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Unpublished MSc.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 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
Return to MS Theses completed in the
Geological
Sciences Program, University at Albany