MARITIME APPALACHIANS 



195 



1000 feet thick, and apparently of continental origin, overlie with marked 

 erosional unconformity Silurian strata of the Arisaig series. 

 . Much of the interior of Gaspe is underlain by sandstones, conglom- 

 erates, and arenaceous shales varying in color from green and drab to red. 

 The type locality is on Gaspe Bay where a section 7000 feet thick rests on 

 the Lower Devonian limestones. 



Upper Devonian beds are present on the north side of Chaleur Bay in a 

 three-unit sequence. The lower formation consists of pebble conglom- 

 erates and sandstones and 450 feet of coffee-colored shale. The middle 

 formation consists of a coarse pebble-and-boulder conglomerate with 

 gray matrix. It is only 45 feet thick. The upper formation is 385 feet 

 thick and consists of gray shales and shaly sandstones. 



On the western side of Passamaquoddy Bay, in the St. Andrews region of 

 ' New Brunswick, near the Maine border, on the opposite side of the bay on 

 Mascarene Peninsula, at Black Harbour south of St. George, and on some of 

 the adjacent islands are areas underlain by beds of red sandstone and conglom- 

 erate that are correlated with the Perry conglomerate of Maine. 



The beds lie for the most part with low dips and in gende folds. In places 



they rest unconformably on the Silurian rocks, and in places are in fault contact 



i against them. The conglomerates contain boulders of the Silurian and pre- 



Silurian rocks and of the St. George granite intrusive rocks. On Hill Island two 



basic amygdaloidal lava flows are interbedded with the red sediments, and simi- 



; lar volcanic rock shows on Howard Island. Locally the beds are cut by dark 



j dykes. Similar dykes and flows are associated with the conglomerate beds at St. 



j Andrews (Alcock, 1947). 



Carboniferous System 



Carboniferous strata underlie extensive areas of New Brunswick and 

 i Nova Scotia. They also underlie all of Prince Edward Island and the Mag- 

 dalen Islands in the Gulf of St. Lawrence, and they crop out along the 

 north shore of Chaleur Bay. They represent Mississippian, Pennsylvanian, 

 and possibly part of Permian time, and are the source of coal, oil, gas, and 

 gypsum in New Brunswick and Nova Scotia. They are generally softer 

 i and more susceptible to erosion than the older Paleozoics and form the 

 lowlands. The lowlands of the geomorphic map of Fig. 12.1 are, therefore, 

 I about coincident with the Carboniferous beds. See also the Geologic Map 

 of North America. 



Fig. 12.4. Correlation chart of the Carboniferous formations of New Brunswick and Nova 

 Scotia. Reproduced from Alcock, 1947. 



