The debate concerning the origin of the Whin Sill of NE England during the early and mid-nineteenth century
In-situ Aptychus in Cleviceras from the Mulgrave Shale Member of the Whitby Mudstone Formation (Jurassic) of Port Mulgrave, Whitby
High Force, Teesdale. The columnar jointed dolerite of the Whin Sill forms the upper part of the waterfall and overlies with apparent local conformity partially metamorphosed sedimentary rocks of the Alston Formation. See the paper by Holliday in this part, p. 29.