G. Eiclding — Old Red Sandstone of Forfarshire. 397 



exposed. The magnitude of that break has been insisted on by many- 

 writers, but no description, I think, could be quite so impressive as 

 those cliff- sections. Moreover, of late years, there seems to have been 

 a tendency in many quarters to minimise its importance. In most 

 localities the relation between the two sets of rocks is a matter of 

 inference rather than observation. This fact at once explains the 

 willingness to pass lightly over this unconformity, and at the_ same 

 time makes it the more desirable to have an adequate description of 

 a locality where its magnitude can be clearly seen. 



7 » ? I'C 



Fig. 1. — Sketcli-map of the Geology of Forfarshire. 



iifote. — This map is to a considerable extent hypothetical, especially in Kincardine, 

 but I believe the general distribution of the various subdivisions is in the main 

 correct. 



The attempt to collect and review the published work bearing on 

 this question soon proved that no satisfactory result could be attained 

 without a complete investigation of the wide and involved question 

 of the relation of the Old Eed Sandstone and Carboniferous deposits. 

 This carried me far beyond the limits I had originally conceived for 

 this communication, and it became obvious that the subject must be 



