late pliocene and quaternary glaciations of new zealand abstract evidence of late pliocene glaciations is fragmentary the ross glaciation in northwest south island is correlated with the first marine faunal evidence of marked cooling in the wanganui basin in southern north island it is inferred to be in the 2 6 2 4 ma age range the porika glaciation in a separate area of northwest south island is younger judged by palynology and is correlated with a cooling 2 2 2 1 ma bp inferred from stratigraphic evidence of lowered sea level in the wanganui basin a gap of 1 5 ma in the record of glaciations is largely filled by wanganui basin marine sediments although an unconformity cuts out the record between ca 1 45 and 1 0 ma bp since then the many sedimentary cycles caused by sea level changes are presumed to be glacio eustatic in origin uplifted interglacial marine terraces back to marine oxygen isotope stage 17 and river terraces formed by cold climate aggradation are linked into the cyclic sequence through loess and tephra in their cover beds east of the south island cores from the dsdp site 594 in the southwest pacific record the earliest glaciation and higher in the core nine periods of south island glaciation in the last 0 7 ma onshore because of uplift and erosion only the last four glaciations assigned to oxygen isotope stages 10 8 6 and 4 2 are identified being named nemona waimaunga waimea and otira glaciations they are best known in north westland northwest south island where the relations of glacial outwash and interglacial shoreline deposits are displayed the late otira glaciation stage 2 is radiocarbon dated as beginning somewhat before 22 3 ka bp culminating ca 18 ka bp and ending at ca 14 ka bp when rapid deglaciation began a relatively small advance at ca 12 ka bp may have been followed by little change until after 8 6 ka bp recession was then followed by a period of advance from ca 5 ka bp until recent centuries and a subsequent recession that still continues

direct correlation of terrestrial and marine paleoclimatic records from four glacial interglacial cycles dsdp site 594 southwest pacific abstract over the last 350 ka changes in the composition of vegetation on new zealand inferred from pollen analysis of the upper 40 m of dsdp site 594 at 2 4 ka sample intervals reflect regional climatic variations which appear synchronous with implied variations in glacier fluctuation and in global climatostratigraphy described from sedimentary and oxygen isotope records from the same samples nelson et al 1985 pollen assemblages from isotope stages 1 5e 7a 7b and 9 are distinguished by conifer and broadleaf forest taxa which vary in composition between the last four interglacials suggesting significant differences in precipitation temperature and or migration rates glacial pollen assemblages which imply the expansion of herbland and decline in forest components show less variation and generally indicate comparatively cool conditions on the east coast of south island interstadial vegetation is composed of a mosaic of shrubland herbland vegetation the close correspondence between variations in the amplitude and timing of these continuous records of forest development in the changing vegetation of south island new zealand and oxygen isotope climatostratigraphy supports previous suggestions that late quaternary southern and northern hemisphere climatic fluctuations were essentially synchronous

the last glacial maximum in central and southern north island new zealand a paleoenvironmental reconstruction using the kawakawa tephra formation as a chronostratigraphic marker abstract kawakawa tephra formation comprising oruanui ignimbrite flow member and aokautere ash airfall member represents the products of an exceptionally large and widespread volcanic eruption from taupo volcanic centre in the north island of new zealand the eruption occurred during the last glacial maximum and is radiocarbon dated at c 22 6 ka b p thermoluminescence ages are in broad agreement with the radiocarbon age the presence of aokautere ash in loess deposits in alluvial gully fills on river terraces and its absence from unstable sites permits a detailed assessment of geomorphic activity during the last glacial maximum widespread erosion of regolith aggradation of river valleys and deposition of loess particularly in the period following eruption of the kawakawa point to a cold dry variable climate a collation of pollen data for sediments containing aokautere ash and those 14c dated in the range 17 23 ka shows that tall forest was highly restricted in the central and southern parts of the north island an apparently subalpine grassland shrubland was present at sites from present sea level to over 800 m elevation suggesting that factors other than lower temperatures such as exposure to wind and frost fire and reduced rainfall were important in controlling vegetation patterns we conclude that the interval 23 13 ka b p broadly equivalent to oxygen isotope stage 2 represents the period of greatest environmental change in the north island

origin and consequences of cyclic ice rafting in the northeast atlantic ocean during the past 130 000 years deep sea sediment cores recovered from the northeast atlantic ocean were examined in order to elucidate the influence of the earth s orbital parameters on major ice rafting analyses of coarse grained ice rafted debris and planktonic foraminifers revealed a strong reaction to the precession signal since 130 000 yr b p dropstone layers have been deposited each half period of a precessional cycle 11 000 1000 yr ice rafting occurs during times of winter minimum summer maximum insolation and summer minimum winter maximum insolation in the first case high summer insolation forces meltwater discharge from the ice sheets into the polar seas which subsequently enhances formation of sea ice during the winter in the second case growth of continental ice enhances iceberg production which also leads to a salinity reduction of surface seawater both situations result in a southward penetration of polar water thus the marine record of dropstones documents ice rafting not only during weichselian stades but also during cold events within interstades the regularity of ice rafting yields a useful framework to calibrate and elucidate climatic changes not only in the region of the north atlantic ocean but also in remote areas such as the pacific ocean and the antarctic

the erosion response to quaternary climate change quantified using uranium isotopes and in situ produced cosmogenic nuclides abstract studying how catchment erosion has responded to past climate change can help us better understand not only how landscape evolution operates but also predict the consequences of future climate change on soil resource availability recent years have seen the development of tools that allow a quantitative assessment of past changes in catchment erosion this work reviews the principles of the application of in situ produced cosmogenic nuclides and uranium isotopes to quantifying past erosion rates results highlight the role of periglacial processes and mass wasting in dictating how catchment erosion responds to climatic variability at the 10 kyr scale at the million year scale it is more difficult to untangle the role of climate and tectonics a strong coupling exists at the 10 kyr to 100 kyr scales between climatic cycles and the transfer time of regolith from source to sink this coupling reflects changes in sediment source that are either set by changes in vegetation cover at the catchment scale or by the storage of sediments on continental shelves at a larger scale although further analytical developments are required for these tools to reach their full potential existing works suggest that in the near future they will provide unprecedented quantitative insights on how soil and fluvial systems adapt to external perturbations climatic tectonic and or anthropic

palaeoenvironmental reconstruction from the last interglacial using phytolith analysis southeastern north island new zealand phytoliths extracted from loess resting conformably on lacustrine sediments in southeastern north island new zealand provide a nearly continuous vegetation climate record spanning the time period from the last interglacial marine oxygen isotope stage 5 to the present phytoliths reveal changes in vegetation patterns following changes in climate correlation between tree shrub phytolith fluctuations and the specmap oxygen isotope curve between marine oxygen isotope stages 1 and 5 suggest that changes in the ratio of arboreal to non arboreal phytoliths directly result from changes in climate these data generally support the existing pollen and diatom record this study confirms the usefulness of phytolith fossils for providing environmental and climate information from the quaternary sedimentary record especially in cases where the deposits contain no fossil pollen or diatoms copyright 2000 john wiley sons ltd

chronology of palaeoclimatic change at the end of the last glaciation analysis of sediments recorded in a piston core located east of southern north island new zealand gives a detailed record of climate change at the end of the last glacial accumulation rates1 of both detrital quartz and biological carbonate and biogenic silica components of the sediment are much higher during glacial than post glacial time and they all show a synchronous rapid decline at 14 700 yr bp we attribute this to a decline in intensity of the strong glacial westerly winds in the new zealand region as the polar winds contracted to their present latitudes2 6 the greatest rate of quartz accumulation occurs between 16 200 and 14 700 yr bp and is not matched by any change in carbonate or silica accumulation we believe this reflects accelerated fluvial transport of detritus out of the mountain ranges and consequently increased aeolian dust transport before the decline of the polar westerlies

paleoenvironmental reconstruction of a well preserved stage 7 forest sequence catastrophically buried by basaltic eruptive deposits northern new zealand abstract forest remnants buried by catastrophically emplaced volcanic deposits are identified on the shores of the manukau harbour in northern new zealand carbonaceous muds associated with the fossil forest were investigated through a combination of stratigraphy chronology and palaeoecological proxies the fossil forest was destroyed and buried by phreatomagmatic explosions from the adjacent maungataketake volcano small trees beetle and pollen assemblages indicate a northern conifer forest growing adjacent to a wetland on or near a coastal plain the pollen record shows forest compositional changes in particular a period of agathis australis dominance between two phases of dacrydium cupressinum dominance concomitant developments in the wetland flora may have been linked to changes in groundwater conditions as sea level fluctuated across the coastal plain despite overall similarity to the modern flora and fauna both beetle and pollen assemblages include elements that are found today at higher elevations in the region indicating that slightly cooler climate conditions existed during late mis 7 compared to present we estimate this temperature depression at less than 1 c relative to the present broadly consistent with the late mis 7 marine odp 1123 record located east of new zealand this study clearly demonstrates the complementarity of coleopteran and palynological analyses and the utility of a multi proxy approach to reconstructing terrestrial environmental change

long continental pollen sequence from washington state u s a correlation of upper levels with marine pollen oxygen isotope stratigraphy through substage 5e abstract fossil pollen from a 7 70 m core and a pit excavated 2 20 m deep in a mire at humptulips located on glacial drift of the olympic peninsula in western washington state presents a continuous record of vegetation since the middle pleistocene chronostratigraphic relations established from sedimentation rates based on finite and infinite radiocarbon dates in the upper 2 m of the deposit cover the last glacial cycle illinoian glaciation and apparently older millennia the pollen stratigraphy contained in 16 pollen assemblage zones shows a sequence of vegetation types including tundra park tundra woodland and closed confierous forest comparison with pollen and oxygen isotope stratigraphy of marine core y72 11 1 from the pacific ocean off oregon establishes direct continental marine correlation of upper levels at humptulips through substage 5e

late quaternary development of left bank dominant levees in the bounty trough new zealand abstract the bounty trough encompasses an extensive submarine channel system that arises on the otago fan complex off the south island new zealand and extends 1000 km eastward to feed a large fan on the 4500 m deep pacific ocean floor channels are bordered by prominent levees which on the steep otago fans are mainly narrow sandy ridges by comparison the gently sloping floor of the trough supports broad low relief muddy levees in most cases levees display preferential development on the left side of the channel facing down channel we argue this preference results not only from the coriolis deflection of channel full turbidity currents but also from bottom currents and centrifugal forces operating at channel bends basement relief and locally high sedimentation rates at channel confluences may also influence levee height piston cores reveal two distinct phases of levee growth related to late quaternary climatic cycles during glacial times rivers discharged directly into the bounty trough turbidity currents travelled and overspilled the entire length of the bounty channels thereby producing the main phase of asymmetric levee growth and terrigenous deposition such turbidite deposition was punctuated by bouts of hemipelagic sedimentation in interglacial periods river borne sediment was diverted away from the trough which became the site of predominantly pelagic sedimentation represented by a drape of foraminiferal nannoplankton ooze over channels and levees alike however levees on the otago fan complex still received terrigenous sediment presumably reworked from the adjacent continental shelf

vegetation and climate in southern hemisphere mid latitudes since 210 ka new insights from marine and terrestrial pollen records from new zealand abstract paleo vegetation records developed from marine sedimentary sequences offer considerable potential for examining changes in terrestrial climate beyond the range of 14 c dating because they can be independently dated by 18 o stratigraphy here we present the first pollen record of vegetation from a marine core site in the tasman sea tan0513 14 42 18 s 169 53 e 110 km west of new zealand s south island an independent chronology provided by correlating the globigerina bulloides 18 o record at tan0513 14 to a global isotope stack shows that the record extends back to 210 ka glacial to interglacial changes in palynomorph content are characterised by shrub and podocarp broadleaf forest taxa respectively and are correlated with similar changes in the ca 150 kyr long terrestrial pollen record from okarito pakihi bog 110 km to the south southeast both records are placed on the same timescale by matching variations in dacrydium cupressinum and fuscospora between sites with a unique tie point provided by the ca 25 4 ka kawakawa tephra our southern hemisphere mid latitude vegetation records show forest extent is greatest during periods of low ice volume high mean annual sea surface temperature masst and anti phased with local insolation intensity however there are several features not attributable to changes in mean annual temperature first a fundamental change in forest composition occurred at termination ii tii with a loss of southern beech nothofagus from the study area second the amplitude of masst change through mis 5 is not reflected in corresponding changes in forest extent suggesting other feature s of regional climate seasonality frostiness ice cover exert important controls over vegetation patterns at these latitudes

quaternary deposits and landscape evolution in northeast southland new zealand abstract three kinds of quaternary sediments are present in northeast southland aeolian deposits terrace gravels and hill slope colluvium the aim of this paper is to review and describe the quaternary sediments and erosion pattern of northeast southland and reconstruct the likely climate under which sedimentation and erosion occurred aeolian deposition occurred intermittently from 250 000 yr b p but stratigraphic studies indicate widespread erosion of loess in the period 80 000 25 000 yr b p before a final period of loess accumulation in the late otiran 18o stage 2 terrace gravels are attributable to two sources a younger suite of three terraces is attributed to aggradation phases of the mataura river an older suite of three more weathered terraces is attributed to aggradation by a river flowing eastwards through the waimea plains from lumsden to gore the river is named the lumsden river at about 180 000 yr b p this river ceased flowing through the waimea plains colluvium on hill slopes is regionally stratified into two layers the lower deposits are identified as weathered sand and gravel sized colluvium derived from argillite and siltstone screes dated as being formed before 29 000 yr b p and attributed to 18o stage 4 the upper stonier deposits are attributed to 18o stage 2 the erosion and deposition pattern of aeolian deposits terrace gravels and slope colluvium cannot be explained by a temperature drop of c 5 c calculated for the last glacial period we conclude that on lowlands vegetation cover was periodically limited by extreme droughts and cold windy conditions causing erosion of previously deposited loess and encouraging scree formation on slopes during these periods the severe climate of northeast southland approximated to that of a cold desert

evidence for a change in the periodicity of tropical climate cycles at 2 4 myr from whole core magnetic susceptibility measurements the earth s orbit about the sun is influenced by gravitational interactions with the moon and other planets the resulting orbital perturbations give rise to cyclical variations in orbital eccentricity obliquity and precession with periods of 100 41 19 and 23 kyr respectively1 these variations are climatically important because they affect the seasonal and latitudinal distribution of solar radiation magnetic susceptibility measurements in deep sea sediment cores can be used as a sensitive indicator of temporal variations in the concentration of terrigenous material supplied to the sea bed here we use this approach to study the evolution of cycles of terrigenous sedimentation at ocean drilling program sites in the arabian sea and the eastern tropical atlantic we show from spectral analyses of the two susceptibility time series spanning the past 3 2 3 5 myr that the records are driven strongly by orbital forcing before 2 4 myr before present bp both records are strongly influenced by the 23 and 19 kyr periodicities but after 2 4 myr they are both significantly influenced by the 41 kyr periodicity this shift coincides with the beginning of major northern hemisphere glaciation which indicates for the indian ocean site that the supply of terrigenous sediment carried by monsoonal winds has responded to the rapid increase in ice cover at this time we cannot however exclude possible effects of changes in bottom water circulation on the susceptibility record of the atlantic site

obsidian hydration dating of fluvially reworked sediments in the west yellowstone region montana abstract this study evaluates obsidian hydration dating in postglacial fluvial terraces cut into an outwash plain near west yellowstone montana fluvial transport fractures obsidian grains however some old hydration rinds may be preserved thus a grain may record several fracturing events the most recent fracturing event at west yellowstone is recorded in surface sediments from all of the terraces which were cut in a shorter period of time than the technique can discern they formed about 19 000 1000 yr ago using published hydration rate estimates and a mean rind thickness of 6 34 0 14 m 1 se alternatively the application of published hydration rate constants for the obsidian cliff flow with an estimated effective hydration temperature of 1 4 c yield an age of 24 400 1100 yr 1 se thicker rinds record fracturing during bull lake glaciation and cooling cracks from the emplacement of several source flows much of the observed spread in rind thicknesses 6 34 1 69 m 1 sd is probably the result of chemically induced variations in hydration rate terrace ages based on a single rind would range from 13 000 to 39 000 yr 1 sd therefore it is inappropriate to 1 use a set of hydration rate constants determined from a single sample to calculate ages for multiple artifacts or geological samples 2 date an archaeological or geological event on the basis of a single artifact or 3 generate a chronostratigraphy on the basis of individual dates as a function of depth multiple evaluations of source chemistry and hydration rates and multiple rind measurements are required to date fracturing events

dust accumulation in the new zealand region since the last glacial maximum abstract loess is widespread in new zealand deposits 1 m thick cover 10 of the land area it has mainly been derived from dust deflated from river floodplains during the last glacial maximum lgm dust accumulation continues today downwind of major river floodplains most loess is quartzofeldspathic having its origins in mesozoic and neogene rocks of the axial ranges and hill country in the central north island there are deposits of volcanic loess derived from aeolian reworking of tephras loess morphology and properties vary greatly due to diverse parent materials post depositional climates and drainage conditions the widespread 26 170 cal yr kawakawa tephra provides a datum for calculating mass accumulation rates mars rates are mostly within the range 70 150 g m 2 yr 1 but enhanced deposition at one site gave a rate of 360 g m 2 yr 1 contemporary mars of 40 100 g m 2 yr 1 were determined for distances of 1 75 0 4 km downwind of the rakaia river lgm mars of quartz for two marine cores p69 q858 drilled 100 300 km east of new zealand are 40 70 g m 2 yr 1 the mar of the aeolian component of p69 is estimated to be ca 15 g m 2 yr 1

a direct link between the china loess and marine δ 18 o records aeolian flux to the north pacific most studies of quaternary climates conducted during the past 150 years have focused on glacial sequences and for the past 25 years marine sediments have provided significant further understanding of glacial and interglacial palaeoclimates an important goal of palaeoclimatology however to link the well known detailed continental records to marine records of similar resolution has yet to be realized the classic loess sequences of china provide an apparently continuous record of continental climate over the past 2 4 million years1 2 the oxygen isotope 18o timescale developed from the marine record3 gives us a global chrono stratigraphy of late pleistocene climates previously it has been suggested in studies of the aeolian component in pelagic sediments that it may be possible to link these two records directly by finding a suitable core from the north west pacific downwind from china4 5 here we report the results of such an effort for core v21 146 fig 1 and tie the last 500 000 years of the chinese loess soil sequence directly to the 18o timescale and in so doing refine the dating of regional loess and soil horizons

a spectral analysis procedure for dating quaternary deep sea cores and its application to a high resolution brunhes record from the southwest pacific abstract date 32 is a fast and easily used computer program developed to date quaternary deep sea cores by associating variations in the earth s orbit with recurring oscillations in core properties such as carbonate content or isotope composition starting with known top and bottom dates distortions in the periodicities of the core properties due to varying sedimentation rates are realigned by fast fourier analysis so as to maximise the spectral energy density at the orbital frequencies this allows age interpolation to all parts of the core to an accuracy of 10 kyrs or about 1 5 of the record duration for a typical brunhes sequence the influence of astronomical forcing is examined and the method is applied to provide preliminary dates in a high resolution brunhes record from dsdp site 594 off southeastern new zealand

chilean and southeast pacific paleoclimate variations during the last glacial cycle directly correlated pollen and δ18o records from odp site 1234 abstract joint pollen and oxygen isotope data from ocean drilling program site 1234 in the southeast pacific provide the first continuous record of temperate south american vegetation and climate from the last 140 ka located at 36 s 65 km offshore of concepcion chile site 1234 monitors the climatic transition zone between northern semi arid summer dry winter wet climate and southern year round rainy cool temperate climate dominance of onshore winds suggests that pollen preserved here reflects transport to the ocean via rivers that drain the region and integrate conditions from the coastal mountains to the andean foothills down hole changes in diagnostic pollen assemblages from xeric lowland deciduous forest characterized by grasses herbs ferns and trees such as deciduous beech nothofagus obliqua mesic valdivian evergreen forest including conifers such as the endangered prumnopitys andina and subantarctic evergreen rainforest comprised primarily of southern beech n dombeyi reveal large rapid shifts that likely reflect latitudinal movements in atmospheric circulation and storm tracks associated with the southern westerly winds during glacial intervals mis 2 4 and 6 rainforests and parkland dominated by nothofagus moved northward into the region at the mis 6 5e transition coeval with the rapid shift to lower isotopic values rainforest vegetation was rapidly replaced by xeric plant communities associated with mediterranean type climate an increased prominence of halophytic vegetation suggests that mis 5e was more arid and possibly warmer than mis 1 although rainforest pollen rises again at the end of mis 5e lowland deciduous forest pollen persists through mis 5d and 5c into mis 5b substantial millennial scale variations occur in both interglacial and glacial regimes attesting to the sensitivity of the southern westerly belt to climate change comparison of the cool mesic n dombeyi rainforest assemblage from site 1234 with 18 o in the byrd ice core shows that on time scales longer than 10 ka cool moist conditions in central chile were coherent with and occurred in phase with antarctic cooling this is also likely at millennial scales although rainforest pollen lags antarctic cooling with exponential response times of about 1000 years which plausibly reflects the ecological response time to regional climate change

palynology of oxygen isotope stage 6 and substage 5e from the cover beds of a marine terrace taranaki new zealand abstract cover beds on uplifted quaternary marine terraces in the taranaki wanganui area of new zealand include organic deposits which yield abundant pollen in the west at ohawe marine shore platform deposits are overlain by laterally extensive lignites and laharic breccia interbedded with alluvium and capped by tephra rich loess following a time of presumably interglacial marine deposition on the platform a long period of glacial climate is suggested by pollen floras dominated by grass and shrubland taxa trees were sparse but the abundance of podocarps nothofagus and tree ferns increased during at least one interval suggesting minor climatic amelioration near the top of the section a major change in regional vegetation is recorded by a dominance of pollen derived from podocarp hardwood forest taxa including ascarina interpreted as indicating a fully interglacial climate the marine platform previously assigned to oxygen isotope substage 5e is now placed in stage 7 the overlying deposits were deposited during glacial stage 6 while interglacial substage 5e is recorded by sediment and pollen assemblages near the top of the section

climatic and vegetation control on sediment dynamics during the last glacial cycle as climate is changing rapidly there is an increasing need to understand how water and soil resources respond to climate change soil and sediment dynamics are sensitive to several external factors such as climate vegetation type and distribution human activity and tectonic activity however the relationship between erosion and changes in these factors is difficult to constrain with current available approaches here we show that uranium isotopes in sediments from river paleochannels can be used to reconstruct variations in the residence time of sediments in a catchment over the past 100 k y we find that sediment residence times increase by an order of magnitude during interglacials compared to glacial periods this is interpreted as a change in sediment stores in the landscape that are tapped by catchment erosion young upland soils during glacial periods reworking of old alluvial sediments during interglacials a direct correlation is found between the sediment residence time and climatic parameters sea surface temperature atmospheric carbon dioxide content and paleorainfall estimates suggesting that during a glacial cycle sediment dynamics closely follow variations in climate however this relationship is not simple because there is no correlation between sediment residence time and paleodischarge estimates because sediment residence time variations correlate with changes in vegetation inferred from pollen data it is hypothesized that the influence of climate on erosion over a glacial cycle may be indirect and operates via the influence of climate on the type of plant ecosystems within a catchment if verified elsewhere this conclusion would emphasize the important role of biology in the physical evolution of earth s surface here observed over a 100 k y time scale

late quaternary sea surface conditions at dsdp hole 594 in the southwest pacific ocean based on dinoflagellate cyst assemblages investigation of organic walled dinoflagellate cyst distribution in 118 surface sediments from the southern ocean documents the relatively high diversity of cyst taxa 46 species and distinct cyst assemblages in relation to surface water masses and temperature gradient the antarctic water is characterised by the dominance of selenopemphix antarctica accompanied by brigantedinium spp and impagidinium pallidum the subantarctic water association consists mainly of nematosphaeropsis labyrinthus impagidinium paradoxum and impagidinium sphaericum whereas the subtropical water association is dominated by operculodinium centrocarpum and spiniferites membranaceus multivariate analyses non metric multidimensional scaling demonstrate the relationships with sea surface conditions and enable the application of the best analogue method on the southern ocean dinoflagellate cyst data base for reconstructing past sea surface conditions the dinoflagellate cyst record from dsdp 594 45 31 41 s 174 56 88 e 1204 m southern margin of the chatham rise shows important fluctuations in species composition from glacial to interglacial over the last 140 000 yr reconstruction of winter and summer ssts reveals much lower temperature than present by 6 to 10 c during marine oxygen isotope stages 6 4 and 2 and higher temperature by 2 3 c during substage 5e copyright 2001 john wiley sons ltd journal of quaternary science

climate and sea level during oxygen isotope stage 7b on land evidence from new zealand abstract strata at landguard bluff near wanganui new zealand preserve a clear record of relative sea level changes during oxygen isotope stage 7 two relative high sea level stands during stages 7a about 210 000 yr ago and 7c about 240 000 yr ago are separated by a relative low sea level stage 7b that was at least 32 m lower than present pollen analysis of sediment deposited during stage 7b indicates climate at the time was up to 3 c cooler than present the climate and sea level evidence from landguard bluff are consistent with oxygen isotopic evidence from deep sea cores indicating a marked cooling during stage 7 which is closely associated with a summer radiation minimum centered at about 230 000 yr ago in the northern hemisphere

the last glacial maximum lgm in western south island new zealand implications for the global lgm and mis 2 abstract the morainic and outwash deposits of the larrikins la and moana mn formations in north westland are correlated with the m5 t5 and m6 t6 deposits in south westland the la m5 deposits resulted from two separate otira glaciation glacial advances la 1 m5 1 la 2 m5 2 of essentially similar extents pollen sequences in peats and coverbeds extending from before to after the kawakawa tephra 26 500 cal yr bp indicate an extensive period of cold with a slight amelioration beginning shortly before tephra deposition this amelioration which is supported by interpretation of coverbed sequences in south westland separates the la 1 m5 1 and la 2 m5 2 advances the three westland glacial advances la 1 m5 1 la 2 m5 2 and mn m6 culminated at ca 28 000 21 500 and 19 000 cal yr bp the last being followed by major rapid glacier retreat pollen and caco 3 records from dsdp 594 east of the south island reflect contemporary glacier fluctuations on the east side of the southern alps they show the last major cold period as lasting from ca 34 000 to ca 16 000 years ago a period starting before the culmination of the la 1 m5 1 advance and ending later than the beginning of glacier retreat from the mn m6 advance the period from the la 1 m5 1 culmination to the mn m6 culmination represents the lgm in new zealand a slightly longer lgm is recorded in chile and a long lgm may also be indicated in australia a long lgm in the southern hemisphere is supported by the global sea level curve and by the regional antarctic temperature criteria of the vostok ice core these different records indicate a southern hemisphere lgm beginning at least as early as 27 000 years ago much earlier than the ocean last isotope maximum lim from 21 500 to 18 000 years ago the beginning of mis 2 defined primarily from deep sea benthic 18 o at 24 000 years is well after the beginning of ice advances leading to the southern hemisphere lgm a review of global land and ocean correlations is desirable

climate of the last glaciation in new zealand based on aerosolic quartz influx in an andesitic terrain abstract on western north island new zealand a record of climatic change during the last glaciation is preserved in a terrestrial coverbed sequence of dominantly andesitic provenance here a succession of five loess like andisol units postdates the global high sea level stand of oxygen isotope substage 5e

last interglacial beetle fauna from new zealand abstract fossil beetles from two last interglacial lake deposits from southern wairarapa central new zealand are provisionally ascribed to marine oxygen isotope stages mis 5a e both assemblages represent ecological successions from lake margins to forest the lower sample mis 5e is characterized by species found today in northern new zealand these species including lorelus crassicornis dasytes laticeps cryptobius nitidius stenomalium sulcithorax psilocnaeia nana and microbrontes lineatus represent a southward displacement from modern distributions by up to 700 km climate reconstruction indicates that temperatures at the time of deposition were 1 6 2 5 c warmer in the summer january and 2 3 3 2 c warmer in the winter july than at present these results match local and regional pollen and phytolith findings of warmer wetter conditions at the thermal maximum of the last interglaciation in contrast the upper sample is characterized by species that have widespread modern day distributions this indicates that modern conditions were attained later in mis5 after the mis 5e thermal maximum

preservation of the last aggradation phase in climate driven terraces evidence from late quaternary reach specific fluvial dynamics of the allier river france there is limited knowledge about the preservation of aggradation phases in quaternary fluvial records previous numerical modelling of erosion and deposition in late quaternary allier river france generated the prediction that this river has reach specific fluvial dynamics related to climate driven tributary sediment flux dynamics to test this prediction new optically stimulated luminescence osl samples were collected of the late quaternary fx terrace at five locations along a stretch of 60 km osl dates of both quartz and feldspar sand grains indicate that all relatively basalt poor sediments display significantly different ages for each reach ranging from 36 3 2 0 to 21 1 2 3 ka the more basalt rich terrace body consistently yields ages in the range 21 1 1 7 to 16 1 1 5 ka suggesting contemporaneous aggradation along the whole studied allier reach during this interval our own new osl date of a tartaret eruption around 16 8 2 5 ka also fits this time window suggesting a direct link with volcanic activity however there are many more dated volcanic events that coincide with the older basalt poor units making it less likely that a direct link between terrace sediment basalt content and volcanic activity exists the timings of the dated depositional events in mis 3 and 2 all match with simulated climate drivers and published landscape erosion rates counterintuitively the volcanic chaine des puys area supplied more sediment during the cold and dry last glacial maximum basalt content in the allier terrace sediments reflects climate related sediment flux dynamics upstream the scarcity of older basalt poor sediment bodies from mis 4 and 3 in the fx terrace suggests that less sediment was supplied and or the intermittent erosional phases in the allier were very effective at removing them we hypothesize that this observation of predominant preservation of the last aggradation phase could be a common phenomenon in most climate driven terraces 2020 the authors earth surface processes and landforms published by john wiley sons ltd

near synchroneity of new zealand alpine glaciations and northern hemisphere continental glaciations during the past 750 kyr 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

late pleistocene glacial stratigraphy of the kumara moana region west coast of south island new zealand abstract on the south island of new zealand large piedmont glaciers descended from an ice cap on the southern alps onto the coastal plain of the west coast during the late pleistocene the series of moraine belts and outwash plains left by the taramakau glacier are used as a type section for interpreting the glacial geology and timing of major climatic events of new zealand and also as a benchmark for comparison with the wider southern hemisphere in this paper we review the chronology of advances by the taramakau glacier during the last or otira glaciation using a combination of exposure dating using the cosmogenic nuclides 10 be and 36 cl and tephrochronology we document three distinct glacial maxima represented by the loopline larrikins and moana formations separated by brief interstadials we find that the loopline formation originally attributed to oxygen isotope chronozone 4 is much younger than previously thought with an advance culminating around 24 900 800 yr the widespread late pleistocene kawakawa oruanui tephra stratigraphically lies immediately above it this formation has the same age previously attributed to the older part of the larrikins formation dating of the larrikins formation demonstrates there is no longer a basis for subdividing it into older and younger phases with an advance lasting about 1000 years between 20 800 500 to 20 000 400 yr the moana formation represents the deposits of the last major advance of ice at 17 300 500 yr and is younger than expected based on limited previous dating the timing of major piedmont glaciation is restricted to between 25 000 and 17 000 yr and this interval corresponds to a time of regionally cold sea surface temperatures expansion of grasslands at the expense of forest on south island and hemisphere wide glaciation

age dating and the orbital theory of the ice ages development of a high resolution 0 to 300 000 year chronostratigraphy using the concept of orbital tuning a continuous high resolution deep sea chronostratigraphy has been developed spanning the last 300 000 yr the chronology is developed using a stacked oxygen isotope stratigraphy and four different orbital tuning approaches each of which is based upon a different assumption concerning the response of the orbital signal recorded in the data each approach yields a separate chronology the error measured by the standard deviation about the average of these four results which represents the best chronology has an average magnitude of only 2500 yr this small value indicates that the chronology produced is insensitive to the specific orbital tuning technique used excellent convergence between chronologies developed using each of five different paleoclimatological indicators from a single core is also obtained the resultant chronology is also insensitive to the specific indicator used the error associated with each tuning approach is estimated independently and propagated through to the average result the resulting error estimate is independent of that associated with the degree of convergence and has an average magnitude of 3500 yr in excellent agreement with the 2500 yr estimate transfer of the final chronology to the stacked record leads to an estimated error of 1500 yr thus the final chronology has an average error of 5000 yr