184-5.] BINNEY ON THE NEW RED SANDSTONE. 13 



gradually passing into that rock, which in its turn is sometimes seen 

 passing successively into the magnesian limestones and lower new 

 red sandstone, where these deposits have been met with, but is more 

 frequently found resting on the carboniferous strata without their 

 intervention. The thickness of the two lower members of this for- 

 mation is extremely variable. 



The dip of the new red sandstone is nearly to all points of the 

 compass at different places, but in the east of South Lancashire and 

 Cheshire the main dip is towards the south-west. On the west side 

 of the same counties it is to the south-east and north-east. Although 

 at present no perfect synclinal axes can be traced, owing to the 

 numerous lines of fault that traverse the new red sandstone plains, 

 scarce any one can examine the dips of the strata without being 

 convinced that all the forces which elevated the coal-fields of Lan- 

 cashire and Flintshire in latter times have materially affected the 

 position of the new red sandstone formation. 



General description of the Lancashire coal-field. — The carboni- 

 ferous strata commonly known by the name of the Lancashire coal- 

 field occupies the chief part of the southern division of the county 

 of Lancaster, and extends into adjoining portions of the counties of 

 Chester, Derby and York. Coals have been worked from near 

 Macclesfield to Colne, a distance of about forty-six miles north and 

 south, and from Tarbock to Todmorden, about forty miles in a line 

 from W.S.W. to E.S.E. The. latter however is by far the greatest 

 width of the field, and much exceeds its average, for in the southern 

 part there is not more than a mile in horizontal distance from the up- 

 per new red sandstone to the millstone grit. The area of the field 

 might indeed be extended over considerable portions of the moorlands 

 of Cheshire, Derbyshire, Yorkshire and Lancashire, occupied by mill- 

 stone grits, but I have only noticed the country lying between points 

 where collieries are now or have been in operation, not including the 

 two small seams of coal which sometimes, but not always, occur be- 

 tween the first and second millstone grits. The last-named deposit 

 is the lowest rock of what in this coal-field may be truly termed the 

 carboniferous (coal-bearing) strata, and can be conveniently assumed 

 as their lowest boundary, although it is well known that elsewhere 

 in England, as well as in Scotland and Ireland, coals are found lying 

 at great depths below them. The limestone shales of Roecross, Tint- 

 wistle beyond Mottram, and those of Pendle Hill near Burnley, are 

 taken as the base of the deposit, and full 6600 feet of strata, termi- 

 nating with the red clays lying above the limestones of Ardwick near 

 Manchester, and containing about 120 different seams of coal, have 

 been ascertained. How much more lies under the new red sandstone 

 remains yet to be proved. This outline shows the coal-field in ques- 

 tion to be the most perfectly developed of any in England, and there- 

 fore admirably adapted for investigating the true upper boundary of 

 the carboniferous strata. 



This coal-field may be divided into three groups, namely the 

 upper, middle and lower. 



The first is assumed, for the sake of convenience, to include all the 



