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Maria Papanikolaou

maria Maria Papanikolaou

Cambridge Quaternary
Department of Geography
University of Cambridge
Downing Place
Cambridge CB2 3EN
England, UK

Phone +44 1223 766575
Fax +44 1223 333392
e-mail mp350@cam.ac.uk

Research Interest and Current Projects

Maria began her PhD in October 2002 funded by the State Sholarships Foundation of Greece. She submitted her thesis on 1 October 2008.

Her PhD project addresses the palaeoenvironmental and paleoclimatic reconstruction in the area of the Ionian Sea, central Mediterranean Sea, during the Plio-Pleistocene period. The study focuses on the study of two sites, the ODP marine core, Site 963 and the outcrops of SE Zakynthos island. The response of dinoflagellate cysts and the interplay between tectonics and sea level change are examined during the intense climatic variations of the Pleistocene period. The transition from Early to Middle Pleistocene is marked by a gradual shift from low-amplitude and high-frequency (40.000 ky) to a high-amplitude and low-frequency (100.000 ky) periodicity of climatic cycles around 1 Ma. More intense sea-level fluctuations are therefore expected by the end of the Early Pleistocene. The 0.9 My cooling onset is expressed in the sedimentary sequence of Zakynhtos island through an unconformity which separates silts from calcarenites. However, discriminating between global sea-level changes and regional changes due to vertical motion of the western Hellenic arc can be a difficult task.The concurrent study of the two sites serves the correlation and comparison of bioevents, magnetostratigraphic boundaries, isotopic records and dinoflagellate cyst assemblages.

The outcrops of Gerakas peninsula can be classified into three different formations ranging in age from Upper Pliocene to Middle Pleistocene, each separated by an unconformity. Briefly, the three formations indicate repetitive alternations between colder, deeper and shallower, warmer marine environments separated by two non-depositional or erosional phases. Agios Nikolaos Formation (Fm) consists of calcareous sandstones deposited in a coastal shallow-water setting and some lagoonal marly horizons at the base. Kalogeras Fm consists of calcareous sandstones (member a) which grade into alternating yellow sandy marls and calcarenites (member b) which grade to pure blue marls (member c). Gerakas Fm consists of clayey silts.


The Early Pleistocene unconformity separating the Gerakas Fm from the Kalogeras Fm occurred between the Brunhes/Matuyama boundary (MIS 19) and the top of Jaramillo subchron (MIS 27). It is therefore suggested that the unconformity is related to the regressional effect of marine isotope stage (MIS) 22, which is the first major cooling event during the Early Pleistocene. The estimation of the younger unconformity between Kalogeras and Agios Nikolaos formation is hoped to be dated through Sr isotopes.

The ODP marine core Site 963, 50 km south of Sicily, is being studied on:
- the dinoflagellate cysts distribution during the early-middle Pleistocene transition. 71 samples (temporal resolution of 3.37-13.5 Ky) for dinoflagellate cysts analysis have been selected from depths which coincide to oxygen isotope samples in order to examine the response of dinocysts across the glacial-interglacial cycles and speculate on the association of the cold and warm water assemblages.
- the biostratigraphy which is poorly established for this fossil group during the Pleistocene and is also inadequately studied in the Mediterranean Sea.
Biostratigraphy, magnetostratigragphy and oxygen isotope stratigraphy are already well established for the Site 963 and therefore provide a reliable chronology.
The sampling interval extends from 0.64 to 1.14 Ma.

Methods used

- Geological mapping (1:10.000) in order to identify the extent and structure of the formations comprising the sedimentary sequence of SE Zakynthos.
- Sediment description for determining the depositional environment
- nannofossil biozonation for dating and correlation of the sedimentary sequence to the ODP marine core Site 963.
- magnetostratigraphy (AF and thermal demagnetization)
- dinoflagellate cysts distribution for environmental and biostratigraphical purposes.
- 87Sr/86Sr isotope ratio on shells, in order to estimate the chronology of the youngest unconformity.



bay ger
Transitional beds marls and calcarenites. Brunhes / Matuyama boundary has been identified in this location. Bay Kalogeras, SE Zakynthos island. Unconformity between clayey silts and sandstones in the Early Pleistocene.

Participation in Projects


Microzonic study of the Community of the island Thira (Santorini).
Project leader: Dr D.I.Papanikolaou, University of Athens. 2000-2001

Climatic cycles and volcanic activity in the SE Aegean: The role of primary production and the response of continental ecosystems during the last 30.000 years in the submarine basin of Nisiros. Project leader: Dr M.D.Dermitzakis. University of Athens. 2004-2006.

Member

Quaternary Research Association
American Association of Stratigraphic Palynologists
International Association of Sedimentologists
Cambridge Philosophical Society


Meetings


Sea level measurements-GBS. Wegener meeting in collaboration with the National and Technical University of Athens. Athens 2001.

Abrupt climate change: evidence, mechanisms and implications. Discussion-Meeting. The Royal Society, London. 2003

Early-Middle Pleistocene transitions: the land-ocean evidence. International Conference, Department of Geography, University of Cambridge, April 4, 2003. (Sponsored by INQUA, QRA and the Godwin Institute for Quaternary Research.)

Posters


Distribution of dinoflagellate cysts during the Early--–Middle Pleistocene transition in the central Mediterranean Sea, ODP Site 963. 2Papanikolaou, 2M. & Head, M. J.
11th International Palynological Congress, Granada, Spain 3-8 July 2004. Dinoflagellate cysts and dinoflagellate biology.

Early-Middle Pleistocene transition in marine sediments on the Gerakas peninsula, SE Zakynthos island, Greece.
Papanikolaou M., Triantaphyllou M., Broadley L., Gibbard P., Platzman E,.
32nd International Geological Congress in Florence, Italy, 2004.

Tectonic evolution of the Ionian thrust belt, NW Greece.
L.Broadley, E.Platzman, J.Platt, J.Milsom, M.Papanikolaou, S.Matthews.
32n International Geological Congress in Florence, Italy, 2004.