74 Geological Society. 



greatest vertical development in Derbyshire, and thence thinned 

 away northward and westward. The author now gave the results 

 of his subsequent investigations while engaged in the survey of the 

 Pendle Range and the neighbourhood of Burnley and Blackburn, 

 which have shown that the increase in the thickness of the sedi- 

 mentary deposits is continued into that district, the aggregate thick- 

 ness of the Coal-measures, the Millstone-grit, and the Yoredale 

 series being in the Burnley district 18,635 feet, while in Leicester- 

 shire it has dwindled down to 3100 feet. In discussing the ques- 

 tion of the source of these sediments, the author came to the con- 

 clusion that they were derived from a primaeval Atlantis, — a view 

 which he considered to be strengthened by the fact that the Carbo- 

 niferous sedimentary strata of North America also swell out towards 

 the north-east, and become attenuated towards the south and west. 



3. " Observations on the relative Ages of the leading physical 

 Features and Lines of Elevation of the Carboniferous district of 

 Lancashire and Yorkshire." By E. Hull, Esq., B.A., F.R.S., of 

 the Geological Survey of Scotland. 



The author first described the Pendle Range as a great arch of 

 Carboniferous rocks, bordered on the north and south by a succes- 

 sion of parallel (VV.S.W. to E.N.E.) arches and troughs, to all of 

 which he assigned a Prsepermian age. He regarded them as be- 

 longing to the earliest of three consecutive periods of disturbance, 

 to which all the principal flexures and faults of the district may be 

 referred. The Pennine Chain, which runs nearly north and south, 

 he believed to have been upheaved during a later period, namely, 

 the close of the Permian, while the numerous north-west faults of 

 the district under consideration he referred to the close of the 

 Jurassic period. Mr. Hull described in detail the evidence upon 

 which these conclusions rested, observing that immediately upon the 

 close of the Carboniferous period the northern limits of the Lanca- 

 shire and Yorkshire coal-fields were determined by the upheaval 

 and denudation of the beds along east and west lines, the coal-fields 

 themselves retaining their original continuity across the region now 

 formed of the Pennine Hills, from Skipton southwards. At the 

 close of the Permian period these coal-fields were dissevered by the 

 uprising of the area now formed of the Pennine range, by lines of 

 upheaval ranging from north to south, nearly at right angles to the 

 former, this fact being of itself an evidence of difference of age. In 

 conclusion the author pointed out that the denudation of the rocks 

 of the district may be referred to seven periods, beginning with the 

 commencement of the Permian and ending with the Postglacial ; he 

 defined the duration and effect of each of these periods, and stated 

 the evidence on which his conclusions rested. 



