Vice-President’s Address. 197 
( An upper or ‘‘Cement-stone” group, so-called, 
because it is made up, in some distriets, of alterna- 
tions of blue shaly clays and argillaceous lime- 
stones. But in the Edinburgh area it consists in 
pea | the upper part of grey sandstones and shales with 
C . seams of oil shale and a fresh-water limestone (the 
3 ereeat Burdiehouse Limestone). On the coast of Fife, on 
Group. 
| the other hand, the beds are ehiefly marine, and 
| more like the overlying series. These changes are 
| attributed to the beds having been deposited on 
an uneven surface, which was not all enveloped 
| until the Calciferous Series was completed. 
A lower or Red Sandstone group. No particular 
1 band is used to divide this from the preceding, 
| On the Borders and in Berwickshire a platform 
\ of contemporaneous volcanic rock serves for a 
| boundary. But in Haddington volcanic activity 
L 
| 
| occurred at a later date, and in other parts towards 
Lower or 
| 
| 
L 
Red Sand- 
stone Group. 
the close of the Cement group, or far on in the 
Carboniferous Limestone Series. The group con- 
sists chiefly of red and green marls and sandstone, 
| passing down into, and barely distinguishable 
from, the Upper Old Red Sandstone. The latter, 
however, is often absent, in which case the Red 
Sandstone group rests unconformably on the 
Lower Old Red Sandstone or Silurian Rocks.} 
Upper Old Red Sandstone.? 
The Carboniferous Limestone Series of England. 
Calciferous Sandstone Series of Scotland 
own nomenclature, and that great caution should be exercised in attempting 
to correlate the divisions of one district with those of another.” 
‘The system, commonly in use in educational books throughout the 
country, of placing the local subdivisions of each district in a vertical 
column, and of arranging those which are supposed to be equivalent along a 
horizontal line, may, in Professor Green’s opinion, be of use as an aid to the 
understanding, but if intended to represent the way in which nature works, 
can only be mischievous.” 
‘*The carrying out of the system leads to a forced and unnatural classi- 
fication in all districts, except in those which happen to have been selected 
as forming an area of typical development, and gives an appearance of 
synchronism which is generally untrue.” 
‘* The particular case referred to by Professor Green has been met by the 
Geological Survey recently. The term Carboniferons Limestone having 
proved inapplicable, it was made more elastic by adding the word Series. 
Thus the Yoredale Rocks and Carboniferous Limestone are now grouped 
together under the name of Carboniferous Limestone Series. The name 
Bernician, which had been used by S. P. Woodward in 1856 for the Lower 
Carboniferous Rocks, was independently suggested by Prof. G. A. Lebour in 
1875, for the Carboniferous Limestone Series in those parts of the North of 
England, where the Carboniferous Limestone and the Yoredale Beds blend 
in such a way as to form a link between the Yorkshire and the Scottish types 
of the series. The lower part of the Lower Carboniferous (the Calciferous 
Sandstone of Scotland and the Upper Old Red Sandstone or Carboniferous 
Basement Beds) are included by many authors under the name Tuedian, 
originally proposed in 1855 by Mr Tate for the Calciferous Sandstone Series, 
and subsequently advocated by Professor Lebour.” 
1The Red Sandstone group is now mapped by the Geological Survey of 
Scotland as Upper Old Red Sandstone, 
2 ** Corresponding to the Carboniferous Basement Beds of England. The 
same beds are referred to by both names on the Border.” 
