IRONSTONE FORMATION OF THE FOREST OF DEAN. 269 
I may cite, as a capital instance of the kind of fault produced by 
erosion, the " Horse," which occurs in the Coleford High Delf Vein, 
and which has been followed over two miles in length, presenting an 
average breadth of 260 yards. Mr. Buddie has described the circum ■ 
stances connected with this fault, and has represented certain minor 
phenomena, of apparently the same description, known as the " Lows," 
as tributaries to the ancient main channel ("Geological Transactions," 
Vol. VI). I am inclined, however, to refer the greater number of the 
" Lows," or so-called subsidiary channels, to the same origin as the fault 
at Ruardean, which I have just described, and I am supported in this 
view by the fact, that the quartz pebbles and roUed pieces of coal, 
which are found in the sand and drift (now converted into sandstone), 
that occupied the main channel, do not occur in the " Lows," — which, 
moreover, are not all of them connected, as represented in Mr. Buddie's 
plan, with the " Horse." 
In the sandstone of the coal-measures many instances occur of 
irregular and oblique lamination, affording a proof that the beds were 
not formed by the gradual deposition of particles mechanically 
suspended in the water, but rather by drifts of sand pushed along the 
bottom by the action of currents. The following section was sketched 
near Cinderford Bridge : 
IfiON Oee Fokmation. 
I have mentioned, incidentally, that between the double veins of the 
Woorgreen and Starkey coals, and beneath the Upper Trenchard Vein, 
there occur in beds of shale bands of ironstone of sufficient thickness and 
vulue, in places, to be worked. These ironstones are all of a similar 
