Geologic History Of The Portland Area PDF Download

"To discover astonishing rocks and landforms in the Beaver State, all that is required is a good map, a sense of adventure, and Oregon Rocks, a guide to 60 of the most compelling geologic sites in the state. The well-chosen destinations span the state's geologic history from the Triassic marble at Oregon Caves to the 240-year-old lava dome on Mt. Hood. With more active volcanoes than any other state in the Lower Forty-Eight, Oregon boasts towering behemoths, steaming fumaroles, and eroding cinder cones. Geologist Marli Miller will guide you through the ash and lava from recent eruptions to find evidence of older ones, including a supervolcano possibly produced by the Yellowstone hot spot before it tracked east, and lava that flowed all the way to the coast from eruptions near the Oregon-Idaho border. Although residents of eastern and western Oregon may not admit they have anything in common, the barnacled sea stacks near Cannon Beach and Tillamook are composed of the exact same rock as stacked lava flows on the Columbia Plateau. With beautiful photographs and informative figures and maps, this guidebook will unite Oregonians in their pursuit of outdoor exploration, be it rock hounding, peak bagging, beachcombing, or contemplating their place in the long history of the Earth"--