Calcareous nannofossil, ostracode and foraminifera biostratigraphy of Plio-Pleistocene deposits, Rhodes (Greece), with a correlation to the Vrica section (Italy)

Erik Thomsen,Tine L Rasmussen,Annette Hastrup

doi:10.1144/jm.20.2.143

Erik Thomsen, Tine L Rasmussen + Show 1 more

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https://doi.org/10.1144/jm.20.2.143

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Abstract

Abstract. The Kalithea Bay section is situated on the southeastern coast of the island of Rhodes. The section comprises a sedimentary sequence ranging from brackish water gravel and nearshore sand to deep-water clay. The brackish water and nearshore deposits are assigned to the Kritika Formation, while the deep-water deposits are assigned to the Lindos Bay clay. Calcareous nannofossil biostratigraphy shows that the age of the marine sequence is Early Pleistocene. The brackish water sediments cannot be dated with any degree of certainty. The marine deposits are rich in ostracodes and foraminifera and several species have been recognized, which previously have been used as biostratigraphic markers in the Plio-Pleistocene deposits of Rhodes. Biostratigraphic correlation between the Kalithea Bay section and the Plio-Pleistocene boundary stratotype at Vrica, southern Italy, shows that the ostracodes and foraminifera events generally are diachronous relative to the calcareous nannofossil events. The only exception is the first occurrence of the benthic foraminifera Hyalinea balthica. As calcareous nannofossil events are thought to be virtually synchronous within the Mediterranean region, it is concluded that the diachroneity is due to a relative delay in the appearance of ostracodes and foraminifera at Kalithea, caused by differences in the palaeobathymetric settings between the two sites.

Highlights

The island of Rhodes is situated in the southeastern Aegean Sea on the southern rim of the Anatolian plate in an active tectonic regime (Fig. 1)
The Plio-Pleistocene sediments range from fluviatile gravel to upper slope clay, and it is characteristic that sediments representing widely different environments may be found in close succession within a single outcrop
In this study we examine the biostratigraphic value of ostracodes and foraminifera by correlating the Kalithea Bay section to the Vrica section, southern Italy

Summary

Introduction

The island of Rhodes is situated in the southeastern Aegean Sea on the southern rim of the Anatolian plate in an active tectonic regime (Fig. 1). Plio-Pleistocene beds, known for their rich faunas and floras, occur scattered over large parts of the island, with marine facies well developed along the southeast coast (Mutti et al, 1970; Meulenkamp et al, 1972; Hanken et al, 1996; Fig. 2a). The palaeoenvironmental information retained in the Plio-Pleistocene deposits has not been fully exploited so far, due to a severe lack of biostratigraphic data (Hanken et al, 1996). The deposits are patchily preserved in small, isolated basins, all with slightly different geological histories, and facies shifts, both vertically and horizontally, are often extremely rapid. Without good age determinations and reliable biostratigraphic correlations our understanding of the history of the island can only be very incomplete

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