C. LAPWORTH ON THE MOFFAT SERIES. 



293 



The first of these exposures occurs at the Old Copper-mine ; here 

 a horizontal shaft runs from the level of the stream into the flank 

 of the steep ridge to the southward, and exhibits a small section of 

 shattered Birkhill Shales, faulted against thick-bedded grits, off 

 which they dip, apparently to the northward, at steep angles. The 

 black shales are much contorted and stained with the green carbo- 

 nate of copper, the presence of which originally led to mining-opera- 

 tions at the spot. The fossils obtainable are those of the M.-gregarius 

 zone, viz. Monograptus gregarius (Lapw.), M. tenuis, Diplograptus 

 tamariscus (Nich.), and a few others. 



Fig. 22. — General Section through the Hartfell exposure. 



Auohencat 

 Burn. 



S.E. 



Hartfell 

 Spa. 



Newton Fell. 



Billscleuch 

 Burn. 



K.W. 



D. Greywackes and flagstones. 

 B. Birkhill shales : 2. Upper; 1. Lower. 

 B. Hartfell shales : b. Upper ; a. Lower. 

 A. Glenkiln shales. //. Faults. 



The second exposure is met with about 200 yards higher up the 

 stream. The black shales, which are here pierced by a small f el- 

 stone dyke, show the nodules and variegated mudstones of the higher 

 M.-gregarius zone, and yield in some abundance Monograptus gre- 

 garius (Lapw.), M. fimbriatus (Nich.), M. lobiferus (M'Coy), Diplo- 

 graptus vesiculosus (Nich.). 



In the Spa Score itself, immediately above the mineral spring, 

 the greywackes cap the south cliff for a long distance, and are either 

 in a perpendicular attitude or dip steeply to the south-east. They 

 are immediately underlain by a few feet of shattered shale and mud- 

 stone, much wrinkled, and weathering of a pale orange colour, but 

 exhibiting several conspicuous seams of white- clay shale. These 

 form the summit of a great mass of highly contorted black shales 

 and flags, pierced by dykes of felstone. In spite of their greatly 

 shattered and, indeed, more or less altered character, we easily re- 

 cognize the zone of Monograptus gregarius, with its characteristic 

 variegated mudstone seams ; and two long parallel rows of hard black 

 flags projecting above the general face of the cliff from end to end are 

 immediately assigned to the D. -vesiculosus band. The strata are so 

 convulsed that it would be impossible to lay down any line of demar- 



