Geologic Setting
Bellingham offers a unique natural setting for the study of earth sciences. The region has a fascinatingly rich geologic history, lying along the zone where oceanic crustal plates collide with the North American continent. The oldest rocks occur in the North Cascade Mountains and along the coastal hills and adjacent San Juan Islands. These sedimentary, igneous, and metamorphic rocks were originally deposited more than 100 million years ago, far to the south of their present location. The motion of the earth's crustal plates has since transported these rocks several thousand miles northward, until they collided with the western edge of North America. The resulting compression caused the rock layers to become highly folded and faulted, producing spectacular mountain peaks.
Prior to the rise of these mountains, Northwest Washington was covered by a broad swampy river valley. Over a period of about 10 million years, the river system deposited a 15,000 foot thick blanket of sandstone, shale, and coal, forming the thickest sequence of non-marine sediments in North America (the Chuckanut Formation). The WWU campus is built upon this bedrock, and local outcrops contain fossils of palms, ferns, conifers, and other semitropical plants that flourished about 50 million years ago. Other relatively young rocks were formed by the intrusion of magma, producing bodies of granite that contain deposits of gold, silver, and copper.
The modern landscape includes many features that formed during the Ice Age. Only 15,000 years ago the Bellingham area was covered by a mile-thick sheet of ice, and extensive alpine glaciers still occur in the local mountains; outside of Alaska, 80% of the nation's glaciers are found in the North Cascades. During the Ice Age, a period of volcanic activity resulted in the formation of huge ice-covered volcanoes. The nearest of these is Mount Baker, a huge ice-covered peak that produces occasional steam plumes visible from Bellingham. The waters melting from its vast ice field join the swift currents of the Nooksack and Skagit Rivers, reaching the coastal tide flats after a journey of only 40 miles. Here they mingle with the green marine waters that have so deftly sculpted the beaches, cliffs, and islands of Puget Sound.
