The Geology of Lochruttox. 13 



at Riggfoot. This upper valley is traversed by a small 

 stream, LJnder-the-Brae Lane, which lower down is named 

 Merkland Burn, from the moss through which it discharges 

 into the Loch. The outlet, which is known as the Lade, as 

 it emerges from the Loch runs north between the Moat Farm 

 on the left and Shealinghill on the right. It Hows rapidl\ 

 along a rocky bed past an old meal mill, and, lower down, 

 a sawmill, until it encounters in front of the waterworks a 

 series of flat hollows. These alluvial flats extend along its 

 course until it unites with the Bogrie Burn, the united waters 

 being known as the Glen Burn. The high water leval of the 

 Loch is 305 feet above sea level. The leading features of the 

 landscape are large expanses of marshy flats along the upper 

 shore and long winding ridges on the western flank. 



Geological Features. 



The underlying rock is of a uniform nature throughout 

 the whole district, and consists of bands of hard greywacke 

 and occasional bands of hard shale. This strata is near 

 the base of the Silurian formation, and may be classed as 

 of the same age as the Gala rocks of South Scotland or the 

 Tarannons of Wales. Owing to a tremendous lateral pres- 

 sure, the rock has been thrown up into innumerable folds, 

 with the result that the strata in this district are generally 

 vertical and sometimes inverted. The folds are arranged in 

 a series of arches varying from a few feet to miles. The 

 domes of the arches are continually being removed by 

 denudation, laying bare the upturned edges of these old 

 rocks in such a way that bands of hard greywacke and 

 softer shale are arranged side by side on the rock surface 

 of the present age. The long axes of these folds lie from 

 north-east to south-west, and the result of a prolonged course 

 of weathering has been to wear out the softer shales into 

 hollows, leaving the hard bands protruding. This gives a 

 wrinkled or corduroy appearance to the landscape. Pro- 

 bably the finest exhibition of this form of weathering, which 

 is common to the whole tableland, can be seen in these rocky 

 knolls running from Easthill and Tregallon to the Glen Burn. 

 The strike of the rock here is almost east and west, con- 



