Definition of sequences through ichnocoenoses and taphofacies: An example from the Sácaras Formation (early Cretaceous, eastern Spain) A. Giannetti a, ⁎, P. Monaco b a Departamento de Ciencias de la Tierra y del Medio Ambiente, Universidad de Alicante, Apdo.99, 03080 Alicante, Spain b Dipartimento di Fisica e Geologia, Universitá degli Studi di Perugia, via Pascoli snc, 16123 Perugia, Italy abstract article info Article history: Received 31 March 2015 Received in revised form 30 July 2015 Accepted 1 August 2015 Available online 7 August 2015 Keywords: Ichnocoenoses Taphonomy Sequence stratigraphy Albian Betic Cordillera Southeastern Spain An integrated taphonomical, ichnological and sedimentological analysis has been carried out on the Albian deposits of theSierra Helada section (Province of Alicante, southeastern Spain). This allowed recognition and detailed characterization of the shallowing- and coarsening-upward sequences present in these deposits. Twenty sequences were detected throughout the section. They contain the following, from bottom to top: (1) the bottom of the sequence characterized by very fine-grained marls rich in echinoid tests and echinoid trace fossils with very little evidence of physical reworking—it records a distal platform, low-energy environment; (2) marls inter- bedded with fine-grained calcarenites, rich in large Thalassinoides and slightly reworked echinoid tests, with common bioclast-armored tubes (Ereipichnus geladensis), recording low-energy background conditions but in- creasing energy of the sedimentary events, (3) coarse-grained calcarenites rich in different types of small to large Thalassinoides and E. geladensis horizons, showing the intense and frequent action of storms and directed currents on the seafloor, and (4) coarse-grained, cross-bedded calcarenites, rich in Ophiomorpha nodosa, depos- ited under high-energy background conditions in the shallowest part of the sequence, recording the presence of shifting dunes in the inner platform. Occasionally, also the record of a rapid transgression has been pointed out through the presence of condensed tapho- and sedimentary facies and mixed ichnocoenoses at the top of the se- quence just after an erosive surface. The defined ichnoceonoses and their distribution throughout the sequence reflect the shifting from a distal expression of the Cruziana Ichnofacies to the shallower archetypal Cruziana Ichnofacies and finally to the high-energy, shallow-water Skolithos Ichnofacies. The distribution of taphofacies and ichnocoenoses and development of the sequences all through the section show a general transgression followed by a regressive phase, which fit with the third-order curves described for the area on the basis of pure sedimentological analysis in previous studies (Castro et al., 2008). © 2015 Elsevier B.V. All rights reserved. 1. Introduction The complex interaction between ichnology and sedimentary en- vironments has been analyzed with major attention since the 1970s (e.g., Książkiewicz, 1977; Seilacher, 1978, 2007; Ekdale, 1985; Wetzel and Aigner, 1986; Monaco et al., 1994, 2010; Bromley, 1996; Pemberton et al., 2001; Uchman and Krenmayr, 2004; Monaco and Checconi, 2008). Alongside the classical study of ichnofacies, special attention has been devoted to ichnocoenoses, which are trace fossil assemblages derived from the activity of a single endobenthic community (Bromley, 1996; Curran, 2007). Al- though they suffer of the loss of information typical of each fossil community (Radwański and Roniewicz, 1970), ichnocoenoses are very useful in high-resolution stratigraphy (Monaco et al., 2012), since they may point out minor paleoenvironmental changes. In shallow marine environment, ichnocoenoses may be accompanied by biostratinomic analysis of skeletal concentrations (see live/dead interactions in the genesis of bioclastic beds as a key element for the reconstruction of sedimentary dynamics; Kidwell, 1991). This leads to the occurrence of rhythmic alternation of burrowed facies, also conditioned by cyclic sea-level changes (Ekdale, 1985; Frey et al., 1990; Erba and Premoli Silva, 1994; Monaco et al., 1994, 2005; Fürsich, 1998; Giannetti and Monaco, 2004; Mángano and Buatois, 2007; Savrda, 2007). The present work adds new data to the preliminary studies carried out in the Albian section located in southeastern Spain (Sácaras Forma- tion, Sierra Helada, Monaco et al., 2005; Giannetti et al., 2014) with the aim to detect and describe the strict interaction between shallow-water ichnocoenoses and taphocoenoses. The integrated study of twenty shallowing-upward sequences allowed for the characterization of a typical repeated sequence based on the analysis of the taphonomic characters and taphofacies described by Giannetti et al. (2014) and of ichnological features such as the ichnotaxa present, their diversity, abundance and tiering. Palaeogeography, Palaeoclimatology, Palaeoecology 438 (2015) 70–80 ⁎ Corresponding author. E-mail addresses: alice.giannetti@ua.es (A. Giannetti), paolo.monaco@unipg.it (P. Monaco). http://dx.doi.org/10.1016/j.palaeo.2015.08.002 0031-0182/© 2015 Elsevier B.V. All rights reserved. Contents lists available at ScienceDirect Palaeogeography, Palaeoclimatology, Palaeoecology journal homepage: www.elsevier.com/locate/palaeo