I20 
The American Geologist. ^"^"^^' i^°2. 
nltiniately they will be found to Ix^ at the very bottom of the 
Archean. They would then be in the same position as the 
Kawishiwin, of ^linnesota. and might be considered the pres- 
ent representative of the orig:inal igneous crust of the earth; 
the two igneous ranges which are represented further east on 
the map of Mr. Dresser corresponding to two other similar 
ranges which have been described in Minnesota south from 
the oldest greenstone range. There is at least a suggestive 
parallelism which can be expressed thus : 
Minnesota. Eastern Toivnships. 
Giant's range (at Twin peaks). Sutton mountain. 
Mesabi range (at Gabbro lake). Stoke mountain. 
Sawteeth range. Lake Megantic. 
N. H. W. 
REVIEW OF RECENT GEOLOGICAL 
LITERATURE. 
United States Geological Survey, Tweitty-first Annual Report to the- 
Secretary of the Interior, 1899-1900. Charles D. Walcott, Director- 
Part III. General Geology, Ore and Phosphate Deposits, Philippines. 
Pages 644, with 68 plates, and 104 figures in the text. Washington,. 
1901. 
The first paper of this volume is by Prof. William H. Hobbs, on "The 
Newark System of the Pomperaug Valley. Connecticut," in 160 pages, 
illustrated by 17 plates and 59 figures. This area of the Newark series,, 
though only about ten miles long and two miles wide, is exceedingly 
interesting on account of its development of nearly vertical joint planes 
and systems of faults. It had been fruitfully studied and described by 
Percival and Davis. For the more detailed studies noted in this re- 
port it was partly mapped on the large scale of four inches to a mile, 
with exact locations of nearly every rock outcrop. Specimens of fossil 
wood from the lowest member of the series are determined by F. H. 
Knowlton as Araucarioxylon virginianum, before described and named 
by him from Newark areas in Virginia and North Carolina. 
Thomas A. Jaggar, Jr., contributes the second paper. 'The Lacco- 
liths of the Black Hills." in pages 163-30.^, with plates 18-47, and figures 
60-102. His summary of field observations and geologic inferences is 
in part as follows : "Igneous intrusions of rhyolite and phonolite por- 
phyries accompanied or immediately, followed a great movement of 
uplift in the area now occupied by the Black Hills. This uplift arched 
the horizontal strata of the plains into an elongate dome ; schists be- 
