Transcriber’s Note

Cover and Table of Contents created by Transcriber and placed in the Public Domain.


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.