378 Geological Society. 



matter are the colouring principle of the limestone strata in this 

 group, there are no workable beds of coal subordinate to it on any 

 of the lines of section. 



2nd. The next great group comprehends no less than eleven 

 groups of the author's sections, and in several mountains is more than 

 1000 feet in thickness. It is essentially composed of mountain 

 limestone, sandstone, and shale. The limestone groups are stated 

 to be five in number, and to be very remarkable for their regularity 

 in all the various sections : the lowest contains the black compact 

 beds now extensively quarried in the North of England for marble ; 

 the highest group represents the twelve-fathom- limestone of the 

 mining districts; it contains beds made up of an incredible number 

 of encrinital stems, and is also quarried for marble. The shales are 

 carbonaceous, and contain three or four beds of coal, some of which 

 are of good quality, and are extensively worked for domestic use : 

 the most remarkable of these beds occurs under the twelve-fathom- 

 limestone. 



3rd. The highest complex group includes all the deposits con- 

 nected with the millstone grit, and is stated to be more than 500 

 feet in thickness. It includes three distinct deposits, to which the 

 author gives the name of millstone grit; and several beds of carbo- 

 naceous shale, one of which contains a bed of coal three feet thick 

 and of good quality. Besides this there are one or two other coal- 

 beds, but of very inferior value, seen here and there along the lines 

 of section. 



After entering on many minute details, which it is impossible 

 to notice in this abstract, the author describes five transverse sec- 

 tions, drawn nearly east and west from different points in the prin- 

 cipal line of section across the prolongation of the great Craven 

 fault, described in a former paper. By the help of these sections 

 he points out the peculiar relative movements of the grauwacke 

 and carboniferous chains during the period of elevation which pre- 

 ceded the new red sandstone. At the foot of Barfell, above Sed- 

 burgh, a mass of the carboniferous system, six or seven hundred 

 feet in thickness, has been torn up from the foundations of the 

 mountain and placed in an inverted position. 



From all the previous details the author draws a series of con- 

 clusions, and shows : 



1st. That the region described in the paper, forms a connecting 

 link between the northern and southern ends of the carboniferous 

 chain ; and that the carbonaceous deposits are gradually more and 

 more interlaced with the limestone in the range towards the north. 



2ndly. That many of the coal-beds alternating with the mountain 

 limestone must have been deposited in the waters of a deep sea ; 

 that no fresh. water shells appear associated with the fossils of these 

 beds; and that the highest part of the Yorkshire coal-fie!ds was 

 probably deposited in shallow bays and estuaries, inasmuch as Pec- 

 tens and Ammonites are there found associated with fresh-water 

 genera. 



3rdly. That, with limited exceptions, the same species of fossils 

 are found in all the beds of limestone ; but wherever there is a change 



of 



