Produced by Charlie Howard and the Online Distributed Proofreading Team at http://www.pgdp.net (This file was produced from images generously made available by The Internet Archive) Transcriber’s Notes Table of Contents created by Transcriber and placed in the Public Domain. Italic text is enclosed in _underscores_. Other notes will be found at the end of this eBook. THE JOURNAL OF GEOLOGY _MAY-JUNE, 1893._ CONTENTS On The Typical Laurentian Area of Canada 325 Melilite-Nepheline-Basalt and Nepheline-Basanite from Southern Texas 340 Some Dynamic Phenomena Shown by the Baraboo Quartzite Ranges of Central Wisconsin 347 The Chemical Relation of Iron and Manganese In Sedimentary Rocks 356 Some Rivers of Connecticut 371 Geological History of the Laurentian Basin 394 Editorials 408 Reviews 410 Analytical Abstracts of Current Literature 419 Acknowledgments 423 ON THE TYPICAL LAURENTIAN AREA OF CANADA. The name Laurentian was given by Logan in 1854 to the great series of rocks forming the Laurentides or Laurentian Mountains, a district of mountainous country rising to the north of the River and Gulf of St. Lawrence, and extending in an unbroken stretch along the shore of the latter from Quebec to Labrador, a distance of nine hundred miles. This district, with its continuation to the west as far as Lake Huron, being situated in the Province of Quebec and the adjacent portion of the Province of Ontario, and forming part of the main Protaxis of the continent, is the “Original Laurentian Area” of Logan. The Laurentian rocks are now known to extend far beyond the limits of this area to the west and north, constituting, as they do, by far the greater part of the Protaxis, and underlying (with subordinate patches of Huronian) an area of somewhat over two million square miles.[1] The area above referred to is, however, the one which was first studied and described; it is the “Typical Laurentian area,” and to it the observations in the present paper will be as far as possible confined.