LOWER LIAS. 
STRATA EXPOSED IN CONSTRUCTING FILTON-AVONMOUTH RAILWAY. 9 
(B) The Charlton Section. 
The next cutting to be described is at Charlton, one mile West 
of Filton. Considerable interest in this section arises from the fact 
that a complete series of the Rhsetic beds is here exposed. The 
cutting is nearly one mile long, interrupted for 300 yards in the 
middle portion by a tunnel. 
The beds at this place are arranged in feeble anticlinal and syn- 
clinal flexures, especially noticeable in the cutting West of the tunnel. 
The dip averages about 3 degrees to the E.N.E. ; this is sufficient to 
bring within observation all the strata from the Lower Lias to the 
Keuper Marls, although, at the time of writing (July, 1908), the 
excavations have not been carried to the level of the permanent way. 
The horizontal section (vide page S) indicates the general arrange- 
ment of the strata, and the position of the more important beds ; 
it takes no account, however, of the slight flexures above noted. 
The following details of the strata down to the level of the bone 
bed were compiled chiefly from observations made near the East face 
of the tunnel, and those below the bone bed from the Western cutting. 
'XS 
a 
Charlton Railway 
Ft. 
Limestones, grey, weathering I 
yellow, thinly bedded, dis- y 2 
turbed and rubbly j 
Limestone, grey, shelly, in two layers 0 
0 ^ 
Shale 0 
Limestone, blue 0 
Shale 0 
Limestones, three thin beds, with 
clay partings 0 3 
Limestone, hard, blue 0 5 
Limestones, four thin beds, with 
shale partings 1 1 
Cutting. 
In. 
f Lima cf. punctata. Sow. 
L. tuherculata, Terq. 
L. hettangiensis, Terq. (small 
specimens)., 
Pholadomya Fraasi, Oppel. 
Pleuromya crowcomheia, Moore, 
Tate. 
Astarte ohsoleta, Dunk. 
Pinna Hartmanni, Ziet. 
Myoconcha psilonoti, Quenst. 
Ostrea liassica, Strickl. 
Pleuromya croivcombeia, Moore, 
Tate. 
Protocardium PhilUpianum, 
Dunk. 
Vnicardium ( Lucina ) arenacea, 
\ Terq. 
Limestone, light grey, argillaceous 0 8 
Limestone, rubbly, pale yellow ... 0 10 
Lijiiestone, grey, surface covered! ^ 
with shells j 
.Shale, blue ... 
At corny a (Thracia) cf. subruga- 
losa. Dunk. 
Modiola minima. Sow. 
M. liasina, Terq. 
Pinna Hartmanni, Ziet. 
Turbinate Gasteropods. 
Modiola, minima. Sow. 
M. minima. Sow, Moore. 
Gervillia precursor, Quen. 
PlicatiUa intusstriata, Emm. 
Lima valoniensis, de France. 
Protocardhiin Phillipianum, 
Dunk. 
[Pleuromya croiccombeia, Moore, 
J Tate. 
Plicatula intusstriata, Emm. 
^Macrodon liettangiensis, Terq. 
[Pleuromya crowcombeia, Moore, 
.J Tate. 
\ Modiola minima. Sow., Moore. 
^Pseudomonotis decussata, Miinst. 
4 Pseudomonotis decussata, Miinst. 
a2 
