﻿1851.] BRODIE ON BASEMENT BEDS OF THE OOLITE. 209 



The same characters are presented by the Pisolite at Cleeve on the 

 north-east, and at Crickley on the south, where it admits of the same 

 subdivisions and contains identical fossils, although its average thick- 

 ness is probably rather more*. South of Birdlip and along the more 

 south-western range of the Cotswolds, the Pisolite disappears, but its 

 absence is more than compensated for by the increased thickness of 

 the Ammonitiferous oolite and inferior sands, the latter of which at 

 Wotton-under-Edge are estimated by Mr. Lycett to be about 40 feet 

 thick, and near Minchinhampton to average from 35 to 40 feet ; 

 while up the Chalford valley they are reduced (he says) to less than 

 half that amount, and they probably thin out northwards where they 

 are succeeded by the Pisolite. The next strata between the sands and 

 the Pisolite, which constitute the lowest of the Inferior Oolite round 

 Cheltenham, have not been previously noticed, or have been erro- 

 neously classed with the Pisolite, to which they obviously do not 

 belong ; one portion being especially interesting as forming a bone- 

 bed, although of limited extent and thickness. 



Feet. In. 



'D. — Immediately below C. of the Pisolite is a ferruginous Oolite, 

 made up of small, brown, oval, shining grains like small seeds, 

 cemented together by a sort of calcareous paste of a yellow and 

 brown colour. It is characterized by Belemnites and Ostrece ... 3 



E. — Yellow sand without fossils \\ 



F. — Hard, dark grey, approaching to brown, shelly, crystalline 

 limestone containing Belemnites, some Ammonites, Pectines_ (P. 

 lens), Terebratulce (especially T. bidens), Lima, AmpMdesma, 

 Gervillia, and Serpulce. Bones, Scales, Coprolites, and Teeth of 

 Fish are dispersed throughout the mass, and may be most readily 

 distinguished on the surface, intermixed with the same brown 

 oval grains as in D. higher up. The Limestone has been bored 

 into by Lithodomi, and the cavities are often filled up with frag- 

 ments of bones, &c. At its junction with the sand, E. above, it is 

 of a yellow colour, and it passes into a yellow, ferruginous, pure, 

 sandy, micaceous stone, with fewer oval particles, full of Belem- 

 nites, Ammonites, Pectines, and numerous fragments of Bones, 

 Scales, and Coprolites. On the whole, Belemnites are more abun- 

 dant than Ammonites at Leckhampton 1 



Brick-coloured and dark yellow sandy marl, with broken Shells, 



chiefly Pectens, and small spines of Cidaris 3 



4. — Blue micaceous shale (Upper Lias). 



At this particular spotf, the junction of the Oolite and Lias is well 

 exposed ; but, with the exception of Crickley Hill, this is the only 

 locality along the whole line of the outer escarpment of the Cotswolds 

 where it may be observed, owing to the quantity of debris and rubble 

 which covers the slopes of these hills. Hence it is almost impossible 

 to trace these lowest beds with any degree of accuracy, although it is 

 evident that throughout the whole of the line, from Cleeve to Wotton 



* The Pisolite extends, in all probability, in a north-easterly direction towards 

 Winchcomb. The Oolite marl occurs there and at Chipping Campden, on the 

 north-eastern extremity of Gloucestershire, with the usual characteristic fossils. 

 At the latter place, my friend Mr. Gavey informs me that the freestone rests imme- 

 diately upon the Lias ; so that the Pisolite is entirely wanting. At present, how- 

 ever, our information of the Oolitic series in that district is very scanty, but I 

 trust his zeal will soon remedy this deficiency. 



f The junction of the Oolite and Lias is seen in a corner of the lowest quarry 

 where sand is obtained, looking towards the north-west. 



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