The Carboniferous Inliers at Codrington and Wick, Gloucestershire

Abstract

On the eastern side of the Bristol coal-basin, south of Chipping Sodbuiy, the Lower Carboniferous rocks are concealed by Mesozoic strata. Near Codrington and in the vicinity of Wick, however, they are exposed as a number of small inliers. These inliers are the subject of the present paper. The Codrington Inliers are situated 2 miles, the Wick Bocks Inlier 5 miles, and the Grandmother's Rock Inlier, 6½ miles south of the continuous outcrop (see fig. 1, p. 332). The last-mentioned inlier is 14 miles north of the Mendip outcrop. The village of Wick is 7 miles east of Bristol, and the Wick Rocks Inlier, which lies on the north side of the village, occurs on the same line of latitude as the Avon Gorge, some 9 miles away to the west. The several inliers expose, although not quite completely, a succession of beds ranging from the Tournaisian (Upper Zaphrentis Zone) to Coal Measures yielding a Yorkian flora. The upper part of the Syringothyris and the base of the Seminula Zones are not exposed, and within the ‘Millstone Grit’ a non-sequence undoubtedly occurs. The arenaceous beds with thin intercalated limestones (D 3 ) which succeed the limestone sequence (see table, p. 333) are better exposed in the Wick Rocks Inlier than anywhere else in the Bristol District. Although these beds are well developed on the north-west side of Bristol—at Clifton and Redland, they are no longer accessible there. Generally speaking, the strata exposed in these inliers have a westward dip, but the actual