scholarly journals Microplankton composition off NW Iberia at the end of the upwelling season: source areas of harmful dinoflagellate blooms

2008 ◽  
Vol 355 ◽  
pp. 31-43 ◽  
Author(s):  
BG Crespo ◽  
IG Teixeira ◽  
FG Figueiras ◽  
CG Castro
Keyword(s):  
Source Areas ◽  
Nw Iberia ◽  
Harmful Dinoflagellate

Detrital zircon age fingerprinting of NW and SW Iberia Variscan basins: Constraints for the pre-Pangea terrane assemblage analysis and paleogeography

2020 ◽  
Author(s):  
Ícaro Dias da Silva ◽  
Manuel Francisco Pereira ◽  
Emílio González Clavijo ◽  
José R. Martínez Catalán ◽  
Juan Gómez Barreiro ◽  
...  
Keyword(s):  
Statistical Analysis ◽  
Detrital Zircon ◽  
Sedimentary Basins ◽  
Zircon Age ◽  
Drainage Systems ◽  
Middle Ordovician ◽  
Source Areas ◽  
Provenance Studies ◽  
Sedimentary Environments ◽  
Nw Iberia

<p>Synorogenic basins could be linked to a wide variety of sedimentary environments, from continental to deep-marine, in distinct geodynamic settings. The sedimentary evolution of synorogenic basins is mainly controlled by the existence of relief rejuvenation and denudation within and in the surroundings areas. Accumulation of sediment in such basins could react to changes in tectonic settings. Successive extensional or contractional events that are common during the formation of an orogenic belt can induce variations on basin depth, basin depocenter migration and/or repetition of sedimentation-erosion cycles.</p><p>Detrital zircon age fingerprinting of sedimentary basins has proven to be a very sensitive tool for analyzing large and local scale changes in source-terranes, contributing to refine regional paleogeographic models. Recognition of potential source areas could be done by using statistically robust techniques. Kolmogorov-Smirnoff test (K-S) and Multidimensional Scaling (MDS) has been successfully applied to define the fingerprints of sedimentary rocks using detrital zircon age populations and compare with those from potential terrane sources. Comparative statistical analysis of detrital zircon age populations from particular sources and basin strata may be useful to prove sedimentary provenance and distance from source areas, to identify intra-basin sediment recycling and to track multi-source mixing along drainage systems.</p><p>During the Late Devonian-Carboniferous amalgamation of Pangea extensive marine sedimentation occurred in the Variscan orogen on both Laurussia and Gondwana collision margins. Remains of such synorogenic basins are currently located in different sectors of the European Variscan belt, including Iberia.</p><p>Recent provenance studies conducted in SW Iberia Variscan basins have distinguished the contribution of three distinct terrane sources “Gondwana-”, “Laurussia-” and “Variscan magmatic arc-” types, in some cases admitting sediment recycling and mixing of sources. Statistical analysis of detrital zircon age population from NW Iberia Variscan basin allowed us to distinguish two major sources a “Middle Ordovician-Silurian magmatic episode”-type and a “Gondwana”-type. These two types appear to correspond to source areas belonging to the nearby autochthonous and allochthonous units. Gondwanan-type source includes six sub-types whose contributions varied throughout synorogenic basins evolution, indicating that where sedimentary recycling seems to have been relevant.</p><p>Provenance studies on Variscan basins proved to be essential to test if whether or not NW Iberia and SW Iberia synorogenic basins have developed in geographical proximity of Paleozoic Laurussian- or Gondwanan-terrane sources. The differences found between the sources of NW and SW Variscan basins suggest that they would be geographically separated and influenced by independent drainage systems. This finding has provided a better understanding of the framing of Iberia synorogenic basins in paleographic models of Pangea amalgamation.</p><p>Acknowledgements: This study was supported by SYNTHESIS3 project DE-TAF-5798, by “Estímulo ao Emprego Científico – Norma Transitória” by CGL2016-78560-P (MICINN) and by FCT- project UID/GEO/50019/2019 - Instituto Dom Luiz.</p>

An updated sediment source areas inventory in the Rio Cordon catchment (Dolomites)

2017 ◽  
Vol 42 ◽  
pp. 10-13 ◽  
Author(s):  
Caterina Ferrato ◽  
Jessica De Marco ◽  
Paolo Tarolli ◽  
Marco Cavalli
Keyword(s):  
Sediment Source ◽  
Source Areas

Presumed Trade and Aberrant Pottery

1949 ◽  
Vol 5 ◽  
pp. 130-145
Author(s):  
Alex D. Krieger
Keyword(s):  
Mississippi Valley ◽  
Lower Mississippi Valley ◽  
Great Range ◽  
Source Areas ◽  
Site Occupation ◽  
Foreign Origin ◽  
Pronounced Deviation

The pottery in the following sections is not considered to belong to the Alto Focus complex, but to occur with it at different points in the Davis site occupation by trade or other means. If the writer appears to vacillate over what is and what is not trade pottery here, it is due in part to the problem of separating what could have been produced at the site (as extreme variations of resident styles) from what probably was not (because of some distinctive attribute which would mark it as foreign). In certain cases of pronounced deviation, a foreign origin is obvious enough, particularly when the source areas are well known. But where the whole tradition is similar as in the clay-tempered pottery of the lower Mississippi Valley region, and a great range of decorative techniques was employed for long periods of time, the problem is not easy.

Seismic response of large earth dams in near-source areas

2021 ◽  
Vol 132 ◽  
pp. 103807
Author(s):  
Stefania Sica ◽  
Angelo Dello Russo
Keyword(s):  
Seismic Response ◽  
Earth Dams ◽  
Source Areas

scholarly journals Probabilistic identification of rockfall source areas at regional scale in El Hierro (Canary Islands, Spain)

Geomorphology ◽  
2021 ◽  
Vol 381 ◽  
pp. 107661
Author(s):  
Mauro Rossi ◽  
Roberto Sarro ◽  
Paola Reichenbach ◽  
Rosa María Mateos
Keyword(s):  
Canary Islands ◽  
Regional Scale ◽  
Source Areas ◽  
El Hierro

scholarly journals Potential Source Areas for Atmospheric Lead Reaching Ny-Ålesund from 2010 to 2018

Atmosphere ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 388
Author(s):  
Andrea Bazzano ◽  
Stefano Bertinetti ◽  
Francisco Ardini ◽  
David Cappelletti ◽  
Marco Grotti
Keyword(s):  
North American ◽  
Enrichment Factors ◽  
Atmospheric Particulate Matter ◽  
Back Trajectory ◽  
Pb Isotope ◽  
Back Trajectories ◽  
Source Areas ◽  
The North ◽  
Central Asian ◽  
Pb Concentration

Lead content, enrichment factors, and isotopic composition (208Pb/206Pb and 207Pb/206Pb) measured in atmospheric particulate matter (PM10) samples collected for nine years at Ny-Ålesund (Svalbard islands, Norwegian Arctic) during spring and summer are presented and discussed. The possible source areas (PSA) for particulate inferred from Pb isotope ratio values were compared to cluster analysis of back-trajectories. Results show that anthropogenic Pb dominates over natural crustal Pb, with a recurring higher influence in spring, compared to summer. Crustal Pb accounted for 5–16% of the measured Pb concentration. Anthropogenic Pb was affected by (i) a Central Asian PSA with Pb isotope signature compatible with ores smelted in the Rudny Altai region, at the Russian and Kazakhstan border, which accounted for 85% of the anthropogenic Pb concentration, and (ii) a weaker North American PSA, contributing for the remaining 15%. Central Asian PSA exerted an influence on 71–86% of spring samples, without any significant interannual variation. On the contrary, 59–87% of summer samples were influenced by the North American PSA, with higher contributions during 2015 and 2018. Back-trajectory analysis agreed on the seasonal difference in PSA and highlighted a possible increased influence for North American air masses during summer 2010 and 2018, but not for summer 2015.

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