. 
196 Proceedings of the Royal Physical Society. 
have occasion to refer to this table again, when dealing with the 
correlation of the Scottish and English Carboniferous rocks. 
Taste IT. 
Generalised Index of the Carboniferous Rocks of Scotland. By 
B. N. Peach, F.R.S. 
An upper group of red sandstones, shales, etc., with 
Black Sreup. coal seams becoming lenticular. Probably the 
Gannister Beds of England. The ‘‘Slaty Band 
Cy 
pper or-Red thin coals, probably equivalent to the Pennant 
g Sandstone Grit of England. This group rests with a gentle 
g ; Oe unconformity on the beds below. 
= | Alternations of sandstones, shales, fireclays, with coal 
2 4 seams, forming the greater portion of the coal-fields 
ee of Scotland. 
& Lower or Similar beds, but with thick sandstones, and the 
| 
Ironstone” is used conventionally as the base line. 
ticular seams of coal. These pass up into the 
Coal-Measures above, and down into the Car- 
boniferous Limestone below, the divisions being 
arbitrary in both cases. The base line is consti- 
tuted in the eastern side of Scotland by the Castle- 
cary Limestone, and in the western (where the 
Castlecary is absent) by the Arden or Calmy 
Limestone, 
Millstone 
Grit. 
An upper group of sandstones and shales containing 
at least three limestones, viz., the Castlecary, the 
Calmy or Arden, and the Index Limestone, and 
occasionally some workable coals. The Index 
Limestone receives its name from its position 
immediately above the workable coal seams of the 
next group. 
A middle group of sandstones and shales, with 
several workable seams of coal and ironstone. 
A lower group of sandstones, shales, etc., with three 
or more bands of limestone, of which the Hurlet 
is the most important. The top of the group is 
taken arbitrarily at the Hosie Limestone. The 
base line is formed over the greater part of Scot- 
land by the Hurlet Limestone, but in parts of 
Ayrshire and Lanarkshire is drawn at the Wee 
Limestone, 60 feet below the Hurlet. 
( 
| 
4 
| 
( 
| 
Gone shales, and coarse fireclays, with len- 
| 
4 
| 
| 
The Yoredale Rocks of England 
Carboniferous Limestone Series of Scotland.! 
1 ‘Carboniferous Limestone Series of Scotland. This name, however, is 
now used in England for the: Yoredale, Rocks and Carboniferous Limestone 
collectively, as previously stated.—A. S.”" 
The statement referred to here is that given on pages 138, 139 of the same 
_ Report, from which the following is extracted :— 
“<Tn the case then of such a formation as the Carboniferous, it seems to me 
that the right thing is for each district to have its own subdivisions and its 
