Abstract

The district which is the subject of the present communication has attracted the attention of geologists since the days of Playfair (46) who, in his ‘Illustrations of the Huttonian Theory’ published in 1802, alludes to a visit that he paid, with Lord Webb Seymour, to Chapel-le-Dale and Thornton Force, and describes the unconformity between the Carboniferous Limestone and the underlying slates. Sedgwick (50), in a paper read before the Geological Society in 1831, described and illustrated the succession of the Carboniferous rocks which occupy the country between Penyghent and Kirkby Stephen. That paper, which shows a keen insight into the general structure of the district, was not printed in the Transactions until 1835.

The same year saw the publication of John Phillips's (44) classic work—‘The Illustrations of the Geology of Yorkshire’ the second part of which, ‘The Mountain Limestone District’, was issued in the following year. Phillips confined his attention to the lithological succession, and made no attempt to describe the distribution of the fossils, or to make use of them for the subdivision of the series, the palæontological portion of the work forming really an independent communication. It was impossible, however, that so careful an observer should fail to notice that certain fossils were more abundant at some horizons than at others, and, although he does not allude to this fact in the work mentioned above, it is evident that it did not entirely escape his notice: for, in his Presidential Address (45, pp. xxxviii-xxxix) to the Geological Society