64 
ended there as in Somersetshire with the elevation and overthrow 
of the Carboniferous rocks, but has been continued in the form of 
a fault, the older strata having been forced up an inclined plane 
in the line of fracture, over the upturned edges of the Carboni- 
ferous beds, which they had in the first instance overturned, and 
occasionally carrying masses of the Carboniferous Limestone with 
them, as these are frequently met with out of their proper place. 
‘The extent of the Great fault may be judged by the fact that in 
some cases the Devonian beds of the Dinant basin are said to 
have been thrust Northwards as far as the centre of the Namur 
basin, where they covered up the Coal Measures, in proof of which 
many pits in the neighbourhood of Liege have reached the Coal 
Measures beneath the Devonian, 
To illustrate this it is only necessary to point to a section of 
the coalfield to the West of Mons,* where the Carboniferous 
Limestone, as well as the Upper, Middle and Lower Devonian 
are found in inverted order resting on the overturned Coal 
Measures, presenting complications which are very difficult to 
-account for. 
The Boundary fault, so called because the Coal Measures 
are bounded by it on the S., appears to be an attendant 
fault connected with the greater dislocation, but as already 
explained, not always present with it. The strata lying between 
these two faults generally consist of Carboniferous Limestone and 
Devonian, which are separated by the Great fault from the 
older rocks to the 8., and by the Boundary fault from the Coal 
Measures on the N. 
The “ Reversed fault” is a line of fracture passing up through 
the Coal Measures, generally in an oblique direction with a 
steep rise to the N., but occasionally in a more horizontal 
direction with a more gradual rise to the N., presenting in such 
cases a very close resemblance to the Overlap fault of Radstock, 
with which it is probably analagous. 
* See Section No, IT. 
