7 m high on the Turkish and Crimean coasts. In the western Black Sea regions the wave height is two
or three times smaller. The run-up values strongly depend on bathymetry and topography peculiarities. The run-in value in
case of the tsunami generated by a 1,000-m asteroid is up to eight times larger than in case of a 250-m impactor, depending
on location. The results reported herein are upper limit values. In case of the 250-m asteroid, the real wave amplitude may
be up to two times smaller. The uncertainty factor decreases in case of larger asteroids. Ways of diminishing the social consequences
are briefly discussed. 相似文献
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Viorel Badescu 《Icarus》2011,216(2):485-491
Bodies with water, ammonia or ethane oceans are possible in interstellar space. This may happen for optically thick atmospheres of methane, ethane and carbon dioxide. 相似文献
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Hysteretic behaviour of reinforced concrete members is strongly dependent on local conditions such as quality of materials, workmanship, construction and design practice. Low strength concrete was found in most of the damaged concrete structures after the earthquakes that have hit Eastern Europe in the past 50 years. Quality of concrete had a great impact, especially on shear controlled reinforced concrete short columns. Existing models of the effective strength, stiffness and deformation capacity of structural members need to be confirmed locally by experimental research as the large data sets used to calibrate the analytical models comprise results obtained on specimens with various characteristics. In this study, effective stiffness and deformation models available in literature are compared with the results of an experimental testing program conducted by the authors to investigate the hysteretic response of reinforced concrete short columns with low concrete strength, designed and detailed according to the local practice in the past. The hysteretic behaviour of the specimens is presented together with a comparison of the experimental data with predicted values and conclusions on the suitability of the applied models are drawn. 相似文献