The distribution and paleoclimate implications of periglacial landforms in eastern Australia

Slee, Adrian John (2016). The distribution and paleoclimate implications of periglacial landforms in eastern Australia PhD Thesis, School of Geography, Planning and Environmental Management, The University of Queensland. doi:10.14264/uql.2016.93

Attached Files (Some files may be inaccessible until you login with your UQ eSpace credentials)
Name Description MIMEType Size Downloads
s42738527_thesis_aslee.pdf Thesis (open access) application/pdf 20.98MB 0

Author Slee, Adrian John
Thesis Title The distribution and paleoclimate implications of periglacial landforms in eastern Australia
School, Centre or Institute School of Geography, Planning and Environmental Management
Institution The University of Queensland
DOI 10.14264/uql.2016.93
Publication date 2016-02-26
Thesis type PhD Thesis
Supervisor James Shulmeister
Kevin Kiernan
Total pages 234
Total colour pages 61
Total black and white pages 173
Language eng
Subjects 040606 Quaternary Environments
040607 Surface Processes
040601 Geomorphology and Regolith and Landscape Evolution
Formatted abstract
It is widely recognised that during the Late Quaternary, glaciation was limited in Australia, especially away from Tasmania. This contrasts with the widely recognised occurrence of periglacial landforms in SE Australia, particularly in Australian Alps and Tasmania. However, very little research has been undertaken into these landforms. The aim of this thesis is to investigate the extent and timing of Late Quaternary periglacial conditions in south-eastern Australia and to understand the geomorphic processes and environments associated with these landforms. This thesis presents an updated understanding of the distribution, morphology and climatic significance of periglacial landforms in eastern Australia. The thesis is divided into two sections. The first section is focused on modern ‘active’ periglacial landforms found primarily in the mountainous areas of Tasmania and focuses on two studies of modern freeze-thaw processes in western Tasmania. At higher elevations (1000 m) notable freeze-thaw features are active at the present time including stone banked lobes on Mt Rufus. Freeze-thaw features were identified to only 150 m above sea-level near Queenstown. However, these low elevation freeze-thaw landforms are small scale features associated with short periods where shallow ground ice forms. The second section of the thesis focuses on relict periglacial landforms that display no evidence of modern activity and most likely relate to late Quaternary cold climate conditions. It primarily focuses on the block deposits of eastern Australia, their morphology, distribution and climatic significance. Block deposits and associated landslide deposits from northern New South Wales to Tasmania were mapped. Four sites were studied in more detail and dated using surface exposure dating (SED). They yielded ages ranging from early Holocene to OIS 5 which are internally consistent within sites but vary widely between sites. These data provide evidence for repeated phases of periglacial activity during the last glacial cycle. At Guyra, several phases of mass movement were recognised with large scale landslides associated with a much earlier warm and humid climate dominating the landscape. Freeze-thaw landforms of the late Quaternary are superimposed on these older forms. The scale of last glaciation cooling is indicated by evidence for a possible nivation hollow bounded by a pronival rampart located near the town of Guyra (29°30’S). From this site a cooling range of 8-11°C is inferred, but additionally, relatively moist conditions are required for the nivation feature to form.

The concept of a relatively humid glaciation also emerges from the mapping of the freeze-thaw landforms on a regional basis. In particular the occurrence of block deposits and screes in northern New England in patterns matching the modern precipitation gradient indicates that freeze-thaw was preferentially concentrated in a zone parallel to the coast. It is inferred that this zone represented an area of intermediate moisture landward of the divide separating a region that was too wet (along the divide) from areas further west that were too arid for the maximum development of periglacial landscapes. This zone falls between the modern 850 and 1000 mm isohyets but it was not possible to specify the LGM rainfall. The fact that the zone parallels modern rainfall boundaries indicates that modern (easterly dominated) circulation was dominant at that time also. Further south, periglacial landforms are more widely distributed.
Keyword Periglacial
Block stream
Surface exposure dating

Document type: Thesis
Collections: UQ Theses (RHD) - Official
UQ Theses (RHD) - Open Access
Version Filter Type
Citation counts: Google Scholar Search Google Scholar
Created: Mon, 15 Feb 2016, 14:09:38 EST by Adrian Slee on behalf of Learning and Research Services (UQ Library)