

WILLIAMS.] J. w. DAWSON. 245 



gray, yellowish, and purple sandstone, 180 feet thick. They are locally 

 calcareous aud arenaceous. Southwest of Mirainiche River the cal- 

 careous conglomerate is much disturbed by eruptive masses. Refer- 

 ence is also made to the Brighton outlier, which is situated between 

 the north and south branches of Beccaguimac River, and contains 

 Devonian plants. Although fossils of Devonian type have been found 

 in this formation, in its physical characters it resembles the Lower 

 Carboniferous rocks. Other small areas were noted to the northwest 

 in Windsor Settlement. 



Dr. Dawson reports the following correlation and classification for 

 Canadian Carboniferous rocks in 1873 1 1 



The Carboniferous rocks of Canada lie unconformably upon the De- 

 vonian and Upper Silurian formations. The author classifies them as 

 follows : 



(1) Horton Bluff series, or Lower Carboniferous Coal Measures, consisting of hard 

 sandstones, calcareous shales, with conglomerate and grit, bituminous shales, and 

 underclays, with plants and coal seams, with fishes and footprints of Batrachians. 



(2) Windsor series, or Lower Carboniferous limestone and gypsiferous beds; 

 marine and holding shells of the Lower Carboniferous period, containing limestones, 

 marls, clays, and gypsum. 



(3) Millstone grit series, consisting of conglomerate, shales, sandstone, and thin 

 beds of coal, containing Naiadites. Thickness 5,000-6,000 feet. 



(4) (a) Middle coal formation, and the (&) upper or newer coal formation. 



The Lower Carboniferous deposits of Gaspe" and Bay Chaleur, New 

 Brunswick, consist mainly of sandstones and conglomerate, with few 

 fossils, while in southern New Brunswick the bituminous shales attain 

 a great thickness, as also does the Millstone grit. On Salmon River, 

 West, East, and Middle Rivers of Pictou, the Millstone grit consists 

 of chocolate sandstones and shales holding plants. Beneath the Mill- 

 stone grit of Pictou, known as the " New Glasgow Conglomerate," 

 occurs a hard sandstone holding fossils, which Mr. Dawson regarded 

 as of Devonian age. 



The author gave the following list of equivalents of the divisions pro- 

 posed for the Canadian rocks, viz : 



I. — Equivalents of the Lower Carboniferous Coal Measures, or Horlon series: 



(1) The "Vespertine group" of Rogers in Pennsylvania. 



(2) The " Kinderhook group " of Worthen in Illinois. 



(3) The "Marshall group" of Winchell in Michigan. 



(4) The "Waverly sandstone" (in part) of Ohio. 



(5) The " Lower or False Coal Measures" of Virginia. 



(6) The "Calciferous sandstone" of McLaren, or "Tweedian group " of Tate in 



Scotland. 



(7) The "Carboniferous slate" and "Coorahala grits" of Jukes in Ireland. 



(8) The " Culm " and " Culm Grauwacke " of Germany. 



(9) The "Grauwacke" or "Lower Coal Measures" of the Vosges, as described 



by Schimper. 



Dawson, J. W. : Introductory sketch of the geology of the Lower Carboniferous Coal Measures, and 

 Millstone grit, with the equivalent formations ahroad. Geol. Survey Canada : Report on Fossil Plants 

 of the Lower Carboniferous and Millstone grit of Canada. Montreal, 1873. Pp. &-14. 



