﻿420 



ME. L. EICHARDSON ON THE EHJETIC AND [Aug. I905, 



As I have indicated above, the rubbly beds of the White Lias 

 probably occur not far below the floor of the quarry, and rest upon 

 the Cotham Marble. The strata below the Sun-Bed and above the 

 rubbly deposits at Blue Lodge are 2 feet 2 inches thick (see p. 418): 

 here, however, the equivalent deposit must be of double that 

 thickness, since White-Lias limestones, 4 feet thick, are exposed 

 without any indication of the rubbly beds. 1 



Some 4 miles distant from the Barton-Farm Quarry is the instruc- 

 tive section at Newbridge Hill, on the outskirts of Bath. When I 

 visited the section, the Cotham Marble was the lowest bed that 

 could be studied in situ. The following record is compiled from 

 details noted by the Rev. H. H. Winwood, F.G.S., 2 my own notes 

 being in square brackets : — 



Thickness in feet 



(B. Sun-Bed '0 



Limestones, with an occasional 



parting of clay 5 



Rubbly limestone with clay-1 

 White ! partings, passing downward I r 



Lias, j into bluish bands. Very fossi- j 



liferous towards the base ... J 



Blue clay 



Limestone 



l, Reddish-brown clay 



( [1] Landscape Stone [or Cotham 



Marble] 



r/etic ^ PI Bight- blue or grey shales j 



j [3] Darker - shaded band about [ o 



the centre [ 



>ht-blue or grey shales J 



inches. 



4 ^ 



l[4]Lh_ 



Gasteropoda ; Lima, 

 Pecten, Plicatula 

 intus-striata,Modiola 

 [aff. minima, Moore],. 

 Myacites [Pleura- 

 mya\, Axinus, Car- 

 dium rhceticum [Pro-- 

 tocardium Philip- 

 pianwni], [Ostreal. 



Avicula [Pseudo- 

 mo not is] fallax. 



Estheria minuia and 

 traces of vegetable 

 matter in the band 

 about the centre. 



From these few sections it will be observed, (1) that the White 

 Lias comes above the Cotham Marble and below the Ostrea- 

 Beds ; and (2) that it increases in thickness, as it is traced from 

 north to south. The component beds of the White Lias successively 

 overlap one another, and this implies elevation in the north, 

 depression in the south: a conclusion also arrived at from 

 investigations in Glamorganshire. 



YII. SUMMAEY. 



(i) The Sully Beds, or the upper portion of Etheridge's ' Grey 

 Marls,' belong to the Hhaetic Series, as shown by the fossils, and 

 are distinct from the ' Tea-Green Marls ' of the Keuper, which do 

 not contain fossils. 



1 The White Lias is exposed in road-sections at Barrow Hill, about a mile 

 north of the Barton -Farm Quarry ; while the junction of the Rhastic and 

 Keuper is seen in the road-cutting a short distance to the west, or some 

 300 yards east of Wick Forge. A thin deposit of red sand, containing Acrodus 

 minimus, Saurichthys acuminatus, Gyrolepis Alberti (scales), ' Sargodon 

 tomicus' (Lepidotusf), fragments of bones, and small quartz-pebbles, probably 

 represents the Bone-Bed. 



2 Proc. Bath Nat, Hist. & Antiq. F.-C. vol. ii (1871-73) pp. 204-11. 



