113 



upper portion is horizontally stratified with numerous examples of 

 disturbance, while, towards the boulder-clay, it is very imperfectly 

 assorted by water. Throughout the upper portion of the mass there 

 are beds of silt or brick-clay. 



The author then proceeded to the consideration of the great de- 

 posits of brick-clay and stratified sand at Portobello and Granton. 

 At the former place the clay is finely stratified, graduating by 

 alternations with fine sand, into the incumbent sand. At Granton 

 the brick-clay is very imperfectly stratified, and is abruptly covered 

 with a mass of gi'avol distinctly assorted by water. 



On comparing the relative position of the boulder-clay, gravel, 

 sands, and silt, and their transitions, the author considers them as 

 the production of a single series of changes, and in the later stages 

 as having a soil with plants and animals at no great distance. 



The subject of Erratics was next brought under the notice of 

 the Society ; and the author remarked that those which occur on the 

 surface, at the north end of Salisbury Crags, had probably been 

 exposed by the washing away of the boulder-clay. There were no 

 angular blocks resting on the surface to be seen in the immediate 

 neighbourhood, such as abound in the district around Aberdeen, and 

 which are different from the contents of the inferior clay. 



The Marine Diluvium next occupied the attention of the author. 

 He stated that this deposit occurred on the sea- shore from Portobello 

 to Granton, and had been regarded as an ancient sea-beach, now 

 exposed in a raised position by an elevation of the land. The 

 author, after illustrating the character of a modern sea-beach, 

 stated that this bank of shells did not exhibit any of the characters 

 of a beach, but gave unequivocal proofs of its being storm-raised, in 

 the mixture of littoral and deep water shells, in overturned boulders 

 with limpets, barnacles, &c., in their original position, in the direc- 

 tion of flat stones in the bed, and in the appearances of stratification. 

 This view the author stated had been foixed upon him by an exami- 

 nation of the prolongation of the same bed at Borrowstonness, and 

 which he had published in Dr Thomson's Annals of Philosophy, for 

 August 1814. 



The author concluded his remarks by stating, that the sea-shells 

 found a few feet below the surface of the carse clay at Clackmannan, 

 Stirling, &:c., were in like manner derived from a violent inundation 

 of the sta, and could not be considered as an old sea-beach — an opi- 

 nion which had been adopted by several of the authors of illustrations 

 of the geology of the district, on very insuflfiicient grounds. 



