The age and correlation of the Skiddaw Group (Early Ordovician) sediments of the Cross Fell inlier (northern England)

The Skiddaw Group in the Cross Fell inlier comprises the Catterpallot Formation of latest Tremadoc or earliest Arenig age, the Murton Formation of Arenig age, and the Kirkland Formation of early Llanvirn age. Each of these formations can be correlated with formations in the Skiddaw Group of the Lake District. The faulted contact of the Catterpallot and Kirkland formations is the probable extension of the Causey Pike Fault (CPF), which separates two distinct sequences in the Skiddaw inlier of the northern Lake District. Contrasts across the CPF in the Cross Fell inlier reflect those seen in the Skiddaw inlier. The CPF is a major basement structure, separating markedly different successions in the Ordovician strata of northern England.