PRESIDENTIAL ADDRESS. 17 
a little closer to the continental masses than the earth- 
quake zones. 
These volcanic belts fall naturally into two divisions 
namely, those which are dormant and those which areactive. 
In general the dormant members lie farther from the 
trenches than the active ones. Recurrence is made to this 
point at another place. Both types are confined to the 
Pleistocene Period. 
(d) The Plateau Rings and “Island Ares.’’—The Eastern 
Pacific, from Alaska to Patagonia, is bordered by high 
plateaus, arranged in belts both parallel and subparallel to 
the coast and separated from each other by tectonic valleys. 
Hxamples of these great highland belts are the Andes, the 
Cascades, the Selkirks, the Rockies, and the various Sierras, 
The Western Pacific is bordered by belts of continental 
plateau and interplateau valleys similar in disposition to 
those of the Cordillera of Western America, the quantita- 
tive factor, however, being less pronounced in the case of 
the former, The real counterparts of the American cor- 
dillera must be sought in the more marginal portions of the 
Western Pacific Basin itself. These western homologues 
include Japan, the Carolines, Ladrones, Mariannes, Philip- 
pines, New Guinea, Solomons, New Hebrides, New Cale- 
donia, New Zealand, Fiji, Tonga, and Samoa, together with 
their distant outliers, such as the Hawaiian, Cook, Society, 
and Paumotu Groups. The deep-sea troughs lying parallel 
to these groups are the counterparts of the intermontane 
valleys of the Cordillera, and the deep seas which break 
the continuity of the island orientation are the exaggerated 
counterparts of the radial warpings and faultings of the 
syntactic arcs of the cordilleran regions. The main island 
arcs are, in reality, plateaus, or elevated plains, of erosion. 
The valleys which ornament them in places appear to be 
B—May 3, 1922 
