NOTES ON THE GEOLOGY OF THE VALE OF EDEN. 



Prok. p. F. KENDALL, M.Sc, F.G.S., 

 Leeds. 



The Yorkshire Geological Society will make its Easter excur- 

 sion to the Appleby district, and, though no excuse is necessary 

 for transgressing the artificial boundaries that limit our county, 

 there are peculiar reasons why we should overrun them in 

 this particular direction. Not only do the outcrops of many 

 formations run across, but many important problems in the 

 geology of Yorkshire depend for their full elucidation upon the 

 study of this area, and to none is it more important than to 

 those connected with the events of the Glacial Period, and 

 the still larger tectonic questions relating to the origin and 

 history of the Pennine faults. The following notes are penned 

 in the hope that a general description of the geological features 

 lavishly displayed there, and the often very controversial 

 problems awaiting solution will whet the appetites of those 

 who intend to participate. 



The broad, structural features of the Vale become at 

 once apparent when the geological map is consulted. The 

 Carboniferous i^ocks rising in a bold escarpment from the margin 

 of the older rocks (Ordovician and Silurian) of the Lake District 

 and the Howgill Fells, dip steeply aw'ay to the north-east, and 

 descend beneath an unconformable cover of Permian and 

 Triassic the largely drift-covered outcrops of which form the floor 

 of the Vale. On the eastern side, the Vale is dominated by 

 the abrupt, almost precipitous, wall of the Cross Fell range, 

 another escarpment of Lower Carboniferous rocks upthrown 

 by the gigantic system of the Pennine Faults. Between the 

 Trias, however, and the Cross Fell escarpment, there is inter- 

 posed a long narrow slip of Silurian and Ordovician rocks, 

 thrust up between nearly parallel faults — this is the Cross Fell 

 Inlier. A rough illustration of the disposition of the rocks 

 may be obtained by taking a piece of cardboard, the size of 

 this page, and cutting a horizontal slit from about an inch from 

 the top left-hand corner to near the right-hand corner. Then 

 cut obliquely from the left end well down the page. Lift the 

 corner, and the flap will represent the northern end of the 

 Pennines, while the portion on the right may represent the 

 Carboniferous rocks underlying the Vale of Eden. 



To the west the older Palaeozoic rocks of the Lake District 

 rise in what is topographically a dome with radial drainage, 

 but a glance at the geological map shows that there is no 

 obvious connection between this dome and the geological 

 structure of the area ; indeed, the laccolitic, lens-shaped, 

 intrusion of igneous rocks invoked by Dr. Marr to explain the 

 • central uplift, remained unsuspected even by he officers of the 

 Geological Survey, who mapped the country. 



1912 April I. 



