Mid-Wenlock acritarchs from a Silurian inlier in the Cheviot Hills, NE England

Six samples from the S margin of the Greyhound Law Inlier on the southern slopes of the Cheviot Hills yielded diverse, moderately well preserved middle Silurian palynomorph assemblages. The taxa present suggest a mid- to late Sheinwoodian or earliest Homerian age, which is in agreement with new graptolite collections of Crytograptus ellesae to Cyrtograptus lundgreni Zone age. Thick-walled Leiosphaeridia, suggestive of deposition in a hemipelagic environment, are common in the assemblages and are associated with diverse non-sphaeromorph acritarchs and some miospores that were derived from shelf areas by turbidity currents. Acritarch and spore colours are consistent with low thermal maturation, with palaeotemperatures probably in the region of 60–130°C.