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fault : and 1 do not think that the lie of the rocks in the 
other sections can be explained except on the supposition 
that the boundary is faulted. The accounts of the colliers 
at Macclesfield also led me to the same conclusion. As far 
north then as Macclesfield I think the evidence is conclusive 
for the boundary being a fault : northwards from this town 
the fault decreases in throw and at last dies out, and the 
boundary becomes an overlap. The point in dispute is — 
Where does the change happen ? 
The following considerations led us to conclude that the 
boundary continues to be a fault for some distance to the 
north of Macclesfield. 
1st. Though we have not data for estimating the exact 
amount of the throw at that time, a boring into the new 
red sandstone shows that it could not he less than sixty 
yards. A fault of this size will require some distance for 
its gradual decrease and final disappearance. 
2nd. The boundary north of Macclesfield is remarkably 
straight, and is a direct continuation of the line, known to 
be a fault, which parts the two formations south of that 
town. Both these facts are in favour of the view taken by 
the Survey. 
I must deny altogether that there is any ground for the 
parallel drawn by Mr. Binney between the boundary we 
are now considering and the junction of the Carboniferous 
and Permian Rocks on the east of the Pennine Chain. The 
radical difference between the two is clear at a glance to 
any one who has learned to seize upon the geological 
meaning of physical features. In the latter case, the Per- 
mian beds rise, all along the junction, from the Carboniferous 
plain in a low hut well-marked escarpment, which winds 
