Deep incision in an Aptian carbonate succession indicates major sea‐level fall in the Cretaceous     

Telm Bover‐Arnal  Ramon Salas  Joan Guimerà  Josep Anton Moreno‐Bedmar 《Sedimentology》2014,61(6):1558-1593

Long‐term relative sea‐level cycles (0·5 to 6 Myr) have yet to be fully understood for the Cretaceous. During the Aptian, in the northern Maestrat Basin (Eastern Iberian Peninsula), fault‐controlled subsidence created depositional space, but eustasy governed changes in depositional trends. Relative sea‐level history was reconstructed by sequence stratigraphic analysis. Two forced regressive stages of relative sea‐level were recognized within three depositional sequences. The first stage is late Early Aptian age (intra Dufrenoyia furcata Zone) and is characterized by foreshore to upper shoreface sedimentary wedges, which occur detached from a highstand carbonate platform, and were deposited above basin marls. The amplitude of relative sea‐level drop was in the order of tens of metres, with a duration of <1 Myr. The second stage of relative sea‐level fall occurred within the Late Aptian and is recorded by an incised valley that, when restored to its pre‐contractional attitude, was >2 km wide and cut ≥115 m down into the underlying Aptian succession. With the subsequent transgression, the incision was backfilled with peritidal to shallow subtidal deposits. The changes in depositional trends, lithofacies evolution and geometric relation of the stratigraphic units characterized are similar to those observed in coeval rocks within the Maestrat Basin, as well as in other correlative basins elsewhere. The pace and magnitude of the two relative sea‐level drops identified fall within the glacio‐eustatic domain. In the Maestrat Basin, terrestrial palynological studies provide evidence that the late Early and Late Aptian climate was cooler than the earliest part of the Early Aptian and the Albian Stage, which were characterized by warmer environmental conditions. The outcrops documented here are significant because they preserve the results of Aptian long‐term sea‐level trends that are often only recognizable on larger scales (i.e. seismic), such as for the Arabian Plate.  相似文献   

GPR survey to confirm the location of ancient structures under the Valencian Cathedral (Spain)     

Vega Prez Gracia  Jos Antonio Canas  Lluis G. Pujades  Jaume Claps  Oriol Caselles  Francesc García  Raul Osorio 《Journal of Applied Geophysics》2000,43(2-4)

This paper describes the ground-penetrating radar (GPR) survey performed inside the Cathedral of Valencia, Spain. It is part of historical studies performed in the Cathedral in order to add information to old maps and documents in the Cathedral Archives and also to analyze the extent and importance of potentially destructive moisture areas that were appearing on the floor. The construction of the Cathedral of Valencia occurred in three stages, all of which are well-documented in the Cathedral Archives with detailed drawings, maps, and charts. The radar data were successful in locating crypts, ossuaries, sepulchers, and graves, and the location of ancient walls that existed before the final Cathedral expansion. Three cultural layers corresponding to the three periods of construction were also identified corresponding to the Roman, Arabian and Middle Age Epochs. Measurements of relative sub-floor moisture were obtained by comparing dielectric permittivity changes and radar velocity differences between materials in humid and non-humid areas.  相似文献   

The exoplanet handbook     

Josep M. Trigo‐Rodríguez 《Meteoritics & planetary science》2012,47(3):449-451

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March 1, 2005 Daylight Fireball Over Galicia (NW of Spain) and Minho (N. Portugal)     

José Angel Docobo  Josep Maria Trigo-Rodríguez  Jiri Borovicka  Vakhtang S. Tamazian  Vera Assis Fernandes  Jordi Llorca 《Earth, Moon, and Planets》2008,102(1-4):537-542

A daylight bolide was observed over Galicia (NW Spain) and Minho (N. Portugal) on March 1, 2005 at 15 h10 min ± 3 min UTC. We interviewed 23 eyewitnesses of the event in order to obtain the azimuth, altitude, and slope of the fireball’s trajectory. Reports suggest an atmospheric ending height below 20 km, indicating that meteorite survival was likely. From the reconstructed trajectory and the fireball’s duration, we obtained the approximate heliocentric orbits for the meteoroid. Assuming an entry velocity higher than 20 km s⁻¹ which is consistent with its estimated duration, the meteoroid originated in the asteroid belt.  相似文献   

Meteorites and the early solar system II,edited by Dante S. Lauretta and Harry Y. McSween,Jr.     

Josep M. Trigo‐Rodríguez 《Meteoritics & planetary science》2008,43(5):989-991

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Management alternatives to offset climate change effects on Mediterranean fire regimes in NE Spain   总被引：1，自引：0，他引：1  

Lasse Loepfe  Jordi Martinez-Vilalta  Josep Pi?ol 《Climatic change》2012,115(3-4):693-707

Fire regime is affected by climate and human settlements. In the Mediterranean, the predicted climate change is likely to exacerbate fire prone weather conditions, but the mid- to long-term impact of climate change on fire regime is not easily predictable. A negative feedback via fuel reduction, for instance, might cause a non-linear response of burned area to fire weather. Also, the number of fires escaping initial control could grow dramatically if the fire meteorology is just slightly more severe than what fire brigades are prepared for. Humans can directly influence fire regimes through ignition frequency, fire suppression and land use management. Here we use the fire regime model FIRE LADY to assess the impacts of climate change and local management options on number of fires, burned area, fraction of area burned in large fires and forest area during the twenty-first century in three regions of NE Spain. Our results show that currently fuel-humidity limited regions could suffer a drastic shift of fire regime with an up to 8 fold increase of annual burned area, due to a combination of fuel accumulation and severe fire weather, which would result in a period of unusually large fires. The impact of climate change on fire regime is predicted to be less pronounced in drier areas, with a gradual increase of burned area. Local fire prevention strategies could reduce but not totally offset climate induced changes in fire regimes. According to our model, a combination of restoring the traditional rural mosaic and classical fire prevention would be the most effective strategy, as a lower ignition frequency reduces the number of fires and the creation of agricultural fields in marginal areas reduces their extent.  相似文献   

Recent results on X-ray novae and microquasars at radio and infrared wavelengths     

Josep Martí 《Astrophysics and Space Science》2001,276(1):3-12

The Spanish MINISAT program has been structured in three main stagesplus several associated developments, achieving a modular family of lowcost platforms in the small satellite segment, designed to use mainly in lowearth orbit (LEO) applications. The first stage of the MINISAT programhave concluded with the complete development and orbit qualification ofthe platform MINISAT 0 together with the operational experiences is beingachieved to perform the scientific mission 01, launched on April 21^st 1997. The second stage of the MINISAT program consist of the modularupgrading of the platform 0 to reach the maximum performances orplatform MINISAT 1 to do earth observation missions. The first missionwith the platform 1 started the phase A of feasibility study in 1995. Thethird stage of the MINISAT program will consist of the development of theplatform MINISAT 2 that will be an adaptation of the platform MINISAT1 to be able to do communication missions even in the geostationary orbit.  相似文献   

Stratigraphic and structural controls on groundwater flow in an outcropping fossil fan delta: the case of Sant Llorenç del Munt range (NE Spain)     

Marc Anglés  Albert Folch  Oriol Oms  Eudald Maestro  Josep Mas-Pla 《Hydrogeology Journal》2017,25(8):2467-2487

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Application of Multiple Point Geostatistics to Non-stationary Images   总被引：5，自引：2，他引：3  

Luis Manuel de Vries  Jesus Carrera  Oriol Falivene  Oscar Gratacós  Luit Jan Slooten 《Mathematical Geosciences》2009,41(1):29-42

Simulation of flow and solute transport through aquifers or oil reservoirs requires a precise representation of subsurface heterogeneity that can be achieved by stochastic simulation approaches. Traditional geostatistical methods based on variograms, such as truncated Gaussian simulation or sequential indicator simulation, may fail to generate the complex, curvilinear, continuous and interconnected facies distributions that are often encountered in real geological media, due to their reliance on two-point statistics. Multiple Point Geostatistics (MPG) overcomes this constraint by using more complex point configurations whose statistics are retrieved from training images. Obtaining representative statistics requires stationary training images, but geological understanding often suggests a priori facies variability patterns. This research aims at extending MPG to non-stationary facies distributions. The proposed method subdivides the training images into different areas. The statistics for each area are stored in separate frequency search trees. Several training images are used to ensure that the obtained statistics are representative. The facies probability distribution for each cell during simulation is calculated by weighting the probabilities from the frequency trees. The method is tested on two different object-based training image sets. Results show that non-stationary training images can be used to generate suitable non-stationary facies distributions.  相似文献   

New archaeo‐stratigraphic data for the TD6 level in relation to Homo antecessor (Lower Pleistocene) at the site of Atapuerca,north‐central Spain     

Antoni Canals  Josep Vallverdú  Eudald Carbonell 《Geoarchaeology》2003,18(5):481-504

The sediments of the TD6 level of Gran Dolina Cave at Sierra de Atapuerca, Burgos, Spain, consist of a series of mud flows with angular clasts. The TD6 deposit has two parts: an upper part, known as the Aurora stratum, which yields Homo antecessor remains, and a lower part with rather homogeneous sediment. The excavation of TD6 level did not reveal a sequence of diachronic occupations. Instead, the contextual and stratigraphic studies permitted us to describe and delimit the micro‐units forming the TD6 deposit. The study of the distribution of archaeological remains based on vertical archaeological profiles, using an archaeo‐stratigraphic method, allowed us to document the occurrence of a series of archaeological levels within the apparent homogeneous deposit. Variations in the density of archaeological remains along the archaeo‐stratigraphic levels permitted us to define two occupational cycles in TD6. These cycles seemingly show increased activities through time, culminating in the Aurora level with the presence of cannibalized Homo antecessor remains. © 2003 Wiley Periodicals, Inc.  相似文献