Review of Recetit Geological Literature. 323 
basic residuum of the alkaline magma, or whether it belongs together 
with the phonolytes and quartz-asgirite rocks, to a different series 
from the rhyolyte-andesyte rocks. 
In the district described gold occurs in the Algonkian, Cambrian, 
and Carboniferous, and in placers of recent formation. It occurs 
associated with pyrite; in quartz veins with silver and lead; and free. 
Silver is also found. 
Dr. Irving has covered only a portion of the region affected by 
the Black hills intrusions. In this field he has confined himself to 
description and to the farther elaboration of previously formulated 
hypotheses. The differentiation of rock magmas is a subject for 
which, as Mr. Irving himself states, this region is admirably calcu- 
lated to provide data. This problem has been barely touched by him 
and it is to be hoped that additional data may be found from farther 
investigation of" the Black hills and of the Bear Lodge mountains. 
When such investigation takes place Dr. Irving's determinations will 
be of undoubted value. I. H. o. 
The Moraines of Southeastern South Dakota and their Attendant 
Deposits ; by James E. Todd, U. S. G. S. Bull. 158, pp. 1-168. 
This volume is a preliminary report, treating of a relatively small 
portion of the Dakota loop of the great moraine. It furnishes valu- 
able data upon several Pleistocene problems; — the origin of loess, 
the distribution of glacial drift, and post-Pliocene oscillations of the 
earth's crust. The greater part of the report is descriptive of glacial 
deposits in South Dakota and Nebraska. Two moraines are found, 
the outer one which extends to the Missouri river, marking the 
maximum extent of the ice in the second glacial epoch. Outside oi 
this moraine deposits of a previous epoch are found; of these deposits 
loess is the most abundant. Mr. Todd discusses the formation ol 
loess, believing it here to be of fluvio-lacustrine origin. The* inner 
moraine represents a halt in the retreating ice and is much less 
prominent than the outer. Inside the second moraine is the flat of 
lake Dakota: Mr. Todd discusses the age of the trough of the Mis- 
souri river, and concludes that the evidence is in favor of a post 
glacial excavation. i. H. o. 
Elements of Mineralogy, Crystallography, and Blowpipe Analysis, 
from a Practical Standpoint, including a description of all common or 
useful minerals, with tests necessary for their idefitification, the recog 
nition and meastcrement of their crystals, and a concise statement of 
their uses in the arts. By Alfred J. Moses and Charles Lathkoh 
Parsons. Octavo 414 pages, 664 cuts, new enlarged edition, <;2.oo, New 
York, IQOO, D. Van Nostrand Company. 
The title describes this book fully. It is one of the interesting and 
valuable series of the science faculty of the School of Mines of Colum- 
bia University, New York, although, in this instance, Prof. Parsons is of 
New Hampshire College, Durham, N. H. Its design is for the student of 
the technical school and for all courses in mineralogy where mineralogy 
