Volcanic stratigraphy of the Quaternary La Garrotxa Volcanic Field (north-east Iberian Peninsula)

2014 ◽  
Vol 29 (6) ◽  
pp. 547-560 ◽  
Author(s):  
XAVIER BOLÓS ◽  
LLORENÇ PLANAGUMÀ ◽  
JOAN MARTÍ
Keyword(s):  
Iberian Peninsula ◽  
Volcanic Field ◽  
Volcanic Stratigraphy ◽  
North East ◽  
Garrotxa Volcanic Field

scholarly journals Space–time evolution of monogenetic volcanism in the mafic Garrotxa Volcanic Field (NE Iberian Peninsula)

2013 ◽  
Vol 75 (11) ◽  
Author(s):  
C. Cimarelli ◽  
F. Di Traglia ◽  
D. de Rita ◽  
D. Gimeno Torrente ◽  
J-. L. Fernandez Turiel
Keyword(s):  
Iberian Peninsula ◽  
Time Evolution ◽  
Volcanic Field ◽  
Space Time ◽  
Monogenetic Volcanism ◽  
Garrotxa Volcanic Field ◽  
Ne Iberian Peninsula ◽  
Space Time Evolution

Biogeographical patterns derived from remote sensing variables: the amphibians and reptiles of the Iberian Peninsula

2009 ◽  
Vol 30 (2) ◽  
pp. 185-206 ◽  
Author(s):  
◽  
◽  
◽  
Keyword(s):  
Remote Sensing ◽  
Iberian Peninsula ◽  
Gap Analysis ◽  
Hierarchical Cluster ◽  
Environmental Data ◽  
Species Density ◽  
Biogeographic Patterns ◽  
North East ◽  
Density Maps ◽  
Reptile Species

AbstractThe biogeographic patterns in species density of herptiles were analysed in the Iberian Peninsula. Geoclimatic regions were identified using a PCA. Individual habitat suitability (HS) models for 23 amphibians and 35 reptiles at 10 × 10 km scale were calculated with ENFA, using 12 environmental factors established with Remote Sensing (RS) techniques. The species presence proportion in each geoclimatic region was calculated through a cross-tabulation between each potential occurrence model and the geoclimatic regions. Species chorotypes were determined through Hierarchical Cluster Analysis using Jaccard's index as association measure and by the analysis of marginality and tolerance factors from individual HS models. Predicted species density maps were calculated for each geoclimatic region. Probable under-sampled areas were estimated through differences between the predicted species density maps and observed (Gap analysis). The selected PCA components divided the Iberian Peninsula in two major geoclimatic regions largely corresponding to the Atlantic and Mediterranean climates. The Jaccard's index clustered herptiles in two main taxonomic groups, with distribution similar to the Atlantic and Mediterranean geoclimatic regions (7 amphibian + 13 reptile species in three Atlantic subgroups and 16 amphibian + 22 reptile species in four Mediterranean subgroups). Marginality and tolerance factor scores identified species groups of herptile specialists and generalists. The highest observed and predicted species density areas were broadly located in identical regions. Predicted gaps are located in north-western, north-east and central Iberia. RS is a useful tool for biogeographical studies, as it provides consistent environmental data from large areas with high accuracy.

The control of preexisting faults on the distribution, morphology, and volume of monogenetic volcanism in the Michoacán-Guanajuato Volcanic Field

2020 ◽  
Vol 132 (11-12) ◽  
pp. 2455-2474 ◽  
Author(s):  
Martha Gabriela Gómez-Vasconcelos ◽  
José Luis Macías ◽  
Denis Ramón Avellán ◽  
Giovanni Sosa-Ceballos ◽  
Víctor Hugo Garduño-Monroy ◽  
...  
Keyword(s):  
Hanging Wall ◽  
Temporal Distribution ◽  
Volcanic Field ◽  
Fault System ◽  
Volcanic Stratigraphy ◽  
Listric Fault ◽  
Tectonic Processes ◽  
State Of Stress ◽  
Geological Map ◽  
Scoria Cones

Abstract Interactions between volcanic and tectonic processes affect the distribution, morphology, and volume of eruptive products in space and time. The Queréndaro area in the eastern Michoacán-Guanajuato Volcanic Field affords an exceptional opportunity to understand these relationships. Here, a Pleistocene lava plateau and 20 monogenetic volcanoes are vented from an active ENE-striking segment of the Morelia-Acambay fault system. Thirteen scoria cones are aligned along this structure, vented from an extensional gap in between two rotated hanging wall blocks of a listric fault. A new geological map, volcanic stratigraphy, and 40Ar/39Ar dating indicate that this lava plateau and volcanic cluster were emplaced from 0.81 to 0.25 Ma by 11 intermittent eruptive epochs separated by ca. 0.05 Ma, emplacing a total magma volume of 5 km3. Petrography and chemistry of rocks suggest that all volcanic structures were fed by three different magma batches but vented from independent feeder dikes. Our results indicate that preexisting faults exert a strong influence on volcanic spatial and temporal distribution, volcanic morphology, magma volume, and eruptive dynamics in this area. ENE-breached and ENE-elongated scoria cones indicate parallel subsurface fissure and feeder dikes. Additionally, points of maximum fault dilation at depth related to a transtensive state of stress coincide with less fragmented deposits and larger magma volumes. Furthermore, this study raises important questions on the geodynamics of volcano-tectonic interactions possible in similar monogenetic volcanic alignments worldwide.

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