The Stockdale Shales

§1. Introduction. We propose, in a series of papers, to supplement the observations which have been previously published upon the divisions, organic remains, and subdivisions of the Lower Palæozoic Rocks of the Lake-district and adjoining areas. In the investigation of the geological structure of any such complicated region as the Lake-district, the first step necessarily consists in the determination of those rock-divisions which are developed in the area in question to an extent which renders them capable of representation on the one-inch map of the Ordnance Survey. When the first step has been satisfactorily accomplished, the general structure of the region may be said to be determined; but there may, nevertheless, remain many points of great geological interest and importance which still require solution. Thus, it is now generally recognized that in any region a set of deposits may have been formed so slowly that a thickness of only a few feet of such may mark a lapse of time represented elsewhere by many hundreds of feet of sediment. In such cases a more minute subdivision of the strata than can be represented upon an ordinary geological map becomes necessary, and it is also essential to enter into a detailed examination and comparison of the organic remains of the different beds. By this method of investigation very important results have already been obtained in other regions, and we see no reason to doubt that the application of the same method to the study of the Palæozoic Rocks of the Lake-district will result