336 Correspondence — Mr. John Smith. 



C0I^I^:E]s:P03iT^D:E]3iTc:F!. 



RECENT VOLCANIC ASH BEDS. 



SiK, — On May 29tli I examined some sections at Neilston, in 

 Eenfrewsbire, pointed out to me by Mr. John Mackie, M.E., of 

 that place. They are just to the east of the extensive Thread Works, 

 and are exposed by the levelling of the ground for an extension of 

 the same factory. The principal sections at present exposed are 

 three in number : — 



(a) Next the present virorks (north-west side of cutting) there is 

 fine sand pretty regularly bedded, V7ith a little cross-bedding, and 

 blocks in it up to 5 feet in diameter. 



(b) At the south-west side of cutting there is coarse gravel with 

 a little sand — at some places with clay — with blocks up to 7 feet in 

 diameter. The blocks are mostly traps of the neighbourhood ; some 

 of them are striated. I saw two fine-grained greywackes ; and 

 Mr. Mackie has had cai'ted up to his garden a block of grey granite 

 with large felspar crystals. 



(c) The most interesting section of all is towards the south-east of 

 the cutting. The material between it and the other two sections 

 had been cut away before I saw it, so that its relative position to 

 them could not be made out. 



It is composed of Volcanic Ash Beds interlaminated with irregular 

 beds and bands of loose sand. Part of the Ash occurs as consolidated 

 masses apparently concreted in position (they do not appear to 

 be bombs). 



The ash is so pure, that it is difficult to understand how it could 

 have come there unlessit had been thrown out of a volcano ; and 

 the loose sand interbedded with it gives the deposit an exceedingly 

 recent appearance. 



There is nothing in the section to indicate its relationship to any 

 known deposit, and it would be mere conjecture to suggest to what 

 age the Ash Beds may belong ; an exposure of perhaps 150 feet 

 in length can be examined, and at one part I counted five beds of 

 sand in a vertical face of ash of 9 feet in depth. 



Surface of Ground. 



^Si£;5^^S^^S^^^^Q££SS^ 



Loose sand interbedded with Volcanic Ash, Neilston, Eenfrewshire. 



John Smith. 

 MoNKREDDiNG, KiMViNNiNG, May 31, 1897. 



