Re-deposited rhodoliths in the Middle Miocene hemipelagic deposits of Vitulano (Southern Apennines, Italy): Coralline assemblage characterization and related trace fossils Alessio Checconi a, ⁎, Davide Bassi b , Gabriele Carannante c , Paolo Monaco a a Dipartimento di Scienze della Terra, Università degli Studi di Perugia, Piazza dell'Università 1, I-06100 Perugia, Italy b Dipartimento di Scienze della Terra, Università degli Studi di Ferrara, via Saragat 1, I-44122 Ferrara, Italy c Università degli Studi di Napoli “Federico II”, Largo S. Marcellino 10, I-80138 Napoli, Italy abstract article info Article history: Received 16 April 2009 Received in revised form 31 December 2009 Accepted 8 January 2010 Available online 21 January 2010 Communicated by M.R. Bennett B. Jones G.J. Weltje Keywords: Coralline red algae Ichnology Palaeoecology Middle Miocene Southern Apennines Italy An integrated analysis of rhodolith assemblages and associated trace fossils (borings) found in hemipelagic Middle Miocene Orbulina marls (Vitulano area, Taburno–Camposauro area, Southern Apennines, Italy) has revealed that both the biodiversity of the constituent components and taphonomic signatures represent important aspects which allow a detailed palaeoecological and palaeoenvironmental interpretation. On the basis of shape, inner arrangement, growth forms and taxonomic coralline algal composition, two rhodolith growth stages were distinguished: (1) nucleation and growth of the rhodoliths, and (2) a final growth stage before burial. Nucleation is characterized by melobesioids and subordinately mastophoroids, with rare sporolithaceans and lithophylloids. The rhodolith growth (main increase in size) is represented by abundant melobesioids and rare to common mastophoroids; very rare sporolithaceans are also present. The final growth stage is dominated by melobesioids with rare mastophoroids and very rare sporolithaceans. Each rhodolith growth stage is characterized by a distinct suite of inner arrangement and growth form successions. Well diversified ichnocoenoeses (Gastrochaenolites, Trypanites, Meandropolydora and/or Caulostrepsis, Ento- bia, Uniglobites, micro-borings) related to bivalves, sponges, polychaetes, barnacles, algae, fungi, and bacteria are distinguished in the inner/intermediate rhodolith growth stage, while mainly algal, fungal and bacterial micro-borings are present in the outer final growth stage. Rhodolith growth stages and associated ichnocoenoeses indicate significant change in the depositional setting during the rhodolith growth. In the Vitulano area, the Middle Miocene rhodolith assemblages formed in a shallow-water open-shelf carbonate platform, were susceptible to exportation from their production area and then to sedimentation down to deeper-water hemipelagic settings, where the rhodoliths shortly kept growth and were finally buried. Such re-deposition of unlithified or only weakly lithified (i.e. rhodoliths and intraclasts) shallow-water carbonates into deeper-water settings was likely favoured by storm- generated offshore return currents rather than sediment gravity flows. © 2010 Elsevier B.V. All rights reserved. 1. Introduction Crustose coralline red algae (Corallinales, Sporolithales, Rhodo- phyta) can grow as free-living forms (rhodoliths) constituting extensive beds worldwide over broad latitudinal and depth ranges (e.g. Adey, 1986; Minnery, 1990). Rhodoliths can be very abundant in shallow-water carbonate depositional systems becoming dominant facies components such as in rhodolith beds and crustose coralline algal pavements in different shallow-water (e.g. tidal channels as well as in reefs; Adey and MacIntyre, 1973; Bosence, 1983a; Perrin et al., 1995; Foster, 2001) and deeper-water (e.g. Minnery, 1990; Iryu et al., 1995) settings. Modern rhodolith beds are diversified benthic communities with a variety of coralline growth forms and their detritus associated with other biotic components, over coarse or fine carbonate soft substrates. In these rhodolith habitats, which consti- tute one of the Earth's macrophyte dominated benthic communities (Foster, 2001), biodiversity can be very high (Steller et al., 2003). Rhodoliths require water motion (waves and currents) or bioturba- tion to maintain their unattached and unburied state (e.g. Bosence, 1983b; Braga and Martín, 1988; Littler et al., 1990; Foster et al., 1997; Marrack, 1999; Foster, 2001; Braga et al., 2003). In the rhodoliths varied physical and biological processes are preserved as taphonomic signatures and are important constraints for rhodoliths' cycles because these processes influence the composition Sedimentary Geology 225 (2010) 50–66 ⁎ Corresponding author. Tel.: +39 0755852696; fax: +39 0755852603. E-mail address: paleodot@unipg.it (A. Checconi). 0037-0738/$ – see front matter © 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.sedgeo.2010.01.001 Contents lists available at ScienceDirect Sedimentary Geology journal homepage: www.elsevier.com/locate/sedgeo