62 



ME. L. RICHAKDSON ON THE EH^TIC OF 



[Feb. 



(ii) Stratigraphical Details. 



Marston-Road section. — This section, thus named by 

 Moore, is still open, and was visited by the Geologists' Association 

 in 1890 1 and again in 1909 2 ; bat, in the report of the earlier 

 excursion, while there are some remarks on the Inferior Oolite, 

 there are none on the Rhaetic. 



Charles Moore records that 



' The Hbffitic deposits are represented in the western end of this section by 

 a friable marl, about 10 inches thick, in which occur teeth of Acrodus, Sargodon, 

 etc., and vertebrae of Lepidotus, whilst in the floor of the quarry Carboniferous 

 Limestone is seen.' (Q. J. Gr. S. vol. xxiii, 1867, p. 482.) 



In 1908 a party of the Cotteswold Naturalists' Field Club visited 

 this neighbourhood. 3 The details which I have obtained and 

 recorded below have been checked by both that Club and the 

 Geologists' Association. 



Marston-Boad Section, Holwell. 



Thickness in feet indie 



Inferior Oolite 

 {(Garantiana) . 



Lias 



Kh^tic 

 (Westbury 



Beds). 



C Limestone, hard, dense,con- 

 (. glomeratic at the base . . . 



N on- sequence. 



Limestone, hard, whitish," 

 sparry, pebbles of pure 

 white limestone (? Lang- 

 port Beds) at the base. 

 Top portion considerably 

 bored by LitJiophagi 



Non-sequence. 



'Limestone,somewhat sandy "^ 

 and earth}', with fragments („ 

 of Carboniferous Lime - C 

 stone ) 



0< 



Acantliothyris 

 (Schloth.), Terebratula 

 (?) globata, auctt., Syn- 

 cyclonema demissum 

 (Phil.), Isocardia sp., 

 Trigonia sp. indet., 

 Ostrea sp. 



Variable in thickness. 



<j Shale, j'ellow, gritty, cal- ") ~ 

 careous ) 



Breccia in intermittent S 

 patches, firmly adherent to [ 

 the Carboniferous Lime- t 

 stone J 



Unconformity. 



C Acrodus minimus Ag. ? 

 \>< Gyrolepis alberti Ag., 

 (. and vertebrae. 



{Full of fragments of 

 Pteria contorta(Povt\.), 

 Chlamys valoniensis 

 (Defr.), and Proto- 

 cardia. 

 ! Usual fish-remains. 



Carboniferous ... Carboniferous Limestone, presenting a very irregular surface. 



Leaving this quarry, and descending the hill to Holwell, we 

 notice a quarry on the right just before crossing the brook. This is 



1 Proc. Geol. Assoc, vol. xi (1890-91) p. clxxiii. The precise position of the 

 section is where the boundary-line of the Inferior Oolite and Carboniferous 

 Limestone is shown on the Geological Survey map, and immediately below the 

 ' o ' in Holwell. 



2 Ibid. vol. xxi (1909) p. 220. 



3 Proc. Cotteswold Nat. F. C. vol. xvi (1909) pp. 224-25. 



4 Q. J. Gr. S. vol. lxiii (1907) p. 399. 



