GEOLOGICAL RELATIONS. 1 9 



deposits ; the latter, thick slaty and sandy sediments, sparingly calcareous, 

 probably occupying largely the space between the littoral and pelagic 

 regions of original deposit. Except for the fossils, there is rarely any 

 lithological similarity between the formations of the two regions. 2. 

 There is nothing yet known in the more eastern region of the formations 

 between the Quebec and Medina. 3. The Upper Silurian is scarcely 

 known in the Upper St. Lawrence valley, while it predominates in the 

 east. It will be seen very soon that the Devonian and Carboniferous 

 are entirely confined to the eastern district. 4. Metamorphism has 

 operated to some extent upon the strata in the east, and not in the 

 valley. 



Devonian. The lowest member of the Devonian or the Oriskany sand- 

 stone is well developed in Maine, between Parlin pond and Masardis, 

 crossing the upper end of Moosehead lake. At its southern extremity the 

 formation rests upon granites, gneisses, and Huronian schists. These 

 strata consist of slates, slaty grits, and sandstones, having a thickness of 

 2880 feet along the Canada road, the structure being that of a shallow 

 synclinal. On Moosehead lake the Cauda-galli grits have a considerable 

 development. The same formation is found in Nova Scotia, in Annapolis 

 county, bordering the Bay of Fundy. The iron ore of Nictaux comes 

 from this group. I understand that there are small areas of this forma- 

 tion in New Brunswick, which have not yet been described by geologists. 



On Lake Memphremagog there are extensive developments of the 

 Upper Helderberg limestone. The formation can be traced continuously 

 as far south as Montpelier, Vt., and it occurs at several localities at the 

 north-east, as at Dudswell, Lake Aylmer, on the Touffe des Pins, a tribu- 

 tary of Chaudiere, etc. These rocks evidently are not the same with the 

 Helderberg strata of New Hampshire. 



On the Gulf of St. Lawrence is a great development of Devonian sand- 

 stones, called Gaspe by Sir William Logan. They are 7000 feet thick, 

 the upper portions having a red color. The whole series presents analo- 

 gies with the Upper Devonian formations of New York, as both contain 

 similar plants. The map shows two large areas of the Gaspe sandstones 

 north of the Bay of Chaleur. In northern Maine there seem to be sev- 

 eral small areas of the same formation. Near St. John, N. B., the Upper 

 Devonian sandstones have been studied with considerable care by Bailey, 



