374 Reviews—The Geology of the Lake District. 
RHVIEWS- 
I.—Tue Gerotocy or tHE Laxe District anD THE ScENERY AS 
INFLUENCED BY GuoLoercaL Srructorre. By J. KE. Mang, Sce.D., 
F.R.S. 8vo; pp. xii, 220, with 51 illustrations and coloured 
seological map in pocket of cover. Cambridge: at the University 
Press, 1916. 12s. net. 
| cae geologist who is already acquainted with the Lake Country, 
or who is intending to visit it, will be grateful to Dr. Marr for 
the present volume. In this he has collected his numerous memoirs 
and addresses in the form of a connected narrative, and as he has also 
included the results obtained by previous or contemporaneous workers 
the book forms a complete epitome of what is known of the geology © 
and physiographical development of the district. 
The work is intended primarily for the student, but by printing in 
smaller type such details as are of special interest to the trained 
eeologist the author has attempted to adapt it also to the requirements 
of the general reader. As a rule scientific books which cater for 
different classes of readers fail to satisfy either, but we think that the 
present author has succeeded admirably in his object. This we feel 
is due in the first place to his really intimate knowledge of the 
district, and secondly to his ability to place the essential facts in 
an interesting and attractive form, a gift with which readers of 
the author’s work on Zhe Scientific Study of Scenery are already 
- familiar. 
The book opens with a brief review of the pioneer work in the 
district, due honour being accorded to Jonathan Otley, the Father of 
Lakeland Geology, a charming portrait of whom appears in the 
frontispiece. After a brief summary of the general structure of 
the district there follows a description of the Lower Paleozoic rocks 
and of the structural changes which took place in the area after their 
deposition. In this chapter we have a detailed consideration of the 
nature of the folding, faulting, cleavage, and metamorphism which has 
affected these rocks. Three views are quoted in this connexion— 
(1) that the Borrowdale rocks are in reality older than the Skiddaw 
slates and brought into their present position by an overthrust 
boundary fault; (2) that the apparent succession is the true one and 
that the fault between the two groups is a thrust plane; (3) that the 
fault at the base of the Borrowdale Series is not an overthrust but 
a ‘lay fault’ associated with a thrust plane. The latter is the 
view advocated by Dr. Harker and the author, who conclude 
that the movement resulted in folds having a general H.N.E. 
and W.S.W. direction which were accompanied by horizontal 
movements producing the lay fault between the Skiddaw Slates and 
Borrowdale lavas and between the latter and the Coniston Limestone. 
These are accompanied by normal faulting, but also by horizontal 
movements along vertical planes or ‘tear faults’ with the pro- 
duction of ‘shatter belts’. It is of interest to note that the 
