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Marine Deposites on the Margin of Loch Lomond. By the 

 Rev. J. Adamson. 



As to beauty or magnificence of scenery, Loch Lomond 

 has many interesting features common to it with the other 

 Scottish lakes which occupy the chasms of the great primi- 

 tive mountainous district ; it is, however, more closely con- 

 nected with a different set of hollows. Tt is the most cha- 

 racteristic example of a group of long ranges which lie to- 

 gether, and nearly parallel to each other, but which, instead 

 of following the direction of the mountain recesses, stretch 

 almost perpendicular to it, generally cutting through the 

 transition and part of the primitive rocks, together with the 

 older members of the secondary class. All the others of 

 those valleys are connected with the sea by means of the 

 Frith of Clyde, and are partly filled with its salt water, and 

 enlivened by its appropriate animals. There is reason 

 enough to believe that this was at one time the condition of 

 Loch Lomond ; but at present we find there, along with the 

 ocean's depth, only the remains of its inhabitants. 



One of these marine deposites was about eight or ten feet 

 above the highest level of the present waters. It lay in a 

 small hollow, under a projecting precipice of limestone, close 

 to the margin of the lake. The only remains of it now are 

 some fragments of a very compact calc-tuff, containing sea- 

 shells disseminated through it. The limestone rock is now 

 quarried; and the calc-tuff, being the most accessible and 

 richest limestone, was first carried off for use. The shells 

 appear to have been accumulated in a situation exposed to 

 the stalactite droppings from the lime rock. In the interior 

 of the tufa, they are chiefly the Myrtilus edulis, or its conge- 

 ners ; but the surface is sprinkled with imbedded specimens 

 belonging to the genera Planorbis and Helix, which have ac- 

 cidentally fallen upon it. This quarry is on the east side of 

 the lake, about two miles north-west from the mouth of the 

 Endrick, and on the north side of the great range of islands 

 composed of secondary conglomerate, which stretches across 

 the southern end of the lake. The limestone is on the lands 

 of his Grace the Duke of Montrose, and is worked for his 



