Review of Recent Geological Literature. 241 
less evidently stratified rocks of volcanic origin, comprising amygdaloids, 
agglomerates, and other more massive materials which apparently 
represent old lava-flows. No unconformity has been proved to occur 
throughout the whole of the Palaiozoic series, but the examinations 
were not sufficient to detect any stratigraphic break unless of a very 
obvious character. The Mesozoic era is represented also by strata of 
Cretaceous and Laramie age, which rest quite unconformably on all 
the older formations, though they have since been to some extent in- 
volved in their flextures. A paper by Dr. Dawson on the glaciation of 
this district has already appeared in the American Geologist, 
April, 1889. 
Seven appendixes of this report treat of the fossils, plant collections, 
zoology, lithology, meteorology, astronomic observations, and Indian 
tribes. 
The next memoir of this volume is a Report on the geology of the min- 
ing district of Cariboo, British Columbia. By Amos Bowman, mining 
engineer; 49 pages, with maps, sections and panoramic views from 
mountains. Cariboo, as a political division, embraces a complete sec- 
tion across the northern interior plateau, from the Cascade range to 
the Rocky mountains, within the Fraser basin; but the portion speci- 
ally surveyed lies wholly east of the Fraser river, being an area about 
fifty miles square, from Quesnel lake northward. This tract includes 
some of the richest placer mining in the world, having j-ielded nearly 
half the gold product of British Columbia since 1860, or not less than 
$15,000,000, chiefly from a few miles in length of auriferous drift in 
several valleys. 
Note to accompany a Preliminary Map of the Duck and Riding Moun- 
tains in Northwestern Manitoba. By J, B. Tyrrell. (Part E, of the 
same report, pp. 16, with map.) 
This report discusses the general physiographic features of a pre- 
viously unknown portion of north western Manitoba and gives a review 
of the glacial and Post-glacial phenomena that have largely contributed 
to impress on the country its surface characters. It is divided into two 
distinct portions, viz : An eastern lightly sloping alluvial plain, for- 
merly covered by the waters of the post-glacial lake Agassiz, and a 
western table land presenting a steep escarpment to the east and a 
gentle decline westward towards the present valley of the Assiniboine, 
in the upper portion of which a post-glacial lake, called "lake Assini- 
boine" is shown to have formerly lain. The mountains or table land 
consist in the main of Cretaceous rocks, but these are overlain by a 
considerable thickness of morainic detritus, in places heaped in irregu- 
lar hills, thickly strewn with gneissic boulders. After the retreat of the 
continental glaciers towards the Archean area towards the north and east 
a local nev6 was left on the summit of the Duck mountains which sent 
down glaciers into the wide valleys cut out by the floods that had 
rushed from the front of the receding continental glacier. Eviden- 
