USA, California, Shasta: Subway Cave Lava Tubes
The lava of the Hat Creek flow was discharged in large volumes from a series of north-south fissures (cracks in the earth). This river of lava located near the town of Old Station, crawled northward 16 miles, covering the floor of Hat Creek Valley. While the top crust cooled and hardened, rivers of red-hot lava insulated by the newly formed rock above, continued to flow. Eventually,…