290 C. LAP WORTH ON THE MOEEAT SERIES. 



Annan the Moffat Shales are exposed in a deep gorge lying along 

 the course of the Grarple Water, a small tributary of the Evan. 

 Deep, narrow, and overhung with a thick growth of trees and 

 underwood, the picturesque little glen is a favourite resort of tourists 

 and pleasure-seekers. The burn toils between perpendicular cliffs 

 of the hard grits and greywackes of the Gala group, more than 

 ordinarily coarse and massive, and weathering of a dull purple 

 colour. About half a mile from the mouth of the gorge the grits 

 retreat from the edge of the stream, which here flows through a 

 narrow haugh of alluvium, and lays bare in its course several capital 

 exposures of the highest division of the underlying Moffat Series. 



The most ancient strata visible at this spot belong to the D.-vesiculo- 

 sus zone of the inferior division of the Birkhill Shales. They form 

 a low arch, the axis of which crosses the course of the stream at a 

 very oblique angle. This arch is conspicuously exhibited at the 

 point N. of the plan, in the north bank of the stream. Two small 

 exposures of the overlying beds are apparent a little below. In 

 that on the southern margin of the burn a partially inverted section 

 shows the junction of the Lower and Upper Birkhill Shales. The 

 latter are the grey flaggy shales and dark seams of the lower 

 beds of the M.-spinigerus zone, with white-clay bands and calcareo- 

 ferruginous nodules. Fossils are abundant and in good preserva- 

 tion, principally Monograptus Hisingeri (Carr.), M. Clingani (Carr.). 

 A small section on the opposite side of the stream exposes grey and 

 black shales somewhat higher in the vertical series. 



In the prolongation of the axis of the main anticlinal to the south- 

 west, a highly fossiliferous exposure of the M.-gregarius zone is visible 

 in the south bank of the stream. The strata are greatly disturbed ; 

 but their soft, highly pyritous nature, and the numerous intercal- 

 ated seams* of variegated mudstone, enable us to identify them at 

 first glance with the corresponding beds of Dobb's Linn. They 

 yield excellent specimens of Rastrites peregrinus (Barr.), Mono- 

 graptus gregarius, M. leptotheca (Lapw.), M. cyphus (Lapw.), M. 

 lobiferus (M'Coy), M. intermedins (Carr.), Diplograptus palmeus 

 (Barr,), D. tamariscus (Nich.). 



Fig. 21. — Gar pie Linn. 



N.W. 



D. Thick-bedded purple grits and flags. 

 Cb. Purple and grey shales with black seams. 

 3. Monograptus Halli. 2. M. spinigerus. 

 Ca. Contorted black flaggy shales with partings of variegated mudstone. M. 

 triangulatus, &c. /. Fault. 



About a hundred yards above this point the stream suddenly 



