Notes on the Relations of the Lincolnshire Carstone

Abstract

The Carstone of Lincolnshire lies immediately below the Red Chalk, and rests upon the fossiliferous clays and limestone known as the Tealby Beds. The Tealby Beds were described in detail for the first time in 1867 by Professor Judd; and their relations to the Speeton section, and to beds of the same age throughout Northern Europe, were discussed in 1870 by the same observer. In 1883 the survey of the district was completed, with the result of verifying in almost every particular the conclusions which had been so ably worked out by Professor Judd. On one point only I ventured to form a somewhat different opinion, namely on the relations of the Carstone to the Red Chalk above and to the Tealby Beds below. The following table gives (in brief) the correlations advocated by Prof. Judd, and shows also the names of the various subdivisions which have been adopted for the Survey publications, and which will be used in this paper :— The Carstone, which was doubtfully correlated with the Upper Neocomian of Speeton, was believed by Prof. Judd to be quite unconformably overlain by the Red Chalk. This theory of an unconformity, however, has not been confirmed by an examination of the numerous sections of the junction that are exposed. The overlap of the Carstone by the Red Chalk, which at first sight seems strongly to support Prof. Judd9s view of their relations, appears to be due to the steady attenuation of the Carstone northwards that is shared by