Journal of the Virtual Explorer

The Aston and Hospitalet domes display a complex metamorphic and tectonic evolution, involving early Variscan main deformation and medium pressure metamorphism which was overprinted by one or more thermal events of later or late Variscan age. The sequence of metamorphic phases is similar, though not exactly the same as in the smaller Bossòst structural and metamorphic dome in the Central Pyrenees. Results of recent studies of the Bossòst dome are helpful in providing a framework to the reconstruction of the Aston and Hospitalet metamorphic evolution. Notably, the presence of metastable assemblages which hint at polymetamorphism: an early medium pressure event followed by a higher temperature-lower pressure event along a clockwise P-T path. To further quantify these conclusions, additional fieldwork, individual mineral composition and calculations of pseudosections are planned.