Landslides in the Transantarctic Mountains: lower Jurassic and older strata displaced in late Mesozoic to late Cenozoic time

ABSTRACT

Eight landslides, seven certain and one possible, have been identified in the central Transantarctic Mountains and one at Carapace Nunatak, south Victoria Land. Four consist of Kirkpatrick Basalt lavas alone, two comprise Kirkpatrick lavas with associated pyroclastic rocks, one consists of Hanson Formation beds and Kirkpatrick lavas, and one involves Fremouw Formation strata. One possible block, of uncertain origin, consists only of Hanson Formation beds. All rocks comprising the displaced blocks, except one, are Early Jurassic in age. The exception is the inferred slide involving the Triassic Fremouw beds. The locations of some landslides are consistent with emplacement on present-day topography, which has been little modified since the middle Miocene, but the time of emplacement of others is either Oligocene to pre-middle Miocene or pre-dates the onset of glaciation in Eocene/Oligocene time. The older landslides reflect fortuitous preservation of an ancient landscape not unlike that of today, one dominated by horizontal beds consisting of resistant dolerite sills and quartz-rich sandstones alternating with intervals of weak fine-grained sedimentary beds, and capped by basalt lavas. The landslides are interpreted to document three stages in landscape evolution: a pre-glaciation semi-arid landscape, an early warm-based glacial environment, and a late cold-based glacial setting.

KEYWORDS:

• Transantarctic Mountains
• landslides
• pre-glaciation
• warm-based glaciation
• cold-based glaciation
• palaeotopography

Acknowledgements

Field work on which this paper is based was conducted principally in the 1966–1967, 1967–1968 and 69–70 seasons but also during later seasons. All were supported by the Office of Polar Programs, National Science Foundation (principally NSF grants G-534, G-1159 and GA-12315). Discussions with Peter Barrett are much appreciated. Suggestions and comments by Stewart Jamieson and an anonymous reviewer have greatly improved the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

All data in support of this paper are available from the author [D. H. E.] on request.

Correction Statement

This article has been corrected with minor changes. These changes do not impact the academic content of the article.

Additional information

Funding

The fieldwork on which this paper is based was supported by the National Science Foundation, USA [principally grant numbers G-533, G-1139, GA-12315].