Vol. 50.] ON TEE PURBECK BEDS OF THE VALE OF WARDOUR. 49 



surface. An upright and rooted stump of a tree (exogenous) was 

 found in it, the stem standing about 6 feet high, and a portion of 

 this is still preserved at the quarries ; a specimen of Cycadeoides 

 microphylla was picked up on the talus just below, and doubtless 

 came from this bed. Fragments of wood are common in it. 



We find that Prof. J. F. Blake has given a section of this quarry 

 which differs little from the above, but he remarks that the section 

 does not agree with Fitton's account. We cannot find, however, 

 that Fittou gave any account of this section, which was probably 

 not exposed at the time he wrote, for he only observes that 

 " among the loose matter at the top of these quarries is botrvoidal 

 carbonate of lime, passing into compact freshwater limestone, like the 

 ' Cap ' of Portland." (Trans. Geol. Soc. ser. 2, vol. iv. 1836, p. 255.) 

 We think that Prof. Blake must have made some confusion 

 between Chilmark and Chicksgrove, for he mentions both places in 

 connexion with the same section. It was Chicksgrove Mill quarry 

 which Fitton described in detail, and the slab of stone referred to 

 by Prof. Blake which is preserved at the Museum of Practical 

 Geology in Jermyn Street, and is supposed to show the junction 

 of marine Portland with freshwater Purbeck, must also have come 

 either from Chicksgrove or Wockley. The succession at these two 

 localities is substantially the same, but is very different from that 

 of Chilmark. The Chicksgrove section is now obscured and 

 weathered ; the quarry at Wockley, however, is still worked, and the 

 following succession of beds was there displayed in 1890 : — 



Feet. Inches. 



''Hard, flaggy, oolitic limestone, with Cyprids 1 6 



Soft marly stone passing down into argillaceous marl 1 6 



Sandy brown clay 3 



Grey oolitic stone with Cyprids 4 



Laminated, grey, sandy marl passing down into soft, yellow, 



sandy marl; Cyprids 1 8 



Layer of brown clay 2 



Hard tufaceo us limestone 1 (J 



Soft, white, silty marl, interlaminated in the upper part with 



layers of brown sandy clay 1 9 



Parting of black and brown clay 1 



Rather hard, whitish, laminated marl 1 2 



■{ Dark-grey, sandy and earthy clay 9 



Buff-coloured, laminated, marly limestone 2 6 



Black laminated clay, including a layer of grey limestone 



from 1 to 1 6 



Yellow ferruginous stone 1 



Soft, yellowish, sandy marl, overlying an undulating bed of 

 grey marly limestone, beneath which is disturbed tough 



grey marl 5 



Laminated brown and grey clay, with patches of black clay : 



rests on the uneven surface of the bed next below -4 



Hard, whitish, chalky limestone with Cyprids, and a layer of 



cherty stone with small lenticules of flint at the top 1 3 



l^Sof t, grey an d white, laminated marl 6" 



I Hard flaggy limestone with black flints at the top, passing 



\ down into chalky and shelly limestone 2 3 



[ Chalky limestone, with Portland fossils 14 



Q. J. G. S. No. 197. e 



Ph 



