Abstract
Kythera Island is located on the prominent submarine horst between
Crete and the Peloponnese in the southwestern part of the Aegean.
The structure of Kythera is characterized by a pile of tectonic
slices derived from different paleogeographic zones. The upper
unmetamorphosed units comprise pelagic limestones and cherts of
Pindos zone emplaced by thrusting in the Eocene on top of Tripolis
zone neritic limestones. These units are separated from the lower
metamorphosed unit of Phyllite-Quartzite (PQU) exposed in the
northern part of Kythera by an extensional detachment fault of
Late Miocene age. The lower tectonic unit of PQU was affected by
high-pressure/low-temperature blueschist metamorphism during or
after the middle Miocene, but the higher non-metamorphic carbonate
units were affected only by local recrystallization. Both brittle
and ductile structures related to the extensional detachment can
be mapped near the contact of the contrasting metamorphic and
non-metamorphic units. Brittle extension is expressed in the cover
rocks by dominant NW-SE striking normal faults and related veins
and breccias. Ductile structures in the metamorphic unit include
mylonites and prominent ductile stretching fabrics which have in
different places components of NW-SE and NE-SW extension. Pliocene
sediments are mostly horizontal and cover the detachment
unconformably. Extension was presumably related to rapid
subduction rollback, as previously suggested by others.
Differential movement of and vertical axis rotation in the
Crete-Peloponnese ridge during this process may be linked to
cross-ridge strike slip faults. Evidence of NE-SW dextral faulting
is seen in northern Kythera outcrops, related to a significant
fault of this type between Kythera and the Peloponnese.
Marsellos, A.E., 2006. Mapping of a detachment fault in Kythera
Island and study of the related structural shear sense indicators.
Unpublished MSc. thesis, State University of New York at
Albany. 182 pp., +xix; 1 folded map
University at Albany Science Library call number: SCIENCE
Oversize (*) QE 40 Z899 2006 M37
MS thesis digital text
pdf (10 MB)
Plate 1 - Geological
Map of the Detachment Fault of the north area of Kythera Island
(coloured
geological outcrop map, scale 1:15,000) - 8.6MB pdf file
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the Geological Sciences Program, University at Albany