Mr Maclaren on Ancient Beaches near Stirling. 403 



Explanation of Map, 



Zf z, Zy z. The Carse, an alluvial plain, composed of stratified sand, clay, 

 and gravel, whose surface has the aspect of a dead level. Its 

 general elevation above the high water line at Cambusken- 

 neth Abbey, M, may be about 25 feet, but considerably less 

 at a few places, where the rivers overflow their banks, or have 

 changed their beds. At the head of the Carse, fifteen miles 

 westward, it is nearly 40 feet. 

 F, F, F. The river Forth. 



T. The river Teith, the largest tributary of the Forth. 



N. The river Allan, a considerable stream. 



A. Abbey Crag, an isolated hiU, capped with greenstone, whose 



summit is about 350 feet above the sea. 



B. The village of Bridge of Allan. 



C. The village of Causeyhead. 



S. The hill on which Stirling stands, capped with greenstone, the 



summit of which is about 350 feet above the sea. 

 R. Airthrey hill, whose summit is 500 feet above the sea. 



D. A higher hill, which forms the western prolongation of De- 



myat, 

 L, G, K. Hills bounding the plain on the south. The first is low, the 

 other two are elevated. 



The dotted lines represent the two principal roads on the south 

 and north sides of the Carse. 



The terraces are distinguished on the map by parallel shading 

 lines, the higher by vertical lines, the lower by horizontal. 



The black figures below are sections of the terraces, with por- 

 tions of the contiguous hills. In these sections the line s « 

 represents the level of the sea at Cambuskenneth Abbey 

 (M, in the map) ; the white space above it, the elevation of 

 the surface of the Carse above that level ; and the depth of 

 the black horizontal bands represents the elevation of the 

 terraces above the Carse. For the sake of distinctness, this 

 depth has been made three times greater than it ought to 

 be in proportion to the length. In section 3, the length 

 or horizontal extent has been exaggerated for a similar 

 reason. 

 Xy X, A figure shewing the cardinal points. 



About a mile northward from Stirling is the isolated rock of 

 Abbey Crag, which presents a steep acclivity on its western side, 

 covered with debris. From the foot of this acclivity a terrace of con- 

 siderable height extends westward to the river Allan, and beyond it, 

 forming the northern boundary of the Carse. This terrace seems to 

 mo to present very distinctly the characters of an ancient sea-beach, 

 or rather of two ancient beaches, a higher and a lower ; and there 

 ai-e remnants of corresponding beaches at other parts of the Carse. 



The position of the terraces will be understood from the map pre- 

 fixed, which represents a small portion of the Carse or plain of Stir- 

 ling, with the hills bounding it on the south and north. 



