GEOLOGY AND SCENERY OF NORTHEAST COAST 113 



part of the continent. During that time, to the westward 

 and southward, the sea-bottoms of geological epochs 

 accumulated muds, sands, and gravels aggregating many 

 miles in thickness the rock-materials that now compose 

 the bulk of the emerged continent of North America. 

 During that time, many volcanoes near the Atlantic, many 

 others on the Pacific seaboard, were born, lived active days, 

 and died, to leave more than a hundred thousand cubic 

 miles of lava on plains and broken mountain-land. Dur- 

 ing that time, the Appalachian mountain-system, stretch- 

 ing from Newfoundland to Alabama, was hoisted to lofty 

 heights again and again ; each great uplift was followed by 

 secular wasting that reduced the ranges to flat or rolling 

 plains broken only by remnant hills or low peaks. During 

 that time the Rocky Mountain region of the west was the 

 scene of repeated mountain-building with a similar wastage 

 of its ranges. During that time, the visible rocks under- 

 lying the five million square miles of plain country between 

 the Rockies and the Appalachians and extending from the 

 Arctic to the Gulf of Mexico, were deposited on the bottom 

 of America's Interior Sea at a rate doubtless no more rapid 

 than is now accomplished on the bed of the Atlantic. And 

 yet, for all that immense interval in geological history, no 

 bed-rocks have yet been discovered on the Labrador to tell 

 us of the earth's constructive activities in the region. Such 

 formations may be found in the future, but it is already 

 known that they cannot occupy large areas in the coastal 

 belt. The layered rocks of the Kaumajets once covered 

 much more territory than now; it may well be believed 

 that, formerly, other extended mantles of bedded rock 

 in like manner veneered the Basement Complex. But in 



