scholarly journals Palaeoenvironmental reconstructions during the Meso- to Neolithic transition (9.2–5.3 cal. ka BP) in Northwestern France: Palynological evidences

The Holocene ◽  
2018 ◽  
Vol 29 (3) ◽  
pp. 380-402 ◽  
Author(s):  
Clément Lambert ◽  
Muriel Vidal ◽  
Aurélie Penaud ◽  
Pascal Le Roy ◽  
Evelyne Goubert ◽  
...  
Keyword(s):  
Environmental Changes ◽  
Atlantic Coast ◽  
Pollen Grains ◽  
Cold Climate ◽  
Palynological Analysis ◽  
Neolithic Transition ◽  
The North ◽  
Bay Of Brest ◽  
River Valleys ◽  
Climate Events

Sedimentological, palynological, and micropalaeontological studies carried out throughout the first half of the Holocene, during the Mesolithic/Neolithic transition in the Bay of Brest (i.e. 9200–9000 and 6600–5300 cal. BP) and in the Bay of Douarnenez (i.e. 9200–8400 cal. BP), allowed characterizing coastal environmental changes under the increasing influence of the relative sea-level rise. The gradual flooding of the two studied sites implied a transition from river valleys to oceanic bays as revealed by the gradual retreat of salt marsh environments, as detected through palynological analysis. In addition, these high-resolution studies highlight the regional imprint of the North Atlantic millennial climate variability in north-western coastal environments. Two cold climate events are indeed suggested to have been locally marked by a moisture increase, mainly detected by increases in Lingulodinium machaerophorum, Corylus, and Alnus percentages at 8550 cal. BP in the Bay of Douarnenez and at 6250 cal. BP in the Bay of Brest. Moreover, regarding the Neolithic transition timing in the Bay of Douarnenez, large pollen grains of Poaceae (i.e. Cerealia-type pollen grains) have been detected at around 8600 cal. BP, that is, 1500 years before the general accepted cereal cropping appearance in Western France. These results, consistent with other palynological studies conducted in the French Atlantic coast, could underline a Mesolithic ‘proto-agriculture’ in Brittany.

scholarly journals Modern processes of palynomorph deposition at lakes of the northern region of the Rio de Janeiro State, Brazil

2010 ◽  
Vol 82 (3) ◽  
pp. 679-690 ◽  
Author(s):  
Cynthia F.P. da Luz ◽  
Ortrud M. Barth ◽  
Cleverson G. Silva
Keyword(s):  
Rio De Janeiro ◽  
Mechanical Damage ◽  
Pollen Grains ◽  
Northern Region ◽  
Palynological Analysis ◽  
The North ◽  
Pollen Types ◽  
Lake Bottom ◽  
Superficial Sediments ◽  
Janeiro State

Palynological analysis of pollen, Pteridophyta spores and algae deposited in the superficial sediments at Lagoa de Cima and Lagoa do Campelo Lakes, located in the north of Rio de Janeiro state, was used to determine the spatial variation of the palynomorphs deposition. A total of 67 pollen types were identified at Lagoa de Cima, with an expressive contribution of regional arboreous taxa, hydrophytes and ruderal plants of the pastureland. The depositional pattern of palynomorphs depends on the fluvial leakage, the proximity of the local sedimentation to the inlet of the Imbé and Urubu Rivers and the bathymetry of lake bottom. The highest concentrations of palynomorphs were observed in the decentralized and less deeper area, without the interference of the northeastern wind. At Lagoa do Campelo, a total of 58 pollen types were identified, among which the majority of the pollen grains came from hydrophytes, with the highest concentrations found along the northeastern shore. The southeastern shore showed high percentages of pollen and spores with degraded exine and mechanical damage, due to the transport through the lakeby the currents caused by the wind, confirmed by the depositional trend of damaged palinomorphs along the same direction as the prevailing winds.

Meadows of the North-Eastern Altai

2002 ◽  
pp. 22-31 ◽  
Author(s):  
T. V. Maltseva ◽  
N. I. Makunina
Keyword(s):  
Coniferous Forest ◽  
Wet Meadows ◽  
Abies Sibirica ◽  
Dark Coniferous Forest ◽  
Hay Meadows ◽  
The North ◽  
North Eastern ◽  
Humid Area ◽  
River Valleys

The North-Eastern Altai is an ultra-humid area with climax vegetation represented by tall-herb fir (Abies sibirica) dark-coniferous forest. Its meadows belong to the class Molinio-Arrhenatheretea. The typical asso­ciation Aegopodio podagrariae—Dactyletum glomeratae originates in the watershed clearings after climax forests whereas ass. Hyperici perforati—Agrostietum giganteaereplaces the previous one under mowing and grazing. The Molinietalia wet meadows are widespread in the river valleys. The meadows of ass. Cirsio heterophylli—Calama­grostietum langsdorffii occur on wet soils in small depressions and along floodplain mire margins, and ass. Ca­rici ovalis—Deschampsietum cespitosae comprises typical floodplain hay-meadows on moist, nutrient-rich soils.

scholarly journals Phylogeography in an “oyster” shell provides first insights into the genetic structure of an extinct Ostrea edulis population

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sarah Hayer ◽  
Dirk Brandis ◽  
Alexander Immel ◽  
Julian Susat ◽  
Montserrat Torres-Oliva ◽  
...  
Keyword(s):  
Large Scale ◽  
Wadden Sea ◽  
Atlantic Coast ◽  
Phylogenetic Reconstruction ◽  
Oyster Shell ◽  
Glacial Refugia ◽  
Late Nineteenth Century ◽  
Ostrea Edulis ◽  
Geographic Ranges ◽  
The North

AbstractThe historical phylogeography of Ostrea edulis was successfully depicted in its native range for the first time using ancient DNA methods on dry shells from museum collections. This research reconstructed the historical population structure of the European flat oyster across Europe in the 1870s—including the now extinct population in the Wadden Sea. In total, four haplogroups were identified with one haplogroup having a patchy distribution from the North Sea to the Atlantic coast of France. This irregular distribution could be the result of translocations. The other three haplogroups are restricted to narrow geographic ranges, which may indicate adaptation to local environmental conditions or geographical barriers to gene flow. The phylogenetic reconstruction of the four haplogroups suggests the signatures of glacial refugia and postglacial expansion. The comparison with present-day O. edulis populations revealed a temporally stable population genetic pattern over the past 150 years despite large-scale translocations. This historical phylogeographic reconstruction was able to discover an autochthonous population in the German and Danish Wadden Sea in the late nineteenth century, where O. edulis is extinct today. The genetic distinctiveness of a now-extinct population hints at a connection between the genetic background of O. edulis in the Wadden Sea and for its absence until today.

scholarly journals Striking forest revival at the end of the Roman Period in north-western Europe

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
C. Lambert ◽  
A. Penaud ◽  
M. Vidal ◽  
C. Gandini ◽  
L. Labeyrie ◽  
...  
Keyword(s):  
North Atlantic ◽  
Western Europe ◽  
Anthropogenic Activities ◽  
Sedimentary Environment ◽  
Pollen Grains ◽  
Roman Period ◽  
Freshwater Microalgae ◽  
Environmental Signals ◽  
The North ◽  
North Western

AbstractThe Holocene period (last 11,700 years BP) has been marked by significant climate variability over decadal to millennial timescales. The underlying mechanisms are still being debated, despite ocean–atmosphere–land connections put forward in many paleo-studies. Among the main drivers, involving a cluster of spectral signatures and shaping the climate of north-western Europe, are solar activity, the North Atlantic Oscillation (NAO) varying atmospheric regimes and North Atlantic oceanic gyre dynamics. Over the last 2500 years BP, paleo-environmental signals have been strongly affected by anthropogenic activities through deforestation and land use for crops, grazing, habitations, or access to resources. Palynological proxies (especially pollen grains and marine or freshwater microalgae) help to highlight such anthropogenic imprints over natural variability. Palynological analyses conducted in a macro-estuarine sedimentary environment of north-western France over the last 2500 years BP reveal a huge and atypical 300 year-long arboreal increase between 1700 and 1400 years BP (around 250 and 550 years AD) that we refer to as the ‘1.7–1.4 ka Arboreal Pollen rise event’ or ‘1.7–1.4 ka AP event’. Interestingly, the climatic 1700–1200 years BP interval coincides with evidence for the withdrawal of coastal societies in Brittany (NW France), in an unfavourable socio-economic context. We suggest that subpolar North Atlantic gyre strengthening and related increasing recurrence of storminess extremes may have affected long-term coastal anthropogenic trajectories resulting in a local collapse of coastal agrarian societies, partly forced by climatic degradation at the end of the Roman Period.

scholarly journals Environmental Changes and Cultural Transitions in SW Iberia during the Early-Mid Holocene

2021 ◽  
Vol 11 (8) ◽  
pp. 3580
Author(s):  
Cristina Val-Peón ◽  
Juan I. Santisteban ◽  
José A. López-Sáez ◽  
Gerd-Christian Weniger ◽  
Klaus Reicherter
Keyword(s):  
Dietary Habits ◽  
Environmental Changes ◽  
Source Area ◽  
Direct Access ◽  
Special Focus ◽  
Early Neolithic ◽  
Archaeological Data ◽  
Local Resources ◽  
Climate Events ◽  
The Impact

The SW coast of the Iberian Peninsula experiences a lack of palaeoenvironmental and archaeological data. With the aim to fill this gap, we contribute with a new palynological and geochemical dataset obtained from a sediment core drilled in the continental shelf of the Algarve coast. Archaeological data have been correlated with our multi-proxy dataset to understand how human groups adapted to environmental changes during the Early-Mid Holocene, with special focus on the Mesolithic to Neolithic transition. Vegetation trends indicate warm conditions at the onset of the Holocene followed by increased moisture and forest development ca. 10–7 ka BP, after which woodlands are progressively replaced by heaths. Peaks of aridity were identified at 8.2 and 7. 5 ka BP. Compositional, textural, redox state, and weathering of source area geochemical proxies indicates abrupt palaeoceanographic modifications and gradual terrestrial changes at 8.2 ka BP, while the 7.5 ka BP event mirrors a decrease in land moisture availability. Mesolithic sites are mainly composed of seasonal camps with direct access to the coast for the exploitation of local resources. This pattern extends into the Early Neolithic, when these sites coexist with seasonal and permanent occupations located in inland areas near rivers. Changes in settlement patterns and dietary habits may be influenced by changes in coastal environments caused by the sea-level rise and the impact of the 8.2 and 7.5 ka BP climate events.

Lake and inland dunes as interconnected Systems: The story of Lake Tresssee and an adjacent dune field (Schleswig-Holstein, North Germany)

The Holocene ◽  
2020 ◽  
pp. 095968362098168
Author(s):  
Christian Stolz ◽  
Magdalena Suchora ◽  
Irena A Pidek ◽  
Alexander Fülling
Keyword(s):  
Water Level ◽  
Bronze Age ◽  
Environmental Changes ◽  
High Water ◽  
Alluvial Fan ◽  
Water Levels ◽  
Lake Area ◽  
Dune Field ◽  
The North ◽  
Sand Drift

The specific aim of the study was to investigate how four adjacent geomorphological systems – a lake, a dune field, a small alluvial fan and a slope system – responded to the same impacts. Lake Tresssee is a shallow lake in the North of Germany (Schleswig-Holstein). During the Holocene, the lake’s water surface declined drastically, predominately as a consequence of human impact. The adjacent inland dune field shows several traces of former sand drift events. Using 30 new radiocarbon ages and the results of 16 OSL samples, this study aims to create a new timeline tracing the interaction between lake and dunes, as well, as how both the lake and the dunes reacted to environmental changes. The water level of the lake is presumed to have peaked during the period before the Younger Dryas (YD; start at 10.73 ka BC). After the Boreal period (OSL age 8050 ± 690 BC) the level must have undergone fluctuations triggered by climatic events and the first human influences. The last demonstrable high water level was during the Late Bronze Age (1003–844 cal. BC). The first to the 9th century AD saw slightly shrinking water levels, and more significant ones thereafter. In the 19th century, the lake area was artificially reduced to a minimum by the human population. In the dunes, a total of seven different phases of sand drift were demonstrated for the last 13,000 years. It is one of the most precisely dated inland-dune chronologies of Central Europe. The small alluvial fan took shape mainly between the 13th and 17th centuries AD. After 1700 cal. BC (Middle Bronze Age), and again during the sixth and seventh centuries AD, we find enhanced slope activity with the formation of Holocene colluvia.

Late Pleistocene and Holocene Paleoenvironments of Chalco Lake, Central Mexico

1993 ◽  
Vol 40 (3) ◽  
pp. 332-342 ◽  
Author(s):  
Maria Socorro Lozano-Garcı́a ◽  
Beatriz Ortega-Guerrero ◽  
Margarita Caballero-Miranda ◽  
Jaime Urrutia-Fucugauchi
Keyword(s):  
Volcanic Activity ◽  
Lake Level ◽  
Environmental Changes ◽  
Late Quaternary ◽  
Cold Climate ◽  
Central Mexico ◽  
Pollen Record ◽  
Loss On Ignition ◽  
Southeastern Part ◽  
Saline Marsh

AbstractIn order to establish paleoenvironmental conditions during the late Quaternary, four cores from the Basin of Mexico (central Mexico) were drilled in Chalco Lake, located in the southeastern part of the basin. The upper 8 m of two parallel cores were studied, using paleomagnetic, loss-on-ignition, pollen, and diatom analyses. Based on 11 14C ages, the analyzed record spans the last 19,000 14C yr B.P. Volcanic activity has affected microfossil abundances, both directly and indirectly, resulting in absence or reduction of pollen and diatom assemblages. Important volcanic activity took place between 19,000 and 15,000 yr B.P. when the lake was a shallow alkaline marsh and an increase of grassland pollen suggests a dry, cold climate. During this interval, abrupt environmental changes with increasing moisture occurred. From 15,000 until 12,500 yr B.P. the lake level increased and the pollen indicates wetter conditions. The highest lake level is registered from 12,500 to ca. 9000 yr B.P. The end of the Pleistocene is characterized by an increase in humidity. From 9000 until ca. 3000 yr B.P. Chalco Lake was a saline marsh and the pollen record indicates warmer conditions. After 3000 yr B.P. the lake level increased and human disturbance dominates the lacustrine record.

A Reinterpretation of the Microlithic Industries of Wales

1963 ◽  
Vol 29 ◽  
pp. 99-132 ◽  
Author(s):  
G. J. Wainwright
Keyword(s):  
Short Distance ◽  
The South ◽  
The West ◽  
The North ◽  
South Wales ◽  
North Wales ◽  
River Valleys

The distribution of Mesolithic sites in Wales is controlled to a great extent by the terrain, for physiographically, Wales is a highland block defined on three sides by the sea and for the greater part of the fourth side by a sharp break of slope. Geologically the Principality is composed almost entirely of Palaeozoic rocks, of which the 600-foot contour encloses more than three quarters of the total area. There are extensive regions above 1,500 feet and 2,000 feet and in the north the peaks of Snowdonia and Cader Idris rise to 3,560 feet and 2,929 feet respectively. Indeed North Wales consists of an inhospitable highland massif, skirted by a lowland plateau and cut deeply by river valleys, providing only limited areas for settlement. The hills and mountains of Snowdonia with their extension at lower altitudes into the Lleyn Peninsula, and the ranges of Moelwyn, Manod Mawr, Arenig Fach and Cader Idris, are discouraging obstacles to penetration, save for a short distance along the river valleys. To the east of these peaks are extensive tracts of upland plateau dissected by rivers, bounded on the west by the vale of the river Conway and cleft by the Vale of Clwyd. To the east of this valley lies the Clwydian Range and further again to the east these uplands descend with milder contours to the Cheshire and Shropshire plains.To the south the district merges into the uplands of Central Wales, which are continuous until they are replaced by the lowland belt of South Wales.

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