International Geological Journal - Official Journal of the Carpathian-Balkan Geological Association

Alpine metamorphism in the central segment of the Western Greywacke Zone (Eastern Alps)

Published: Aug 2009

Pages: 319 - 329



Abstract: The metamorphic pattern of the central Western Greywacke Zone (Austroalpine, Eastern Alps) was investigated by organic matter reflectance, Raman spectroscopy on organic matter and clay mineralogical methods. Raman data map a 10 km wide thermal aureole along the contact zone of the Greywacke Zone to the Penninic Tauern Window. The estimated maximum temperatures of 400 °C to 200 °C decrease from South to North, that is from the contact to the uppermost parts of the Greywacke Zone. This pattern is explained by an Oligocene to Miocene thermal pulse, related to the rapid exhumation of formerly deeply buried rocks of the Penninic unit. During this event, advective heat transport and circulating fluids overprinted the Cretaceous higher anchi- to lower epizonal metamorphic pattern of the central Western Greywacke Zone.

Keywords: Eastern Alps, Greywacke Zone, Raman spectroscopy, organic matter, illite Kubler index

Download PDF document