so 
THE SILURIAN ROCKS OF THE EASTERN MENDIPS. 
The information derived from these trenches is sufficient to fully 
establish the fact that to the south-east of Moon's Hill a thin 
development of sediments containing- a Wenlock fauna occurs with 
a dip such that, if no fault intervenes, these rocks overlie the 
andesite of Moon's Hill. The Silurian rocks at the Sunny Hill 
quarry, a quarter of a mile to the west, are on the contrary older 
than the andesite, and the scanty fauna they contain is probably of 
Llandovery ag-e. 
The occurrence of Old Red Sandstone at the point 103 shows 
that the width of outcrop of the Wenlock is here only some 60 
yards, and with a dip of 55° this would indicate a thickness of about 
120 feet. On the other hand, the occurrence of Silurian sediments 
at the spots 98 and 100 is best explained by a fault, as is the sudden 
change in the character of the material met with in the shallow 7 
rail-cutting, — Old Red Sandstone debris, followed by the rock in 
place, being- abundant to the west of a line joining the spots 100 
and 102, while to the east of it Silurian rocks occur. 
Although several trenches were dug- with the intention of pene- 
trating the junction between the Old Red Sandstone and the 
Silurian, this was not accomplished, and it is uncertain whether any 
Ludlow beds occur. No trace of a Ludlow fauna has been met 
with, and the nearness of the gritty mudstone with Wenlock 
fossils at the points 102 and 104 to the Old Red Sandstone at 103 
is such that any Ludlow beds if present at all must be very thin. 
It is probable that the highest Silurians and the lowest Old Red 
Sandstone are both missing, and, as far as the scanty evidence 
available from dips g'oes, there is a considerable discordance be- 
tween the Wenlock and Old Red Sandstone. The Wenlock rocks 
exposed in the trench at 104 were clearly seen to dip at 55° S.S.E., 
while the Old Red Sandstone in the rail-exposure seems to dip at 
about 40° S.S.W. 
If one walks along the rails eastward from 92, a little pond 
will soon be noticed lying- just north of the line. From this 
point eastwards the relations of the rocks are more difficult to 
understand. Old Red Sandstone was proved at the point 105, and 
unfossiliferous gritty beds clearly related to the neighbouring- 
fossiliferous Silurians are seen by the rails at 93. It thus seems 
clear that the Silurian sediments and Old Red Sandstone to the 
east of the pond have the same mutual relationship as those to the 
west. But the trenches in the field to the north-east of the pond 
exposed not andesite but fine tuff or the peculiar coarse ashy 
conglomerate, the nature of which has been one of the most 
puzzling problems presented by this Silurian inlier. The coarse 
ashy conglomerate was formerly exposed in a considerable pit in 
the next field to the north (see QJ-G.S., Vol. lxiii., 1907, p. 228, 
fig-. 4), but this was filled up in 1908, and scarcely a trace of it 
remains. The relations of this deposit to the other rocks are 
difficult to ascertain. It seems most probable that the line of 
junction between it and the andesite to the west is faulted, and 
a fault has been tentatively inserted in the map, but further 
evidence is required to show the relation of the coarse ashy con- 
