Terebella lapilloides Münster, 1833 from the Upper Jurassic–Lower Cretaceous İnaltı carbonates, northern Turkey: its taxonomic position and paleoenvironmental-paleoecological significance

Abstract

IntroductionThe basic types of Jurassic reefs can be grouped into 3 categories according to their paleogeographic setting and the composition of the biota as coral reefs, siliceous sponge reefs, and pure microbialite reefs (Leinfelder, 2001). There exists a great variety of transitional forms between these major categories (Leinfelder, 2001). Additionally, the occurrence of various types of bivalve reefs and red algal reefs from the Jurassic times was also reported (Leinfelder et al., 2002). Apart from the reef categories included in Leinfelder's classification, Schlagintweit and Gawlick (2008) described microencruster-cement boundstones as a separate reef type from the Northern Calcareous Alps of Austria. Displaying many similarities with these carbonate deposits of the Intra-Tethyan domain, coralmicrobial-microencruster reefs were also documented from the southern Intra-Tethyan domain by Pleş et al. (2013). During the Late Jurassic, when one of the largest reefal expansions of the Phanerozoic occurred (Wood, 1999;Kiessling, 2002), mixed coral-sponge reefs were widespread on the isolated Intra-Tethys platform margins, whereas that mixing was rare on North Tethys/North Atlantic shelves due to the predomination of corals over sponges (Leinfelder, 2001).Colonial scleractinian corals and siliceous sponges with a rigid skeleton were the prevailing reef building metazoans of the Jurassic with occasional contribution from coralline sponges (e.g., stromatoporoids) (Leinfelder et al., 1994). These framebuilders were accompanied by diverse encrusting, boring, and free-living benthic metazoans as well as free-growing or encrusting algae or algal-type organisms, which are generally problematic in systematic position (Leinfelder et al., 1993b(Leinfelder et al., , 1994. Among these organisms, some have great importance for the paleoenvironmental/paleoecological interpretations (e.g., for bathymetry, hydrodynamics, sedimentation rate, and oxygen content). The agglutinating annelid Terebella lapilloides Münster is one of those accompanying

Depositional characteristics and constraints on the mid-Valanginian demise of a carbonate platform in the intra-Tethyan domain, Circum-Rhodope Belt, northern Greece

“…The abundance of bioclasts with micritic envelopes also implies that the bulk of associated peloids are products of in situ alteration and breakdown of previously micritized skeletal components (Samankassou et al, 2005). It is noteworthy that the encrusting organism Perturbatacrusta leini thrived in a subtidal setting on the platform interior what makes a difference from its hitherto reported occurrences in platform margin reef/fore-reef and upper slope facies (Schlagintweit and Gawlick, 2011;Kaya and Altiner, 2014;Mircescu et al, 2013;Pleş and Schlagintweit, 2014).…”

“…4) records a significant change in the depositional environment. Progressive deepening of the sea along with decreasing bottom hydrodynamics can be interpreted on the basis of the following micropetrographic trend observed upsection: growing amount of lime mud; transition from grainsupported to matrix-supported depositional fabrics; disappearance of intraclasts, peloids and abraded bioclasts of shallow water organisms; gradual shift to open marine planktonic biota (e.g., calpionellids and calcareous dinoflagellate cysts) in association with Lenticulina foraminifera (see similar examples in Lukeneder and Reh akov a, 2004; Gawlick and Schlagintweit, 2006;Wagreich, 2009;Jamrichov a et al, 2012;Kaya and Altiner, 2014). The decreased relative amount and diminished sizes of reef derived debris in the peloidal-bioclastic packstones/ grainstones compared to the underlying bioclastic-intraclastic grainstones/rudstones reveals proximity of the depositional locus to the platform margin environments, and consequently, reflects sedimentation on the upper slope basinward of the forereef setting (Dragi cevi c and Veli c, 2002; Gawlick and Schlagintweit, 2006) (Fig.…”

“…8f) implying growth in well illuminated water (Schmid, 1995;Leinfelder et al, 1996). The particular absence of agglutinated annelid Terebella and Terebella-Crescentiella association also precludes deposition in deeper water, low-energy environment (Leinfelder et al, 1996;Schmid, 1996;Dupraz and Strasser, 1999;Schlagintweit and Ebli, 1999;Kaya and Altiner, 2014). Further evidence comes from the associated rhaxellid sponges which favored mostly shallow marine environments such as reefs, sheltered inter-reef areas and lagoons (Delecat et al, 2001;Helm and Schülke, 2006;S as aran, 2006;Schlagintweit et al, 2007;Afş ar et al, 2014).…”

“…4) of packstones and grainstones enriched in Crescentiella morronensis Crescenti (former Tubiphytes morronensis Crescenti, see Senowbari-Daryan et al, 2008). This organism having still disputed systematic position (Senowbari-Daryan et al, 2008) is considered as a typical microencruster of the mid-outer shelf and may occur in both shallow and deep water environments (Leinfelder et al, 1993;Schmid, 1996;Dupraz and Strasser, 1999;Senowbari-Daryan et al, 2008;Bonin et al, 2012;Kaya and Altiner, 2014). In this study, progressive shallowing of the marine setting relative to the underlying upper slope deposits, (MFT 3), can be interpreted on the basis of the following evidence: disappearance of calpionellids, calcareous dinocysts, Lenticulina foraminifera and brachiopods; presence of intraclasts and shallow marine fossil assemblage (bryozoans, echinoderms, thick-shelled bivalves, benthic foraminifera); common reworking of the bioclasts; minor amount of lime mud and predominance of grainstones.…”

Late Jurassic facies architecture of the Złoczew Graben: implications for evolution of the tectonic-controlled northern peri-Tethyan shelf (Upper Oxfordian–Lower Kimmeridgian, Poland)

“…Common microencrusters, mostly benthic microbial communities, serpulids, bryozoans, and foraminifers, indicate a low-energy environment, low sedimentation rate and low terrigenous influx (e.g., Reolid and Gaillard 2007). Terebella lapilloides is commonly observed in Upper Jurassic reefs and represents a low-energy setting under dysoxic conditions (e.g., Reolid et al 2005;Kaya and Altiner 2014). The presence of phototrophic microbialites and Crescentiella in thick, massive and bedded limestone, indicates paleodepths above storm-wave base, i.e., around 40-60 m (e.g., Keupp et al 1993;Aurell et al 1995;Leinfelder et al 1996;Matyszkiewicz 1997b;Krajewski 2000).…”