20 research outputs found
The record of the latter glacial and interglacial periods in the Guadalquivir marshlands (Mari López drilling, S.W. Spain)
El estudio de un sondeo de 65 m en las marismas del Guadalquivir permite reconocer siete intervalos que reflejan cambios climáticos y eustáticos e intensa neotectónica durante tres periodos ¡nterglaciares (IS 71, 5 y i) y dos glaciares (IS 6-Riss-, IS 4, 3 y 2-WQrm). Se discute el valor de las 'vetas' como indicadores paleogeográficosPeer reviewe
Experimental Demonstration of a Magnetically Induced Warping Transition in a Topological Insulator Mediated by Rare-Earth Surface Dopants
The record of the lalter glacial and interglacial periods in the Guadalquivir marshlands (Mari López drilling, S.W. Spain)
El estudio de un sondeo de 65 m en las marismas del Guadalquivir permite reconocer siete intervalos que
reflejan cambios climáticos y eustáticos e intensa neotectónica durante tres periodos interglaciares (IS 7?,
5 Y 1) Y dos glaciares (15 6-Riss-, 154, 3 Y 2-Würm). Se discute el valor de las 'vetas' como indicadores
paleogeográficos
Record of anthropogenic environmental impact in the continental shelf north of Barcelona city
International symposium on applications of isotope techniques in studying past and current environmental changes in the hydrosphere and the atmosphere, 19-23 April 1993, Vienna, Austria.--10 pages, 4 figures, 1 tableThe continental shelf off the Barcelona coast receives polluted materials discharged by the Besós and the Llobregat rivers. A marine sediment core from the Besós river mouth in the inner prodelta (TG8) was dated by the analysis of excess 210Pb using a modified version of the CRS/MV method. The mean sedimentation rate was 1.74 ± 0.09 mm/year and its evolution showed a slow decrease from 1923 which became faster from 1962, in good agreement with the two most important periods o f industrial and demographic expansion in Catalonia. Heavy metals concentrations were determined by ICP-AES and showed high values in surface samples for Cr, Cu, Zn and Pb. The observed fluxes reflected well the industrial development of Catalonia, showing two important growth periods during the 1920s and the 1960s. Soot particles were found in all samples by pollen analysis and showed the impact of the combustion of fossil fuel in cars and a nearby fuel oil/natural .gas power plan
A beach-ridge progradation complex reflecting periodical sea-level and climate variability during the Holocene (Gulf of Almería, Western Mediterranean)
Detailed mapping based on aerial photographs at various scales, analysis of morpho-sedimentary units, and radiocarbon
dating of the prograding beach-ridge complex of Campo de Dalı´as (Almerı´a) allow the differentiation of six prograding units.
These are called: H1, 7400–6000 cal BP; H2, 5400–4200 cal BP; H3, 4200–3000 cal BP; H4, 2700–1900 cal BP; H5, 1900–
1100 cal BP; and H6, 500 cal BP–Present. H-units are deposited during periods of high relative sea level and increased
sediment input to the coast. They are bounded by large swales or erosional surfaces associated with lower sea levels and
reduced input of sediment to the coast; these correspond to short periods of increased aridity inside the general arid trend
recorded in the Western Mediterranean since 5.4 ka. Changes in the flux of Atlantic superficial waters into the Mediterranean
Sea, and relative strength of the W/SW winds account for the recorded oscillations of relative sea level.
We deduce a decadal periodicity for the deposition of a beach ridge and the adjacent swale, and suggest that it is related to
fluctuations of the North Atlantic Oscillation (NAO) index and to variations of solar activity. The duration of H-units shows a
quasi-millennial periodicity punctuated by short (hundred years) episodes of reduced progradation or erosion representing
events of increased aridity likely to be related to Bond’s Holocene cold events
Quaternary palaeoenvironmental changes in South Spain
This paper presents the existing differences between the evolution of the
Holocene landscape of the Southeastern and Southwestern areas of the Iberian
Peninsula. Moreover, some palaeoenvironmental characteristics of OIS 4 and OIS 3
of the western Andalusia appear. The five presented sequences have been analyzed
from palynological and geomorphological point of view. The obtained results show
that during the Holocene no significant forest cover existed in the eastern area and
that the different phases identified mainly show an alternation of shrub and steppe
communities, taking place during the fifth millennium a radical transformation of
the landscape and the definitive establishment of the semi-desert conditions that
are registered at the present time. In the western area the evolution of the landscape
is determined basically by the changes of geomorphological conditions of the coast
and the marshland zones of the Guadalquivir and the Tinto-Odiel systems, registering
diverse moments of increase of the aridity conditions, without remarkable changes
in the vegetal landscape. Sequences obtained do not provide evidence of indicators
of human intervention that might be clearly attributable to the pattern of human
activities established in the area until a the two millennium ago
El registro de los últimos periodos.glaciares e ¡nterglaciares en las marismas del Guadalquivir (sondeo Mari López, S.O. de España)
El estudio de un sondeo de 65 m en las marismas del Guadalquivir permite reconocer siete intervalos que reflejan cambios climáticos y eustáticos e intensa neotectónica durante tres periodos ¡nterglaciares (IS 71,
5 y i) y dos glaciares (IS 6-Riss-, IS 4, 3 y 2-WQrm). Se discute el valor de las 'vetas' como indicadores paleogeográfico
The Mazarrón Pb–(Ag)–Zn mining district (SE Spain) as a source of heavy metal contamination in a semiarid realm: Geochemical data from mine wastes, soils, and stream sediments
The Mazarrón epithermal ore deposits (SE Spain) formed in Miocene time in relation to the emplacement of
dacitic–rhyodacitic domes. The Pb–(Ag)–Zn ore deposits are of the high sulphidation vein and stockwork
type. There are two main mining sites: San Cristóbal–Perules (adjacent to the town of Mazarrón) and
Pedreras Viejas. The area is located in the southern realm of a Miocene marine basin surrounded by
mountains in its western, eastern and southern flanks. A main seasonal river (Rambla de las Moreras) crosses
the basin from North to South and is strongly affected by contaminated sediments from the San Cristóbal–
Perules mining site. The mine tailings are extremely rich in Pb (mean=12,400 μg g−1) and Zn
(mean=6100 μg g−1), whereas As concentrations are also very high (mean=650 μg g−1). Our geochemical
survey also covered anthropic soils, stream sediments and the so-called almagres deposits (red alum
calcines). All these environmental matrices have also very high concentrations of Pb, Zn, As, and Cd
compared to our local or world baseline concentrations. The calcines are rich in As (mean=450 μg g−1), and
the main environmental concern relates to the wrong use of these materials as agricultural soils at discrete
sites in the district. Besides, the anthropic soils of the district are very rich in Pb (mean=2550 μg g−1) and
Zn (mean=1870 μg g−1). On the other hand, the seasonal river Rambla de las Moreras receives
contaminated sediments from the San Cristóbal–Perules old mining site and mine wastes, which results in
high concentrations of As (mean=120 μg g−1), Pb (mean=2700 μg g−1) and Zn (mean=1090 μg g−1) in
the sediments. These high concentrations of dangerous contaminants in an area close to a town of 35,000
inhabitants and adjacent to significant agricultural activity may pose a risk to human health
Discussion: Reply to the comments by Mauz, B. and Antonioli, F. on “Sea Level and Climate Changes during OIS 5e in the Western Mediterranean”
We really appreciate the comments by Mauz and Antonioli on our paper (Bardají et al., 2009), but here we respond to the erroneous statements made in their critical reading of our work.
We agree with the authors' historic review of the problems raised when effects of tectonics and sea level oscillations are observed in the record of relative sea-level changes in Western Mediterranean. We should not forget that the Mediterranean itself constitutes a collision plate boundary, with few stable areas within it. Therefore, the study of the Last Interglacial shorelines cannot be simply analysed according to altitude, as they say. What we do not share with Mauz and Antonioli is that “the only solution to this seemed to be determining the age of a coastal deposit using radiometric, dosimetric and chemical dating techniques”.Research financed by Projects CGL2008-3998, CGL2008-04000 and GRACCIE-CSD-2007-00067. CHM acknowledges the financial support from the Science and Engineering Research Council of Canada and the UNESCO Chair for Global Change Study of Université du Québec à Montréal. This paper is a contribution to IGCP495 (Quaternary Land Ocean Interactions: Driving Mechanisms and Coastal Responses), INQUA Commission on Coastal and Marine Processes and CM Work Group Paleoclimatology and Global Change (UCM 910198).Peer reviewe