Notes on Part of the Upper Lias Succession at Blea Wyke, Yorkshire

Summary The Upper Lias at the classic section of Blea Wyke, south of Whitby, is here described in detail for the first time, although work has been confined, at least for the present, to the more critical, upper part of the succession. All the ammonites listed have been collected in situ by the writer so that an attempt can be made to delimit each of the subzones. In the case of the braunianus and lilli subzones the subzonal ammonite-indices have not yet been found in Yorkshire, but a provisional correlation of the equivalent beds at Blea Wyke is here suggested on the grounds that the strata between the fibulatus and variabilis subzones fall into two well-marked divisions. Tables are given showing the vertical ranges of all the fossils found.