Cambrian Period - the first and oldest period of the Paleozoic Era which occurred from 570 milllion years ago and lasted seventy milllion years ago until 500 imllion years ago
 
 

Colorado Plateau - land region in Southwestern United States that includes Northern Arizzona,  Southern Utah, Southwestern Colorado, and Northwestern New Mexico
 
 

continental drift - theory that continental plates under the Earth's crust rupture,  move apart, and collide with one another.  When collision occurs, mountain ranges are created
 
 

cubic feet per second (cfs) - a rate of river flow
 
 

Lake Powell- one of the largest man-made lakes in the world formed behind Glen Canyon Dam.  It is 185 miles long and 250 square miles in area.
 
 

Paleozoic Era - major division of geological time lasting from 570 to 240 million  years ago
 
 

Permian Period - last period of the Paleozoic Era lasting fifty million years from 290 to 240 million years ago
 
 

schists- metamorphic rock, formed from heat and pressure deep within the  Earth's crust.  The predominant mineral is crystal which is aligned in parallel layers
 
 

vulcanism - activity or force from a volcano