348 Review of Beceni Geolor/ical Literature. 
two miles wide. It lias cut across a drift ridge to a deirth of 500 feet, as tlie 
whole area has been rising. With the continued continental uplift to the 
north-east (which has raised the old beach at the outlet about 300 feet 
above the present surface of lake Huron) the waters were backed south- 
ward and overflowed into the Michigan basin and into the Erie, thus 
making the Erie outlet of the upper lakes to be of recent date. This is 
proven l)y the fact that the Georgian beach which marked the old surface 
plane of the upper great lake descends to tLie present water level at the 
southern end of lake Huron, and is beneath the surface of the water upon 
its south-western side as the uplift, whicli has been measured, was to the 
north-east . 
(5.) The Erie basin is very shallow,and upon th^ dismemberment of lake 
Warren, was drained by the newly constructed Niagara river, (except per- 
haps a small lakelet south-east of Long point, Subsequently, the North- 
eastward warping (very much less in quantity than farther northward at 
tl\e Trent outlet) eventually lifted up tlio, rocky outlet and formed Erie 
into a lake in recent times, thus making Erie the youngest of all the 
lakes. The beaches about Cleveland are not those of separated lake Erie,, 
but those of the older and original lake Warren. 
"Zes dislocations de Vceorce terresti-e." By MM. de Margerie & Heim. 
In this work the authors have given an exhaustive monograph on the 
various kinds of displacements occurring in the crust of the earth, 
their appearance and their effects. Beginning with a simple fault in hori- 
zontal strata, they discuss the different kinds of faults and their results 
on the strata, horizontal or inclined, in which they occur. A simple flexure 
forms the text for a chapter on the complicated consequences of such 
flexure on strata. Faults of displacement such as result from the above 
are then distinguished from faults produced by folding and the authors 
then take up the results of horizontal pressure in producing folds, de- 
veloping anticlines and synclines, overthrows, thrust planes, thickening 
of the arches and troughs and thinning of the intervening portions, fan- 
structure, such as is exhibited in the High Alps and the complete sepa- 
ration of the points of the anticlines and synclines by the forward shoving 
of the folds, ending in severance of the sides. The effects of horizontal 
pressure in forming "heaves" and so displacing the adjacent edges of 
strata come in next for treatment and are followed by the important and 
interesting topic of the actual length of the folded beds and their present 
horizontal extent. 
The folding a second time of strata already once crumpled is next con- 
sidered and the many complicated phenomena resulting therefrom are 
well and fully illustrated, showing how intricate maybe the consequences 
resulting from a comparatively simple cause. 
The authors merely glance at the subjects of the origin of faults and 
mention in conclusion some of the secondary effects of folding such as 
"marmorization," "metamorphism," &c., saying that these topics are not 
3'et sufliciently investigated to allow of full consideration. 
The work forms a complete summary of the kinds of faults and the 
mode of their formation and will be of much value to all students of 
physical geology. 
