U105997.pdf (19.57 MB)
The significance of mafic and ultramafic rocks in the crustal development of Northern Greece
thesisposted on 2014-12-15, 10:39 authored by Neil Howard. Berry
That there are a number of distinct ophiolitic belts separating some of the major tectonic zones of Greece and the eastern Mediterranean is generally well known. These have previously been interpreted as the remnants of back-arc basins, Mesozoic rifts, and supra-subduction zone type ophiolites. However mafic and ultramafic rocks present in the region of the Serbo-Macedonian Massif, northern Greece, do not appear to fit this model, and have generally been neglected in tectonic interpretations. The aim of this study is to determine how these bodies arrived at their current position, what is their true nature, and how do the answers to these questions help in the interpretation of the way that this section of continental crust was assembled.;A multidisciplinary approach was taken to this problem. Structural and tectonic measurements and observations led to the conclusion that the main mafic and ultramafic bodies were accreted into the continental crust via a process of subduction accretion. Further to this, the continental crustal material between the main complexes is composed of tectonic melange material and not microcontinental fragments derived from the northern margin of Gondwana. A geochemical investigation of the Vavdos and Volvi Complexes demonstrates that the origin of these generally depleted lithologies was from a plume source, Volvi being thought to be a seamount, and the Vavdos Complex and associated along strike units, thought to be the disrupted remnants of an oceanic plateau. These conclusions have required the re-interpretation of current tectonic models for the region, and a new model is presented at the end of the thesis.
Date of award1997-01-01
Awarding institutionUniversity of Leicester