Review of Recent Geological Literature. 339 
Benton; and the sandstone f Dakota i as together constituting a grand 
group varying locally as submergence progressed— the Colorado group, 
of Hayden — the submergence reaching probably as far east as the Missis- 
sippi river in northeastern Iowa. The later Cretaceous, therefore, is 
farthest east. 
Mr. Beyer describes certain quartz porphyries met with in the sink- 
ing of a deep well in the town of Hull, Sioux county. These are evi- 
dently a part of the acid eruptives accompanying the Sioux quartzyte, 
and, taken in connection with the olivine diabase described in Minne- 
haha county, S. Dak., by Culver and Hobbs (Wis. Acad, vm, 206-210, 
1892) and with other stratigraphic and lithologic relations, it forms a 
strong link connecting the Sioux quartzyte taxonomically with the 
Pewabic quartzyte of northern Minnesota, both being at the base of 
the Taconic. 
Mr. Keyes' "Bibliography of Iowa Geology" is a very extended cross- 
reference dictionary or index, and on it was necessarily spent a very 
large amount of the time covered by the report. It is the most volumi- 
nous portion of the book. It will be very useful for reference for all 
future students of the geology of the state, and cannot be too highly 
commended. 
The volume closes with that indispensable accompaniment of a first- 
class publication, a good index. 
With this publication the Iowa survey takes its place in the front 
rank of state surveys. It is to be hoped it will be maintained until the 
enterprise is completed, which would be a credit to the State and to 
the country. 
Geology, by A. J. Jukes-Browne, F. G. S. (Whittaker's Library of 
Popular Science. ) This little work is intended to give in short a sketch 
of geology as the science is now understood. It deals with geological 
topics in simple language.introducing as few technical terms as possible. 
But it is not a mere popular outline evading all real difficulties by 
ignoring their existence. 
At the outset it treats of the materials whereof rocks are made and 
the great problems of erosion and deposition are here discussed. Then 
the structure and origin of igneous rocks are taken up and volcanoes, 
lava flows and eruptions are explained. 
The second part is entitled "How the rocks were brought into the 
position which they now occupy" and in it the topics of elevation 
and depression, consolidation, contraction, tilting and contortion, fault- 
ing, and thrustiog are discussed. This leads to metamorphism and the 
metamorphic rocks, their formation, origin, and exposure by subsequent 
erosion of overlying strata. 
Part the third enters on paleontology and the various life systems of 
the strata pass in review, with illustrations, and the author concludes 
with the geographical geology of the British Isles. 
The work is well printed and illustrated, though the figures are 
familiar. Indeed we could not look for new ones in a work of this 
nature and scope. 
