THE GEOLOGY OF THE ENGLISH CHANNEL. 147 



M. 11. S. 26° W. Edd., 17-8 miles. 

 Hard chocolate-coloured marl. 



M. 12. S. 26° W. Edd., 17-8 miles. 

 Hard chocolate-coloured marl. 



M. 35. S. 32° W. Edd., 18 miles. 

 Hard chocolate-coloured marl. 



M. 34. S. 28= W, Edd., 185 miles. 



Hard chocolate-coloured marl. 



M. 14. S. 24° W. Edd., 20 miles. 

 Hard chocolate-coloured marl. 



M. 15. S. 27° W. Edd., 20-3 miles. 



Pale red, rather soft marl. 



M. 20. S. 25° W. Edd., 20-5 miles. 



Hard chocolate-coloured marl. 



M. 24. S. 24" W. Edd., 22 5 miles 

 Hard chocolate-coloured marl. 



LIMESTONES. 



The following dolomitic limestones would appear to belong to the 

 New Red Sandstone formation. 



M. 34d. S. 28° W. Edd., 18-5 miles. 



A rather small brown-grey pebble, much bored by saxicava. Freshly 

 broken surface is pale brown, and shows somewhat granular, very 

 uniform, texture. 



The section, examined by the unaided eye, suggests a slightly 

 marked banded structure. The matrix of the rock is a fairly pure 

 crypto-crystalline calcite and dolomite, and minute zoned rhomboids of 

 the latter mineral occur sparsely. But it is so closely set with small 

 sand grains that it might almost be described as a sandstone with cal- 

 careous cement. Most of these clear grains are probably quartz, but 

 some show the repeated twinning of plagioclase felspar. A little 

 brown mica is to be found, and rather numerous rich brown and black 

 specks, which may be rutile. There are also many pale olive 

 patches, distinctly larger than the other granular constituents, some- 

 what ill defined in outline and apparently calcareous. The calcareous 

 ground-mass has here and there a yellowish-brown tint. 



M. 35e. S. 32° W. Edd., 18 miles. 



A very similar rock to the last described. 



M. 21a. S. 25° W. Edd., 21 2 miles. 



A compact horny -textured rock distinctly hard, but bored by 



