BRITISH ASSOCIATION MEETING. 



509 



of Burnley. After which the higher and lower members of the millstone-grit 

 formation are developed in great thickness, passing down into the Yoredale 

 Hocks, or limestone shale, and finally into the Carboniferous Limestone of 

 Clitheroe. Of course, it is to be understood that the whole of the above enu- 

 merated series of strata have not been sunk through at any one place, neither 

 can we point out any particular locality where they are exhibited in section ; 

 but the whole of them crop out between Burnley and the north end of Pendle 

 Hill, and by taking advantage of the cloughs and ravines which present them- 

 selves on the way, nearly the whole of them may be noticed ; or, if a pit were 

 sunk from the centre of the coal-field in Burnley, to a sufficient depth, the 

 entire series would be found to overlie each other in the above stated order. 



In describing the rocks of the Burnley coal-field and their fossils, it will be 

 found convenient to notice them in the ascending order, beginning with the 

 limestone shale, or Yoredale rocks. They consist of very dark and finely- 

 laminated shales, replete with fossils of marine origin, such as shells of the 

 genera Avicula pecten, Goniatites, Orthoceratites, Posodonia, &c, &c. ; they 

 also contain fish remains of various genera, including that of Palceoniscus. 

 The Yoredale series is well developed on the north-west, north, and north-east 

 sides of Pendle Hill, skirting along its base from Pendleton Hall on the west 

 to Burst Clough on the east, a deep ravine which takes its name from the pent- 

 up waters of the morass on Pendle Hill having twice burst forth in great force 

 during the seventeenth century, laying bare the rocks to a height of at least 

 two thousand feet. 



The higher and lower members of the Millstone-grit are the next rocks in 

 the ascending series. 



They consist for the most part of coarse-grained sandstones intermixed with 

 water- worn quarl z pebbles ; being divided by thick beds of strong stony mica- 

 ceous grey shale. 



There are many good sections of these rocks exposed to view in the vicinity 

 of Pendle Hill, where they are dipping nearly south at angles of from twenty 

 to forty degrees, the intensity of dip increasing in a southerly direction. 



The millstone-grit formation is poor in fossils, with the exception of a bed 

 of shale of about twelve yards thick, which occupies a middle position between 

 the higher and lower portions. The outcrop of these shales is exposed in the 

 brook at Roughlee and at Hanson's Scar, near Sabden ; at both of which places 

 it contains fossils of the genera Phragmoceras, Goniatites, Avicula pecten, Posi- 

 donia, and Orthoceratites. 



Near the top of the grit formation there occurs three thin seams of coal, 

 known as the millstone -grit, or Brooksbottom series of coals, the outcrop of 

 which may be seen in the road behind Height House. 



The roof of the lowest of them, which consists of a fine-grained, compact, 

 light-coloured sandstone, has been extensively quarried along the line of its 

 basset on Read Height for road materials, and has been thought by some per- 

 sons to be identical with the gannister, or mountain mine, but from which it 

 differs in the following important particulars : — 1st. It lies a considerable dis- 

 tance below, while the true gannister is known to be above the " Rough Rock." 

 2nd. The hard stone which is found in connection with it forms the roof of the 

 coal and not the seat, as in the case of the gannister ; and, 3rd. Possesses all 

 the characteristics of a roof rock as distinguished from that of a seat rock. 



The next ascending basset is that of the Rough Rock with the Boaredge 

 and probably the Peatheredge coals. A good section of this rock, together 

 with the coals usually found in connection with it, is exposed at Height Side, 

 near Padiham. 



The outcrop of the Rough Rock is followed by that of the gannister, or the 

 mountain mine series of coals. 



