Deformation, metamorphism and fluid infiltration are important processes in crustal evolution. This thesis is concerned with how these processes interact to remodel the crust after orogenesis. Localisation of strain, fluid<i> </i>infiltration and metamorphic reactions all play a part in controlling the rheological properties of rocks deep in the crust and these factors will therefore influence the process of exhumation, and control the structural and metamorphic development of an exhuming terrain<i>. </i>It has been shown that these processes do not act independently. Complex patterns of inter-linked deformation and hydration of metamorphic assemblages are often superimposed, such that orogenic fabrics and mineral assemblages are partially overprinted by exhumation fabrics and assemblages. Thus, a chronology of deformation, metamorphism and infiltration can be determined and by identifying the depths and temperatures at which events occurred, the exhumation process can be unravelled. The island of Syros in the Attic Cycladic blueschist belt of Greece was chosen for study as it is characterised by a high pressure blueschist facies assemblage (T = 450 °C and P >14 Kbars) which has been variably overprinted within the greenschist facies stability field. The partial overprinting has resulted in the preservation of high pressure fabrics. This preservation combined with local down-pressure superimposition of deformation fabrics and recrystallisation allows a chronology of events to be determined making Syros an ideal locality for the study of structural and metamorphic evolution during exhumation. Syros consists of interleaved schist and marble units, with local metabasite horizons. The units are layered and generally dip shallowly to the NE. The partial overprinting of metamorphic assemblages has been used to link down-pressure fabric development, fluid infiltration and metamorphism, whilst the interleaving of lithologies has allowed an assessment to be made of the lithological controls on fluid channelling.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:641773 |
| Date | January 1999 |
| Creators | Bond, Clare E. |
| Publisher | University of Edinburgh |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/1842/12325 |
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