The faunas of the Albany Group in the Girvan area, and their palaeogeographical implications

Abstract

Synopsis The Albany Group, off-shelf equivalent to the Barr Group of the Girvan cover-sequence, yields mid-Ordovician faunas from its constituent Doularg and Craigmalloch formations. The Doularg faunas have been largely described; they are shelly assemblages typical of the Laurentian margin and are correlated with the North American Whiterock Series. Some new trilobite discoveries are reported. The fauna of the Craigmalloch Formation is described here, and consists mainly of pandemic graptolites of the Nemagraptus gracilis Biozone, but includes two trilobites known principally from peri-Gondwanan sites; their occurrence on the Laurentian margin confirms that deep-water trilobites make poor indicators of faunal provinces.