Part 3

Blade A calcite sheet originally deposited in a crack, then later exposed.

Breakdown Heaps of rubble on a cavern floor caused by the collapse of walls or ceiling.

Calcium bicarbonate An unstable compound occurring when carbonic acid contacts calcium carbonate.

Calcium carbonate A mineral with the chemical formula CaCO₃.

Calcite A crystalline form of calcium carbonate.

Carbonic acid A weak acid occurring as a liquid, having the formula H₂CO₃, a mixture of carbon dioxide and water.

Clastic dike A dike made up of fragments of pre-existing rocks.

Column A speleothem formed when a stalactite and a stalagmite meet.

Deposit A natural occurrence of mineral material, such as an iron ore deposit; or in the vocabulary of the speleologist, any cave formation originating from deposition.

Drapery Hanging speleothem in the form of a curtain or drape.

Dripstone A calcite deposit left by dripping water.

Flowstone A calcite deposit left by flowing water along a cave wall or floor.

Fracture A break in rock.

Gallery An underground passage.

Ground water Water within the earth, such as feeds wells.

Helictite A variant form of stalactite which does not hang vertically or which has side growths resembling twisted roots.

Joint A crack, which in limestone forms at an angle to a bedding plane. A series of joints often intersect each other in a four-sided pattern.

Limestone A rock consisting chiefly of calcium carbonate, usually an accumulation of organic remains such as shells.

Marble Limestone crystallized by metamorphism.

Metamorphose To change into a different form, such as changing sedimentary rock (limestone) into a metamorphic rock (marble).

Moonmilk A rare form of hydromagnesite or calcium carbonate which is semisolid.

Phreatic zone The region, below the water table, in which rock is saturated with water.

Popcorn Nodules of mineral deposits formed in such a way as to resemble popcorn.

Rimstone A calcite deposit around the edge of a pool of water.

Sedimentary rock Formed from deposits of sediments or from fragments of other minerals.

Shale A sedimentary rock formed from deposits of clay or silt.

Solution The process by which a substance is chemically combined with a liquid. Also, the state of being chemically so combined.

Soda straw A small, hollow stalactite inside which drops of water descend.

Speleogen A cave feature produced by solution of base rock.

Speleologist One who makes a scientific study of caves.

Speleology The scientific study of caves in all their aspects.

Speleothem A cave feature produced by deposition of mineral.

Spelunker One who explores caves as a sportsman or amateur speleologist.

Stalactite A calcite speleothem which grows downward, icicle-fashion, as a result of deposition by dripping water.

Stalagmite A calcite speleothem which grows upward from a cave floor as a result of deposition by dripping water.

Vadose zone The region lying between the surface of the earth and the water table. Water which seeps or flows through this region under the pull of gravity is called vadose water.

Water table The meeting place of the phreatic and vadose zones. Below it, the rock is saturated with water; above it, water under the pull of gravity is continuously flowing downward.

SUGGESTED READING

Davidson, E. J., “History of the Discovery of the Marble Halls of Oregon.” _Oregon Historical Quarterly_, Vol. 23, pp. 274-276 (1922).

Folsom, Franklin, _Exploring American Caves_. New York, Crown Publishers, Inc., 1956.

Halliday, William R., _Adventure Is Underground_. New York, Harper and Brothers, Publishers, 1959.

Mohr, Charles E., and Howard N. Sloane, _Celebrated American Caves_. New Jersey, Rutgers University Press, 1955.

Wells, Francis G., Preliminary geological map of southwest Oregon. U.S.G.S. Mineral Investigation Map, MF 38, 1955.

_RULES AND REGULATIONS_ (_Briefed_)

1. No person shall enter Oregon Caves unless accompanied by an authorized guide.

2. Children under 6 years of age are not permitted in the caves. A nursery is provided.

3. The destruction, injury, defacement or removal of any of the natural features, rocks, plants, or animals in the caves or Monument is prohibited.

4. No canes, umbrellas or sticks of any kind may be taken into the caves.

5. Dogs and cats must be kept under physical control and are not allowed on trails or in the buildings.

6. Careless disposal of trash is prohibited; please use the containers placed nearby.

THIS IS _YOUR_ NATIONAL MONUMENT Please help keep it clean and undamaged for those who follow you.

ADMINISTRATION

Oregon Caves National Monument is a unit of the National Park Service. Inquiries should be addressed to the Park Manager, Oregon Caves National Monument, P.O. Box 377, Cave Junction, Oregon 97523.

Transcriber’s Notes

—Silently corrected a few typos.

—Added links to images mentioned in the text; reworded some references to fit a presentation without page facing.

—Retained publication information from the printed edition: this eBook is public-domain in the country of publication.

—In the text versions only, text in italics is delimited by _underscores_.