jAsrnART 28, 1898.] 



SCIENCE. 



13"7 



by which the plant makes use of carbon dioxide 

 in building up carbohydrates. 



Chaeles E. Bessey. 



SCIENTIFIC LITERATURE. 

 U. S. Geological Survey. Monograph XVIII. 

 The Marquette Iron-bearing District of Michi- 

 gan, with Atlas. By Charles Richard Van 

 HisE and William Shirley Bayley. In- 

 cluding a chapter on the Republic Trough by 

 Henry Lloyd Smyth. 4to. Pp. xxi + 608. 

 PI. I. -XXXV. Figs. 1-27. Atlas sheets 

 I. -XXXIX. Price, $5.75. 

 The issue of the above monograph marks the 

 completion of another chapter in the investiga- 

 tion of the ancient crystalline rocks of America. 

 ' The book presents the fullest solution yet at- 

 tained of one of the most puzzling and elusive 

 of the many problems confronting geologists. 

 The great economic importance of the region 

 early drew attention to it. First the copper 

 excitement and then the development of the 

 iron interests brought settlers in increasing 

 numbers. The pioneer work of Foster and 

 Whitney established the claims of the rocks 

 upon the attention of geologists, and the long 

 and honorable line of investigators who have 

 devoted time and effort to the understanding 

 of them embraces the names of many of the 

 best workers in this branch of science. 



The monograph opens with a preliminary 

 abstract of its contents, in which a reader who 

 cannot well peruse all its pages will find a suc- 

 cinct exposition of what follows. A brief intro- 

 duction then outlines the larger official reports 

 previously issued, the area to be described, the 

 chief geological classification, the distribution 

 of the principal formations and the broad 

 structural features. In Chapter I. , W. S. Bayley 

 presents a thorough bibliography of all previous 

 literature in the shape of abstracts of each paper 

 or reports chronologically arranged. This has 

 been a heavy task, for the literature is exten- 

 sive (the chapter occupying 148 pages), and the 

 cited articles are difficult ones to sum up con- 

 cisely. Dr. Bayley has, however, done so not 

 only concisely, but with great clearness and 

 thoroughness. In Chapter II. the same writer 

 discusses the Basement Complex. Much light 

 is thrown on this tangle of metamorphosed 



eruptives, but no unwarranted hopes of unravel 

 ing their stratigraphical relations are encour- 

 aged. The Northern Complex is treated under 

 the following subdivisions : The Mona schists, 

 the Kitchi schists, the gneissoid granites, the 

 hornblende-syenite and the intrusives. The 

 Southern Complex is subdivided into the 

 schists, both micaceous and hornblendic, the 

 gneissoid granites, the Palmer gneisses and the 

 intrusives. A few isolated areas are cited 

 within the boundaries of the Algonkian. 



In Chapter III., C. R. Van Hise takes up the 

 description of the Lower Marquette series in 

 detail. The Algonkian rocks form a com- 

 pressed syncline on the whole, with many 

 minor foldings along axes both parallel to the 

 main axis and at right angles with it. The 

 whole series pitch downward to the west, so 

 that as one goes in this direction later and later 

 strata are encountered. The basal formation 

 is the Mesnard quartzite, marking the advance 

 of the sea from the eastward. It also appears to 

 some extent around the northern and southern 

 sides on the east. It is succeeded by the Kona 

 dolomite, the Wewe slate, the Ajibik quartz- 

 ite; the Siamo slate and the Negaunee forma- 

 tion of sideritic cherts, ferruginous slates, ferru- 

 ginous cherts, jaspilite and iron ores. The last 

 named is the stratum of the greatest economic 

 interest, as it contains the chief deposits of ores. 

 The derivation of the latter from the cherty 

 carbonates in troughs of some impervious rock, 

 by the replacement of the chert, is well estab- 

 lished and is a further application of views 

 already presented for the simpler Penokee-Go- 

 gebic district. A stratigraphical break occurs 

 between the Lower and Upper Marquette series. 



In Chapter VI., Professor Van Hise treats 

 of the Upper Marquette series. The Upper 

 Marquette begins with the Ishpeming forma- 

 tion, which is subdivided into the Goodrich 

 quartzite and the Bijiki schists. Considerable 

 ore bodies are in the base of the Goodrich quartz- 

 ite, produced by the erosion of those in the 

 Negaunee formation below, but they are treated 

 under the Negaunee formation, as they are 

 closely associated with it. Above the Ishpem- 

 ing lies the Michigamme of slates and gray- 

 wackes, mica-schists and mica-gneisses. Next 

 follows the Clarksburg of effusive basic lavas 



