A HISTORY OF CUMBERLAND 
Sandstones and shales, thinning westward. 
[The Three Yards, or Acre] Limestone, persistent. 
Sandstones and shales, thinning westward [Six Fadom Hazel]. 
[The Five Yards, or Eelwell] Limestone, persistent. 
Sandstone and shales, thinning westward. 
[The Scar, the Middle or Fourth Sett Limestone], persistent. 
The foregoing strata probably represent what has been called the 
‘Carboniferous Limestone’ of Scotland. 
Sandstones, persistent coal and shales, thinning westward. 
Two thin, but very persistent, limestones [The Cockle-Shell Lime- 
stone, and Post Limestone]. 
Sandstones and shales, thinning westward [Tyne Bottom Plate]. 
[The Tyne Bottom, Simonstone, or Fifth Sett, Limestone], gener- 
ally persistent, but somewhat thinner in north Cumberland. 
Sandstones, shales, and some thin limestones, the two former thin- 
ning westward. 
[The Hardra, Jew, Oxford, or Sixth Sett, Limestone], generally per- 
sistent, but becoming thinner towards the north-east. 
Sandstones and shales, thinning westward of Cumberland, and thick- 
ening to the north-east. 
[Top of the Mountain Limestone], whose calcareous members have 
been already referred to as thinning steadily toward the north- 
west, and as being replaced by the Fell Sandstones and the 
lower half of the Oil Shales of the so-called ‘ Calciferous 
Sandstone Series,’ as they trend towards the north and the 
north-east. 
So far as the Lower Carboniferous Rocks are concerned, Cumberland 
may be regarded as the area within which there set in changes of a 
most important character from both a theoretical and an economic point 
of view. 
Hardly anywhere else in the kingdom can there be found types so 
diverse as the almost purely thalassic limestone series of West Cumber- 
land, the mixed estuarine, marine and volcanic types of the Borders, 
and the normal types of these rocks as developed in the south and south- 
east of the county. In comparing them as a whole with their chrono- 
logical equivalents in Scotland, the salient points of contrast are between 
shallow-water and volcanic types on the north, with dominantly deep- 
water and non-volcanic types on the south. 
(¢@) At the close of the Lower Carboniferous times there appears to 
have been a very general cessation of deposit over a large area in the 
northern parts of Britain, including Scotland. It may have coincided 
with a temporary, but very general, upheaval of the sea bottom, and with 
more or less removal of the sediments already laid down. This episode 
appears to have lasted a considerable time. 
Next followed a second period of slow subsidence and consequent 
deposition, during which the so-called Millstone Grit and the true Coal 
Measures were laid down. Their history may be told in a few words ; 
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