Stratigraphy and sedimentology of Muschelkalk carbonates of the Southern Iberian Continental Palaeomargin (Siles and Cehegín Formations, Southern Spain)

Abstract

The Triassic sediments of the External Zones of the Betic Cordillera were deposited on the Southern Iberian Continental Palaeomargin. Two coeval Ladinian formations, namely the Siles Formation and the Cehegín Formation, are described to illustrate the facies and lithostratigraphic variability in the Muschelkalk carbonates. There has been some dispute over the number of carbonate units present in the Siles Formation. Our studies assign a tectonic origin to these recurrent carbonate units. Both formations comprise only one carbonate unit, which is correlated to the Upper Muschelkalk of the Catalan and Germanic basins and some Iberian Range sections. To characterize the sedimentological features of these formations, 14 facies were deWned. The most widespread sediment was originally lime mud, although bioclastic deposits are also common. In the facies succession, a main transgressiveregressive sequence could be identiWed. According to the facies model proposed here, a muddy coastal and shallowwater platform prograded over mid ramp deposits. There is no evidence for a seawards reefal or oolitic-bioclastic sandy barrier. The most signiWcant feature of this sedimentary interpretation is that these carbonate facies show clear characteristics of an epicontinental platform.

Trace fossils from the Lower Muschelkalk of Raciborowice Górne (North Sudetic Synclinorium, SW Poland) and their palaeoenvironmental interpretation

“…It is also reported from the inner-middle carbonate ramp (Knaust 1998;, and mostly from shallow carbonate deposits (Monaco and Giannetti 2002;Jach 2005;Waite et al 2008Waite et al , 2013Vlahovic et al 2011;Wiedl et al 2012Wiedl et al , 2013. Thalassinoides was described from the upper part of the shallowing upward cycle (Knaust 1998;Pérez-Valera and Pérez-López 2008;Pérez-López and Pérez-Valera 2012).…”

“…The occurrence of Thalassinoides at the transition from a quiet water (middle shelf micritic firmgrounds) setting to higher energy, more nearshore settings (intertidal) is commonly reported (e.g., Pruss and Bottjer 2004). T. suevicus occurring in platy limestones is typical of middle ramp settings and usually occurs in the upper part of shallowing-upward cycles (Knaust 1998(Knaust , 2002Pérez-Valera and Pérez-López 2008;. In the Raciborowice Górne section IA 3 appear twice, always preceeding IA 4 characterising hardground horizons (Text- fig.…”

The Triassic platform of the Gador-Turon unit (Alpujarride complex, Betic Cordillera, southeast Spain): climate versus tectonic factors controlling platform architecture

“…Particularly the westernmost part of Pangaea, during the Middle and Late Triassic, underwent repeated episodes of continental crust thinning leading to flooding from the sea. This evolution was accompanied by several transgressive-regressive cycles recorded in most sectors of the Neo-Tethyan platform system (Delgado et al 1981;Bosellini 1984;Martín-Algarra 1987;Iannace et al 1995;Rüffer and Zamparelli 1997;Gianolla and Jacquin 1998;García-Tortosa 2002;Martín-Algarra and Vera 2004;Martín-Martín et al 2006;Pérez-Valera and Pérez-López 2008;Martin-Rojas et al 2009;Schlager and Keim 2009; among many others).…”

Discussion about the stratigraphic range of "Pseudofurnishius murcianus" van den Boogaard (Conodonta) in the Iberian Peninsula, from the Calasparra section (Murcia, Spain)

“…The column, 90 m thick, comprises five units based on the ammomoid biozonation of Pérez-Valera et al (2005), Pérez-Valera and Pérez-López (2008) and Pérez-Valera et al (2011) (Fig. 2).…”

“…Above it, Muschelkalk deposits consist of carbonate successions of dolomites, limestones and marly limestones, increasingly dominated by marls towards the upper part. This unit was defined as Cehegín Formation (Pérez-Valera and Pérez-López, 2008) and can be correlated with the Majanillos Formation (Pérez-López, 1991) that was defined in the central part of the Betic Cordillera. Finally, a detrital-evaporitic unit with shale, sandstone, gypsum, and occasional basic subvolcanic rocks represents a characteristic Keuper facies that belong to the Jaén Keuper Group (Pérez-López 1991).…”