Columbia River Basalt Group
- Sierpiński triangle (Wikipedia)
The Sierpiński triangle, also called the Sierpiński gasket or Sierpiński sieve, is a fractal with the overall shape of an equilateral triangle, subdivided recursively into smaller equilateral triangles. Originally constructed as a curve, this is one of the basic examples of self-similar sets—that is, it is a mathematically generated pattern that is reproducible at any magnification or reduction. It is named after the Polish mathematician Wacław Sierpiński, but appeared as a decorative pattern many centuries before the work of Sierpiński.
- Steens Mountain (Wikipedia)
Steens Mountain is a large fault-block mountain in the northwest United States, located in Harney County, Oregon. Stretching some fifty miles (80 km) north to south, on its west side it rises from the Alvord Desert at an elevation of about 4,200 feet (1,280 m) to 9,738 feet (2,968 m) at the summit. Steens Mountain is not part of a mountain range but is properly a single mountain, the largest of Oregon’s fault-block mountains.
Columbia River Basalt Group map shows main regions of basalt exposure in Washington, Oregon, Idaho and Nevada, USA. (usgs.gov)