Passage Formation, Classification, and Modification of Lava Tubes

Publication Date


Type of Culminating Activity


Degree Title

Master of Science in Secondary Education

Major Advisor

K. M. Hollenbaugh


During the last 15 years, there has been increased interest regarding the formation of lava tubes in basalt flows. This interest has been created, in part, by the NASA Space Program's geological research and, in part, by an awareness of the paucity of research done in this field. Some of the observations have been recorded on actively forming tubes (Greeley, 1971; Sterns, 1966; MacDonald, 1970) while others have been recorded on tubes already formed (Harter & Harter, 1970; Ollier & Brown, 1965). Two diverging theories on tube-forming processes have been proposed. The primary purpose of this study is to compare these theories of formation and develop a classification which will be applicable to all lava tubes. A secondary purpose is to describe the modification processes that take place after tube formation and which help to determine the final tube shape.

This system will have four major subdivisions. The first three subdivisions are based on the flow characteristics of the lava channel from whence the tube was derived. Each class is recognizable by at least two criteria: the location in the total flow unit; and the structure of the lava flow. The last subdivision or class covers those lava caves which are not formed by flow, but by rifting or pressure changes within the flow.

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