18 



LOWER LIAS SHALE. 



the lines of stratification in the coast cliffs near Bridport, Dorsetshire ; and others which 

 I have described as occupying nearly the same geological position in the Hebrides 1 . 

 Beneath this sandy loam, the quarries in work, (1831,) exhibited the following beds of 

 the Marlstone. 



ft. in. 



1. Lightish yellow micaceous sandstone full of Belemnites 4 o 



2. " Pot-ears." Bluish gray calcareous grit, quarried for troughs 1 6 



3. (C Pendle." Brownish hard calc grit, jointed and fissured 0 10 



4. Wayboard of clay, with some fossils 0 3 



5. " Leathering-bed." Thick-bedded very hard micaceous marlstone, of greenish brown 



colour, charged with fossils, of which Pecten cequivalvis and Belemnites abbreviatus 



are the most abundant 5 0 



6. " Best double Blue." Hardest and best road-stone, weathers to a brown colour .... 1 3 



7. " Lowest Blue." A blue calcareous grit, partially discoloured by the decomposition of 



pyrites . 1 5 



Beneath this bed the water stands upon the clay of the lower Lias, which occupies 

 the sloping sides of the hills. A line drawn to the east, in the prolongation of the 

 surfaces of these beds, would precisely fall upon that part of the escarpment of the 

 Cotteswolds where the strata of the Marlstone, containing similar organic remains, 

 occupy their regular place in the series. It is therefore evident, that the intervening 

 valley has been hollowed out subsequently to the formation of the Lias and the Oolite ; 

 or, in other words, that there was a period when the strata of the Cotteswolds extended 

 in continuity as far as Church Down Hill. The same explanation applies to Oxenton, 

 Bredon, and all the other outlying masses of the Vales of Gloucester and Worcester. 

 (See Map.) 



The Lower Lias Shale, (/. of section,) or great mass of the formation, occupies the 

 greater portion of the Vale of Gloucester and Evesham. 



This Shale, resembling that of Dorset and the lower Shale of Yorkshire,, is a dark- 

 coloured calcareo-argillaceous and finely laminated deposit, containing occasionally 

 cement stones or concretions similar to those described in the Upper Lias. Among the 

 fossils which characterize it in the eastern part of the Vale are 



Ammonites Cheltiensis ; and 5 or 6 other 

 Ammonites of undescribed species, some 

 very small. 



Astacus glaber. N. s. Phillips. 



Avicula incequivalvis. M. C. t. 244. 



Belemnites abbreviatus. M. C.t. 590.f.2,3,&9. 



Belemnites elongatus. Miller, Geol. Trans. 



vol. ii. p. 60. pi. 7- f. 6, 7, & 8. 

 Crenatula ventricosa. M. C. t. 443. 

 Cucullcea elongata. M. C. t. 447- 

 Gryphcea incurva. Parkinson, Org. Rem. vol. 



iii. t. 15. f. 3. 



1 Transactions of the Geological Society, New Series, vol. ii. p. 353. 



