Exceptionally well-preserved giant spermatozoa in male and female specimens of an ostracod Cypria ophtalmica (Crustacea: Ostracoda) from Late Glacial lacustrine sediments of Southern Carpathians, Romania

2012 ◽  
Vol 99 (7) ◽  
pp. 587-590 ◽  
Author(s):  
Sanda Iepure ◽  
Tadeusz Namiotko ◽  
Antonio G. Valdecasas ◽  
Enikö K. Magyari
Keyword(s):  
Lacustrine Sediments ◽  
Late Glacial ◽  
Male And Female ◽  
Giant Spermatozoa ◽  
Southern Carpathians

A Record of Holocene Climate Change from Lake Geochemical Analyses in Southeastern Arabia

2006 ◽  
Vol 66 (3) ◽  
pp. 465-476 ◽  
Author(s):  
Adrian G. Parker ◽  
Andrew S. Goudie ◽  
Stephen Stokes ◽  
Kevin White ◽  
Martin J. Hodson ◽  
...  
Keyword(s):  
North Atlantic ◽  
Lake Level ◽  
Lacustrine Sediments ◽  
Summer Rainfall ◽  
Late Glacial ◽  
Human Occupation ◽  
The North ◽  
Holocene Climate Change ◽  
The North Atlantic ◽  
Geochemical Analyses

AbstractLacustrine sediments from southeastern Arabia reveal variations in lake level corresponding to changes in the strength and duration of Indian Ocean Monsoon (IOM) summer rainfall and winter cyclonic rainfall. The late glacial/Holocene transition of the region was characterised by the development of mega-linear dunes. These dunes became stabilised and vegetated during the early Holocene and interdunal lakes formed in response to the incursion of the IOM at approximately 8500 cal yr BP with the development of C3 dominated savanna grasslands. The IOM weakened ca. 6000 cal yr BP with the onset of regional aridity, aeolian sedimentation and dune reactivation and accretion. Despite this reduction in precipitation, the lake was maintained by winter dominated rainfall. There was a shift to drier adapted C4 grasslands across the dune field. Lake sediment geochemical analyses record precipitation minima at 8200, 5000 and 4200 cal yr BP that coincide with Bond events in the North Atlantic. A number of these events correspond with changes in cultural periods, suggesting that climate was a key mechanism affecting human occupation and exploitation of this region.

scholarly journals Radiocarbon Chronology of Late Glacial and Holocene Sedimentation and Water-Level Changes in the Area of the Gościąż Lake Basin

Radiocarbon ◽  
1994 ◽  
Vol 36 (2) ◽  
pp. 187-202 ◽  
Author(s):  
Anna Pazdur ◽  
M. F. Pazdur ◽  
Tomasz Goslar ◽  
Bogumił Wicik ◽  
Maurice Arnold
Keyword(s):  
Climate Changes ◽  
Global Climate ◽  
Lacustrine Sediments ◽  
Late Glacial ◽  
Lake Basin ◽  
Global Climate Changes ◽  
Laminated Sediment ◽  
Water Level Changes ◽  
Late Glacial And Holocene ◽  
Radiocarbon Chronology

We obtained 14C ages on samples of lake marl and other sediments from cores taken in Gościąż Lake and its environs. Comparison of 14C dates of bulk samples of laminated sediment with varve chronology and available AMS dates of terrestrial macrofossils indicates a reservoir correction of 2000 ± 120 yr for the basal series of lake sediments. 14C dates obtained on peat layers underlying the oldest lacustrine sediments in Gościąż and other lakes consistently locate the beginning of organogenic sedimentation in this area at ca. 13 ka bp. We distinguished three periods of lacustrine gyttja sedimentation in cores taken in Gościąż and adjacent lakes: 11.8–10.2 ka, 8–7 ka and 2.7–2.1 ka bp. From the 14C dates of lithological boundaries in these cores, we reconstruct a pattern of lake-level changes during the last 12 ka, remarkably similar to Swedish lakes and generally agreeing with available records from European and American lakes. The behavior of Gościąż Lake during the last 12 ka fairly well reflects global climate changes in the temperate zone during the Late Glacial and Holocene periods.

Jura glacial lakes: a paleoclimatic and paleoenvironmental evolution since the Late Glacial Period.

2020 ◽  
Author(s):  
Brahimsamba Bomou ◽  
Damien Zappa ◽  
Anne-Marie Rachoud-Schneider ◽  
Jean-Nicolas Haas ◽  
Marina Gärtner ◽  
...  
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Lacustrine Sediments ◽  
Younger Dryas ◽  
Late Glacial ◽  
Glacial Period ◽  
Glacial Lakes ◽  
Late Glacial Period ◽  
Paleoenvironmental Evolution ◽  
Multiproxy Approach

<p>During the retreat of a Würm ice sheet, numerous glacial paleolakes took place in the Swiss and French Jura. Two sites were investigated: the Amburnex Valley site (Switzerland), which evolved in well-developed peatland and the Lake Val (France), which is still persisted as a lacustrine system. During the Late Glacial period, both sites were glacial lakes characterized by a significant accumulation of lacustrine sediments.</p><p>Using a multiproxy approach, this project aims to reconstruct the paleoclimatic and the paleoenvironmental evolution recorded in lacustrine sediments and peatbog deposits since the last 13’000 years.</p><p>The Amburnex core (7m) exhibit a basal morainic deposit from the Würm period, overlain by three meters of lacustrine deposits and four meters of peatland deposits. The Lake Val core (4.5m) consists of the same lithological succession.</p><p>A multiproxy approach based on palynological analyses, grain-size analyses, mineralogical analyses (XRD) and geochemical analyses (TOC, Nitrogen, Phosphorus and Mercury contents; major and trace elements; organic carbon isotopes) have been used to characterize the hydrological and climatic fluctuations, the trophic level and the origin of organic matter in order to reconstruct the paleoenvironmental and paleoclimatic evolution of this area.</p><p>In the Amburnex site, the Bølling-Allerød, the Younger Dryas and the beginning of the Preboreal period have been recognized by palynological analyses and confirmed by carbon 14 dating. During the Oldest Dryas, oligotrophic conditions took place as suggested by the very low concentrations in nitrogen and organic matter. Then, during the warmer Bølling period, an enrichment in total organic carbon (TOC) associated with a decrease in phosphorus content are observed, implying the development of eutrophic conditions and maybe phosphorus recycling. Later in the Allerød period, low TOC and phosphorus contents, associated with varved carbonate deposits, indicate a return to more oligotrophic conditions. New organic matter enrichments are observed in the interval corresponding to the colder Younger Dryas period. These trends are quite consistent with those observed in the Lake Val and reflect significant changes in runoff and nutrient inputs at least at regional scale.</p>

scholarly journals The development and genesis of a small thaw lake filling the Skaliska Basin during the Late Glacial and Holocene

2013 ◽  
Vol 53 (1) ◽  
pp. 69-91 ◽  
Author(s):  
Renata Stachowicz-Rybka ◽  
Andrzej Obidowicz
Keyword(s):  
Lacustrine Sediments ◽  
Late Glacial ◽  
Eriophorum Vaginatum ◽  
Lake District ◽  
Plant Macroremains ◽  
History Of ◽  
Ams Dating ◽  
Late Glacial And Holocene ◽  
Macroscopic Analysis

ABSTRACT The northern part of the Mazury Lake District is marked by the presence of a depression described as the Skaliska Basin. At the end of the Pleistocene, the Skaliska Basin was the site of functioning of a thaw lake, within series of laminated clayey sediments were formed. The surface of the clayey sediments was overlain by a sandy fan. Blocks of dead ice underlying the fan and the overlying surface of the clayey sediments were the origin of small isolated water basins. Since the Allerod they were filled with limnic sediments, passing into peats towards the upper part. In order to reconstruct the vegetational history of the Skaliska Basin and the conditions of sedimentation of the lacustrine gyttjas and peats, several sections were obtained from such basins and subjected to examination of plant macroremains, palaeolimnological analysis and AMS dating. Sedimentation of lacustrine sediments began with sands with an admixture of silt and peat. The beginning of sedimentation of lacustrine sands of aeolian origin falls within the Allerod, whereas the end of that process in ca the middle of the Preboreal. Sands are frequently overlain by a strongly decomposed lacustrine dy sediment. Subsequently a sequence of detritus gyttja accumulated. The complex of gyttjas is interbedded with occasional Scirpo-Typheti peats. Sedimentation of lacustrine sediments is followed by accumulation of peats formed within communities with tall sedges. These communities, according to their compoition, correspond to the associations of Cicuto- Caricetum pseudocyperi Boer. et Siss. and Caricetum elatae Koch. The upper part comprises peats resembling the present-day community of Sphagnum centrale, displaying features of a transition bog. Also the occurrence of Eriophorum vaginatum confirms changes towards ombrotrophic conditions. The uppermost part of the sections often comprises heavily decomposed peat with components no longer identifiable by macroscopic analysis.

Quaternary Moraines vs Catastrophic Rock Avalanches in the Karakoram Himalaya, Northern Pakistan

1999 ◽  
Vol 51 (3) ◽  
pp. 220-237 ◽  
Author(s):  
Kenneth Hewitt
Keyword(s):  
Large Scale ◽  
Lacustrine Sediments ◽  
Rock Avalanche ◽  
Late Glacial ◽  
Terminal Moraine ◽  
The North ◽  
River Terraces ◽  
Rock Avalanches ◽  
Shigar Valley ◽  
Intermontane Basins

AbstractA history and conception of glacial events for the central Karakoram Himalaya, proposed some 80 years ago by Giotto Dainelli, are largely accepted today. However, certain deposits identified as terminal moraine complexes marking glacial episodes were actually emplaced by rock avalanches. In the Skardu and Shigar intermontane basins of Baltistan, at least 15 rock avalanche events were previously mapped as moraine or till. Criteria used for distinguishing these catastrophic landslide deposits emphasize homogeneous lithology of rubble and matrix, clast shape, facies characteristics, the large scale unity of emplacement, and morphological relations to valley topography. The deposits of three events, at Katzarah, Satpura, and the north end of Shigar Valley, have been reconstructed in detail. Thick supraglacial debris does not result in similar deposits. Extensive valley fills, river terraces, large sediment fans, and lacustrine sediments formerly attributed to late-glacial conditions are reinterpreted as postglacial events involving rock avalanches that interrupted fluvial development. Existing reconstructions of glaciations are left in doubt, especially late-glacial events in the central Karakoram, as are the roles assigned to Karakoram, main Indus Valley, and western Himalayan ice.

scholarly journals A New Species of Isoperla (Plecoptera: Perlodidae) from the Southern Carpathians, and Further Contributions to the Fauna of the Ţarcu Mts

2021 ◽  
Vol 55 (2) ◽  
pp. 235-248
Author(s):  
D. Murányi ◽  
T. Kovács ◽  
W. Graf
Keyword(s):  
New Species ◽  
The West ◽  
Male And Female ◽  
A New Species ◽  
Southern Carpathians ◽  
High Range ◽  
Isolated Species

Isoperla nagyi sp. n. is described on the basis of morphology of male and female adults and eggs. The new species is classified as an isolated species within the West Palaearctic Isoperla. It was found in the lower elevations of the Ţarcu Mts that is forming a high range of the westernmost Southern Carpathians. Further contributions are given on the stonefly fauna of the Ţarcu Mts, including notes on the Romanian distribution of Brachyptera bulgarica Raušer, and the taxonomy and distribution of Isoperla pusilla (Klapálek).

Late glacial molluscs from the Cooking Lake moraine, Alberta, Canada

1983 ◽  
Vol 20 (1) ◽  
pp. 160-162 ◽  
Author(s):  
Donald Emerson
Keyword(s):  
Lacustrine Sediments ◽  
Late Glacial ◽  
Warming Trend ◽  
Time Interval ◽  
Radiocarbon Dates ◽  
South Central ◽  
Freshwater Mollusc

Several species of freshwater mollusc, with radiocarbon dates of 10 900 – 9050 years BP, have been recovered from supraglacial and intraglacial lacustrine sediments in the Cooking Lake moraine region of south-central Alberta, Canada. The organisms indicate the onset of a warming trend in the region that lasted at least 2000 years, marking the final stages of melting in the continental Wisconsin ice sheet.This period of climatic amelioration correlates with a similar trend in southwestern Alberta during the time interval 13 000 – 9000 years BP based also on the evidence of late and early postglacial molluscan communities.

scholarly journals Dichrorampha carpatalpina sp. n. (Lepidoptera, Tortricidae), a high mountain species of the Romanian Carpathians

2019 ◽  
Vol 42 (1) ◽  
pp. 37-48
Author(s):  
Sándor Kovács ◽  
Zoltán Kovács
Keyword(s):  
New Species ◽  
Host Plant ◽  
Female Genitalia ◽  
High Mountain ◽  
Flight Period ◽  
Male And Female ◽  
The North ◽  
Sunny Weather ◽  
Romanian Carpathians ◽  
Southern Carpathians

Dichroramphacarpatalpinasp. n., is described from the Southern Carpathians (Romania). It is closely related to D.inconspiqua (Danilevsky, 1948) and D.podoliensis (Toll, 1942). Adults, male and female genitalia, the habitat of the new species are described and figured and some details of the biology are given. The larva and its host-plant, Achilleaoxylobaschurii (Sch. Bip.) Heimerl, are illustrated. The species inhabits the north-facing slopes of the highest regions of the Carpathians. During their flight period from the beginning of July to the beginning of August the moths are on wing in the morning and only in sunny weather.

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