THE GEOLOGY OF SOUTH-EASTERN KINCARDINESHIRE. 929 
IV. THe UNcoNFORMITY BETWEEN THE DowNTONIAN AND [?] UppER CAMBRIAN 
av Ruruery Heap. 
The nature of the junction between the Upper Cambrian and the Downtonian may 
be studied most satisfactorily in the cliff section at Ruthery Head and on the foreshore 
to the east of that headland. To the north extend the green Cambrian strata with 
their main structural planes, whether of cleavage or of bedding, in igneous and sedi- 
mentary rocks alike, dipping to the north-west; to the south lie the red Downtonian 
y 
y 
9 1000 2000 FEET. 7 J 
4 
z 
ee, DYKES 
QUARTZ PORPHYRY 
P| sw sep 
BRECCIA 
DOWNTONIAN 
?2UPPER CAMBRIAN 
SCHISTS 
‘\ DIP OF STRATA 
~\ VERTICAL 
GREY MUDSTONE, %, ” & CONTORTED 
SHALE AND 
SANDSTONE . A141 ___ FAULTS 
Text-Fie. 1.—Sketch-map of Geology of the Coast of Kincardineshire from Cowie to Garron Point.* (2. Campbell.) 
beds highly inclined towards the south-south-east. (See Sketch-map, and Plate I. figs. 
1, 2, and 3.) It is not perhaps difficult to understand why the character of the boundary 
between the two sets of rocks should have been misunderstood, since there are many 
features in the section which suggest the presence of a powerful east-and-west fault. 
The Cambrian rocks for a considerable distance away from the junction have been 
stained red, and are in places very much shattered; the basement beds of the Down- 
tonian consist of breccias made up to a large extent of reddened fragments of the 
underlying Jasper and Green-rock series; and the presence of numerous hitch faults 
tends still further to obscure the nature of the boundary. But, while it may be difficult, 
even after one has become familiar with the rock types, to distinguish the basement 
beds of the Downtonian from the reddened Cambrian rocks, it is always easy to 
recognise the character of the dominant structures in the respective types, and by 
means of these to trace the somewhat irregular course of the junction along the fore- 
shore opposite Ruthery Head. The presence of intercalated beds of jasper in the 
* Reproduced by permission from the Geological Magazine, dec. 5, vol. viii., 1911. 
