152 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. 



causes, we ought rather to class them among the formations which 

 owe their origin to volcanic action. 



These gypseous marls, more or less adjacent to, and (as I con- 

 sider) derived chiefly from the elevated and dislocated mountain 

 limestone, are, in many respects, analogous to the crystalline and 

 clay slates among the more disturbed grauwacke and other dis- 

 tricts ; and I entertain no doubt that other rocks referable to the 

 same origin will be found accompanying such dislocated strata as 

 are traversed by igneous rocks, to a greater or less amount, what- 

 ever the age of the strata may be. 



April 3. 1844. 



John Wilson, Esq., of St. John's Wood ; Andrew C. Ramsay, 

 Esq., of the Ordnance Geological Survey; and Charles Pope, 

 Esq., of Temple Cloud, Somerset, were elected Fellows of this 

 Society. 



The following communications were read : — 



1. On the Occurrence of Fossils in the Boulder Clay. By 

 Robert Harkness, Esq., of Ormskirk. 



There can be no doubt that the presence or absence of fossils in 

 different formations is owing to other causes than the actual exist- 

 ence of animals and vegetables on the spot and at the time of 

 deposition, and is, indeed, generally the result of local circum- 

 stances ; but the " boulder clay," the formation of which the author 

 of the present paper endeavours to explain the cause, presents 

 similar characters in districts widely distant, and is also remark- 

 able for the paucity of its organic remains. 



The deposit in question belongs to the geological period imme- 

 diately antecedent to the existing epoch, and consists of clay con- 

 taining boulders of various kinds of rock, scattered without order 

 through its whole mass. It occurs on various parts of the coast 

 both of Great Britain and Ireland, but appears to be most fully 

 developed in the basin of the Clyde, where it overlies a series of 

 beds of fine clay containing numerous remains of shells. Similar 

 remains have been found in many elevated sea beaches ; and it has 

 been concluded from the examination of them by competent natu- 

 ralists, that the climate must have been more arctic at the time of 

 their deposition than it is now in the places where they are found. 



The author of this communication, referring to the known in- 

 crease of temperature of the earth at increasing depths, and the law 

 of change of temperature in the ocean at certain depths, thinks it 

 possible that, although the land was exposed to intense cold, the sea 

 might yet have contained certain animals requiring greater warmth 

 which may have lived at considerable distance from the surface ; 



