The Billboard
The summit was first visited by Bruce Luyendyk and Kuno Lecha by helicopter in January 1993 during expedition GANOVEX VII. In 1998–99, Christine Siddoway led a geological party from Colorado College that reached the summit by climbing a west route.[1]
Geology
The Billboard is composed of Cretaceous Byrd Coast granite.[2] It is topped by an erosion surface that reaches an elevation of 793 metres (2,602 ft), which is about 700 metres (2,300 ft) above the outlet glacier below.[3] The surface lacks glacial erosion features; however erratics found on the surface provide evidence of overriding by cold-based glacier ice. Features of prolonged surface weathering in a sub-aerial environment are sheeting and weathering pits.[4][3]
References
- ^ Christine S. Siddoway, 2018
- ^ Wade, F. A., C. A. Cathey, and J. B. Oldham. 1977. Reconnaissance geologic map of the Boyd Glacier quadrangle, Marie Byrd Land, Antarctica, Map A-6. Reston, VA: U. S. Antarctic Research Program.
- ^ a b Sugden, D.E., Balco, G., Cowdery, S.G., Stone, J.O., and III, L.C.S., 2005, Selective glacial erosion and weathering zones in the coastal mountains of Marie Byrd Land, Antarctica: Geomorphology, v. 67, p. 317-334
- ^ Stone, J.O., Balco, G.A., Sugden, D.E., Caffee, M.W., Sass III, L.C., Cowdery, S.G., and Siddoway, C., 2003, Holocene Deglaciation of Marie Byrd Land, West Antarctica: Science, v. 299, p. 99-102
This article incorporates public domain material from "The Billboard". Geographic Names Information System. United States Geological Survey.
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