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10 - Early Tertiary vegetation: evidence from spores and pollen
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- By M. K. MacPhail, 20 Abbey Street, Gladesville, New South Wales 2111, Australia, N. F. Alley, Department of Mines and Energy, PO Box 151, Eastwood, South Australia 5063, Australia, E. M. Truswell, Division of Continental Geology, Bureau of Mineral Resources, Geology and Geophysics, PO Box 378, Canberra, ACT 2601, Australia, I. R. K. Sluiter, Department of Conservation and Natural Resources, State Government Offices, 253 Eleventh Street, Mildura, Victoria 3500, Australia
- Edited by Robert S. Hill, University of Adelaide
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- Book:
- History of the Australian Vegetation
- Published by:
- The University of Adelaide Press
- Published online:
- 25 July 2017
- Print publication:
- 31 March 2017, pp 189-261
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Summary
This chapter reviews palynological evidence for the nature of the early Tertiary flora and vegetation of Australia. Because of difficulties in distinguishing between Late Oligocene and Early Miocene palynofloras, the interval of time covered is Paleocene to late Early Miocene, 65 to ca 18.5 million years (Ma) based on the geochronological time scale of Harland et al (1990).
The period is critical in tracing the origins and rise of the modern Australasian vegetation from an early, diverse angiosperm flora, such as that sampled in rift valley sequences along the southern margin of Australia during the Maastrichtian. Whether this flora was representative of inland regions or the northwest margins is debatable (see Twidale & Harris, 1977; Harris & Twidale, 1991), but it is clear that during the Danian a floristically more simple vegetation dominated by conifers and ferns prevailed in coastal/ lowland southern Australia. In most general terms, the subsequent history of the early Tertiary vegetation is the rise to prominence of floristically complex nonseasonal mesothermal-megathermal forest types and their timetransgressive replacement by more open or seasonal mesothermal -microthermal types during the Miocene. The same period saw the final separation of Australia from Antarctica, its northward drift through some 20 degrees of latitude and an irregular but overall decline in global high latitude sea surface temperatures of ca 13 °C from an Early Eocene maximum.
The last major reviews incorporating evidence for the early Tertiary vegetation (Barlow, 1981; Lange, 1982) concentrated upon individual elements within the flora, utilising cytogenetic, cladistic and other phylogenetic studies to augment but also to overcome deficiencies in the fossil database. Since these reviews, the substantial increase in the volume of published and unpublished information allows plant fossils to be used as primary evidence for the history of the early Tertiary flora and vegetation. Not surprisingly, this vegetation is found to have been as heterogeneous in space and labile in time as that of the Quaternary. Accordingly, this chapter concentrates on the fossil record per se, focussing on the sites and on the spore and pollen sequences that are available and what these imply, rather than adopting the broader approach of earlier reviews.
The Shaugh Moor Project: Fourth Report — Environment, Context and Conclusion
- N. D. Balaam, K. Smith, G.J. Wainwright, S. Fordham, M. Girling, H. C. M. Keeley, R. Macphail, R. Morgan, Q. Mould, B. Orme, R. Otlet, H. Porter, D. Tomalin, A.J. Walker
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- Journal:
- Proceedings of the Prehistoric Society / Volume 48 / Issue 1 / 1982
- Published online by Cambridge University Press:
- 23 May 2014, pp. 203-278
- Print publication:
- 1982
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For five years from 1976 to 1980 the archaeology and environment of a block of landscape centred around Shaugh Moor on south-west Dartmoor were analysed prior to the destruction of some of the evidence by china clay working. The investigations began in 1976 with a survey of the field monuments and the initiation of soil, vegetation, small mammal and phosphate studies in addition to the search for peat deposits of sufficient antiquity. From 1977 the programme was determined by the encroachment of the quarries and other works, so that early in that year a group of cairns were excavated (site 10) and subsequently the first of two seasons work on a walled enclosure (site 15) was initiated. The excavation of the enclosure was completed in 1978 and in that year it was also necessary to undertake a small investigation near the northern edge of the project area on the Trowlesworthy cross-dyke (site 202) and near its southern edge on Wotter Playground (site 201). Settlements and field systems were surveyed and excavated on Wotter Common in 1979 and these investigations were completed in 1980 when the Saddlesborough Reave, which crosses the centre of the project area from east to west was also surveyed in detail and sampled by excavation.
More field work could have been undertaken on threatened areas and indeed a limited operation was undertaken in 1981 on the Saddlesborough Reave to confirm some points of detail. Instead, it was thought best to conclude the project after five years, to complete the publication of the results and to allow mature consideration of these so as to generate a new set of questions.
At an early stage the decision was taken to publish the work as a series of annual reports in these Proceedings rather than as a single monograph. The first report (Wainwright et al. 1979) set out the simple research design for the project and contained accounts of the 1976 survey and of the excavation of the cairn group.