Institution: | (1) Dpto. de Ciencias de la Tierra, Universidad de Zaragoza, C/. Pedro Cerbuna, 12, 50009 Zaragoza, Spain;(2) Oklahoma Geological Survey, University of Oklahoma, 100 E. Boyd, Room N-131, Norman, OK 73019, USA;(3) British Geological Survey, Keyworth, Nottingham, NG12 5GG, UK |