Compressive Episodes and Faunal Isolation during Rifting, Southwest Iberia

Abstract

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Crustal structure of the SW Iberian passive margin: The westernmost remnant of the Ligurian Tethys?

“…Sinemurian to Toarcian sediments blanket the isolated basins of the first phase of extension and record progressive deepening of the basin. This Early Jurassic subsidence phase ended at the transition to the Middle Jurassic (Terrinha et al, 2002). Lower Paleogene successions are evidence of incipient regional uplift during this time.…”

“…The second key target achieved through seismic interpretation was to define the offshore extent of the Algarve Basin. Previous authors have considered the Guadalquivir and Portimão Banks as the southern limit of the Algarve Basin (e.g., Gràcia et al, 2003;Matias et al, 2011;Terrinha et al, 2002). This interpretation was mostly driven by the observed thinning of Mesozoic units onto the Guadalquivir Bank (Figs.…”

The transition from Pangea amalgamation to fragmentation: Constraints from detrital zircon geochronology on West Iberia paleogeography and sediment sources

“…the Lusitanian and Alentejo basins along with others located offshore), whereas the Algarve Basin is usually considered to have resulted from left-lateral motion between Africa and Iberia (Ziegler, 1988;Terrinha et al, 2002;Leleu et al, 2016). The majority of the structures that controlled Triassic rifting were also inherited from the Variscan and pre-Variscan deformation (Pinheiro et al, 1996;Soares et al, 2012;Leleu et al, 2016).…”

The tectono-stratigraphic evolution of an Atlantic-type basin: an example from the Arrábida sector of the Lusitanian Basin

“…It is expressed as i) an angular unconformity, ii) an erosional surface, or iii) a paraconformity with a sudden facies change, but there is no evidence of condensation horizons or clastic influxes. The origin of D9 has been discussed, and different possible causes for its occurrence have been proposed, all involving tectonics at a regional, supra-basinal scale, namely: i) regional uplift related to the opening of the Central Atlantic (Rasmussen et al, 1998); ii) tectonic inversion caused either by thermal uplift of a distal stretched portion of the lithosphere or by distal compression induced by thermal subsidence (Terrinha et al, 2002); or iii) regional factors, including climatic, that intensified the global sea-level regressive trend in Iberia (Azerêdo et al, 2002). After this event, the basin returned progressively from lacustrine conditions to a deep-marine external carbonate platform topped by turbidites.…”