Reviews—The Geology of the Lake District. 375 
presence of these ‘tear faults’ was suspected by Sedgwick as long 
ago as 1831. 
The intrusions of Devonian age in the district, namely those of 
Shap, Skiddaw, Eskdale and Wastdale, and Carrock Fell, and their 
metamorphic effects are then considered, and the subsequent erosion 
of some 30,000 feet of Lower Paleozoic rocks, regarding which the 
author remarks: ‘‘That this erosion affected the highest Silurian 
rocks indicates that it took place in Devonian times”; as, however, 
the oldest marine Carboniferous beds of the south-west of England 
are shown on p. 115 to be absent from the northern district the 
period of denudation may have continued into Lower Carboniferous 
times. 
In chapter xiii a brief description of the Upper Paleozoic rocks 
which surround the Lake District proper leads to a discussion of 
the post-Carboniferous changes, and is followed by a description of 
the events which occurred between the time of the formation of the 
dome in Tertiary times and the Glacial period. ‘his is followed by 
an account of the Glacial period, and the volume concludes with 
a short description of the post-Glacial changes in the district. These 
later chapters, which are chiefly concerned with the development of 
the present scenery of the district, will probably be among the most 
interesting to the general reader. 
The book is fully illustrated with bleak and white maps and sections 
in the text reproduced from previous publications by Dr. Harker and 
the author, including a large-scale map of the Shap Granite and its 
associated metamorphic rocks, while an admirable coloured geological 
map on the scale of 4 miles = 1 inch, for which the author acknow- 
ledges his indebtedness to Dr. H. H. Thomas, is contained in a pocket 
in the cover. The only criticism we would make in this is that the 
upper beds of the Ordovician and lowest of the Silurian are represented 
by the same colour, so that there is no visible division between the 
.two systems on the map. This was doubtless determined by the 
technical difficulty of dividing a very varied outcrop, while from 
a physiographical standpoint the Stockdale Shales and Coniston Lime- 
stone are closely associated in producing the Yendale Valley and 
similar depressions to the south of the volcanic massif. The book is 
further embellished by numerous half-tone photographs in the text, 
which have been well selected to show the leading features of 
Lakeland scenery. 
This volume, which will henceforth take its place as the recognized 
authority on this area, is notable not only on account of its admirable 
detailed summary of what is definitely accepted regarding the geology 
of the Lake District, but also for the clear indications regarding the 
points which still require elucidation. With this volume before him 
the future worker ambitious of forging the remaining links in the 
chain of evolution of this fascinating region will indeed have cause 
to bless the name of the gifted author of the Geolog gy of the Lake. 
District. 
