Thomas D. Hamilton HBSc thesis abstract

Thesis Title: 
A Study in Neotectonics of the Polis Graben, Cyprus, using Magnetic Fabrics
Thomas D.
Hamilton
HBSc
2001

AMS (anisotropy of magnetic susceptibility) is a useful tool for identifying petrofabrics, especially when the petrofabrics may be cryptic as in the case of the limestones of the present study.  Although a conventional penetrative tectonic fabric did not overprint the sedimentary fabric in the Polis limestones, the sedimentary fabrics were modified by the stress fields of fault block rotations.  The principal extension directions are recognized from the imposed alignments of certain paramagnetic minerals (micas and clay) and by ferromagnetic magnetite.  By comparing AMS data with structural evidence and seismic data (in the form of Centroid-Moment Tensors) it is possible to compare paleotectonics with neotectonic to prognosticate surface expression of the current tectonic regime.  The paleotectonic regime was expressed as ENE-WSW extension as indicated by AMS and fault orientations and movements; but the current tectonics exhibit ENE-WSW compression as inferred from fault-plane solutions.  This neotectonic regime has expressed itself surficially as a dextral strike-slip motion along one of the major extension faults of the former regime.  The data is also useful to compare with models of development of the tectonic regime of western Cyprus, which displays non-coaxial progressive strain history as a result of the Eratosthenes Seamount interfering with subduction rates of the Cyprus Trench.