Blue Biggs Jasper stone. Blue Biggs Jasper is a silicated volcanic ash. It was formed during a volcanic eruption and is part of a Miocene series of rocks called the John Day Formation, near Biggs, Oregon, USA. It is a decorative stone used for jewellery and trinkets.
Willamette River, by Daniel E. Coe of the Oregon Department of Geology and Mineral Industries, displays a 50-foot elevation range, with lower elevations shown in white and higher elevations in dark blue. Coe used LIDAR data to make the map; he writes that he was inspired by maps of the Mississippi River made by Harold N. Fisk for a 1944 Army Corps of Engineers study. From Atlas of Design.