140 Rev. W. D.Conybcare on a Geological Map of [Feb. 



Physical circumstances also confirm this geographical arrange- 

 ment. 



1. The Northern District. — A chain of hills, denominated in 

 the time of the Roman colonists of Britain the Penine Alps, 

 forms a continuous ridge (locally, I believe, called the back lope 

 of England), through the northern counties, from Northumber- 

 land to Derbyshire. At its northern and soul hern extremities 

 (that is to say, in Northumberland, and the West Fading of 

 Yorkshire, and in Derbyshire), this chain exhibits the carboni- 

 ferous limestone (No. 3 of the carboniferous series). All other 

 parts of it are composed of the shale and grit (No. 2); round the 

 sides of this chain the regular coal measures (No. 1) are disposed 

 so as to constitute several distinct fields. 



These may be enumerated in the following order : (a) The 

 great coal field of Northumberland and Durham, (b) Some 

 small detached coal fields in the north of Yorkshire, (c) The 

 great coal field of South Yorkshire, Nottingham, and Derby. 

 On the south, we find only (d) some successful trials for coal in 

 the neighbourhood of Ashborne, which have, however, never 

 been further prosecuted. On the west (e) the coal field of North 

 Stafford. (/') The great Manchester, or South Lancashire coal 

 field, (o) The North Lancashire coal field, (h) The White- 

 haven coal field ; between this and the preceding coal field, the 

 transition mountains of Cumberland rise on the western side of 

 the Penine chain, but a zone of carboniferous limestone is 

 detached from the Penine chain, and mantles round this group. 

 On the north-west of this zone, the last mentioned coal field 

 reposes. (?) The indications of coal at the foot of the western 

 ■escarpment of Cross Fell. 



2. The Central Coal Districts include four detached fields 

 •emerging from beneath the great plain of new red sandstone 

 covering our midland counties. 



a. Ashby de la Zouch. b. Warwickshire, between Atherston 

 and Nuneaton. c. South Stafford, round Dudley: the coal 

 measures here repose on the transition limestone, Nos. 2, 3, 4, 

 being here deficient, d. Indications of coal near the foot of the 

 Tickey Hill ; also in contact with transition limestone. 



3. Western Districts, subdivided into 



a. North Western, including, 1. A trough of coal measures 

 reposing on carboniferous limestone traversing the town of 

 Anglesea. 2. A coal field resting on the same rock in Flint- 

 shire ; the carboniferous limestone range continuously on the 

 north of the transition mountains of North Wales. 



b. Middle Western, or Shropshire. — This includes several 

 detached fields. 1. In the plain of Shrewsbury. 2. In Coal- 

 brook dale (this reposes on transition limestone). 3. On the 

 summits of the Clee Hills, and in South Shropshire. 4. Near 

 the Abberley Hills (resting on transition limestone). 



c. South Western. — This includes three principal basins occu- 



