Vol. 65.] THE HOWGILL FELLS AND THEIR TOPOGRAPHY. 587 



31. The Howgill Fells and their Topography. By John Edward 

 Marr, Sc.D., F.R.S., F.G.S., and William George Fearnsides, 

 M.A., F.G.S. (Head June 16th, 1909.) 



[Plates XXVIII-XXXL] 



The Howgill Fells form a well-defined geographical unit. They 

 occur as an upland tract of roughly triangular form, the angles 

 being blunted. The northern side of the triangle is defined by the 

 valley in which the village of Kavenstonedale lies. It extends 

 for 8 miles measured in a straight line, in a direction a little north 

 of west, from a point 2 miles south-east of that village to the village 

 of Tebay. This valley was originally watered by the streams of 

 the Lune drainage, although (owing to subsequent diversion) the 

 waters at its eastern end now find their way into the Eden. 



At Tebay the main waters of the Lune flow southwards, and this 

 part of the course of the Lune forms the western side of the 

 triangle for a distance of 8 miles to a point a little west of the 

 town of Sedbergh. The trend of this side is about 5° east of south. 



The third and longest side is curved, and measured along the 

 straight is about 9 miles long. At the north-eastern end it is 

 defined by the .Dent Fault and its parallel fractures as far as 

 Rawthey Bridge, after which it follows the line of the Rawthey to 

 the southern end of the second side immediately west of Sedbergh. 



Along these lines a continuous depression separates the Howgill 

 Fells from the adjoining heights on the west, north, and south-east. 

 The bottom of this depression along the major portion of its length 

 is less than 600 feet above sea-level, and only at the col connecting 

 it with the limestone country to the east of the Dent Fault does it 

 ever rise beyond the 900-foot level. Before the diversion mentioned 

 above the whole of the depression along this boundary was drained 

 by waters carried to the Lune by way of Ravenstonedale and the 

 main valley on the north and west, and by the Rawthey on the 

 south-east. 



Geologically the Howgill tract is almost as well-defined as it is 

 geographically. On the west side, it is true, the strata extend across 

 the Lune from the Howgill Fells to the fells west of that river, and 

 the division is only physiographical ; but on the north and south- 

 east sides it is practically defined by the line of junction between 

 the Silurian and the Carboniferous rocks, though some of the older 

 rocks extend across the Rawthey to form the flanks of Baugh Fell 

 beyond the limits of the Howgill Fells. 



The Howgill Fells, then, consist essentially of Silurian rocks 

 (with inconsiderable patches of Ordovician strata in the neighbour- 

 hood of Rawthey Bridge). These rocks are referable to the divisions 

 known as Stockdale Shales, Coniston Flags, Coniston Grits, and 



