^46 Mr. Lonsdale on the Oolitic District of Bath, 



The "blue clay" (1.). ^vhich is the ''lias upper marl" of the Bath series, is 

 micaceous, and between one and two hundred feet thick. The " gritty lias" 

 ('I.) is the ''bastard oolite" of the cjuarrymen. It is a rubbly stone of a more 

 or less o-ranular structure ; and from the occasional appearance of minute cells 

 lined with ochreous matter, it might be mistaken for a variety of inferior 

 oolite. Hclicina poUtes, Helicina solaroides , and Spirifer Walcottii are found 

 in this bed. Interposed between the ''gritty lias" and the "blue clay" (3.) 

 appears sometimes an irregular bed of dark grey marlstone, abounding with 

 Ammonites, Belemnites, and small concretions of blackish, tough limestone. 

 Between the "blue clay" (3.) and the "corn grit" (4.) in some quarries 

 occur from two to fifteen feet of grey or blueish lias. The "corn grit" is a 

 pale brownish limestone, resting uniformly on the "white lias," and vary- 

 in"- in thickness from eighteen inches to three feet. The "white lias" (5.) 

 differs in no respect from that of Bath, and is constantly accompanied by the 

 "sun bed." The strata from (6.) to (9.) are equivalent to the "lias lower 



marls. 



The following sectional lists are given to illustrate the variations which are 

 presented in the quarries around the village. The first is from an opening- 

 in the road towards Frome, and near the superior junction of the new and 

 old lines. 



Ft. Tn. 



" Gritty lias" 6 



Irregular bed of dark grey marlstone 



" Blue clay," containing concretions of blackish, tough limestone .. 3 



G rey lias 3 



<' Corn grit" (three beds) 3 



"Sun bed" 10 



White lias 



Quarry in the lane between Tining-farm and Water-side. 



"Gritty lias" 



Grey lias 2 



"Corn grit" 2 



"Sun bed" 2 6 



"White lias" 8 



Summit of the hill in the Wells Road. 



"^'Gritty lias," in the field above the quarry 



Blue or grey lias 15 



" Corn grit" (three beds) 3 



"Sun bed" 1 



"White lias" 



