bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lubbock Lake: Late Quaternary cultural and environmental change on the Southern High Plains, USA
Authors: Johnson Eileen , Holliday Vance T. 
Published: February 2007

AbstractLubbock Lake (Southern High Plains of Texas) contains a cultural, faunal, and floral record within a virtually complete geological record spanning the past 11 100+ years. More than 88 archaeological occurrences have been excavated from five major stratigraphic units. The Paleoindian record (11 500–6500yr BP) begins with Clovis‐age occupation (ca. 11 100yr BP) found within fluvial deposits (stratum 1). Subsequent Paleoindian occupations are found in lake and marsh sediments (stratum 2). Archaic occupations (8500‐2000yr BP) are contained within aeolian and marsh deposits (strata 3 and 4). Ceramic occupations (2000‐500yr BP) are found on a soil developed in stratum 4, in marsh sediments (strata 4 and 5), and in slopewash and aeolian sediments (stratum 5). The Protohistoric (500‐300yr BP) and Historic (300‐100yr BP) remains are in slopewash, aeolian, and marsh sediments (stratum 5) and associated soils. The Southern High Plains remained a grasslands throughout the last 11 500 years and neither man nor bison abandoned the region. The successive local faunas reflect changing ecosystems under pluvial to arid to more mesic to semiarid conditions. The occupation of Lubbock Lake through time appears to have been by small groups of people for both economic and short‐term residential uses. These hunter‐gatherer peoples underwent adaptive change brought about by climatic stress and alterations to food resources.
The Late Devensian glaciation along the western margin of the Cheshire‐Shroshire Iowland
Authors: Thomas Geoffrey S. P. 
Published: February 2007

AbstractThe glacial succession in the western part of the Cheshire‐Shropshire lowland records the advance, coalescence and subsequent uncoupling of Irish Sea and Welsh ice‐sheets during the Late Devensian stage. During advance a discontinuous sheet of basal till was emplaced across the floor of the region by subglacial lodgement. On retreat, compression of the Irish Sea ice sheet against bedrock obstruction generated a zone of supraglacial sedimentation resulting in the creation of the Wrexham‐Ellesmere‐Wem‐Whitchurch moraine system, and the formation of a wide range of sedimentary environments, including ice‐marginal sandur troughs, ice‐front alluvial fans, proglacial ribbon sandur, and subglacial, ice‐contact and proglacial lakes. The geometry of sedimentary units, and their lithologic and geomorphic characteristics, display spatially ordered patterns of sediment‐landform assemblage which show that the statigraphic succession is a response to rapidly changing depositional conditions at a retreating supraglacial ice‐margin punctuated by minor still‐stands and ice‐front oscillations.
Evidence of climatic change from oxygen and carbon isotope variations in sediments of a small arctic lake, Canada
Authors: Michel F. A. , Fritz P. , Drimmie R. J. 
Published: February 2007

AbstractRadiocarbon dating of the organic‐rich sediments of Lake Illisarvik in the outer Mackenzie Delta indicates that formation of the lake occurred approximately 9500yr BP, with maximum expansion around 6000 yr BP. Sedimentation rates have remained relatively constant at an average of 0.3mm/yr.13C results on biogenic and inorganic carbonates and organics indicate a change from dominantly terrestrial organics (−27 to −28%0) to submerged aquatic vegetation or plankton (−18 to −23%0) upon formation of the lake (9500yr BP), and a dramatic return to dominantly terrestrial organics at 5800yr BP (δ13C = −27 to −30%0). This latter shift is accompanied by a drastic reduction in the macroflora and fauna populations. 18O results suggest that a warmer climate than today existed prior to the shift at 5800yr BP.
Late Weichselian vegetation, climate, and floral migration at Liastemmen, North Rogaland, south‐western Norway
Authors: Paus Aage 
Published: February 2007

AbstractPalynological results from Liastemmen indicate a tripartite division of the Late Weichselian. In the pleniglacial period, from deglaciation ca. 14000 BP to ca. 13000 BP,Artemisia‐dominated pioneer vegetation on disturbed, mineral‐soil was strongly influenced by cold winters and katabatic winds. The Late Weichselian Interstadial (ca. 13000 BP‐ca. 11000 BP) comprises aSalix‐shrub consolidation phase, and from ca. 12700 BP a tree‐birch phase. In the last 500 years of this period July and January means are estimated to about 16°C and between −2°C and −6°C, respectively. In the Younger Dryas Stadial (ca. 11000 BP‐ca. 10200 BP)Artemisia‐dominated vegetation returns. Three brief climatic deteriorations (ca. 12 250 BP, 11 700 BP, and 11 300 BP), unfavourable to woody vegetation on humus soils, are demonstrated within the interstadial. Critical climatic factors include cool winters and strong winds, exposing vegetation and soil to frost, drought, and erosion. The oldest and strongest oscillation, probably involving local deforestation, is correlated with the ‘Older Dryas deterioration’. Boreal‐circumpolar, eurasiatic, and arctic‐alpine plants dominated the late‐glacial flora. For the majority of the late‐glacial taxa a northward migration is demonstrated. This may also apply forPapaver radicatum, Pinguicula alpina, andPrimula scandinavica, all with bicentric distributions in Norway today.
The origin of deep buried channels of Elsterian age in Northwest Germany
Authors: Ehlers Jürgen , Linke Gerhard 
Published: February 2007

AbstractBuried channels cut to a depth of over 100m into the underlying substratum of North Germany are almost exclusively of Elsterian age. Evaluation of geophysical well logs in the Hamburg area for the first time allows the construction of detailed longitudinal and transverse profiles. It can be shown that an apparently chaotic infill known from borehole records in some cases is actually a regular sedimentary sequence, fining from proximal to distal. Channel formation seems to have been the result of catastrophic meltwater release in the marginal parts of the ice sheet. The channel infill reflects these episodic outbursts of meltwater. During deglaciation, the channel remnants became infilled with fine sediments. The channels ceased to exist as morphologically detectable forms at the end of the Holsteinian Stage.
Middle Pleistocene glacial stratigraphy at Baxter Rivulet, western Tasmania, Australia
Authors: Fitzsimons Sean J. , Colhoun Eric A. , Van De Geer Guus 
Published: February 2007

AbstractMapping, analysis and interpretation of glacigenic sediments in the King Valley, Tasmania has led to a revision of the Pleistocene stratigraphy of Tasmania. The sediments provide evidence of a glaciation that occurred between the Middle Pleistocene Henty Glaciation and the Early Pleistocene Linda Glaciation. TheMoore Glaciationis estimated, on the basis of weathering rinds, amino‐acid dating and palaeomagnetism to have occurred between 400000 and 550000 yrs BP. At Baxter Rivulet, sediments of the Moore Glaciation rest unconformably on highly weathered till and weathered Ordovician limestone and are overlain by outwash gravel of the Henty Glaciation. The Moore Glaciation sediments can be divided into four formations on the basis of lithology, organic content and degree of chemical weathering. The Huxley Formation (oldest) was deposited by an ice advance of the Mt. Jukes Glacier and is overlain by the Baxter Formation. The Baxter Formation consists of a bed of organic silty sand which records a cool non‐forested flora of an interstadial period. The overlying Pyramid and Moore formations are outwash gravels from the Mt. Jukes and King Valley glaciers respectively. Though deposited during the same general ice advance, these two gravels were deposited at different times and show that the glaciers of the West Coast Range had spatially differentiated responses to climatic change.
Holocene floodplain diachronism and inherited downstream variations in fluvial processes: A study of the river Perry, Shropshire, England
Authors: Brown Antony G. 
Published: February 2007

AbstractThis paper attempts to explain downstream variations in the rates and processes of Holocene floodplain formation in a small to medium‐sized, lowland catchment in Central England. Four macro‐reaches were identified and horizons from at least one stratigraphic cross‐section from each were radiocarbon dated. Considerable diachronism was revealed with the basal age and hence minimum residence time of the top two metres varying from 1000‐9000yrs. The trend, a decrease in minimum residence time downstream, is explained by the basin‐and‐gorge bedrock long‐profile inherited from the Devensian glaciation of the area. This is illustrated by a positive relationship between the mean floodplain accumulation rate and the SL index (slope‐stream length product). Pollen analysis of the organic sediments shows that floodplain clearance took place around 1 300 BP, but probably locally, pre‐dated and post‐dated accelerated alluviation associated with agricultural expansion in the catchment. This study concludes that (a) different macro‐reaches in this small to medium‐sized catchment have adjusted in different ways to long‐term catchment changes as part of autogenic floodplain evolution, (b) this has involved a change in the catchment's sediment conveyance characteristics during the Holocene, and (c) an important control on channel behaviour and floodplain sedimentation throughout the Holocene (as well as at present) has been the valley slopes inherited from the Quaternary glaciation of the area.
Neoglacial chronology and floristics in the Middle Teton area, central Teton Range, Western Wyoming
Authors: Mahaney William C. , Spence John R. 
Published: February 2007

AbstractThe relative ages of Neogfacial deposits above 2900m near Cloudveil Dome, Middle Teton, and Teepe glaciers, central Teton Range, western Wyoming, were determined using topographic position, weathering features, lichenometry, vegetation characteristics, and soils. A three‐fold deposit sequence is identified and correlated with the Gannett Peak, Audubon and Indian Basin Neoglacial advances described elsewhere in the Teton and nearby Wind River ranges. While soil profile morphology proved very useful in distinguishing deposits of different age, other age indicators such as clay mineralogy and soil chemistry, proved of only marginal value in age discrimination. This chronosequence, emplaced over the last ∼5000yr, provides an excellent setting upon which to test changes in plant species composition and its use as a relative dating method.Vascular plant species composition cannot be used to discriminate deposits of the different advances, possibly because of random colonisation and establishment combined with extensive mass wasting during the Neoglacial. However, certain vegetation features, such as total cover and species densities, appear useful as relative dating methods.
Postglacial history of alder (Alnus glutinosa (L.) Gaertn.) in the British Isles
Authors: Bennett Keith David , Birks H. John B. 
Published: February 2007

AbstractData from 92 postglacial pollen sequences are used to map the spread and increase of alder (Alnus glutinosa) across the British Isles between 9000 and 5000 years ago. The spread is found to be patchy and erratic in space and time. Consideration of the habitat requirements and reproductive ecology of alder suggest that it spread within Britain and Ireland after about 10 000 yr BP, when suitable habitat for it was scarce. Alder spread across most of Britain and Ireland early in the postglacial but only increased in abundance as (i) suitable habitat became available through changing sea levels, hydroseral successions, and floodplain development, and as (ii) rare weather events produced the necessary conditions for reproduction. Alder is unique among British and Irish trees in its requirement for a suitable habitat isolated among expanses of unsuitable habitats. Because of this, maps of its postglacial population spread and increase do not show the spatial coherence of maps for other forest tree taxa.
Radiocarbon dating the Devensian Lateglacial in Britain: New evidence from Llanilid, South Wales
Authors: Walker M. J. C. , Nerc D. D. Harkness 
Published: February 2007

AbstractRadiocarbon dates are described from a section through Lateglacial and early Flandrian sediments at Llanilid, Mid‐Glamorgan, South Wales. Comparisons between age determinations on the alkali soluble (humic) and alkali insoluble (humin) organic fractions from 12 biostratigraphic horizons reveal the extent of contamination by both older and younger carbon residues. The Llanilid time‐scale suggests that for the Lateglacial, the earliest organic sediments date from around 13 200 yr BP, the early Interstadial Juniperus maximum occurred at ca. 12 400‐12 500 yr BP with a marked decline some 200 years later, the main Betula phase lasted only from ca. 11 700 to 11 400 yr BP and the end of the Interstadial occurred around 11 100 yr BP. The beginning of the Flandrian dates from ca. 10 000 yr BP, the Juniperus maximum occurred approximately 200 years later, the expansion of birch woodland began around 9600 yr BP, while the first hazel arrived in the area at ca. 9300 yr BP. These age determinations are discussed in the context of radiocarbon dates from comparable biostratigraphic horizons in western Britain and the dating of Lateglacial events in the ocean core records from the North Atlantic.
Holocene environmental change in South Georgia: Evidence from lake sediments
Authors: Birnie Jacqueline 
Published: February 2007

AbstractThe Holocene environmental history of South Georgia is important because of the island's location in the Southern Westerlies in an oceanic zone of the world devoid of high resolution terrestrial records. This is the first attempt to interpret a palaeoenvironmental record from lake sediments in South Georgia. It is based on a wide variety of analyses undertaken on cores from two lakes. Both are in the same, unglaciated, drainage basin, but one is at 80 m above sea‐level and near the altitudinal limit for vegetation growth, whereas the other is at 25 m and within the zone of continuous vegetation cover. Results from both lakes indicate shifts of vegetation boundaries, which, together with evidence for changing biotic productivity within the lakes themselves, are interpreted as indicating climatic changes. Radiocarbon dates on the main changes identify a climatic optimum, beginning before 5620 ± 290 14C yr BP, and ending at around 4815 ± 330 14C yr BP, when conditions in the upper part of the catchment were more conducive to plant growth than they are today. The record obtained from the lower lake was shorter, but indicates two periods of harsher climate relative to the present since 4000 yr BP. This interpretation of the lake evidence agrees with other dated evidence of environmental change from peat sections, glacial stratigraphy and geomorphology in South Georgia. Together the work allows an overall reconstruction of environmental change in the Holocene.
Autochthonous block fields in southern Norway: Implications for the geometry, thickness, and isostatic loading of the Late Weichselian Scandinavian ice sheet
Authors: Nesje Atle , Dahl Svein Olaf 
Published: February 2007

AbstractThe consistent geographical and altitudinal distribution of autochthonous block fields (mantle of bedrock weatheredin situ) and trimlines in southern Norway suggests a multi‐domed and asymmetric Late Weichselian ice sheet. Low‐gradient ice‐sheet profiles in the southern Baltic region, in the North Sea, and along the outer fjord areas of southern Norway, are best explained by movement of ice on a bed of deforming sediment, although water lubricated sliding or a combination of the two, may not be excluded. The ice‐thickness distribution of the Late Weichselian Scandinavian ice sheet is not in correspondence with the modern uplift pattern of Fennoscandia. Early Holocene crustal rebound was apparently determined by an exponential, glacio‐isostatic rise. Later, however, crustal movements appear to have been dominated by large‐scale tectonic uplift of the Fennoscandian Shield, centred on the Gulf of Bothnia, the region of maximum lithosphere thickness.
A palaeomagnetic and mineral magnetic study of the loess sequence at Liujiapo, Xian, China
Authors: Thistlewood Laurence , Jianzhong Sun 
Published: February 2007

AbstractEmploying an average vertical sampling interval of 20 cm, oriented samples were collected from 26 m of the loess section at Liujiapo, near Xian, China in order to refine the existing magnetostratigraphic record. Palaeomagnetic results reveal two short reversed‐polarity subzones within a profile of predominantly normally magnetised sediments, an interpretation that is at variance with previous results from this section and from other studies of Chinese loess. Investigation of sediment mineral‐magnetic properties indicates a close correspondence between down‐section variations in intensity of magnetisation, susceptibility and saturation isothermal Journal of Quaternary Science remanence (SIRM), and lithology. The ratios IRM‐100mT/SIRM and SIRM/ susceptibility appear to be particularly sensitive indicators of the degree of soil development and hence of palaeoclimate.
Distribution and provenance of the Baginton Sand and Gravel in the Wreake Valley, northern Leicestershire, England: Implications for inter‐regional correlation
Authors: Rice John 
Published: February 2007

AbstractThe Baginton Sand and Gravel is traced along the lower Wreake Valley as a continuous water‐laid stratum at the base of the drift succession. Its properties closely resemble those previously described from the proto‐Soar valley, namely an upward fining sequence and a composition dominated by pebbles of Triassic and Carboniferous origin. Such a provenance is consistent with the idea that the proto‐Soar once followed a route eastwards past Melton Mowbray, and that the drainage along the lower Wreake Valley has been reversed in the course of Pleistocene times. However, the slope of the sand and gravel train appears to be to the west rather than the east, and the rockhead relief is also inconsistent with an eastward‐flowing proto‐Soar. Until this enigma is resolved, it would be imprudent to use the Baginton Sand and Gravel as the basis for inter‐regional correlations. The issue is further complicated by the preservation at Brooksby of earlier interglacial or interstadial deposits whose temporal affinities remain unclear.
The Balderton Sand and Gravel: Pre‐Ipswichian cold stage fluvial deposits near Lincoln, England
Authors: Brandon Allan , Sumbler Michael G. 
Published: February 2007

AbstractThe Balderton Terrace marks a former course of the River Trent between Newark and the Lincoln Gap. The principal deposit, the Balderton Sand and Gravel, is interpreted as a braided river sediment. Ice wedge casts truncated by intraformational erosion surfaces at many levels indicate syndepositional permafrost. Remnant cover deposits overlying the Balderton Sand and Gravel include the partly aeolian Whisby Sand. Locally, both the upper part of the Balderton Sand and Gravel and the cover deposits exhibit features indicative of temperate climate pedogenesis. All these deposits are affected by subsequent cryoturbation. On the basis of these features and the geomorphological and topographical relationship to other terrace deposits of the area, the Balderton Sand and Gravel and Whisby Sand are regarded as post‐Hoxnian and pre‐lpswichian, i.e. Wolstonian. Electron spin resonance age determinations for fossil elephant teeth and amino acid analyses on molluscs from the Balderton Sand and Gravel suggest correlation with Oxygen Isotope Stage 6. The Balderton Sand and Gravel has yielded a cold‐climate mammalian fauna dominated by woolly mammoth and woolly rhinoceros, though rarer species suggest periods of milder climate. Silts from channels near the base of the deposit have produced pollen, mollusc, ostracod and beetle assemblages also indicating a cold climate.
A pre‐Ipswichian cold stage mammalian fauna from the Balderton Sand and Gravel, Lincolnshire, England
Authors: Lister Adrian M. , Brandon Allan 
Published: February 2007

AbstractThe Balderton Sand and Gravel has yielded one of very few mammalian faunas dated to the penultimate Cold Stage in Britain. The assemblage is dominated by mammoth and woolly rhinoceros, with subordinate horse, red deer, bison, straight‐tusked elephant, musk ox, reindeer, wolf, lion, brown bear and cf. narrow‐nosed rhinoceros. This fauna indicates cold stage conditions, probably including one or more interstadial episodes. The presence of straight‐tusked elephant and cf. narrow‐nosed rhinoceros supports its pre‐Devensian age, and provides corroboration for the occurrence of these taxa in the British Wolstonian. An attempt is made to analyse the fossil collection by preservation type and adhering sediment: the occurrence of individual species appears to be largely uncorrelated with lithology. The Balderton assemblage corresponds well to other British mammal faunas assigned to a cold interval between the Hoxnian and Ipswichian Interglacials.
Holocene vegetation and volcanic activity, Auckland Isthmus, New Zealand
Authors: Newnham Rewi M. , Lowe David J. 
Published: February 2007

AbstractA 12 000 to 4000 yr BP pollen and tephra‐bearing profile from Auckland, New Zealand, provides insights into the vegetation history and evidence for early Holocene volcanic activity in this area centred on the Mount Wellington basaltic volcano. Possibly 500 yr separated initial scoriaceous ash deposition (ca. 9500 yr ago) and subsequent major lava flows (ca. 9000 yr ago) from Mount Wellington. The local vegelation, topography, and drainage patterns were substantially modified during this time, and damming by the lava flows resulted in the formation of Lake Waiatarua in a shallow valley head ca. 9000 yr ago. Diatom evidence indicates that this lake was initially deep (> 5 m) but was shallowing around 4000 yr ago. In contrast to the Mount Wellington eruptions, tephra deposition resulting from distant rhyolitic volcanic activity of the central North Island and Mayor Island has had little effect on the Auckland vegetation during this time interval (12 000–4000 yr ago).Between ca. 12 000 and 10 000 yr ago, conifer‐angiosperm forest was the predominant vegetation cover on Auckland Isthmus, but during the early Holocene, forest dominated by Metrosideros expanded, probably on to fresh volcanic surfaces resulting from the Mount Wellington eruptions. At this time, swamp forest communities developed in Waiatarua valley basin, and included species indicative of moist, mild, relatively frost‐free climates. Some taxa show histories consistent with other records from the northern New Zealand region, including the rise of Ascarina lucida ca. 11 000 to 9000 yr ago, and its subsequent decline, and the expansion of Agathis australis (kauri) forest communities from ca. 6000 yr ago. Taken together the history of local and regional vegetation points to a mild, moist and weakly seasonal early Holocene climate, which subsequently became drier with greater seasonal temperature extremes.