- Columbia River Basalt Group
Columbia River Basalt Group map shows main regions of basalt exposure in Washington, Oregon, Idaho and Nevada, USA. (usgs.gov)- Columbia River Basalt Group Stretches from Oregon to Idaho (usgs.gov)
The thick, layered lava flows of the CRBG erupted as flood basalts, which originate as some of the most highly effusive eruptions in the world. The CRBG sequence a classic example of flood basalt activity that erupted more than 350 lava flows from about 16.7 Ma to 5.5 Ma. The eruptions originated from a series of generally north-northwest-trending linear fissures, ranging from tens to hundreds of kilometers in length, located along the Washington/Oregon/Idaho border. The magma that fed these massive eruptions may have come from a plume-like upwelling from the mantle called a hot spot. Since the time of the CRBG eruptions, the North American plate has moved in a west-southwestwardly motion, and that hot spot is now believed to reside beneath Yellowstone volcano in northwest Wyoming.
- Cytisus scoparius has been introduced into several other countries and continents, outside of its native range, and is commonly classified as a noxious invasive species in western North America, mainly in British Columbia (including on Vancouver Island), California, Oregon, Washington (west of the Cascades), the Sierra Nevada range, fragmented areas of North America’s eastern seaboard, as well as Australia (where it is a declared weed), New Zealand, and in India.
- Field-trip guide to the vents, dikes, stratigraphy, and structure of the Columbia River Basalt Group, eastern Oregon and southeastern Washington (usgs.gov)
This field-trip guide explores the main source region of the CRBG and is written for trip participants attending the 2017 International Association of Volcanology and Chemistry of the Earth’s Interior (IAVCEI) Scientific Assembly in Portland, Oregon, USA. The first part of the guide provides an overview of the geologic features common in the CRFBP and the stratigraphic terminology used in the CRBG. The accompanying road log examines the stratigraphic evolution, eruption history, and structure of the province through a field examination of the lavas, dikes, and pyroclastic rocks of the CRBG
- Oregon (Wikipedia)
Oregon (/ˈɒrɪɡən/) is a state in the Pacific Northwest region of the United States. Oregon is a part of the Western United States, with the Columbia River delineating much of Oregon’s northern boundary with Washington, while the Snake River delineates much of its eastern boundary with Idaho. The 42° north parallel delineates the southern boundary with California and Nevada. The western boundary is formed by the Pacific Ocean.
