Rcvieiv of Recent Geological Literature. 387 
reaching horizons of artesian water, from which it did not rise so far 
as the surface. w. u. 
The Evolution of the Northern Part of the Lowlands of Southeast- 
ern Missouri. By C. F. Marbut. The Uaiversity of Missouri 
Studies, Vol. I, No. 3- Pages viii, 145-207; with six plates (one 
being a folded map on the scale of three miles to an inch). Colum- 
bia, Mo., July, ig02. Price, $1.25. 
An area of about 2,500 square miles is described in this memoir, 
including the lowlands west of the Mississippi on both sides of the 
northeastern part of Crowley ridge, and of its continuation, beyond 
a space of interruption, by the Benton ridge. The geologic formations, 
in descending order, comprise Recent alluvium, of great extent, form- 
ing the surface of the lowlands ; Pleistocene loam aad loess ; Lafayette 
gravels, sands, and clay, referred to the closing part of Tertiary time ; 
and Paleozoic rocks, limestones and sandstone, of Trenton and Cal- 
ciferous age. After the Lafayette period, the country was uplifted, 
and the Lafayette deposits were greatly eroded. This time of uplift 
seems to' the reviewer to be correlative with the principal p.n.rt of the 
Ice age farther north. During the later depression of the land, which 
seems to me referable to the closing part of the Ice ag'e, being indeed 
the cause of its decline, "the mantle of Loess was deposited over the 
uneven surface, filling the vallej^s and building the land up nearly to 
its level before the preceding erosion. Then followed uplift and erosion 
to the present condition of the country. Late in the history of the re- 
gion slight oscilations occurred producing terraces, but they were not 
sufficient in amplitude to interrupt the continuity of the cycle." Erosion 
after the deposition of the loess reached much deeper than the present 
lowlands, and they have been subsequently built up to their .present 
levels with sandy alluvium. A very interesting and complicated history 
of the stream changes is traced during the vast work of erosion in the 
thick deposits of the valley drift, and during the recent upbuilding 
of the alluvial tracts- 
In this greatest watercourse of our continent, the volume of modi- 
fied drift very far exceeded its deposits in the Connecticut and Merri- 
mack valleys of New England, where this part of the drift was earliest 
studied ; but the conditions of its deposition, in the closing stages of 
the Glacial period, and of its speedily ensuing re-excavation, leaving 
remnants as plains a'nd terraces, or in the Mississippi valley as long 
and wide ridges, above the alluvial bottomlands, were of the same 
character in both regions, and are our most important records of Late 
Glacial and Postglacial time. 
Professor Marbut has well supplemented, for this region about the 
north end of the Crowley ridge, the description of its continuation 
more than a hundred miles south into Arkansas, which was given by 
Call and Salisbury in the second volume of the Annual report of the 
Arkansas Geological Survey for 1889. The deposition of sediments 
in the lower Mississippi valley derived from the waning northern ice- 
^hcet was evidently of vast amount; their erosion in southeastern 
