Abstract: The results of pollen, spore, algal and charcoal particle analyses from an 18 m core sample, dating from ca. 730 000-0 a before present (B.P.), from Lake George are described along with an account of a five year study of modern pollen-rain from the same site. Also, pollen analyses of two isolated samples, dating about 4-7 Ma B.P., in a separate core from the same location are reported for comparison. The sedimentary sequence is dated by means of magnetostratigraphy and radiocarbon. The microfossil record from Lake George provides the longest relatively continuous Quaternary continental sequence yet available from Australia and may document one of the world's longest combined record of vegetation, bush-fires, lake levels and climates together with the record of accompanying plant migrations, redistributions and extinctions. It is so far the only chronologically secure Late Cainozoic palynological database available in Australia that spans the entire Brunhes Chron. The altitudinal shifts of vegetation belts inferred from the palynological sequence suggest significant past changes in terrestrial temperatures of the order of glacial-interglacial cycles. It is revealed that the upper treeline was depressed by 1200-1500 m and 300-600 m, respectively, during the glacial maxima and the cool-temperate intervals, and reverted during the interglacials. Assuming an average lapse rate of 0.7 $^\circ$ C per 100 m, the drop in mean temperature for the warmest month (January) with respect to the present during the glacial maxima and the cool-temperate periods respectively may have been about 8-10 $^\circ$ C and 2-4 $^\circ$ C. A series of about eight glacial-interglacial cycles (phases I-XIX) are recognized during the Brunhes Chron at Lake George broadly corresponding to stages 1-19 of the deep sea $^{18}$ O palaeotemperature record. A correlation between the palaeotemperature sequence and the former lake levels at Lake George is presented for the relatively more continuous section, ca. 350 000-0 a B.P., with a view to resolve past precipitation changes. It is inferred that periods of considerably lower precipitation than at present prevailed during the glacial maxima. Conversely, periods of higher precipitation than at present occurred for some considerable lengths of time during the interglacials. In general terms, the precipitation levels increased during both interglacials and interstadials with respect to glacial maxima. The plant microfossil evidence indicates that Eucalyptus- dominated, dry sclerophyll (low, open) forests, now growing in the lake catchment, and probably elsewhere in southeastern Australia are the result of a comparatively recent development. It is shown that the relatively 'fire-sensitive' Casuarina-dominated forests, combined with several equally or more 'fire-sensitive' rainforest taxa, dominated the vegetation for at least half a million years during all but the last two interglacials. The relatively 'fire-tolerant', Eucalyptus-dominated forests started to expand onwards from the last interglacial, some 130 000 years ago, in conjunction with large increases in the amount of charcoal in the sediment. Since then, not only did the amount of charcoal remain at a generally high level but the overall dominance of open, eucalypt forest is maintained throughout during the warmer periods except for a cool-temperate interstadial interval (zone D) during the last glacial. The 'fire-sensitive' Casuarina (under 23 $\mu$ m type) as well as all the rainforest taxa declined at the end of the last glacial and finally disappeared from the lake catchment during the Holocene, culminating in the total extinction of Casuarina type under 23 $\mu$ m during the last few hundred years. Some of the changes in flora during the Brunhes Chron were undoubtedly the result of long-term climatic change but most appear to have been precipitated through increased fire-frequencies only during the last 130 000 years (with the maximum impact occurring during the last 10 000 years), probably on account of the bush-firing activities of early man in Australia. This presupposes the presence of the Aboriginal people some 90 000 years earlier than the oldest available archaeological evidence for human occupation of the Australian continent, a proposition that remains to be tested by future archaeological investigations. In biogeographical terms, the studies reveal that a number of Gondwanic taxa, commonly seen during the late Tertiary in southeastern Australia, survived well into the Pleistocene and finally disappeared during the late Brunhes from Lake George.

Abstract: The present conference on the history of the relationship between atmospheric CO/sub 2/ and the carbon cycle treats data obtained concerning the most recent deglaciation, the Pleistocene, the Zenozoic, and the Phanerozoic-Precambrian Specific attention is given to the geophysical implications of the tropospheric methane cycle, transient response of the marine carbon cycle, factors regulating glacial to interglacial CO/sub 2/ changes, the high latitude ocean as a control of atmospheric CO/sub 2/, and the relationships among atmospheric CO/sub 2/, orbital forcing, and climate Also discussed are the distribution of major vegetation types during the Tertiary, a Strangelove ocean in the earliest Tertiary, high atmospheric CO/sub 2/ as a plausible mechanism for warm Cretaceous climates, and potential estimation errors in carbonate rock accumulation over geologic time

Abstract: Extending in a broad arc that abuts the sandy (non-Gobi) deserts, the loess plateau of northern China1–3 is one of the most massive accumulations of loess in the world. The loess sequence is typically characterized by an alternation of silty or sandy loess with more clay-rich palaeosols. These alternations, in conjunction with their enclosed faunas and distinctive mineralogies, have been interpreted as reflecting Pleistocene glacial/interglacial cycles3–8. Because it holds implications for the climatic and anthropological history of China9,10, the definition of a reliable chronological framework for loess deposition is of great interest. Recent palaeomagnetic studies4,5 have indicated that loess deposition in Shaanxi province commenced ∼2.4 Myr ago. To assess the synchrony of loess accumulation across the loess plateau, we have dated a 330-m-thick loess sequence near Lanzhou, Gansu province. The magnetostrati-graphical results reported here indicate that the base of this loess succession dates from ∼1.3 My r ago. This young age (in comparison to the Shaanxi sequence) is attributed to uplift along the northern fringe of the Tibetan Plateau11 that precluded early Pleistocene loess preservation in this mountainous region. Palaeosols in the basal loess occur, on average, once every 25 kyr, suggesting that climates conducive to soil-forming events may have been modulated by orbital precession in the early Pleistocene.

Abstract: The Brunhes magnetochron (0–730 kyr) at Deep Sea Drilling Project Site 594 off eastern South Island, New Zealand, comprises up to ∼100 m of alternating units of pelagic and hemipelagic ooze formed during interglacial and glacial periods respectively. The youngest hemipelagic interval corresponds to glacial isotope stage 2 and can be correlated with extensive glacial and glacio-fluvial deposits of the late Last Glaciation (∼27–13 kyr BP) on South Island. Inferring the same genetic link for the other hemipelagic sediment units down core, we show here that as many as 12 major episodes of expanded alpine glaciation have occurred on South Island in the past 730 kyr. Each of these glacial episodes coincided with a period of significant 18O enrichment (+2‰) in the core resulting from changes in ocean isotope composition associated with major growth phases of the Northern Hemisphere ice sheets. The inferred history of alpine glaciations on this remote South Pacific island appears to be closely phase-locked (±3 kyr) to world-wide climate changes.

Abstract: Cores from ten holes, drilled to a maximum depth of 30 m, on Tarawa atoll in the central Pacific have been utilised in a study of the Holocene development of the atoll. Four dominant lithologies, in descending order, are cay rock, unconsolidated sediment, corals and leached limestone. Petrographic and radiometric age analyses indicate that the Holocene reef has developed on a previous (last interglacial) reef; the latter shows the effects of both vadose and phreatic freshwater diagenesis. Hydrological investigations beneath the present islands indicate the presence of freshwater lenses up to 29 m thick; the modern lenses are unrelated to freshwater diagenetic imprints preserved within the limestones. Vertical accretion rates of 5–8 m/1000 years for the Holocene reef section on Tarawa are significantly higher than rates measured for other Pacific atolls. The dated coral sequences suggest a more rapid rate of sea level rise during the early Holocene, and a relatively earlier stabilisation of sea level than has been suggested previously.

Abstract: Measurements of fossil meander features along the Sabine River near Merryville, Louisiana reveal that present day discharge is substantially less than when the Deweyville, Prairie, and Montgomery terrace surfaces were active floodplains. Available evidence indicates that these fills were laid down during interstadial or interglacial times and that the large discharges were the product of increased tropical storm activity.

Abstract: There has been much speculation about the history of the Arctic Ocean, particularly its response to the late Quaternary climatic fluctuations1–8. As a result, considerable data have been gathered from Arctic Ocean sediment cores to reconstruct glacial and interglacial Arctic Ocean palaeoenvironments8,9. But even with these data the reconstructions and the correlations with the Quaternary chronostratigraphy have been unsatisfactory, mainly because of the lack of detailed stratigraphical data such as those provided by stable oxygen-isotope stratigraphy10. Here we present stable isotope records from Arctic Ocean sediment cores which can be correlated convincingly with corresponding data from the North Atlantic. Together with lithostratigraphical data, they provide new evidence on Arctic Ocean history in relation to global late Quaternary climatic fluctuations.

Abstract: Strong katabatic winds are frequently generated in glaciated mountain valleys of the Alaska Range by downglacier gravitational flow of chilled air. Stronger katabatic winds probably occurred during late Quaternary time, when glaciers were more extensive, and such winds may have greatly influenced eolian sedimentation. In Nenana River valley and in most of adjacent Teklanika River valley, the entire 1- to 2-m-thick eolian cap is postglacial in age, and the beginning of loess deposition coincides almost exactly with rapid recession of late Wisconsin ice. Previously deposited loess and bluff-edge dunes were apparently deflated during the last glaciation between 25,000 and 12,000 yr B.P. Loess deposition in these mountain valleys thus is exclusively an interglacial phenomenon; glacial phases are characterized by deflation. Meteorological modeling of katabatic winds generated during the last glaciation predicts that paleowind velocities greatly exceeded the entrainment thresholds required for eolian deflation. When both Nenana River and Teklanika River valleys are compared, theoretical differences in the potential for generating katabatic winds and differences in valley physiography explain why pre-Holocene loess is preserved in downstream reaches of Teklanika River valley and not Nenana River valley. The presence of strong katabatic winds in mountain valleys beyond former glacier limits has significant implications for late Pleistocene paleoecology and archeology.

Abstract: The pollen assemblages of a number of surface samples, Quaternary peat profiles and a moraine at Marion Island were analysed. The results, as well as those of previous investigations, were used to reconstruct the vegetation history of the island. Pollen spectra in interglacial deposits suggest that the vegetation at that time probably consisted of a slightly different species assemblage, but was comparable to that of present-day lowland communities along the island's shore. At the end of the Pleistocene and during the Holocene after the glaciers had receded, certain areas supported fjaeldmark vegetation and then were over- grown by mire vegetation. The process, comprising a succession of barren fjaeldmark through Azorella selago peats to mire communities, was probably in- fluenced by local changes in the drainage patterns and moisture availability and was not necessarily the direct result of temperature amelioration. The develop- ment of peat at three near-shore sites between approx. 7000 and 6000 yr BP was possibly related to increasing proximity of the shore lines due to rising sea-levels in the early Holocene. The influence of fauna associated with marine life can be detected in the profiles situated at relatively low altitudes near the shore. The pollen spectra in present-day surface samples from the high altitude region (approx. 200-800 m above sea level) and the fossil spectra in an undated moraine sample were taken to indicate cooler conditions. These spectra are characterized by high counts of Azorella pollen together with relatively high proportions of exotic pollen, indicating poor vegetation cover and low local palynomorph produc- tion. As in earlier studies (Schalke & van Zinderen Bakker, 197 1) the composi- tion of studied Holocene pollen spectra is not indicative of small temperature changes which may have occurred. The oceanic climate possibly helped to dampen such effects.

Abstract: Boreholes and offshore seismic profile surveys in southern Evans Bay, WelIington Harbour, indicate that a drowned river valley has been partly infilled with sediments during two glacial interglacial cycles The original valley was probably eroded along the shatter zone of a late Pliocene fault situated on the eastern side of the bay The infilling sediments include two assemblages: (I) interglacial age (including Holocene) shelly marine sands and muds, which have a palynoflora from flourishing rimu-podocarp forest, and (2) g1acial age gravelly and carbonaceous terrestrial deposits, wh ich have a palynoflora dominated by grasses or, in slightly milder times, by beech and manuka Postdepositional deformation of early Holocene sediments may indicate either further faulting along the shatter zone of the Pliocene fault or an effect of sediment compaction during earthquake stress Deformation of late Holocene sediments is interpreted as differential compaction and slumping being a secondary effect of e

Abstract: The broad topographic framework and erosion surface morphology of west central Tasmania predates the early Pleistocene. The valley systems, however, have been emphasised by glacial erosion which has played a major role in shaping the detailed geomorphology of the mountains. Part of an extensive ice cap that developed in the Tasmanian Central Highlands during the late Cainozoic discharged southwards via a major outlet glacier that occupied the valley of the Derwent River. The heart of the Central Tasmanian ice cap probably lay west of the Du Cane Range. When the ice cover was most extensive the Derwent Glacier was up to 500 metres thick. It may have extended to as low as 230 metres above sea level, 70 kilometres downstream from its source in the cirques of the Du Cane Range. Two diffluent lobes of this glacier spread eastwards to merge with other glaciers in the Nive Valley. Other diffluent lobes extended southwards into the upper Gordon Valley, and westwards into the upper Franklin and Alma valleys. At the maximum phase the Franklin and Alma glaciers were confluent around Mt. Alma, near the present junction of the Collingwood and Franklin rivers. The more westerly glaciers displayed the highest rates of mass throughput hence glacial landforms are more abundant and better developed in the west. Analysis of the post-depositional modification of the glacial landforms and sediments suggests that at least three glaciations took place. The first glaciation was probably early Pleistocene or late Pliocene in age while the most recent and smallest occurred during the late Last Glacial Stage. Glaciation would have demanded colder temperatures and an increased solid precipitation budget, but no major shift in the direction of snow bearing winds is neccessitated. At no stage was the mean annual air temperature likely to have been more than 9° C less than present. The glaciations were probably broadly contemporaneous with those at similar southern latitudes in Andean Patagonia and South Island New Zealand. Like the glaciers of those areas the ice masses of west central Tasmania were mainly of temperate maritime character. The glaciations were accompanied by periglacial activity beyond the limits of the ice. The development of rock glaciers suggests that localised areas of permafrost existed during the Last Glaciation. The glacial oversteepening has greatly facilitated slope retreat in areas of high structural anisotropy, particularly under periglacial conditions. Interglacial weathering and erosion was comparatively innocuous, although the presence of a substantial vegetation cover seems to have been critical to the maintenance of slope stabilty, particularly in steeper and more elevated terrain. The geomorphic evidence does not demand any climate deterioration during the Holocene, The most active geomorphological agent of the Holocene interglacial is humankind.

Abstract: Summary Interglacial deposits lying in a basin in till of Anglian age 7.5 km south east of Hoxne are shown to be of Hoxnian age. The sedimentary record suggests deposition in quiet and flowing water with occasional periods of drying out as the basin filled with sediment. The palaeobotanical record indicates the basin was surrounded by mixed oak forest during the earlier period of deposition and later by a forest dominated by Abies. The depositional environment and the palaeobotanical record at Athelington are similar to those at neighbouring Hoxnian sites.