ON THE SHELL-BEARING DEPOSITS AT CLA^•A, AND OTHEK PLACES. 313 



APPENDIX. 



Report on the ChaiJelhall Clay. By Mr. David Robertson, F.G.S. 



Millport, May 5, 1894. 



The samples of clay that were submitted to me for examination from 

 Chapelhall from depths of 14 to 17 feet were, as taken from the pit, of a 

 dark slatish colour, and when dry of a light grey colour. The mud 

 referred to in the following list is that portion of the clay that passed 

 through a sieve of 96 meshes to the inch, and the sand is what passed 

 through a sieve of 24 meshes to the inch, and the stones are those retained 

 in the same sieve. That whicli is commonly called ' floats ' is that which 

 rises to the surface of the water when the clay is dissolved, after having 

 been dried. The dissolved clay, when stirred up, retained its dark colour, 

 but after standing a little a reddish brown formed on the surface. 



The ' floats ' are not referred to in the subjoined list, as they were all 

 alike in being quite barren of animal remains, and almost of everything 

 else. 



From the Well— No. 1. Dei^th, lift, to lift. 6 in. 



Mud 50 per cent. 



Sand 10 „ 



Stones 38 „ 



The sand consists of white and black grains, the white preponderating 

 greatly, or, I may say, with a small mixture of black grains, both 

 apparently rough or angular. 



The stones mostly water worn, a few portions angular. Few striations 

 were noticed. This may be accounted for as few of the stones are such as 

 would readily take and retain the markings. 



No. 2. Deinh, lift. 16 in. <o 14/;!. 11 in. 



Mud G2 per cent. 



Sand 12 „ 



Stones 26 „ 



The sand consists of white and black grains, mostly white, both angular. 



The stones more or le.ss water worn, but not to any great extent. 

 Many pieces were angular, some appear to have been crushed. No stria- 

 tions were noticed. 



No. 3. Depth, 15/<. to l%ft. 



Mud 50 per cent. 



Sand 18 ,, 



Stones 30 „ 



The sand light grey composition as above. 

 Stones much the same as No. 2. 



No. i. Depth, l<Qft.toVl ft. 



Mud 60 per cent. 



Sand 14 „ 



Stones 25 ,, 



The sand consists of white and black grains, chiefly white. 

 Stones mostly water worn. The pieces of shale generally more or less 

 striated, or indented, or both, and a few bits of coal, some with marks 



