70 A. E. Trueman — The Lias of South Lincolnshire. 



the Rhsetic in this quarry is similar to the one which has been 

 described in the South of England as the " Sun Bed".^ The section 

 was given briefly by the Survey,* but more fully it is as follows : — 



Blue shales with Echinoid spines ..... 



Earthy limestone with Ostrea, Modiola, and Lima rjigantea 

 Hard blue limestone with Modiola ..... 



Laminated blue shale . . . . . . • . 



Sun Bed. Purple limestone ...... 



As shown in Fig. 2, the lowest beds of the Lower Lias, which are 

 well developed at Owthorpe, a mile and a half away, are only 

 thinly represented at Cotgrave Gorse. This, together with the 

 irregular appearance of the surface of the Sun Bed, suggests that 

 a short break in deposition may have occurred in this locality. The 

 occurrence of the Sun Bed at the top of the Bhaetic on Beacon Hill, 

 Newark,^ about half a mile west of the Coddington trench sections, 

 is also interesting, but the section is now overgrown and it is 

 impossible to compare the succeeding deposits. 



Qujt'liorjjt 



CoVordv'eCiorse. 



Fig. 2. — Hydi'aulie Limestones of Owthorpe and Cotgrave Gorse ; 

 the lower beds thinning north-westwards. 



2. LowKR Lias Clays. 

 Apart from their use in brickmaking, these clays have little 

 economic value, and exposures in this area are rare. It is therefore 

 only possible to give an account of scattered observations, the 

 preservation of which may eventually facilitate a more complete 

 study of the district. Deep borings have shown the thickness of 



1 A. E. Trueman, op. cit., 1915, p. 152. 



^ Geology of Melton Mmvhray (Mem. Geol. Surv.), 1909, p. 19. 



^ Geology of South-West Lincolnshire (Mem. Geol. Surv.), 1885, p. 21. 



