The area under consideration extends from the mining town ot Egremont to Scalesmoor Farm in the parish of Lamplugh in West Cumberland, and comprises a tract of country 9 miles in length and rather less than 3 miles in width, running from S.S.W. to N.N.E. It forms the south-eastern margin of the Whitehaven Coalfield, and is the western portion of the “collar” of Lower Carboniferous rocks almost surrounding the older Palæozoic rocks of which the Lake District proper is composed. The area consists in the main of fahly continuous outcrops, but is much disturbed by faulting. In the unravelling of the tectonics of the district, however, the difficulty caused by excessive faulting is counterbalanced by the multiplicity of the borings that have been made during the exploration and development of the valuable haematite deposits associated with the limestones. In no single instance is there an exposure giving a complete section of the sequence, yet with the help of the journals of the “bores” every one of the exposures mentioned in this paper can be placed at its exact horizon with great accuracy.