Friis Hills Drilling Project; coring an early to mid-Miocene terrestrial sequence in the Transantarctic Mountains to examine climate gradients and ice sheet variability along an inland-to-offshore transect

Author(s): Lewis, Adam R.; Levy, Richard H.; Naish, Tim; Gorman, Andrew R.; Golledge, Nick; Dickinson, Warren W.; Kraus, Christoph; Florindo, Fabio; Ashworth, Allan C.; Pyne, Alex; Kingan, Tony
Author Affiliation(s): Primary:
North Dakota State University, Geosciences, Fargo, ND, United States
GNS Science, New Zealand
Victoria University of Wellington, New Zealand
University of Otago, Department of Geology, New Zealand
National Institute of Geophysics and Volcanology, Italy
Webster Drilling and Exploration, New Zealand
Volume Title: AGU 2015 fall meeting
Source: American Geophysical Union Fall Meeting, Vol.2015; American Geophysical Union 2015 fall meeting, San Francisco, CA, Dec. 14-18, 2015. Publisher: American Geophysical Union, Washington, DC, United States
Note: In English
Summary: The early to mid-Miocene is a compelling interval to study Antarctic ice sheet (AIS) sensitivity. Circulation patterns in the southern hemisphere were broadly similar to present and reconstructed atmospheric CO2 concentrations were analogous to those projected for the next several decades. Geologic records from locations proximal to the AIS are required to examine ice sheet response to climate variability during this time. Coastal and offshore drill core records recovered by ANDRILL and IODP provide information regarding ice sheet variability along and beyond the coastal margin but they cannot constrain the extent of inland retreat. Additional environmental data from the continental interior is required to constrain the magnitude of ice sheet variability and inform numerical ice sheet models. The only well-dated terrestrial deposits that register early to mid-Miocene interior ice extent and climate are in the Friis Hills, 80 km inland. The deposits record multiple glacial-interglacial cycles and fossiliferous non-glacial beds show that interglacial climate was warm enough for a diverse biota. Drifts are preserved in a shallow valley with the oldest beds exposed along the edges where they terminate at sharp erosional margins. These margins reveal drifts in short stratigraphic sections but none is more than 13 m thick. A 34 m-thick composite stratigraphic sequence has been produced from exposed drift sequences but correlating beds in scattered exposures is problematic. Moreover, much of the sequence is buried and inaccessible in the basin center. New seismic data collected during 2014 reveal a sequence of sediments at least 50 m thick. This stratigraphic package likely preserves a detailed and more complete sedimentary sequence for the Friis Hills that can be used to refine and augment the outcrop-based composite stratigraphy. We aim to drill through this sequence using a helicopter-transportable diamond coring system. These new cores will allow us to obtain continuous measurements on unweathered material through the terrestrial sequence. Beds of tephra are exposed in outcrop and we expect to encounter these key age markers in the cored sequence. These new high quality, well-dated terrestrial data will be directly compared to marine cores to provide environmental data across a broad onshore-offshore transect.
Year of Publication: 2015
Research Program: IODP Integrated Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; ANDRILL; Antarctica; Cenozoic; Climate change; Friis Hills; Glacial environment; Integrated Ocean Drilling Program; Interglacial environment; Middle Miocene; Miocene; Neogene; Paleoclimatology; Paleoenvironment; Tertiary; Transantarctic Mountains
Record ID: 2016062614
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data supplied by, and/or abstract, Copyright, American Geophysical Union, Washington, DC, United States

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