428 



In the brick and tile works around Paisley, and in the adjoining 

 parishes, recent shells are abundant. Near Renfrew, cockles are so 

 numerous, that a farm and hill, are called Cockle Farm and Cockle 

 Hill. At Johnstown, which is about 8 miles from the sea and at a 

 point about 40 feet above its level, in making a well, there were 

 found bones of fishes and sea-fowls, fragments of sea-weeds, crabs' 

 claws, and numerous laj'ers of shells imbedded in sand and clay, 

 which rested on a deposit of " till " more than 70 feet thick. Besides 

 these localities, recent shells have been noticed at Helensburgh, also 

 near Loch Lomond, at Dalmuir, and the shores of the Firth of Forth. 



With respect to the origin of these deposits, Mr. Smith is of opinion, 

 that the lower or "till" resulted from the violent though transitory 

 action of a body of water; but that the upper was gradually deposited 

 at the bottom of a sea of sufficient depth to protect it from the agita- 

 tion of waves, and that it was raised to its present level by a process 

 analogous to that described by Mr. Lyeil as now taking place on the 

 shores of the Baltic*. 



Of the period when the change was effected, Mr. Smith offers no 

 conjecture ; but he states that it must have been anterior to the oc- 

 cupation of Britain by the Romans, because the terminations of their 

 wall on the shores of the Forth and the Clyde were constructed with 

 reference to the present level of the sea. He also adds, that on the 

 banks of the Firth of Clyde there are vitrified forts and tumuli to which 

 the same observation applies ; and that no human remains or works of 

 art have been found in the clay. 



At his first examination, the author concluded, judging from the 

 sea-worn terraces which skirt the coasts, that the change of level 

 could not exceed 40 feet, but he has since observed the clay at the 

 height of 50 feet j and Mr. Buchanan of Arden has found oyster- 

 shells near Loch Lomond 70 feet above the sea. Mr. Smith, how- 

 ever, believes that at the period when the clay was accumulated and 

 the terraces formed, the relative level of sea and land was stationary, 

 and that, if we may judge from the comparative dimensions of the 

 ancient terraces with those now forming, the period during which 

 the level was thus stationary must have greatly exceeded 2000 years. 



The important question, if the Fauna and Flora of the period when 

 this deposit was accumulated vvere identical with those of the present 

 epoch, Mr. Smith says it would be premature now to determine. A 

 very great proportion of the species of shells, amounting in all to about 

 70, abound in the present seas ; and it is worthy of remark that Asiarte 

 Garensis, which is common in the clay at Helensburgh, is found in 

 great numbers in the Gare Loch ; on the other hand, some of the 

 species have become very rare, if not extinct with reference to the 

 coast of Scotland. 



In alluding to the geological position of the upper deposit, the 

 author says, that it must be placed among the newer pliocene j and 

 as it belongs to one of the first steps in the descending series, every 

 circumstance connected with it should be carefully observed and re- 



* Phil. Trans., 1835, p. L 



