b. 
Cock1LE SyYKE. 
. Limestone. 
30ft. shale; with occasional girdle 
beds ; 4in. coal at top. 
3ft. shale; with girdle beds. 
17ft. sandstone. 
30ft. strong sandstone seen near the 
top; signs of a little limestone 
coming in about 12ft. from the 
top. 
Limestone.} 
38 CO. T. Clough—The Whin Sill of Teesdale. 
RowaNTREE SYKE. 
a. Limestone. 
3ft. calcareous shale. 
14ft. altered shale. 
21ft. Whin. 
25ft. strong sandstone; rests appa- 
rently directly on the Whin; then 
strong girdle beds and sandstone ; 
no shale. 
5ft. limestone. 
12ft. sandstone; thin flags in places. 
4. Limestone. 
In Cockle Syke the vertical distance between the two extreme 
limestones, a and b, is about 80 ft. In Rowantree Syke, if we 
include the Whin, the distance is the same; if we exclude the Whin, 
it is 59 ft. There can be no doubt that the limestones, a and b, are 
correctly correlated in the above sections. Also the section between 
these two limestones has wherever seen in the neighbourhood kept 
very constant, and is not likely to have changed greatly in the short 
distances between the sykes. We are then, apparently, entitled to 
conclude that in this instance, a thickness of sedimentary beds 
equal to the thickness of the Whin is missing where the Whin is. 
In Cockle Syke there is no Whin and we have the normal thickness 
of beds between the two limestones a and 6; between Cockle Syke 
and Rowantree Syke a Whin bed has come in, which in Rowantree 
Syke is 21 ft. thick, and just this thickness of sedimentary beds is 
here missing. 
In Lodge Gill Syke the section is not so clear; there are a good. 
many small strings and veins about, and the beds are in places 
dipping rather high and variously. It would not be safe to place 
much dependence on the data derived from this syke alone. Never- 
theless, the appearances are all in favour of there being still more 
sedimentary beds missing here than there are in Rowantree Syke, 
and at the same time the Whin bed in it is considerably thicker. 
The apparent section is as follows beginning from below :— 
a. Limestone. 2ft. hard fine-grained sandstone. 
10ft. shale: very calcareous in places, 6ft. shale. , 
2ft. Whin. 7ft. hard fine-grained sandstone. 
3ft. shale. 4ft. limestone. 
41ft. Whin. And then about 12ft. up to base of 
1ft. sandy shale. 
Another instance of this kind, not on so large a scale, but more 
accessible, is to be seen at the High Force. I have already 
(Q.J.G.S. vol. xxxii. No. 128) referred to the fact that a 6 ft. Whin 
underflow can be seen starting from the base of the main Whin near 
the North end of the Force, and ending not far from the South end. 
The following diagram (Fig. 4.) represents roughly the changes 
that take place here. At the South end of the section the thickness 
of shale between the base of the main Whin and the top of the 
limestone is about 20 ft. In the middle of the section the total: 
the limestone 8. 
a ~ The limestone 4 is the second thick limestone below the Tyne Bottom limestone ; 
if is about 130 ft. below it. 
