Irregular cooling fractures in basalt, IdahoApril 30, 2017/in /by Marli Miller columnar basalt, colonnade https://geologypics.com/wp-content/uploads/2017/04/geologic-time-pics-logo-300x115.png 0 0 Marli Miller https://geologypics.com/wp-content/uploads/2017/04/geologic-time-pics-logo-300x115.png Marli Miller2017-04-30 19:55:472017-09-23 04:01:04Irregular cooling fractures in basalt, Idaho