Belly of the Whale
The Belly of the Whale is named for the joint and rillenkarren that make the passageway look like a giant ribcage. It is a narrow passageway where the trail bridges over the River Styx. This room shows a clear example of a vertical joint and the impact that the River Styx has had on cave development. The stream also carved erosional features, such as scallops and bevels.
Geology
Room Development
A joint is evident in the center of the ceiling, making the spine of the ribcage. Vertical joints are more common at shallow depths because these joints form when overlying rock is eroded. This releases pressure off of the underlying rock, which widens and causes a crack. More water can then enter and dissolve the marble to form a passage. Because these typically form at shallow depths, vertical joints are less common in the rest of the cave (Palmer 78; Roth 15).
Cave Formations
Many cave formations, like the ones in the Petrified Garden, are speleothems created by deposition. In the Belly of the Whale, speleogens can be found.
Speleogens are formations created by erosion. Water is a powerful agent of erosion and carved out the scallops, bevels, and rillenkarren found in this room.
Rillenkarren make up the ribs of the ribcage in the Belly of the Whale. Rillenkarren are small grooves carved into the walls by acidic water (Lundberg 315; Gines 473).
As the cave drained, streams like the River Styx developed. These underground streams had high rates of flow and turbulent water. Water swirls carved out cave scallops, seen near the far end of the platform. Scallops are spoon-shaped scoops, which get smaller as the stream flow increases (Lundberg 316-317).
Air Flow
The Belly of the Whale has the highest levels of carbon dioxide when compared to the rest of the cave. One average for June, July and August for this areas shows levels seven times that of the surface. This is based on the ongoing measurements by the Oregon Caves resource staff (Hale 2011). Levels of carbon dioxide are higher in this room because of a lack of airflow and the constant release of carbon dioxide from the River Styx.
Bates, Robert and Julia Jackson, ed. Glossary of Geology. Alexandria: American Geological Institute, 1987.
Hale, Elizabeth. Personal Communication. August 12, 2011.
James, Julia. “Carbon Dioxide-Enriched Air.” Encyclopedia of Caves and Karst Science. John Gunn, ed. New York: Fitzroy Dearborn, 2004. 183-184.
Lundberg, Joyce. “Karren.” Encyclopedia of Caves. David Culver and William White, ed. Burlington: Elsevier Academic Press, 2005. 315-321.
Palmer, Arthur. “Cavernous Rocks.” Cave Geology. Dayton: Cave Books, 2007. 78-80.
Roth, John. “Interpretive Manual for the Monument’s Showcave”. Cave Junction: Oregon Caves National Monument, 2011. 14-15, 21.