THE 



JOURNAL OF GEOLOGY 



JULY-AUGUST, igio 



NOTES ON THE GEOLOGICAL SECTION OF MICHIGAN^ 

 PART II. FROM THE ST. PETER SANDSTONE UP 



A. C. LANE 

 Tufts College, Mass. 



INTRODUCTION 



An apology is due for the long gap which has elapsed between the 

 publication of Part I and Part 11. This is due to the fact that I 

 wished to have the benefit of the work of Professors A. W. Grabau 

 and W. H. Sherzer without trespassing upon their rights. This I 

 can now do^ though we are not yet in accord as to interpretation. 

 Perfect accord, however, cannot be expected. An advantage is that 

 in the mean time Schuchert's^ and other paleogeographic studies 

 have appeared. This paper was written before Schuchert's and 

 independently, so that the numerous confirmations of his maps are 

 valuable checks, while discrepancies have not been subject to critical 

 revision. Almost all the places referred to will be found underlined 

 on a map in Vol. V of the Mich. Geol. Survey, and detailed references 

 to the facts upon which the statements of this paper are based will 

 be found in the report for 1908. 



The second, or upper part of the Michigan rocks here described, 

 including Ordovician and Carboniferous, has peculiar interest in 

 many ways. In the first place it stands as the connecting field 

 between the standard New York and the Mississippi Valley rocks. 



1 Part I appeared in XV, 680, of this Journal. 



2 See Grabau's papers in Science, No. 739 (1909), 356; Bull. G.S.A., XVII, 

 567-636; XIX, 540-53. 



3 Bull. G.S.A., XX (1910), 427-606. 

 Vol. XVII, No. 5 393 



