LOFTUSIA CF. ANATOLICA HORIZON IN UPPER MAASTRICHTIAN LIMESTONES OF THE EASTERN GREECE PLATFORM (MOUNT PTOON, BOEOTIA, GREECE): PALAEOBIOGEOGRAPHICAL REMARKS

Researches on upper Cretaceous limestones from the Eastern Greece platform in the area between Kokkinon and Akrefnion (Boeotia, Greece) revealed the presence of a horizon rich in Loftusia cf. anatolica (foraminifer). In this horizon, of late Maastrichtian age, L. cf. anatolica is associated with debris of Rudists, Orbitoides media, O. apiculata, O. gensacicus, Siderolites calcitrapoides, Omphalocyclus macroporus, Hellenocyclina beotica, Miliolidae, Dasycladaceae and echinoderms. It is found in an undisturbed sequence of limestones, where both the underlying and the overlying horizons are of the same facies and contain debris of Rudists, Hellenocyclina beotica, Orbitoides media, Siderolites calcitrapoides, Sulcoperculina sp., Rotaliidae, Mélobesiées,Nummofallotia sp., echinoderms. L. cf. anatolica is confined in the above mentioned horizon and it is found neither in the underlying nor in the overlying beds. This fades reflects an outer shelf environment in front of the rudist reefs. It is the first time that this species is reported in situ in Greece in an undisturbed stratigraphie sequence of upper Cretaceous limestones up to Paleocene flysch

SEDIMENTOLOGY AND BIOSTRATIGRAPHY OF AN UPPER TRIASSIC CARBONATE SUCCESSION OF TRIPOLITZA PLATFORM IN MARI AREA, PARNON MOUNTAIN, SE PELOPONNESUS, GREECE

Η Ανω-Τριαδική ανθρακική ακολουθία στη βάση της πλατφόρμας της Τρίπολης, στην περιοχή Μαρί στο όρος Πάρνωνα, Πελοπόννησος, αποτελείται κυρίως από δολομίτες και σε μικρό ποσοστό ασβεστιτικούς δολομίτες. Λεπτομερής ανάλυση φάσεων και βιοστρωματογραφική μελέτη ανέδειξαν ότι κατά τη διάρκεια του Νόριου-Ραίτιου αποτίθεντο μεσο-υπερπαλιρροιακές και υποπαλιρροιακές (ρηχές λιμνοθαλάσσιες) φάσεις με κυκλική ανάπτυξη στο εσωτερικό της πλατφόρμας, παρόμοιες με αυτές που σχηματίζονταν σε πολλές Αλπικές πλατφόρμες του νότιου περιθωρίου της Τηθύος κατά το ίδιο διάστημα. Διαγενετικές παρατηρήσεις υποδεικνύουν περαιτέρω ότι η ρηχή θαλάσσια ανθρακική ιζηματογένεση διακοπτόταν από διαστήματα υποαέριας έκθεσης και επακόλουθης πρώιμης λιθοποίησης των πρόσφατα αποτεθέντων ιζημάτων. Η εκτεταμένη και πρώιμη κυρίως δολομιτίωση και ανακρυστάλλωση, η παρουσία μετεωρικών συγκολλητικών υλικών κατεισδύοντος ύδατος αλλά ιδιαίτερα η επαναλαμβανόμενη εμφάνιση δολοκρητών οριζόντων στα ανώτερα τμήματα πολλών περιπαλιρροιακών κύκλων υποδεικνύουν σαφώς περιοδική υποαέρια έκθεση των ιζημάτων καθώς και την επικράτηση ημίξηρων κλιματικών συνθηκών στην περιοχή.The Upper Triassic succession in the base of Tripolitza carbonate platform, in the Mari area of the Parnon Mt. in SE Peloponnesus, mostly consists of dolomites and to a lesser extent ofcalcitic dolomites. A detailed fades analysis and biostratigraphical study revealed that during Norian — Rhaetian times inter-supratidal and subtidal (shallow lagoonal) fades presenting cyclic development were deposited in the inner platform, similar to those that were formed in most of the Alpine platforms of the southern margin of the Tethys during the same time period. Diagenetic considerations further indicate that this shallow marine carbonate sedimentation was interrupted by subaerial exposure intervals and subsequent early lithification of the recently deposited sediments. The extensive and, mainly, early dolomitization and recrystallization, the presence of meteoric-vadose cements and specifically the repeated appearance of dolocrete horizons in the upper parts of many peritidal cycles, clearly show periodic subaerial exposure of the sediments, as well as the prevalence of semi-arid conditions in the area

New data on the palaeobiogeography of Loftusia genus (Foraminiferida). An in situ presence of the genus in eastern Greece (Boeotia)

An Upper Maastrichtian horizon rich in Loftusia is for the first time described in situ in Greece in the province of Boeotia. It is found in a continuous undisturbed carbonate sequence of the eastern Greece platform (Subpelagonian zone) of Maastrichtian-Paleocene age followed by flysch sedimentation. Loftusia is found in a facies reflecting an outer shelf environment, associated with debris of rudists, Orbitoides spp., Siderolites calcitrapoides, Omphalocyclus macroporus, Hellenocyclina beotica, Sulcoperculina sp., and echinoderms. Similar fauna, but without Loftusia, is found in the surrounding levels of Late Maastrichtian age as well. This recovery of the genus in the western part of its distribution area, where it is not as abundant as in the eastern part, is considered significant for the palaeobiogeography of the genus in Tethys Ocean during Late Cretaceous. To cite this article: A. Zambetakis-Lekkas, A. Kemeridou, C. R. Geoscience 338 (2006). © 2006 Académie des sciences

Existing and emerging students’ alternative ideas on geodynamic phenomena: Development, controlling factors, characteristics

This paper studies Greek junior high school students’ alternative ideas, both initial and synthetic, on geodynamic phenomena. It comments in detail on students’ concepts on Earth structure, earthquake occurrence, volcano formation, and relief change. Additionally, it attempts to trace and interpret how and why these ideas form (concept development), presenting that initial and synthetic ones are indissolubly attached and utterly directed by environmental interaction. Data analysis verifies that curriculum inadequacy and false scientific terminology in textbooks enforce the generation of alternative ideas. New synthetic alternative ideas on geodynamic phenomena are presented which are mainly characterized by intermittent and fragmentary perspective. Furthermore, the characteristics of both initial and synthetic alternative ideas are outlined, giving emphasis on the facts that students represent geodynamic phenomena as instantaneous events and that they are able to describe the repeatability of the phenomena, but they show difficulty in capturing their continuity. Finally, more factors that control alternative idea development on geodynamic phenomena are highlighted—such as (i) lack of continuous thinking, (ii) distribution, intensity and frequency of geodynamic phenomena, and (iii) current affairs (i.e., pollution, technology evolution, human intervention)—hoping that their revelation will lead to alternative ideas’ decomposition and thus to pure scientific knowledge. © 2021 by the authors. Licensee MDPI, Basel, Switzerland