Sedimentary evolution of a Late Pleistocene temperate red algal reef (Coralligène) on Rhodes, Greece: correlation with global sea‐level fluctuations

Abstract

Autochthonous red algal structures known as coralligène de plateau occur in the modern warm‐temperate Mediterranean Sea at water depths from 20 to 120 m, but fossil counterparts are not so well‐known. This study describes, from an uplifted coastal section at Plimiri on the island of Rhodes, a 450 m long by 10 m thick Late Pleistocene red algal reef (Coralligène Facies), interpreted as being a coralligène de plateau, and its associated deposits. The Coralligène Facies, constructed mainly by Lithophyllum and Titanoderma, sits unconformably upon the Plio‐Pleistocene Rhodes Formation and is overlain by a Maerl Facies (2 m), a Mixed Siliciclastic‐Carbonate Facies (0·2 m) and an Aeolian Sand Facies (2·5 m). The three calcareous facies, of Heterozoan character, are correlated with established members in the Lindos Acropolis Formation in the north of the island, while the aeolian facies is assigned to the new Plimiri Aeolianite Formation. The palaeoenvironmental and genetic‐stratigraphic interpretations of these mixed siliciclastic‐carbonate temperate water deposits involved consideration of certain characteristics associated with siliciclastic shelf and tropical carbonate shelf models, such as vertical grain‐size trends and the stratigraphic position of zooxanthellate coral growths. Integration of these results with electron spin resonance dates of bivalve shells indicates that the Coralligène Facies was deposited during Marine Isotope Stage 6 to 5e transgressive event (ca 135 to 120 ka), in water depths of 20 to 50 m, and the overlying Maerl Facies was deposited during regression from Marine Isotope Stage 5e to 5d (ca 120 to 110 ka), at water depths of 25 to 40 m. The capping Aeolian Sand Facies, involving dual terrestrial subunits, is interpreted as having formed during each of the glacial intervals Marine Isotope Stages 4 (71 to 59 ka) and 2 (24 to 12 ka), with soil formation during the subsequent interglacial periods of Marine Isotope Stages 3 and 1, respectively. Accumulation rates of about 0·7 mm year−1 are estimated for the Coralligène Facies and minimum accumulation rates of 0·2 mm year−1 are estimated for the Maerl Facies. The existence of older red algal reefs in the Plimiri region during at least Marine Isotope Stages 7 (245 to 186 ka) and 9 (339 to 303 ka) is inferred from the occurrence of reworked coralligène‐type lithoclasts in the basal part of the section and from the electron spin resonance ages of transported bivalve shells.

Onset of temperate carbonate sedimentation during transgression in a low-energy siliciclastic embayment (Pliocene of the Val d’Orcia Basin, Tuscany, Italy)

“…For example, the studied unit is part of the transgressive systems tract and sea-level rise is known to play an important role for the production of temperate-water carbonates (Carey et al 1995;Tucker 2003;Wilson and Vecsei 2005) including red algal dominated facies (Nalin et al 2008;Titschack et al 2008). Moreover, there are good indications that during the Middle Pliocene, climatic and oceanographic conditions in the Mediterranean were amenable to the establishment of temperate carbonate factories which left a record of widespread shallow-marine calcarenite bodies (Roveri and Taviani 2003;Capozzi and Picotti 2003).…”

Growth of Mediterranean reef of Cladocora caespitosa (L.) in the Late Quaternary and climate inferences

“…A massive upload of sediment due to alluvial inputs is the most probable cause of the decline of the Santa Teresiola bank, as indicated by the presence of the reefs as a unique entity in 'vital' position. Maximum transgression sea-level scenarios are also assumed for Pleistocene C. caespitosa banks on the Tyrrhenian side of Calabria, Italy (Bernasconi et al 1997), whilst C. caespitosa colonies described from Late Pleistocene (MISs 5e-d) coastal facies on Rhodes, Greece, developed at the beginning of a regressive sequence (see Titschack et al 2008).…”

Late Holocene uplift of Rhodes, Greece: evidence for a large tsunamigenic earthquake and the implications for the tectonics of the eastern Hellenic Trench System

“…We do not use the uplift measurements at Charaki and Rhodes Town marked by black circles for the reasons discussed in Section 3.2. The solid blue line marks the region of the coast where uplifted marine terraces are seen, and blue dots mark reported elevations of the lowest terrace (Gauthier 1979;Titschack et al 2008). The region where any late Holocene uplift might be expected to be observed in the resistant limestone cliffs, if it were present, is marked by 'absence of uplift'.…”

“…Holocene uplift is small (Gauthier 1979;Titschack et al 2008). The co-location of the uplifted palaeoshorelines and the marine terraces suggests that uplift of Rhodes is tectonic in origin, and has continued through the Quaternary.…”