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Washington Washington 10,000 year old glaciated land Basalt lava Plateau Rivers of Washington Excellent drainage patterns and a through-flowing river No tin or iron Farm Land Volcanoes in Washington http://www.dnr.wa.gov/Publications/ger_ ftg1_yakima_valley_wine_country.pdf Geological Provinces of Washington Northern Cascade Mountains Olympic Peninsula Now to the continental glacier Most Recent Continental Glaciation 100,000 to 17,000 years ago Notice that glaciers extend well out into the Pacific Ocean How did First Nation People get across Canada and into the USA and Mexico? Igneous Rocks of Northern Washington Area of complex plutonic igneous and metamorphic rocks Igneous Rocks not along the Cascade Trend And here Permian Rocks: 250 million years ago Not here But remember this one in Idaho and eastern Oregon & Washington The Columbia Plateau Northern Cascades plutonic & metamorphic rocks Columbia Plateau Willapa Hills Multiple *Basalt lava flows *Basalt lava flows: similar rock to Oceanic Crust Columbia Plateau Basalt Lava Flow Multiple lava flows About 4 million years old Similar to oceanic crust What rocks were covered by the basalt? The Source for the Lava Flows of Washington Exotic subcontinents rafted in from the Pacific <100 million years old 4 million year old Columbia Basalt lava flows Cross Section Source area for basalt lavas Permian Rocks: 250 million years ago Not here Source of the basalts of Oregon & Washington Source of Lava Flows; SE Washington Younger Exotic Pacific terranes Oldest Exotic Pacific terrane North American Continental Crust 1–2 billion years old On the British Columbia