The Late Miinicsota Survey. — Winchell. 253 
In 1884 I had the pleasure and honor to read to Section E, 
as its chairman, a vice-presidental address, the burden of which 
was to show the varied interpretations that had been given to 
the Archean and Huronian rocks of the Northwest, and to at- 
tempt to tabulate the parts, as then understood, in a systematic 
scheme. The conclusion of that address was a statement that 
utter confusion reigned, and that no order or classification 
could be presented. Today that statement would not be true. 
After prolonged and careful field examination and minute 
work in the laboratory the order of the main parts of the Arch- 
ean is recognized, and unanimously adopted by all the geolo- 
gists who are at present concerned in Archean geology in the 
lake Superior region. The only differences now extant pertain 
to the naming of the parts, and the comparative rank which 
the various features of Archean geology should maintain in 
the general scheme. There are also many differences of detail 
as to origin and relationship of the various rocks, but a great 
advance has been made in the establishment of a recognized 
general scheme. The next twenty-five years may result in as 
marked progress in the settlement of these minor questions. 
REVIEW OF RECENT GEOLOGICAL 
LITERATURE. 
Esquisse strati graphiquc ct pctrographiqiic dii Bassin de la Tafna (Al- 
gerie). Louis Gkntii.. 5 plates (3 geological charts). 536pp. Algiers, 
1902. Adolph Jourdan. 
Previous to this publication, 211 papers or memoirs had l)ecn pub- 
lished relating to Algeria, as listed by the author, most of them in the 
French language, but the earliest was that Dr. Shaw in English, in 
1743. The province was occupied l)y the French about 1830. 
The oldest rocks of the region descrilied may be Archean, but, al- 
though they are styled "primitive'- by the author, their characters depart 
considerably from well-known Archean. They occupy but a small 
geographic area, but they are found in the form of bombs thrown out 
by volcanic action of recent date, also in the area of the Triassic gyp- 
sum. They are essentially garnetiferous gneiss with sillimanite. The 
oldest sedimentary rock of ascertained age is Permian and its age is 
expressed doubtfully. The most of the region described and mapped is 
occupied by Cretaceous and 1'ertiary rocks and their eruptivcs. and by 
later eruptives. The valley of the Tafna is in the extreme western part 
of Algiers. Near the western margin is the granite of Nedroma which 
