Tempestite facies models for the epicontinental Triassic carbonates of the Betic Cordillera (southern Spain)

Abstract

This study focuses on storm deposits in the Muschelkalk facies of the Betic Cordillera (southern Spain) and interprets their deposition mechanisms. Three types of storm deposit are distinguished: (i) pot/gutter casts; (ii) tempestite beds; and (iii) storm-winnowed deposits. Each deposit provides information about the carbonate platform environment in which it was deposited. The tempestite models proposed are: (i) the bypass-zone tempestite model, occurring in a muddy ramp at the epicontinental basin margin. This model is characterized by potholes and gutters that form in a shoreline bypass-zone during storms; (ii) the gradient-current tempestite model in which frequent tempestite beds are related to storm gradient currents. Thickness and grain size decrease towards the deep distal ramp; and (iii) the winnowed deposit tempestite model whereby storm deposits are winnowed and deposited in the same environment with only short lateral transport having occurred. This model evokes more restricted and shallower conditions, lagoons or inland seas. The distribution of all these deposits in the stratigraphic sections studied corroborate the eustatic third-order cycle identified, although the different features of the storm deposits and their positions in each section indicate a subsidence varying in time and space. In the transgressive stage, the margins of the epicontinental basin were a well-developed ramp with potholes and gutters. In contrast, during the high sea-level stage, storm deposits generated tempestite beds or storm-winnowed deposits in the different areas. The epicontinental carbonate platform with ramp edges evolved into a complex depositional system of coastal and shallow-marine environments with lagoons and restricted inland seas. Thus, the epicontinental platform underwent substantial change from the Late Anisian to the Late Ladinian and this is reflected in its storm deposits.

Paleogeographic significance of Upper Triassic basinal succession of the Tamar Valley, northern Julian Alps (Slovenia)

“…Bivalve coquinas with internal erosional surfaces are interpreted as tempestites (Schlaf 1996;Pérez-López & Pérez-Valera 2012), and they support the idea of an episodically high-energy environment above the storm wave base, whereas the fossil assemblage suggests normal marine conditions. A nearshore, shallow water depositional setting was suggested by De Zanche et al (2000) for the Tor Formation at Cave del Predil.…”

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

“…Recently, MacEachern et al (2012) and suggested that it characterizes mainly the Glossifungites ichnofacies. B. triadicus is common in carbonates of very shallow to intertidal marine environments (Knaust 1998;Pérez-López and Pérez-Valera 2012).…”

“…However, a few reports on the Middle Triassic carbonate successions of Germany (e.g. Knaust 1998Knaust , 2007a, southern Spain and Italy (Sardinia) (Rodríguez-Tovar et al 2007;Rodríguez-Tovar and Pérez-Valera 2008;Knaust and Costamagna 2012;Pérez-López and Pérez-Valera 2012) were published recently.…”

Taphonomic implications from Upper Triassic mass flow deposits: 2-dimensional reconstructions of an ammonoid mass occurrence (Carnian, Taurus Mountains, Turkey)

“…Current induced alignment, winnowing and earth quakes or storm events (Aigner 1985;Brett & Baird 1986;Seilacher & Aigner 1991;Hips 1998;Radley & Barker 1998;Storms 2001;Pérez-Lopéz & Pérez-Valera 2012) are discussed as trigger factors for such gravity forced 'event beds'. The described examples are thus autocyclic (Einsele et al 1991b), formed by nonperiodic mass flows and/ or turbidites endemic to the tectonic setting (Bouma et al 1982;Cook et al 1982;Howell & Normark 1982;Tucker & Wright 1990;Potter et al 2005;Hornung 2008).…”

“…debris flows, grain flows or turbidity currents; Middleton & Hampton 1973, 1976Flügel 1978Flügel , 2004Lowe 1982 Kawakami & Kawamura 2002;Potter et al 2005;Nichols 2009;SEPM 2014), also termed gravity flows or density currents, will be discussed in respect to resedimentation of sediments and biogenic components. The determination of specific mechanisms in terms of the genesis concerning event bed deposition, storm deposition, shell accumulation and the consequences for the facies and bioclastic fabric were reported and discussed in Aigner (1982aAigner ( , 1985, Einsele & Seilacher (1982), Kreisa & Bambach (1982), Brett & Baird (1986), Kidwell (1986Kidwell ( , 1991aKidwell ( ,b, 1993a, Kidwell et al (1986), Tucker & Wright (1990), Brett & Seilacher (1991), Chuanmao et al (1993), Einsele et al (1991a,b), Seilacher & Aigner (1991), Soja et al (1996), Hips (1998), Fürsich & Pandey (1999), Martin (1999), Storms (2001), Lukeneder (2003aLukeneder ( ,b, 2004a, Fernández-López (2007), Montiel-Boehringer et al (2011), andPérez-Lopéz &Pérez-Valera (2012). The result is a detailed succession of abundance or accumulation layers (i.e.…”