Oct., 1892. Silurian outlier west of caer caradoc. 
217 
THE SILURIAN OUTLIER WEST OF CAER 
CARADOC.* 
BY e. s. cobbold, assoc.m.inst.c.e., f.g.s. 
The geology of the neighbourhood of Church Stretton is 
exceedingly complicated, and contains many unsolved 
problems of great interest, various groups of strata and 
rocks having been thrown together by great earth movements, 
so that their relationships to each other, and comparative ages, 
are exceedingly difficult to make out. The whole of the Caer 
Caradoc country seems to be cut up by loop faults into a 
number of detached areas of a more or less lenticular shape, 
and it is with one of the simpler of these areas that the 
following remarks are concerned. 
An inspection of the geological map of the district will 
show an elongated area coloured grey, parallel with Caradoc 
Hill, on its western side, reaching from a little north of the 
farm called Botvyle to a point near the Church Stretton 
Railway Station, and streaked in two places with blue lines 
representing limestone. 
On looking at the wide stretch of the same colours to the 
east in the Wenlock Edge and Ludlow district, one’s attention 
is called to three strongly marked blue lines which run almost 
continuously from Buildwas and Wenlock on the north to 
Ludlow and Aymestry on the south. These blue lines mark 
the outcrops of the three principal Silurian limestones, which 
form very distinct horizons in the strata of that age, and the 
question arises which (if any) of these horizons are indicated 
by the blue lines in the outlier.f 
The Three Limestones.— These three horizons are known 
as the Woolhope or Pentamerus limestone occurring almost 
at the base of the Silurians of Shropshire ; the Wenlock 
limestone near the middle of the series ; and the Aymestry 
limestone occupying the middle of the upper or Ludlow 
division. 
* Read at the Conversazione of the Midland Union of Natural 
History Societies, held at The Quinta, near Oswestry, August 23rd, 
1892. 
f Murchison, in the “ Silurian System,” mentions the outlier as being 
of Lower Ludlow and Aymestry age, while the Geological Survey 
Map marks it b 6 , indicating the Wenlock rocks. 
