Basalt is a type of igneous rock which forms when lava cools at the Earth’s surface. Basalts have very fine, sometimes even indistinguishable, crystals because the rocks solidified quickly unlike granitic rocks which formed very slowly deep underground. Many of the Okanagan basalts formed during the tertiary period. The oldest of these rocks (about 50 mya) make up Dilworth Mountain, Knox Mountain, Layer Cake Hill, and Black Knight Mountain. Up to 30 individual more recent basaltic flows occur near Kelowna. The King Edward flow erupted 11 to 20 mya and the Kallis Formation flows erupted less than 7 mya. One of the most striking views of these basalts occurs along the 201 FSR along the West Kettle River valley south of Big White. Two of these flows are represented at stage one and stage two of this earthcache.
Okanagan Geology: British Columbia,Third Edition. Murray A. Roed and John D. Greenough, editors. 2014. Okanagan Geology Committee, University of British Columbia Okanagan.
To log this cache: Name at least two specific and descriptive differences between the rocks you find at stop 1 and stop 2. You do not need to do them in any particular order.
Please do not post your pictures of the columns themselves, as we want people to go for a drive and solve it in person!
Note: There is no cell reception on this section of the 201 Forest Service Road, so please ensure you've downloaded coordinates before leaving town! Except for a short distance between the two stages, the FSR is wide enough for two vehicles to easily travel side-by-side, however for this short distance it is narrower and requires additional caution (watch for other cars, and be prepared to pull over slightly towards the column side). Any car capable of safely going over a high speed bump should be fine to travel this road, however depending on conditions when you travel you may wish to have higher clearance. Winter tires are required October 1-May 31, and the road may not be passable when there is significant snowfall. Watch for signs.