288 C LAPWORTH ON THE MOFFAT SERIES. 



§ III. Description of the Sections of the Moffat Series to the North 

 of the Moffat- Yarrow Valley. 



In the great sheet of thick-bedded arenaceous strata ont of which 

 is carved the broad mountain ridge of Whitecombe and Hartfell, 

 with its bounding valleys of Annandale and Meggatdale, a large 

 number of exposures of the dark shales and mudstones of the Moffat 

 Series are apparent. Judging from their geographical arrangement, 

 it is tolerably evident that, as usual, they are disposed in several 

 subparallel lines or bands, each of which wiU probably be found to 

 mark the position of one of the more important anticlinals of the 

 rocks of the region. In none of these bands have we the same clear 

 evidence of continuity among the black beds as that furnished by the 

 ground to the south of the Moffat valley. At the same time there 

 are few individual sections so complete or satisfactory as the 

 majority of those already described. Fortunately, however, our 

 thorough acquaintance with the lithology and fossils of the various 

 zones enables us to identify them almost at a glance ; and, as their 

 original sequence has been conclusively established, we can now 

 afford to dispense with a large proportion of the confirmatory 

 evidence so necessary in our preliminary investigations. 



It will be seen from the general map of the district (PL XI.) 

 that seven bands of dark shale are present to the north of the 

 Moffat valley, viz. those of (1) Dobb's Linn, (2) Polmoody, (3) 

 Frenchland, (4) Carrifran and Garple, (5) Auchencat Burn, (6) 

 Hartfell Spa, and (7) Headshaw Linn. 



It will be needless to describe each of these with the same care as 

 that we have bestowed on the typical bands to the south of the 

 Moffat- Yarrow valley. Indeed, from the very doubtful continuity 

 at the surface of the strata of which these bands are composed, the 

 same method of treatment is obviously inapplicable. In this case it 

 will be more satisfactory if we describe in brief the chief exhibitions 

 of the dark shales, and give such a general account of the remainder 

 as may suffice to make it clear that, in the northern half of the 

 Moffat district, the zones and fossils of the Moffat Series are 

 identical with those in our former sections, and that they stand in 

 precisely similar stratigraphical relations to the neighbouring grey- 

 wackes. 



For this purpose we may conveniently regard the present region 

 as being composed of the three areas drained respectively by (1) the 

 Annan and its chief tributary, the Evan, (2) the water of Meggat, 

 and (3) the Moffat water. 



The best sections are found in the first-named area, those least 

 satisfactory (with the notable exception of Dobb's Linn, already 

 described) in the area drained by the Moffat water. 



(a) Basin of the Upper Annan. 



i. Frenchlancl Burn (PI. XIII. PlanE). — One of the most intelligi- 

 ble exposures of the Birkhill Shales to the north of the Moffat valley 



