BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA 



Vol. 2, pp. 85-124 February 5, i89i 



A LAST WORD WITH THE HURONIAK 



BY ALEXANDER WINCHELL, LL. D., F. G. S. A. 



[Read hefore the Society December 30, 1890.) 



CONTENTS. 



Page. 



Citations from the Founders touching the Typical Area 86 



Murray's earliest Description 86 



Logan's Description 86 



Murray on the Grouping and Details 87 



Murray and Logan on the Region South of the Ottawa 90 



Logan on Rocks North of Lake Huron 90 



Introduction of the Name "Laurentian" 90 



Murray employs the Terms " Laurentian " and " Huronian " 91 



Murray on the Constitution of the Huronian 91 



Citations from the Founders touching the Vicinity of Lake Superior 93 



Logan's first Report 93 



Murray's Account of the same Region 93 



Points established 94 



Logan's Identification of Huron and Superior Rocks 94 



Remarks on the Identification 95 



Proposal of the Name " Huronian " 96 



First Use of the Name 96 



Hunt's Use of the Name 96 



Logan's Proposal of " Laurentian " and " Huronian " 96 



Mature Definition of " Huronian " 98 



Two Systems united under the Name " Huronian " 100 



Structural Discordances in the Lake Huron Division 100 



Evidence from the Documents 100 



Evidence from Personal Observation 102 



Evidence from Independent Observation 103 



Lithological Discordances in the Lake Huron Division 104 



Murray's and Logan's Descriptions 104 



Personal Observations. 105 



Irving's Observations 106 



Discordances in the Lake Superior Division 107 



Logan's Views 107 



Views of Hunt and Lawson 108 



Summary of Logan's Conception 108 



Views of the Author 109 



XIV— Bull, Geol. Soc. Am.. Vol. 2, 1890. (^S) 



