REVIEWS gr 
The Geology of the Lake District and the Scenery as Influenced by 
Geological Structure. By J.E.MaArr. Cambridge: Cambridge 
University Press, 1916. Pp. 220, figs. 51, map in pocket. 
The English Lake District is well adapted to call forth the interest 
of the geological student by reason of the variety of its geological struc- 
ture and the significance of its physical features. As an increasing 
number of those interested in geology visit it each year, and the need of 
a special treatise upon its geologic features has come to be felt, the 
author has prepared a condensed account of the geology of this pic- 
turesque area. 
The Lake District proper is composed of Lower Paleozoic strata, but 
its borders are formed of a roughly annular girdle of newer strata, partly 
of Carboniferous age, but partly belonging to the Permian and Triassic. 
The Lower Paleozoic rocks were profoundly affected by the great Cale- 
donian orogenic disturbance at the close of the Silurian. Great over- 
thrusts of the Scottish Highland type appear to have developed here 
also, though the author considers “lag fault’ as an alternative hypothesis 
in the explanation of the observed phenomena. 
The last third of the book describes and discusses the critical features 
of the Pleistocene ice sheet, which, by its erosive and depositional work, 
has contributed so much to the beauty and interest of this celebrated 
region. RoC 
Origin of the Iron Ores at Kiruna. By REGINALD A. DALy. Veten- 
skapliga och praktiska Undersékningar. Lappland. Anord- 
nade af Loussavaara—Kiirunavaara Aktiebolag. Geology 
NOs Sao tockholm Tons Pp io, gs. 4 
Professor Daly, thoroughly familiar with the writings of Geijer, 
Stutzer, and others, has made a short field study of the Kiruna district, 
particularly of the nature and origin of the numerous small inclusions 
of iron ore scattered through the quartz porphyry which forms the 
hanging wall of the ore bodies. These are commonly held to be xeno- 
lithic inclusions derived from an older invisible ore body, but the writer 
concludes, as a result of his field study, that the ore inclusions represent 
so many frozen-in units of differentiation modified in part by later 
resorption. The ore bodies are believed to have formed by the gravi- 
tative assemblage of similar units at the base of the quartz porphyry. 
Geijer has emphasized the view that both the iron ores and quartz 
porphyry are of extrusive origin. Professor Daly, following Stutzer, 
