Mess Lake Lava Field black young basalt. Its westernmost and southwesternmost ends are flanked by the Mess Creek Escarpment, forming a steep prominent cliff. This cliff exposes several layers of black columnar basaltic lava flows with distal rock fragments and pyroclastic deposits. Eruptions of the young Mess Lake Lava Field basalts cascaded down this steep lava cliff similar to what occurs at the island of Hawaii and covered some of the columnar basalt jointing. Near Mess Lake, inactive hot springs can be found and are most likely associated with the most recent eruptive activity in the Mess Lake Lava Field. Hot springs are closely
Boring Lava Field quartzite-pebble xenoliths (rock fragments enveloped in a larger rock during the latter's development and solidification) can be observed among local cinder specimens, dating from Miocene to Pliocene Troutdale deposits. While the volcanic rock of Boring Lava was being emplaced over rock from the Troutdale formation, there was deformation that uplifted and dropped fault blocks to the southeast of Portland. Along the Washougal River, a large landslide occurred as a result of failure due to the Boring lava pushing down on rock from the Troutdale formation. Intrusions of Boring Lava formed outcrops at Highland Butte, La Butte, and potentially in the