A Late Pleistocene clockwise rotation phase of Zakynthos (Greece) and implications for the evolution of the western Aegean arc

Abstract

Palaeomagnetic measurements have been carried out on Eocene to Pleistocene sediments on the Ionian island of Zakynthos, NW Greece. Magnetostratigraphic constraints, biostratigraphic analyses of planktonic foraminifera and calcareous nannofossils provide a reliable time frame for these deposits. The results show that no significant rotation occurred between 8.11 and 0.77 Ma, but that Zakynthos underwent a 21.6º š 7.4º clockwise rotation between 0.77 Ma and Recent. Thus, our data indicate a rapid rotational event, in contrast to continuous rotation since 5 Ma as previously postulated [Laj et al., Tectonophysics 86 (1982) 45-67]. We speculate this late Pleistocene tectonic rotation phase to be linked to rapid uplift in the Greek region which results from rebound processes caused by (African) slab detachment underneath the Ionian islands.

Neogene evolution of the Aegean arc: paleomagnetic and geodetic evidence for a rapid and young rotation phase

“…Simpli¢ed geological map of the outer Aegean arc with sample/site localities (see also Appendix 1). For the exact location of sites from Zakynthos we refer to Duermeijer et al [6].…”

“…The analysis and interpretation of the natural remanent magnetization followed routine procedures detailed elsewhere [6]. The paleomagnetic results of each region (Appendix 1) are characterized on the basis of several criteria and we distinguish three types of demagnetization behavior.…”

Post- Alpine Late Pliocene – Middle Pleistocene Uplifted Marine Sequences in Zakynthos Island

“…The compilation of single and composite sections shown in Fig.7 infers that the latest synorogenic deposits in Paxos unit, those of Agios Sostis and Kalamaki sections (Fig.1), are of latest Mioceneearliest Pliocene age (Dermitzakis, 1978;Duermeijer et al, 1999). In particular, these deposits display the Messinian transition from the clastic sequence into evaporitic beds (laminated gypsum, gypsum arenites, balatino, gypsum conglomerates), which are overlain by "trubi" limestones and calcareous marls.…”

“…However, detailed geological mapping by Dermitzakis et al (1977) proved the existence of two similar unconformities within the Quaternary succession with the distinction of three formations (Figs 2, 3). Later studies (Triantaphyllou, 1993;Triantaphyllou et al, 1997;Duermeijer et al, 1999;Broadley et al, 2006;Papanikolaou, 2008) have better constrained the age of the above stratigraphic succession within the Quaternary and, with the support of biostratigraphy and magnetostratigraphy, have determined with accuracy the chronostratigraphic extension of each formation (Papanikolaou, 2008) (Fig. 4).…”

“…The landscape behind Zakynthos town is a distinctive slightly inclined sedimentary sequence to the north with blue marls at the base capped by brown-reddish sandstones, which form a pronounced marine terrace with steep cliffs and the old castle on top. Biostratigraphic and magnetostratigraphic studies on the popular Citadelle section at Zakynthos town, have shown that it incorporates the Gelasian/Calabrian boundary (until recently Plio/Pleistocene boundary) (Bizon and Müller, 1977;Mirkou, 1987) and the latest Pliocene (Triantaphyllou 1993(Triantaphyllou , 1997Duermeijer et al, 1999;Suballyova et al, 1999).…”