Late ordovician glaciomarine deposits (orea shale) in the sierra de albarracin, Spain
Abstract A description and interpretation is given of marine, fragment-bearing arenaceous shales occuring near the Ordovician/Silurian boundary in northeast Spain. These deposits, known as the Orea Shales, have been reported before as non-glacial or questionably glaciomarine. Sedimentary features and scanning electron microscopical examination of quartz grains, however, reveal that much of the debris has been supplied by ice-rafting (paratillite). Close similarity between these Spanish deposits and coeval Normandian paratillites, supports the theory that the Iberian Peninsula and northwest France belonged to one depositional realm, probably forming a microcontinent (Armorica) separated from the glaciated Gondwanaland.