DEPOSITED IN WATER. 
9 
nodular substances, sometimes pyritous, often sparry, with portions 
of orthoceratites and lituites, in the substance and on the surfaces of the 
tables. 4. A discoverable laminar structure of the tables, parallel to their 
surfaces, which does not however allow of cleavage. 
Supposing this evidence sufficient, there appears reason to admit 
the cleavage planes of the Ingleton slate, to be coincident with the stra- 
tification, because of the similar interlamination of the s;alliard. It 
must follow that the ‘ bate’, of the Ribblesdale flags and Ingleton slate, 
is the only representative here known of those ‘ cleavage’ planes in the 
older slate rocks, which in Borrowdale, on Ulswater, in Langdale, in 
Charnwood forest, from my own observation, and throughout North 
Wales, on the testimony of Professor Sedgwick, I maintain to be 
transverse, (but not rectangled), to the stratification. 
Upon the view here advanced, we can not avoid admitting some 
i e markable deductions. 1. The great change of mineral character and 
structure in the slaty rocks along the same, or nearly the same, lines 
°f stratification, as between the Ribblesdale and Ingleton slate. 2. The 
complete overthrow of the slate rocks to nearly vertical positions, and 
the subsequent wearing down of their surface to a remarkably even 
plane. 3. The great thickness of these rocks, which in Ribblesdale can 
not be less than two miles. 
vVith regard to the value of the Ribblesdale flags, it is to be observed 
that so many deteriorations from joints, rows, nodules, &c., make the 
opening of a quarry rather a hazardous speculation, especially as it 
is known from experience that the separation of the tables or flags 
t>' es on]} to a moderate depth, and that these coalesce sooner in dry 
giound than where the rock is bathed in water. 
CARBONIFEROUS SYSTEM, 
with its y Umbllan slat y g rou P of sandy rocks, fine slates, and flags, 
1 S lmest °nes, and various porphyritic and conglomerated ad- 
