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A palaeoenvironmental and palaeofire record from Dunphy Lake, Warrumbungle Mountains, south-eastern Australia / Jamie Lobb.

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posted on 28.03.2022, 13:28 authored by Jamie Lobb
This study addresses a significant geographical and temporal gap that exists in the Holocene record of fire and palaeoenvironmental conditions in the region of the Warrumbungle Mountains in eastern Australia. A multi-proxy approach (sedimentology, geochemistry, geochronology and macro-charcoal) was used at Dunphy Lake. A persistent, deep lake phase between ~18.2-16.8 ka was followed by a transition to infrequent dry and wet phases which continued to the present day. The detailed Late Holocene macro-charcoal record spans the last ~2.2 ka and shows that the main periods of enhanced fire activity coincide with an intensification of El Niño Southern Oscillation. High macro-charcoal concentrations overlap with the deposition of coarse sediment (sand) in Dunphy Lake, suggesting that some fires occurred at similar times to episodes of significant runoff and sediment flux from the catchment associated with intense dry to wet phases. An increase in macro-charcoal during the last ~2.2 ka also coincides with an increase in sediment accumulation rate from a long-term average of 0.0265 cm a⁻¹ to 0.0329 cm a⁻¹. Pollen was only present in the top of the profile, but indicates the occurrence of periodic wet and dry conditions during the last ~0.42 ka. These findings demonstrate a relationship between past fire events and post-fire aggradation, showing that an increase in fire and sedimentation during the Late Holocene is a complex response to environmental change.

History

Table of Contents

1. Introduction -- 2. Reconstructing environmental conditions and fire histories in lake environments -- 3. Late Holocene fire history and palaeoenvironmental conditions at Dunphy Lake, Warrumbungle National Park, eastern Australia -- 4. Conclusion.

Notes

Theoretical thesis. Bibliography: pages 55-63

Awarding Institution

Macquarie University

Degree Type

Thesis MRes

Degree

MRes, Macquarie University, Faculty of Science and Engineering, Department of Environmental Sciences

Department, Centre or School

Department of Environmental Sciences

Year of Award

2015

Principal Supervisor

Timothy John Ralph

Additional Supervisor 1

Kira Westaway

Additional Supervisor 2

Yoshi Kobayashi

Rights

Copyright Jamie Lobb 2015. Copyright disclaimer: http://www.copyright.mq.edu.au

Language

English

Jurisdiction

New South Wales

Extent

1 online resource (iv, 69 pages) colour illustrations, colour maps

Former Identifiers

mq:44828 http://hdl.handle.net/1959.14/1072480