Palaeoproterozoic UHT metamorphism in the Lewisian complex and North Atlantic region

Abstract

Palaeoproterozoic ultra high temperature (UHT) metamorphism of the Lewisian complex in South Harris and the North Atlantic regions were examined. The characteristic features of the UHT metamorphism in the South Harris can be summarized as a) mineral textures and constituent mineral associations are concordant with anti clockwise metamorphic history, b) presence of subduction related various precursory rocks lead to formation of various types of sapphirine bearing rocks, and c) heat source that established UHT metamorpism in South Harris is the emplacement of igneous suite in the magmatic arc at c. 2.18 1.87 Ga. In the North Atlantic region, possible UHT metamorphism were reported from the Boothia Somerset granulite terrane, Taltson Thelon orogen and Kolvista Umba zone during 1.9 2.0 Ga. Precise correlation between UHT in South Harris and these terranes are not clear, although magmatic arc or island arc are considered to be reasonable tectonic setting for the UHT metamorphism in the Palaeoproterozoic North Atlantic region.

Preservation of evidence for prograde metamorphism in ultrahigh‐temperature, high‐pressure kyanite‐bearing granulites, South Harris, Scotland

“…It has previously been proposed (Whitehouse & Bridgwater, 2001; Baba, 2004) that the high‐ P metamorphism on South Harris occurred in response to collisional burial of a magmatic arc and associated accretionary wedge sediments shortly after emplacement of the SHIC. This interpretation is consistent with the counterclockwise P–T path derived for these rocks, involving magmatic heating prior to the onset of collisional burial.…”

Ultrahigh-Temperature Metamorphism in the Palni Hills, South India: Insights from Feldspar Thermometry and Phase Equilibria

“…Sapphirine-granulites Mafic granulites Prakash et al, 2006a Eastern Ghats belt, India Spinel-granulites Dasgupta et al, 1995 Sapphirine-granulites Mohan et al, 1997 Sapphirine-granulites Sarkar et al, 2003 Garnet-granulites Santosh et al, 2004 Napier Rogaland, Norway Granitic gneisses Moller et al, 2002 Saxon Massif, Germany Sapphirine-granulites Rotzler and Romer, 2001 Schwarzwald, Germany Garnet-granulites Marschall et al, 2003 Epupa Complex, Namibia Garnet-Opx granulites Brandt et al, 2003 Highland Complex, Sri Lanka Sapphirine-granulites Garnet-granulites Santosh et al, 2004 Kontum Massif, Vietnam Garnet-Opx-Sill-Crd gneisses Osanai et al, 2004 Lewisian Complex, Scotland Sapphirine-granulites Baba, 2003Baba, ,2004 Peter Raase for providing the feldspar thermometer programs and T. Saito for discussions and comments on this work. Anonymous reviewers are thanked for their constructive comments.…”