XI.—The Geology and Vegetation of Late-glacial Retreat Stages in Scotland

1958 ◽  
Vol 63 (2) ◽  
pp. 221-264 ◽  
Author(s):  
J. J. Donner
Keyword(s):  
North America ◽  
Lake Sediments ◽  
Late Glacial ◽  
Glacial Retreat ◽  
Second Stage ◽  
Pollen Diagrams ◽  
History Of ◽  
The Alps ◽  
Two Stages ◽  
Glacial Periods

SynopsisThe last major retreat stages of the ice in Scotland have been correlated with the different periods of vegetational history as shown by pollen diagrams. The end-moraines can be divided into two stages, the first stage being the Perth Readvance Moraine, during which the ice extended outside the Highlands. The Aberdeen Readvance Moraine probably also belongs to the same stage. During the second stage, here called the Highland Readvance, valley glaciers reached to the mouths of the Highland valleys where small moraine ridges were formed.Samples from mainly lake sediments near the moraine were studied, and the pollen diagrams from them show the general vegetational history of the Late-glacial and Post-glacial periods. The same zones as in other parts of the British Isles are used in the diagrams.The geological and pollen analytical evidence suggests that the Highland Readvance Moraine was formed during the Late-glacial Zone III, and that the Perth Readvance is older than the Alleröd interstadial. The Highland Readvance can now be correlated with the moraines in Scandinavia, the Alps and North America, where they already have been dated.

The interpretation of some post-Glacial vegetation diversities at different Lake District sites

1965 ◽  
Vol 161 (984) ◽  
pp. 310-323 ◽  
Keyword(s):  
Lake Sediments ◽  
Drainage Basin ◽  
Large River ◽  
Single Type ◽  
Lake District ◽  
Drainage Basins ◽  
Radiocarbon Dates ◽  
Pollen Diagrams ◽  
History Of ◽  
The Individual

The lake sediments which have been described by Mr Mackereth contain pollen and other plant remains which record the broad outlines of vegetational history. Many pollen diagrams are now available from the one ecologically homogeneous area of the central Lake District; their similarities record the effects of a single type of climate on an area of uniformly ancient rock, while their diversities record the individual history of each drainage basin. The large river valley lakes such as Windermere represent an integration of the many small drainage basins of which the river systems are made up; a simpler ecological picture is presented by the small lakes or tarns. Mackereth’s hypothesis, based on purely chemical evidence, that the lake sediments are derived from a series of soils washed in from the drainage basins, is supported by all the pollen evidence. Two deductions are made from this accepted assumption—first, that radiocarbon assay of the lake muds would be of comparatively little value, since the organic matter in any sample may have originated from a soil and be much older than its date of incorporation in the lake mud, and secondly that the presence of derived pollen from soils must be considered in interpretation of the pollen diagrams. The outline of the ecological history of the Lake District attempted here must therefore be built up by synthesis and comparison, but, as yet, in the absence of radiocarbon dates. The advantages of lake sediments for post-Glacial investigation—to set against their limitations—are that there is no overwhelming local pollen component as in fen or bog peats, and that stratigraphical changes in the sediments provide evidence for major changes in erosion rate, which can be correlated with vegetation changes shown in the pollen diagrams—as can chemical changes related to soil changes in the drainage basins.

Studies in the Post-glacial history of British vegetation XIV. Late-glacial deposits at Moss Lake, Liverpool

1959 ◽  
Vol 242 (689) ◽  
pp. 127-149 ◽  
Keyword(s):  
Late Glacial ◽  
Raised Bog ◽  
Stratigraphic Sequence ◽  
Day Range ◽  
Thermal Maximum ◽  
Lycopodium Annotinum ◽  
History Of ◽  
Identification Of Species ◽  
Glacial Periods ◽  
Fen Plants

Investigations of deposits at a built-over site near the centre of Liverpool disclose a basal stratigraphic sequence characteristic of the west-European Late-glacial period. Detailed pollen analyses confirm that the deposits extended from the Late-glacial (Zone I) to the Post-glacial thermal maximum (Zone VII a ). The lake was overgrown in Zone VI by floating sphagna , and in Zone VII a typical raised bog developed. Macroscopic remains of lake and fen plants were recovered in great abundance and together with frequent non-tree pollen these permitted a detailed reconstruction of the vegetational history of both the lake and the surrounding upland. Several species of notably disjunct or restricted present-day range have been recorded here, Cotoneaster cf. integerrima Medic., Elatine hexandra (Lapierre) D.C., Lycopodium annotinum L., Pilularia globulifera L., and Linum anglicum Mill., whilst tentative identification of species such as Agropyron junceiforme, A. & D. Löve, Gentiana campestris (L.), Lotus uliginosus Schkuhr, and Vicia sepium L. cast new light on the natural status of other British plants. Numerous further records confirm and extend our knowledge of the history of the British flora, especially in the Late-glacial and early Post-glacial periods.

XIX.—The Late-glacial History of the Highlands and Islands of Scotland

1955 ◽  
Vol 62 (3) ◽  
pp. 769-928 ◽  
Author(s):  
J. K. Charlesworth
Keyword(s):  
Late Glacial ◽  
Glacial Period ◽  
Glacial History ◽  
The West ◽  
Orkney Islands ◽  
Second Stage ◽  
Late Glacial Period ◽  
The North ◽  
Moray Firth ◽  
History Of

SynopsisFrom the abounding moraines, drainage features (fig. 21) and other marginal indications an attempt has been made to reconstruct the successive phases of the ice in its retreat into the corries of the Highlands and Islands (Pl. I). Two late-glacial stages are recognised. During the first, the Highland Glaciation, an ice-margin ran from the Orkney Islands across the mouth of the Moray Firth to the Buchan and out to sea north of Aberdeen. Twelve substages (A–L) of retreat, arbitrarily selected, have been traced through the country, except in the Moraineless West where they are unrepresented.At the maximum of the second stage, the Moraine Glaciation, the ice readvanced to the line stage M (beaded line in Pl. I). The retreat from this line, the inner boundary of the Moraineless West and of the 100-foot raised beach (Pl. I), is divided into nine substages (N–V), based upon a consideration of snowlines. Substage N corresponds to the 50-foot raised beach, substage P to an important readvance.The snowline throughout the late-glacial period ran in the west parallel with the meridians and rose eastwards. The disposition of the snowlines for stage M is given in fig. 22, p. 900.The distribution of the ice in the British Isles during the North British, Highland and Moraine Glaciations is represented in fig. 23, p. 923.

Joule, Mayer, and Others: A Decade-and-a-Half-Long Debate over Priority in the Discovery of the Mechanical Equivalent of Heat

2021 ◽  
Vol 42 (4) ◽  
pp. 609
Author(s):  
Boris Bulyubash
Keyword(s):  
Scientific Community ◽  
Second Stage ◽  
Mechanical Equivalent ◽  
Royal Institution ◽  
Private Correspondence ◽  
History Of ◽  
University Of Edinburgh ◽  
William Thomson ◽  
Two Stages ◽  
The University

This article reviews the history of a debate over priority in the discovery of the mechanical equivalent of heat that was centered around J. P. Joule and J. R. von Mayer. The following two stages may be distinguished in this debate. During the first stage, those involved in it were Joule and Mayer themselves. While Mayer presented a numerical value for the mechanical equivalent of heat, which was based on the data from Gay-Lussac’s experiment, Joule determined the value of this coefficient in his own experiment although he did it later than Mayer (actually, Joule was unaware of Gay-Lussac’s experiment). This article shows that, in the end, Joule and William Thomson, who also participated in the debate, recognized (even though formally and with reservations) Mayer’s priority. During the second stage of the debate, its participants were British scientists who supported Mayer or Joule. Thus, Mayer’s priority was supported by Professor J. Tyndall of the Royal Institution in London and it was he who initiated the resumption of the discussion. Joule’s priority was advocated by Professor W. Thomson of the University of Glasgow and Professor P. Tait of the University of Edinburgh. It is noted that a personal animosity between Tyndall and Tait, as well as Tyndall’s competitive attitude towards Thomson, had a significant impact on the tone of the debate, and the examples of Tait’s provocative remarks and Tyndall’s reactions are provided. Joule’s involvement during the second stage of the debate that was mostly limited to private correspondence between himself, Tait, Thomson, and Tyndall, is discussed. Over the time elapsed after the first stage of the debate, the level of rejection of Mayer’s arguments by the scientific community had decreased significantly. The awarding of the Royal Society’s Copley Medal to Joule (1870) and Mayer (1871), both of them nominated by Tyndall, came as a symbolic conclusion of the debate.

Chironomidae (Diptera) and Postglacial Climate at Marion Lake, British Columbia, Canada

1987 ◽  
Vol 27 (1) ◽  
pp. 89-102 ◽  
Author(s):  
Ian R. Walker ◽  
Rolf W. Mathewes
Keyword(s):  
British Columbia ◽  
North America ◽  
Lake Sediments ◽  
Sediment Core ◽  
Late Glacial ◽  
Pollen Data ◽  
The Holocene ◽  
Stratified Lakes ◽  
Chironomid Assemblages ◽  
Chironomid Community

AbstractChironomid (midge) remains analyzed from an 8.95-m-long sediment core from Marion Lake reveal successional changes over the last 12,000 yr since deglaciation. A late-glacial Heterotrissocladius-dominated association characterizes the earliest sediments. Succeeding this community, at the onset of the Holocene, is a Tanytarsini-dominated assemblage. The transition between these communities occurs during a time of rapid climatic amelioration, preceding an early Holocene xerothermic interval. The late-glacial fossil fauna is suggestive of more northerly affinities. Similar sequences have been reported in late-glacial lake sediments elsewhere in North America and in Europe. The composite picture of these chironomid assemblages suggests the gradual retreat of a formerly widely distributed, cold stenothermous fauna. The response of the chironomid community accords well with paleoclimatic inferences based on pollen data at the lake. Subsequent postglacial changes are less pronounced and most are probably attributable to the gradual shallowing of the basin. Chironomid remains from shallow, weakly stratified lakes may yield valuable paleoclimatological data.

Late Quaternary Vegetation of Southern Isla Grande De Chiloé, Chile

1988 ◽  
Vol 29 (3) ◽  
pp. 294-306 ◽  
Author(s):  
Carolina Villagran
Keyword(s):  
Climatic Change ◽  
Pollen Analysis ◽  
Tree Species ◽  
Late Quaternary ◽  
Late Glacial ◽  
Pollen Diagrams ◽  
History Of ◽  
Valdivian Forest ◽  
Nothofagus Dombeyi ◽  
Pollen Records

Late-glacial-Holocene forest history of southern Isla Chiloé (latitude 43°10′ S) was reconstructed on the basis of pollen analysis in three profiles (Laguna Soledad, Laguna Chaiguata, Puerto Carmen). Prior to 12,500 yr B.P. pollen records are dominated by plant taxa characteristic of open habitats (Zone I). From 12,500 yr B.P. to the present, tree species predominate in the pollen records (Zones II–V). Between 12,500 and 9500 yr B.P. ombrophyllous taxa (Nothofagus, Podocarpus nubigena. Myrtaceae, Fitzroya/Pilgerodendron, and Drimys) are frequent in all pollen diagrams, suggesting a wetter and colder climate than the present. Between 9000 and 5500 yr B.P. Valdivian forest elements, such as Nothofagus dombeyi type, Weinmannia, and Eucryphia/Caldcluvia, dominate, indicating a period of drier and warmer climate. From 5500 yr B.P. onward, the expansion of mixed North Patagonian-Subantarctic forest elements and the increased frequence of Tepualia suggest increased rainfall and temperatures oscillating around the modern values.The change from open to forest vegetation (ca. 12,500 yr B.P.) probably represents the most pronounced climatic change in the record and can be interpreted as the glacial-postglacial transition in the study area.

Quaternary Vegetation History of the Mississippi Embayment,

1980 ◽  
Vol 13 (1) ◽  
pp. 111-132 ◽  
Author(s):  
Paul A. Delcourt ◽  
Hazel R. Delcourt ◽  
Ronald C. Brister ◽  
Laurence E. Lackey
Keyword(s):  
North America ◽  
Vegetation History ◽  
Deciduous Forest ◽  
Late Glacial ◽  
Eastern North America ◽  
Mississippi Valley ◽  
Yellow Poplar ◽  
Mississippi Embayment ◽  
Creek Watershed ◽  
History Of

AbstractNonconnah Creek, located in the loess-mantled Blufflands along the eastern wall of the Lower Mississippi Alluvial Valley in Tennessee displays a sedimentary sequence representing the Altonian Substage through the Woodfordian Substage of the Wisconsinan Stage. The site has a biostratigraphic record for the Altonian and Farmdalian Substages that documents warm-temperate upland oak-pine forest, prairie, and bottomland forest. At 23,000 yr B.P., white spruce and larch migrated into the Nonconnah Creek watershed and along braided-stream surfaces in the Mississippi Valley as far as southeastern Louisiana. The pollen and plant-macrofossil record from Nonconnah Creek provides the first documentation of a full-glacial locality in eastern North America for beech, yellow poplar, oak, history, black walnut, and other mesic deciduous forest taxa. During the full and late glacial, the Mississippi Valley was a barrier to the migration of pine species, while the adjacent Blufflands provided a refuge for mesic deciduous forest taxa. Regional climatic amelioration, beginning about 16,500 yr B.P., is reflected by increases in pollen percentages of cooltemperate deciduous trees at Nonconnah Creek. The demise of spruce and jack pine occurred 12,500 yr B.P. between 34° and 37° N in eastern North America in response to postglacial warming.

scholarly journals Studies of the post-Glacial History of British vegetation VII. Lake sediments: Pollen diagrams from the bottom deposits of the North Basin of Windermere

1947 ◽  
Vol 233 (596) ◽  
pp. 137-175 ◽  
Keyword(s):  
Deep Water ◽  
Late Glacial ◽  
Birch Wood ◽  
Glacial History ◽  
The North ◽  
Bottom Deposits ◽  
Pollen Diagrams ◽  
Plant Remains ◽  
Glacial Clay ◽  
History Of

Eight pollen diagrams from cores lying approximately on an east to west transect across the North Basin of Windermere and macroscopic plant remains identified from these cores are described and figured. The marginal cores show a well-developed late-glacial succession of two layers of barren laminated glacial clay, separated by a detritus silt containing plant remains which indicate a cold-temperate birch wood flora; it is suggested that this succession may be correlated with the Upper and Lower Dryas clays separated by the cold-temperate Allerod layer of Continental authors. The post-glacial deposits, which are most completely represented in the deep-water cores, show similar phases of forest history to those already recognized in England and Wales, but the apparent over-representation of Pinus in deep-water deposits and the absence of Fagus and Carpinus introduce complications into any attempt to apply to these deposits the zonation scheme worked out for the East Anglian fenland.

scholarly journals STUDY OF THE HOLOCENE STAGE OF FORMATION OF THE DNIESTER VALLEY IN THE EASTERN CARPATHIAN FORELAND

2020 ◽  
pp. 118-139
Author(s):  
Andriy Yatsyshyn ◽  
Piotr Gębica
Keyword(s):  
Cross Sections ◽  
Radiocarbon Dating ◽  
Large Scale ◽  
Alluvial Deposits ◽  
The Holocene ◽  
Meandering Channel ◽  
Pollen Diagrams ◽  
Human Economic Activity ◽  
History Of ◽  
Two Stages

The article describes the main stages of studying of the floodplain and the first floodplain terrace of the Dniester river within the Eastern Carpathian Foreland fragment of the valley, and evaluates the results of existing studies. It is discovered that during all the stages of the research morphological and morphometric parameters of the floodplain and the first floodplain terrace of the Dniester river, morphology and facie structures of the alluvial accumulations, as well as palynological analyses of biogenic accumulations buried in an alluvial series are performed. The results obtained during the palynological analyzes are used to date the erosion-accumulation cycles and to reconstruct the physical-geographical conditions of the time of the floodplain and the first floodplain formation of the Dniester terrace. The radiocarbon dating of biogenic sediments buried in alluvial series is also actively conducted at the last stage of the research. The array of geological and geomorphological information collected at the first two stages of research made it possible to establish that, first, the first floodplain terrace and floodplain were formed during the Holocene in the Dniester Valley. The first floodplain terrace (the height of which reaches 4–6 m above the Dniester riverbed) can be considered as a high floodplain which is often covered by high floods. The terrace is accumulative, but unlike all other terraces of the Dniester it is devoid of the loess cover. In the cross-sections of its accumulations the deposits of the alluvium of the channel facies builted of pebbles are exposed and covered with the alluvium of the floodplain facies composed of sands, sandy loams and loams. The total thickness of alluvium reaches 9–10 m and it doesn’t varysignificantly downstream of the Dniester. Except the Upper Dniester basin, where the thickness of the alluvium increases to 10–18 m, and the layers of peat are found. The floodplain is 4–5 m above the Dniester riverbed and is built of alluvium of the channel facies, dominated by sand and pebble series. In someplaces floodplain is covered with sandy or loamy deposits of floodplain facies. Secondly, in the Eastern Carpathian Foreland part of the Dniester valley the course of fluvial morpholitogenetic processes was regulated not only by climatic changes and neotectonic movements, but also by human economic activity. During the XIX–XX centuries especially large-scale human influence was on the Dniester riverbeds by construction of flood ramparts, reclamation canals, etc. The results of recent geomorphological research conducted within the studied fragment of the river valley particularly palynological and radiocarbon dating have significantly improved the idea of morphology, structure and history of floodplain formation and the first floodplain terrace of the Dniester. The research revealed that the accumulation of alluvium of the first floodplain terrace which is above the Dniester riverbed reaches 5,5–6,5 (7) m and started to develop in the late Pleistocene (Bølling–Allerød interstadial) (13 000–11 000 years ago (GI–1)). Presumably in the early Dryas (11 000–10 000 years ago (GS–1)), the first floodplain terrace was dissected by the meandering channel of the Dniester. The alluvial deposits that fill these large paleomeanders are still well preserved and are often exposed in the ledges of the first terrace. The further development of the floodplain and first floodplain terrace of the Dniester river was taking place in several stages such as the end of the boreal, the beginning of the atlantic, the end of the atlantic, subboreal, the beginning of the subatlantic, as well as during V–VI, X–XII and XIV–XVI centuries. These stages are identified in correlation with the cycles of humidification of the climate and the growth of fluvial activity of riverbeds (flood phases). As a result of the intensification of erosion-accumulation activity of the Dniester the two – three levels of Holocene floodplain were formed up to 4–5 m and 3–4 m high. The first traces of human activity within the studied fragment of the Dniester valley were dated by subboreal and recorded by the presence of grain pollen in the spore-pollen diagrams of Mainych (Upper Dniester Basin) and Tsvitova (Galician-Bukachiv Basin) sections. Key words: Dniester valley; floodplain; the first floodplain terrace; alluvium; phases of floods; Allerød; early Dryas; Holocene.

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