Re-visiting the structural and glacial history of the Shackleton Glacier region of the Transantarctic Mountains, Antarctica

ABSTRACT

Only at Cape Surprise, central Transantarctic Mountains, is there exposed stratigraphic evidence for major offset along the range front, which marks a major boundary in Antarctica. Several faults parallel to the range front have been identified in the Devonian to Triassic Gondwana strata in the hinterland. Analysis of the stratigraphy based on field observations and the United States Geological Survey (USGS) aerial photographs, in conjunction with USGS topographic sheets and satellite-derived elevation measurements, suggests an array of faults with varying orientations and displacements. Fault offsets range up to an estimated 850 metres. No additional range-parallel faults have been identified and no clear pattern of faulting is evident in the hinterland of the frontal escarpment. Faulting may date from the time of slow uplift during the Cretaceous as well as the more rapid Cenozoic uplift of the range. Only a few faults in the hinterland can be allied with the fontal fault system. Cenozoic uplift and associated denudation was accompanied by glaciation of Antarctica, which is documented by Sirius Group strata. These deposits, which pre-date today’s polar landscape, are older than mid Miocene, and in part may date from the earliest stages of warm-based glaciation in the early Oligocene.

KEYWORDS:

• Transantarctic Mountains
• Beacon stratigraphy
• Cenozoic
• faults
• Sirius Group
• glaciation

Acknowledgements

Field work on which this paper is based was conducted principally in the 1970–1971 and 1995–1996 seasons, with additional minor field observations during the 2007–2008 season. DEMs produced using data from Maxar. David Saddler gave invaluable help with Figure 4. Reviews by Paul Fitzgerald and an anonymous reviewer improved the manuscript significantly. Byrd Polar and Climate Research Center contribution no. 1619. Satellite imagery (Figure 4) provided by the Polar Geospatial Center under NSF-OPP awards 1043681 and 1559691. DEM provided by the Byrd Polar and Climate Research Center and the Polar Geospatial Center under NSF-OPP awards 1543501, 1810976, 1542736, 1559691, 1043681, 1541332, 0753663, 1548562, 1238993 and NASA award NNX10AN61G, and the Blue Waters Innovation Initiative.

Disclosure statement

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

Data availability statement

Supplemental files (Text plus Figures S1-S7) are geological maps at a scale of 1:250,000 of the Shackleton Glacier region, Transantarctic Mountains. Maps are JPEG images. These data are openly available in Figshare at https://doi.org/10.6084/m9.figshare.20490108.

Additional information

Funding

All were supported by the Office of Polar Programs, National Science Foundation, Wahington DC (NSF grants GA-26652, OPP-9420498, and OPP-0636824).