Stratigraphy and tectonics of the central and eastern portions of the Columbia River Flood-Basalt Province; an overview of our current state of knowledge

The Miocene Columbia River Flood-Basalt Province is one of the youngest and perhaps the best studied flood-basalt province on Earth. This field guide describes an three-day field trip through the central, eastern, and western portions of the Columbia Plateau region of this province, visiting field localities that have been key to understanding the geologic and structural history of this province. The guide provides a brief summary of our current understanding of the geologic and tectonic evolution of this flood-basalt province. Recent refinements in Columbia River basalt stratigraphy have confirmed the huge size of many of the Columbia River basalt flows (1000-5000 km (super 3) in volume) and a wide range of emplacement rates. The emplacement rate estimates range from as low as one to two months to as high as three to four years. Many aspects of Columbia River basalts volcanism appear to be associated with regional-scale deformation (e.g., regional-scale subsidence, flooding, and faulting).