Detailed structural and mineralogical mapping was undertaken in an area of 130 square kilometres within the Pennine Zone of the south-east Tauern Window, the Eastern Alps. A coherent tectono-metamorphic history is established for this area. Three pre-Alpine metamorphic events are recognised. The Alpine history involves two discrete phases of intense penetrative deformation which occurred under conditions of rising temperature, a widespread phase of thermal crystallisation at 35-40 mybp representing the attainment of maximum temperatures, and a minor post-metamorphic phase of deformation. The regional tectonic significance of this sequence is discussed. The spatial variation in Alpine peak metamorphic conditions is examined in terms of the distribution of mineral zones and isograds in metapelites. Staurolite+biotite assemblages were developed at low structural levels, and chloritoid+biotite assemblages along a thin wedge-shaped zone. Barrovian and Stonehavian facies series are both represented. Oxygen isotope studies on whole-rocks and mineral separates suggest that widespread circulation of metamorphic fluids did not occur during Alpine metamorphism. Thermodynamic calculations indicate that metamorphic conditions during the Alpine thermal peak were 570ºC and 7 kb at the basement-cover interface. These results can be reconciled both with models in which tectonic burial alone was sufficient to cause Alpine metamorphism of the Pennine Zone and with models in which a transient high heat flow regime is invoked.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:454012 |
| Date | January 1979 |
| Creators | Droop, Giles T. R. |
| Contributors | Oxburgh, E. R. |
| Publisher | University of Oxford |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://ora.ox.ac.uk/objects/uuid:9e05b3e5-9cc4-45b6-8210-614e32fb92a4 |
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