88 BULLETIN: MUSEUM OF COMPARATIVE ZOOLOGY. 



than is now registered in actual elevations. Recent studies have shown 

 that the whole coast of Acadia has been lately drowned to a fairly uni- 

 form depth of about 250 feet. Adding this figure to present heights 

 we find that the peneplain must have once stood above sea-level 1,250 

 to 1,450 feet in Southern New Brunswick, 1,050 to 1,250 in the zone of 

 the Cobequids, 800 feet along the axis of North Mountain, and at sea- 

 level some score of miles to seaward of the existing southeast Atlantic 

 coast-line. The maximum uplift occurred in the New Brunswick High- 

 land, for there is reason to believe that the facet was on the northwest 

 warped down toward the great Carboniferous basin. This may have 

 been in the nature of a revival of crustal energies acting along the same 

 axis of warp which located the original Devonian basin, and parallel to 

 which post-Pleistocene faulting has taken place (Matthew, '94, pp. 35, 3G). 

 A secondary warp, transverse to the first one mentioned, seems to have 

 affected the facet west of the St. John-Digby line, produced to Cape Sa- 

 ble. The relatively rapid fall in the crest-elevation of the Triassic trap 

 ridge from Digby Gut to Briar Island certainly suggests a direction of 

 tilt different from that of the eastern division of the ridge. Corresponding 

 thereto is the similar westward slant of the facet from a point twenty 

 miles east of the St. John River, and on the Southern Plateau west of 

 Digby. Finally, this westward tilt would explain the low position of the 

 ancient peneplained rock-surface at Passamaquoddy Bay and in the State 

 of Maine. 



The Second Cycle : the Development of the 

 Triassic Lowlands. 



One immediate result of these warps would be the revival of the rivers 

 that lay on the peneplain. This would mean the wearing out of valleys 

 beneath the facet, especially on the less resistant rocks. On account of 

 stream adjustment inherited from the long preceding cycle, the soft belts 

 would at the initial stage of the new cycle, be subject to particularly 

 rapid attack. Since those belts are longitudinally arranged, their re- 

 spective valleys and valley-lowlands would have Appalachian trends. 

 Such, in brief, is believed to be the origin, not only of the Cornwallis- 

 Annapolis Valley (Plate 6), but also of the valleys now drowned to form 

 the Minas Basin (Plate 10), Chignecto Channel, St. Mary's Bay, and 

 possibly the Bay of Fundy itself. It is evident that we cannot decide 

 these questions of origin with all desired fulness, for stream erosion has 

 here been strikingly supplemented by marine and glacial erosion, and the 



