426 Expedition to the 



in the Geological transactions," that the coast of I^abrador is 

 composed of rocks of granite, sienite, schist, and serpentine;" 

 but we see no reason to consider it an inaprobable one. With 

 the northern boundary of that vast formatitn of secondary 

 which certainly occupies a large portion of the interior of this 

 continent, we are unacquainted. On the southeast, its limit 

 is the irregular border of the transition of the Alleghanies, 

 commencing between the Alabama, and Tombigbee rivers, 

 and running northwest to fort Anne near lake Champlain.' 

 From this point a narrow, and perhaps interrupted stripe of 

 secondary extends through the valley of lake Champlain to 

 the upper part of St. John's river. The island and moun- 

 tain of Montreal, are of secondary limestone. The country 

 also between St. John's, and La Prairie, is most probably 

 secondary, as is much of that along the St. Lawrence below 

 Montreal. From the termination of the transition near the 

 confluence of the Alabama and Tombigbee, the secondary 

 rocks continue on the southwest, sometimes concealed by 

 the recent alluvial formations of the IVIississippi valley, to 

 the Black lake river near Natchitoches. Beyond this point, 

 the information we have is not satisfactory. From this, 

 turning northwest, we may for the present, consider the 

 Red river of Louisiana, as the boundary of the secondary 

 or rather the limit of our acquaintance with this formation. 



Beyond the Ozark Mountains, the district between the 

 Red river and the Canadian is occupied by the Red sand- 

 stone of the salt formation, which is undoubtedly to be con- 

 sidered secondary. How far it extends to the west beyond 

 the sources of Red river and the Canadian, v/e are unable to 

 determine. At the base of the easternmost ridge of the 

 Rocky Mountains south of the High Peak, and at no very 

 great distance north from Santa Fe, the boundary again be- 

 comes determinate. From this point it runs nearly north, 

 one hundred and fifty miles, where it crosses the river Platte. 

 From the narrative of Lewis and Clark, we are enabled to de- 

 termine with sufficient accuracy that it crosses the Missouri 

 not far from the falls, in longitude about 107'' W. Beyond 

 this point the little information we have we owe to sir Alex- 

 ander Mackenzie. He informs us that great quantities of 

 coal are found about the sources of the Saskatchawin, which 

 lie near the Rocky Mountains, and between 50^ and 55^ 

 north latitude. The coal bed which he describes, lies on the 



* Maclure's Observations, p. 50. 



