Late Quaternary erosion events in lowland and mid-altitude Tasmania in relation to climate change and first human arrival

摘要: Abstract The establishment of a chronology landscape-forming events in lowland and mid-altitude Tasmania, essential for assessing the relative importance climatic human influences on erosion, present erosion risk, has been limited by small number ages obtained limitations dating methods. In this paper we critically assess previous Tasmanian studies, list published radiocarbon considered to be dependable, new thermoluminescence (TL) 25 sites around consider evidence hypotheses that processes at low mid altitudes have been: (1) purely climatically controlled; (2) influenced both anthropogenic (increased fire frequency) effects. A total 94 dependable finite (calibrated ‘as measured’ TL optically stimulated luminescence (OSL) determinations) are listed deposits comprising dunes, colluvium, alluvium loess-like aeolian deposits. Two fall >100 ka period, 15 period 65–35 ka, 77 35–0.3 ka. There was sustained increase recorded 35–15 ka, as reflected greater dated during period. We three possible biases may affected age distribution obtained: dating, sampling bias, preservation bias. Sampling bias favoured more recent dune strata, but unlikely significantly distorted obtained. Long intermittent deposition is two (Southwood B; c. 59–28 ka Dunlin Dune; 29–14 ka) there no regional loess such found New Zealand. timing increased Tasmania between 35 30 ka approximately coincides with ten-fold dust accumulation 33 Antarctic Dome C ice core. absence widespread before 35 ka, abrupt time, frequent association products charcoal, arrival people 40 cal ka, known use fires Aborigines maintain areas non-climax vegetation suggest ecosystem disturbance fires, drier climate than presently prevailing, contributed after 35 ka. Thus record provides circumstantial support proposition dispersal southeast Australia accompanied significant ecological change.