52 MESSES. W. E. ANDEEWS AND A. J. JUKES-DEOWNE [Feb. 1894, 



Feet. Inches. 



Dark brown soil 1 



12. Weathered niarlstone or ' lias ' 1 



11. Buff-coloured marl, with two seams of grey clay 6 



10. Soft, fine-grained, marly oolite, with thin layers of harder 



compact marlstone in the lower part 2 3 



9. Soft, yellowish, calcareous oolitic sand 9 



8. Very hard limestone, consisting of shelly layers alternating 



with seams of compact marlstone 10 



7. Soft marl in thin layers 8 



6. Soft, yellowish, oolitic stone, with thin layers of marl 2 6 



5. Hard grey limestone, full of shells 2 4 



4. Firm oolitic stone, almost a pisolite in places, with inter- 

 laminated layers of marl in the lower part and a 2-inch 



layer of brown marly clay at the base 3 3 



3. Soft calcareous stone, passing clown into hard limestone with 



vertical joints, and lying in thick courses 3 3 



2. Soft, grey, laminated, argillaceous marl 1 



1. Firm buff-coloured marlstone, breaking with semiconchoidal 



fracture; base not seen 3 



22 4 



Limestone No. 3 is of estuarine origin, for the central part is 

 full of marine shells, Corbula alata, with small species of Pcrna, 

 Cardium, and Leda, Serpida, and small Univalves. There are also 

 many angular hollows left by the solution of salt-crystals ; the walls 



are so crushed in, that some of them look like four-rayed ^ / 



stars ; some are empty, others are filled with a yellowish ] ( 

 ferruginous earth. ^ ""> 



Nos. 6 and 9 are curious oolitic sandstones ; when treated with 

 dilute hydrochloric acid the mass of the rock disappears, but if the 

 residue is washed and evaporated a very small quantity of fine sand 

 remains, consisting of minute grains of clear translucent quartz. 

 Such granules probably form the nuclei of some of the oolitic 

 grains, but most of these must be purely calcareous. 



The higher bed No. 10 is only partially oolitic, and appears to be 

 a mixture of oolitic particles with triturated shells of Cyclas, Cyprids, 

 etc. ; but no specifically recognizable Cyprids were observed. 



The dip of the beds at this quarry is about 4° north, probably 

 lessening southward, in which direction the ground rises ; and on 

 the top of Lady Down there are quarries in nearly horizontal 

 Middle Purbeck beds. At a lower level again, on the southern 

 side of the common, by the lane leading to Chicksgrove, layers of 

 marlstone and oolite like those at Ridge can be seen ; and the base- 

 ment-beds of the Lower Purbeck, with the hard chalky limestone 

 below, cross the lane at its lower end. 



Similar oolitic beds are also exposed in the bank at the western 

 end of the lane leading from Chilmark quarries to Teffont, and 

 here they contain the characteristic Lower Purbeck form Cypris 

 purbeckensis. 



Beds of the same kind were also proved in 1890 below the 

 Middle Purbeck, at the bottom of the large quarry at Teffont Evias. 



