Climate changes during the Early–Middle Triassic transition in the E. Iberian plate and their palaeogeographic significance in the western Tethys continental domain

Abstract

Until recently the climate of the Early-Middle Triassic at low latitudes was broadly considered as generally temperate-warm with no major climate oscillations. This work examines the climate of this period through a detailed study of the sedimentary, plant, soil and mineral records of continental rocks (Buntsandstein facies) in eastern Iberian basins. Our findings indicate temporal climate variations for these near equator (10º-14ºN) regions and unveil the significance of such variations in the southern Laurasian domain. *Revision with No Changes Marked Click here to view linked References Iberia was crossed by prominent irregular highs separating marked corridors or isolated areas. This palaeogeography, prevailing since Variscan tectonics, clearly conditioned dominant climates and their geographical distribution. No clear climate belts developed in these conditions. However, isolated internal climate zones separated by elevated areas are identified. This palaeogeographic configuration and the low latitudinal position of Iberia determined central Iberia highs in the southernmost border of Laurasia, beyond which more humid conditions clearly extended towards the equator reaching the present-day Moroccan Meseta and Argana Basin.

Basin‐scale fluvial correlation and response to the Tethyan marine transgression: An example from the Triassic of central Spain

“…The Triassic Buntsandstein and Muschelkalk facies of latest Anisian to early Ladinian were deposited during a time span of ~2 to 4 Ma (Figure 3; e.g. Muñoz et al., 1992; López‐Gómez & Arche, 1993a, 1993b; Borruel‐Abadía et al., 2015). Assuming a transgression distance of 80 km, derived from outcrop data used in this study, a rate of transgression advance of 0.04–0.02 m/year can be estimated.…”

“…This increased stability is favoured by a changing climate in the basin caused by the Tethyan marine transgression. Regular precipitation periods and, in general, a wetter climate resulted in vegetation growth on the floodplains thus increasing bank stability and sinuosity (Borruel-Abadía et al, 2015;López-Gómez et al, 2012;Preto, Kustatscher, & Wignall, 2010). A wetter climate is supported by the Pangaean monsoonal circulation, which reached its maximum strength during the Triassic and counts as a major factor for the continent-wide increase in precipitation from the Permian to the Early Triassic (Parrish, 1993 In general, accommodation space was outstripping sediment supply in the early synrift stages and diminished through time resulting in an increase in sinuosity accompanied by a decrease in slope before the final marine flooding surface.…”

“…Detailed descriptions of the Permo‐Triassic sediments have been made (see Arche & López‐Gómez, 1999a, 1999b; Arche & López‐Gómez, 1999; Arche, López‐Gómez, Marzo, & Vargas, 2004; Borruel‐Abadía et al., 2015; Bourquin et al., 2011; Bourquin, Durand, Diez, Broutin, & Fluteau, 2007; Diez et al., 2010; López‐Gómez & Arche, 1993a, 1993b; López‐Gómez & Arche, 1993a, 1993b; López‐Gómez & Arche, 1997; López‐Gómez et al., 2002; López‐Gómez et al., 2012; Ramos et al., 1986; Sopeña et al., 1988; Van Wees, Arche, Beijdorff, López‐Gómez, & Cloetingh, 1998). Formations throughout the basin were named differently according to their location along the NW‐SE striking axis of the Iberian Ranges and specifically the Castillian Branch.…”

“…In early Permian times, the Iberian Peninsula occupied the central‐eastern side of Pangea, in the southernmost part of the Laurasia megacontinent and near the western margin of the Tethys Sea (Borruel‐Abadía et al., 2015; De la Horra et al., 2012). The breakup of Pangea led to the development of three main rift systems (Catalonia‐Valencia‐Prebetic, Pyrenean‐Asturian and Iberian Basins) in Iberia, which continued to the middle Cretaceous, until the Peninsula was separated from the European continent (Salas et al., 2001).…”

Integrated multi-stratigraphic study of the Coll de Terrers late Permian–Early Triassic continental succession from the Catalan Pyrenees (NE Iberian Peninsula): A geologic reference record for equatorial Pangaea

“…The URU/Buntsandstein boundary is commonly an angular unconformity (Gisbert et al, 1985;Gretter et al, 2015;Mujal et al, 2016aMujal et al, , 2017, as also occur in the other Permian-Triassic Iberian basins (Borruel-Abadía et al, 2015) and generally in the whole Western Europe (Bourquin et al, 2011). This is not the case of the Coll de Terrers area (Alt Urgell, Catalonia, NE Iberian Peninsula; Fig.…”