Verticulum Tar Tunnels

The Verticulum Tar Tunnels were mines in the 1800s in the Tessian side of the Verticulum range. It is now denoted as a national park. The entrance to the Tar Tunnels are in Pourrenton, Tessan. It was discovered when the Parken Industries Mine struck a soft wall where minor reported black tar oozing from the walls. Excavation around the area lead to the discovery of a large tar pit in a limestone cave.

Location
The Tar Tunnels are located in Pourrenton, Depefestio. It is made up of a mine shaft that connects into a cave that contains a large tar pit. Above the lake, there is approximately ten feet of highly acidified salt water (carbonic acid was dissolved into it) that floats atop the layer of asphalt.

Origin
The bitumen (geologic deposits of natural asphalt) was formed from kerogen, a byproduct of cellular decomposition underground. The kerogen was converted into asphaltene, the sample of which, in the Verticulum Tar Tunnels was high in bitumen. Most likely, the acified salt water came from dissolved limestone, which created carbonic acid, which was then concentrated due to the high humidity level. The lake is heated by a magma that is found nearly three miles further down. Thus, the temperature of the lake is approximately 37-45C. Occasionally, bitumen bubbles through the salt water, then pops at the surface and creates a thin film. The film sinks down slowly in flakes, and has the appearance of snowflakes.