264 C. LAPWORTH ON THE MOFFAT SERIES. 



Hartfell and Birkhill divisions ; but no positive proof of this is obtain- 

 able, as the southern slope is gentle and overgrown with turf at this 

 point. 



(c) Structure of the Glen. 



The evidence already collected is amply sufficient to enable us to 

 determine the arrangement of the Moffat Series in this locality. 



The strata are arranged in three parallel anticlinals. Of these 

 the southerly one is by far the most important. Its axis runs in a 

 straight line almost coincident with the bottom of the gorge. The 

 level of this axis gradually declines to the west-south-west, so that 

 newer and newer beds meet and cross over it as we proceed in that 

 direction. The lowest beds exposed are the Glenkiln Shales, which 

 occupy the bed and north bank of the stream, from the foot of the 

 small burn entering from the north until they reach a point opposite 

 the centre of the main cliff. Here they « nose in" upon the anti- 

 clinal, and the black beds of the Hartfell Series cross over one by 

 one. They are followed in a similar manner by the " Barren Mud- 

 stone," through which the axis of the anticlinal runs to the foot of 



the cliff. . , , ,i 



The second anticlinal exposes the Birkhill Shales m the hollow 

 at the top of the cliff. The third exposes the Rastrites-maximus 

 band in the greywackes beyond the summit. 



Within the limits of the main cliff, as we have seen, the se- 

 quence is quite easy of comprehension ; but in the streams to the 

 north-east the contortion is so excessive that few beds are recogni- 

 zable, and the various zones are inextricably intermingled. 



Passing down the stream below the glen, however, an excellent 

 section is visible (fig. 4), which enables us not only to completely 

 confirm our former conclusions, but gives us a good idea of the 

 dislocated character of the rocks of the neighbourhood. 



Pig. 4. — Section in Selcoth Burn. 



D. Purple and grey flagstones and graywackes. 



C. Grey and purple shales with grey and black seams. 



3. Zone of Bastrites maximits. 2. Zone of Monograptus spinigerus. 

 Ca. Black flags and shales with Monograptus gregarius, Diplograptus vesicufosus. 

 Bb. Pale mudstones, non-fossiliferous. 

 ///. Faults. 



Along this line the Moffat Series emerges from below the grey- 

 wackes in six distinct anticlinals. The axis of each of these arches 

 is inverted, the degree of inversion gradually decreasing as we 

 descend the course of the stream. ' With one doubtful exception each 



