Hostname: page-component-78c5997874-v9fdk Total loading time: 0 Render date: 2024-11-18T07:31:05.449Z Has data issue: false hasContentIssue false
  • English
  • Français

The metamorphosed olistostromes and turbidites of Andros Island, Greece, and their tectonic significance

Published online by Cambridge University Press:  01 May 2009

P. Mukhin
P. Mukhin
Affiliation:
Institute of Earth Sciences, The Hebrew University of Jerusalem, Givat Ram, Jerusalem 91904, Israel
Get access Rights & Permissions [Opens in a new window]

Abstract

The blueschists of Andros Island consist of a probable Permian-Eocene metasedimentary rock succession (meta-sandstone, marble, chert), containing large bodies of magmatic rock (serpentinized ultra-mafic rocks, gabbros and granodiorite). The development of a layer-parallel foliation and axial plane cleavage, followed by two phases of intense deformation with recumbent folding, almost completely obliterated the primary bedding and stratigraphic relations in the metamorphic complex. The main features of the geological evolution of Andros, that is, the original environment of deposition and the character and direction of tectonic transport, have been hitherto unclear because of this deformation. The present sedimentological and structural study has led to the discovery of preserved relics of primary sedimentary structures, including graded bedding and chaotic sedimentary breccias. Associated turbidite and olistostromic formations can be recognized at three stratigraphic levels in the Andros Island’s reconstructed column. Some layers of the metasedimentary rocks, having preserved clear signs of the layer’s top and bottom, were also used for the identification of the primary anticlines and synclines among widespread developed recumbent folds. This study has shown that the structural style of the last synmetamorphic recumbent folds with northwest vergence is the same, independent of the direction of the present axial plane dips. This data can be interpreted as a result of monovergent tectonic transport in the last metamorphic event. The analysis of structural relations between primary bedding and first synmetamorphic foliation proves that most of the stratigraphic succession has been preserved in a normal stratigraphic position after the first blueschist and before the second greenschist deformation stage.

Type
Articles
Information
Geological Magazine , Volume 133 , Issue 6 , November 1996 , pp. 697 - 711
Copyright
Copyright © Cambridge University Press 1996

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Avigad, D. & Garfunkel, Z. 1991. Uplift and exhumation of high-pressure metamorphic terrains: the example of the Cycladic blueschist belt (Aegean sea). Tectonophysics 188, 357–72.CrossRefGoogle Scholar
Avigad, D., Matthews, A., Evans, B. W. & Garfunkel, Z. 1992. Cooling during the exhumation of blueschist terrain: Sifnos (Cyclades), Greece. European Journal of Mineralogy 4, 619–34.CrossRefGoogle Scholar
Blake, M. C. Jr, Bonneau, M., Geyssant, J., Kienast, J. R., Lepvier, C., Maluski, H. & Papanikolaou, D. 1981. A geologic reconnaissance of the Cycladic blueschist belt, Greece. Geological Society of America Bulletin 92, 247–54.2.0.CO;2>CrossRefGoogle Scholar
Bonneau, M. 1984. Correlation of the Hellenide nappes in the south-east Aegean and their tectonic reconstruction. In The Geological evolution of the Eastern Mediterranean (eds Dixon, J. E. and Robertson, A. H. F.), pp. 517–27. Blackwell, Oxford: Geological Society of London Special Publication.Google Scholar
Coleman, R.G. 1977. Ophiolites. Berlin: Springer-Verlag.CrossRefGoogle Scholar
Durr, S., Altherr, R., Keller, J., Okrusch, M. & Seidler, E. 1978. The median Aegean Crystalline Belt: stratigraphy, structure, metamorphism, magmatism. In Mediterranean orogens (eds Closs, H., Roeder, D. and Schmidt, K.), pp. 455–78. Scientific Report no. 38, Inter-Union Commission on Geodynamics.Google Scholar
Dixon, J. E. & Ridley, , Syros, J.. Exursion guide to the field trip on Seriphos, Syros and Naxos. In Chemical Transport in Metasomatic Processes (ed. Helgeson, H. C.), pp. 489–501. NATO ASI series, no. 218. Dordrecht.Google Scholar
Hall, R., Audley-Charles, M. G. & Carter, D. J. 1984. The significance of Crete for the evolution of the Eastern Mediterranean. In The Geological evolution of the Eastern Mediterranean, vol. 17 (eds Dixon, J. E. and Robertson, A. H. F.), pp. 499–515. Blackwell, Oxford: Geological Society of London, Special Publication.Google Scholar
Papanikolaou, D. J. 1978. Contribution to the geology of Aegean sea: the island of Andros. Annales Geologiques des Pays Helleniques 29, 477–553.Google Scholar
Papanikolaou, D. J. 1987. Tectonic evolution of the Cycladic blueschist belt(Aegean sea, Greece). In Chemical Transport in Metasomatic Processes (ed. Helgeson, H. C.), pp. 429–50. NATO ASI series, no. 218. Dordrecht.CrossRefGoogle Scholar
Reinecke, T., Okrusch, M. & Richter, P. 1985. Geochemistry of ferromanganoan metasediments from the Island of Andros, Cycladic blueschist belt, Greece. Chemical Geology 53, 249–78.CrossRefGoogle Scholar
Schlestedt, M., Alterr, R. & Matthews, A. 1987. Evolution of the Cycladic crystalline complex: petrology, isotope geochemistry and geochronology. In Chemical Transport in Metasomatic Processes (ed. Helgeson, H. C.), pp. 389–428. NATO ASI series no. 218. Dordrecht.CrossRefGoogle Scholar
Schliestedt, M., Bartsch, V., Matthias, C., Matthews, A. & Henjes-Kunst, F. 1994. The P-T Path of Greenschist-Facies Rock from the Island of Kithnos. Chemie der Erde 54, 281–96.Google Scholar