678 REPORT— 1886. 



11. On Deposits of Diatomite in Slcye.^ By W. IvisoN Macadam, F.G.S.^ 

 and J. S. Grant Wilson, F.0.8. 



This newly discovered deposit occurs in several places in the north-east part of 

 the island, and, in all, extends over an area of about 58 square miles. The tw& 

 places especially described are : (a) Loch Ouithir, where the diatomite lies under 

 3 feet 8 inches of turf and peat. It has been proved in 19 bore-holes to a depth of 

 8 feet 4 inches, the bottom not reached. It probably extends to a depth of at 

 least 14 feet. This deposit is very piure, containing' in a calcined sample 99-20 per 

 cent, of diatomaceous matter, (b) Loch Moukstadt. Here the deposit is some- 

 what irregular in its thickness and in the thickness of the overlying peat, &c. 

 The diatomite is rather less pure than in Loch Cuithir, but it contains 93*55 per 

 cent, of diatomaceous matter. 



' For fuller details, see papers by the authors, in Min. Mag., vol. vii. (No, 32)^ 

 p. 35, 1886 ; and Iram. Geol. Soc. Edinb., vol. v. (Part 2), p. 318, 1887. 



