steenssite geology

Steens Mountain Geology

Steens Mountain was created by normal faulting. The fault on the east side is moving faster than the fault on the west side creating a tilted fault block. That is why there is a gentle slope on the west side and a more abrupt drop on the east side. It is 9300 feet at it's highest point and about 20 miles long.

Steens Eastside Steens Westside

What Steens Mountain is made of. In order from newest to oldest (from top to bottom of the mountain).

Steens Basalt Basalt with Large Plagioclase Grains

Steens Mountain Volcanic Series Poorly Stratified Flows and Breccias

Pike Creek Formation Volcanic Tuff and Breccia, Pink and Reddish Rhyolite, Thunder Eggs

Alvord Creek Formation Primarily Cinders and Ash

Rock Table Geology Climate Table