Bioerosion on Late Pleistocene (MIS 7 and MIS 5e) marine molluscs A palaeoclimatological and palaeoecological comparison with modern beaches (Río Negro, Argentina)

2021 ◽  
Author(s):  
Melisa P. Charó ◽  
Gisela D. Charó ◽  
Guillermo Aceñolaza ◽  
Jose L. Cavallotto
Keyword(s):  
Late Pleistocene ◽  
Marine Molluscs ◽  
Rio Negro ◽  
Mis 5E

scholarly journals Quaternary Marine Mollusk Associations of the Last Interglacials in North Patagonia (Argentina): Paleoecology and Paleoclimates

2021 ◽  
Author(s):  
M.P. Charó
Keyword(s):  
Habitat Heterogeneity ◽  
Buenos Aires ◽  
Global Changes ◽  
Buenos Aires Province ◽  
The North ◽  
Rio Negro ◽  
The Pacific ◽  
The Pacific Ocean ◽  
Crassostrea Rhizophorae ◽  
Mis 5E

Deposits of different Quaternary marine transgressions are largely exposed in the Argentine north Patagonian littoral (39°15′S–41°02′S), south of the Buenos Aires and north of Río Negro provinces. The malacological associations of 84 sites were studied. Among them, 31 belong to Pleistocene deposits of the interglacials ≥ MIS 9, MIS 7, MIS 5e, 29 to Holocene deposits of the interglacial MIS 1, and 24 sites of modern beaches. These sites yielded 7385 fossils among valves and shells, of 78 species (42 bivalves and 36 gastropods), including 11 micromolluskan species. The record of the bivalves Crassostrea rhizophorae in the south of the Buenos Aires Province, and Anomalocardia brasiliana (both currently inhabiting lower latitudes), and very likely the gastropod Tegula atra (inhabiting today the Pacific Ocean) in the north of Río Negro Province, suggests that interglacials MIS 7, MIS 5e and MIS 1 were warmer than today. However, the associations determined for the studied interglacials have not changed in their composition, but in abundance of species, except for the latitudinal shifts of the three mentioned species, and the presence of cold to temperate water taxa since the MIS 1 in the ecotonal area of the north of Río Negro Province. Changes in the associations of northern Patagonia during the Quaternary derived from global changes (sea surface temperature, salinity, etc.), and the existence of habitat heterogeneity in each of the areas, that enabled the co-existence of different bivalve and gastropod species of the local benthic marine malacofauna.

Stratigraphy and chronology of Late Pleistocene loess-paleosol sequence of the East European Plain and correlation with Late Pleistocene archives of Europe

2021 ◽  
Author(s):  
Svetlana Sycheva ◽  
Manfred Frechen ◽  
Birgit Terhorst ◽  
Sergey Sedov ◽  
Olga Khokhlova
Keyword(s):  
Late Pleistocene ◽  
Forest Fire ◽  
Western Europe ◽  
East European Plain ◽  
East European ◽  
Mis 3 ◽  
Soil Sediment ◽  
Rfbr Grant ◽  
Mis 5E ◽  
Eemian Interglacial

<p>A detailed pedocryostratigraphic scheme of the Late Pleistocene periglacial region of the East European Plain has been developed on the basis of study of the paleorelief, sediments, paleosols, and cryogenic horizons. OSL and <sup>14</sup>C-dating of paleosols and sediments in Aleksandrov quarry and in other sections made it possible to substantiate this scheme and correlate it with analogous ones for different regions of Europe. The loess-paleosol sequence in Aleksandrov quarry (51º05'N, 36º08'E) does not have an analogous with respect to the completeness in the whole East European Plain. In the filling of paleobalka the Ryshkovo paleosol of the Mikulino interglacial (MIS 5e) is observed. Over this paleosol, the Valdai soil-sediment series (MIS 5d – MIS 2) is located. It includes four interstadial soils, two of them of the Early Valdai (Kukuevo and Streletsk ones), and two, sometimes three, of the Middle Valdai (Aleksandrov, Hydrouzel и Bryansk ones). The OSL date, 127 ± 8 ka BP, (beginning of MIS 5e) was obtained for a sample taken from the bottom of the Ryshkovo soil. The interglacial soil is overlain by the Seym layer formed mainly from destroyed and redeposited horizons of this soil. For the upper part of the Seym layer, OSL dates of 115 ± 7 ka BP and 112 ± 20 ka BP were obtained (MIS 5d). But the process of burial of Ryshkovo soil in the bottom of the paleobalka began at the end of the interglacial after a catastrophic forest fire. Large post-permafrost deformations - pseudomorphosis is confined to Selikhovodvor loess - MIS 4 (65 ± 8 ka BP). Two soils occurring between Seym and Selikhovodvor loesses: Kukuevo and Streletsk - Early Valdai (MIS 5c and MIS 5a). For Mlodat loess which separates those two soils (MIS 5b), OSL dates of 91 ± 1 and 89 ± 7 ka BP were obtained. For paleosols of Middle Valdai (MIS 3), <sup>14</sup>C-dates were obtained: Aleksandrov (53.742 - 2.124 ka cal BP) and Bryansk soils (37.618 ± 0.668 ka cal BP). For Tuskar loess, which separates Alexandrov and Bryansk soils, OSL dates of 50 ± 3 and 51 ± 3 ka BP were obtained. The new stratigraphic scheme of Late Pleistocene agrees with the ideas of researchers from Eastern, Central, and Western Europe , which allows the following correlations. The identified paleosols correspond to the following intervals: Ryshkovo – Eemian interglacial (127-117 ka BP); Kukuevo to Amersfoort + Brørup – Saint-Germain 1 (105-95 ka BP); Streletsk – Odderade to Saint-Germain 2 (about 85-75 ka BP); Aleksandrov to Oerel (56-53 ka BP); Hydrouzel to Moershoofd – Poperinge (44-45 ka BP) and Hengelo (40-38 ka BP); and Bryansk (33-27 ka BP) to Stillfried B, Denekamp or Grand Bois interstadials. The reconstructed Late Pleistocene loess-paleosol sequence has the most similar structure with loess-paleosol sequences of Ukraine, with sequence Dolní Věstonice in Moravia (Czech Republik), Stillfried in Austria and Mainz-Weisenau in the Rhenish area (Germany), and other archives. <strong>This work was supported by RFBR, grant N19-29-05024 mk. </strong></p>

Dactyloidites ottoi (Geinitz, 1849) in Bahamian Pleistocene Carbonates: A Shallowest-marine Indicator

2021 ◽  
pp. SP522-2021-69
Author(s):  
H. Allen Curran ◽  
Bosiljka Glumac
Keyword(s):  
Late Pleistocene ◽  
Carbonate Sediments ◽  
The Bahamas ◽  
Shallow Marine ◽  
Fine Detail ◽  
Plant Remains ◽  
Mis 5E ◽  
Deposit Feeding ◽  
First Time ◽  
Host Sediment

AbstractThe rosetted trace fossil Dactyloidites ottoi (Geinitz, 1849) is reported and described for the first time from late Pleistocene (MIS 5e) carbonates of the Bahama Archipelago in shallowing-upward, shelly calcarenites from Great Inagua and Great and Little Exuma islands. The distinctive, fan-shaped D. ottoi specimens from the Bahamas, while not preserved in fine detail and not revealing a shaft, compare favourably in shape and size with specimens from other localities around the world, including the oldest well-documented specimens from the Jurassic of Argentina. D. ottoi is interpreted as a fodinichnion formed by the activity of a deposit-feeding worm, probably a polychaete, consuming marine-plant remains within host sediment. The late Pleistocene palaeodepositional environment of these carbonate sediments is interpreted as within the lower foreshore-upper shoreface zone in full marine, tropical waters. This discovery of D. ottoi marks an addition to the Bahamian shallow-marine ichnocoenose within the Skolithos ichnofacies.

Expansion of Magellanic Moorland during the Late Pleistocene: Palynological Evidence from Northern Isla de Chiloé, Chile

1988 ◽  
Vol 30 (3) ◽  
pp. 304-314 ◽  
Author(s):  
Carolina Villagrán
Keyword(s):  
Late Pleistocene ◽  
Late Quaternary ◽  
Marked Change ◽  
Climatic Conditions ◽  
Annual Precipitation ◽  
Palynological Analysis ◽  
Wetland Development ◽  
Average Temperature ◽  
Rio Negro

The late Quaternary vegetation of northern Isla de Chiloé is inferred from palynological analysis of a section in the Río Negro drainage (42°03′S, 73°50′W). At ca. 30,500 yr B.P., maxima of Astelia and Donatia occurred, suggesting wetland development. From that time until ca. 27,000 yr B.P., steppe indicators such as Compositae/Gramineae dominated, suggesting drier conditions. After 27,000 yr B.P., the moorland shrub Dacrydium gradually increased, reaching a maximum by 18,000 yr B.P. At this time Astelia increased again, suggesting development of cushion bog during cold and wet conditions. The glacial-postglacial transition is characterized by a marked change from peaty sediments to clays, a decrease in the cushion bog flora, and the prevalence of Gramineae/ Compositae and swamp taxa. This vegetation prevailed until ca.7000 yr B.P. when forest taxa became dominant. The floristic pattern inferred from the pollen spectra of the Rio Negro section suggests that the late Pleistocene vegetation of Chiloé resembled modern Magellanic Moorland vegetation (52°–56°lat S). Based on climatic conditions presently associated with Magellanic Moorland, its occurrence in Chiloé at low elevations during the late Pleistocene implies a decrease in average temperature of at least 4°C and an increase in annual precipitation of at least 1500 mm.

Amazonian Paleodunes Provide Evidence for Drier Climate Phases during the Late Pleistocene–Holocene

2002 ◽  
Vol 58 (2) ◽  
pp. 205-209 ◽  
Author(s):  
Arnaldo Carneiro Filho ◽  
Dominique Schwartz ◽  
Sonia H. Tatumi ◽  
Thierry Rosique
Keyword(s):  
Late Pleistocene ◽  
Amazon Basin ◽  
Climate Regime ◽  
Humid Climate ◽  
Dune Stabilization ◽  
Negro River ◽  
Rio Negro ◽  
Ecological Changes ◽  
Rio Negro Basin ◽  
Global Glaciation

AbstractRecent studies on relict eolian dunes in the Rio Negro basin, northern Amazon, Brazil (00°35′N, 63°14′W), indicate a drier climate regime during the Late Pleistocene–Holocene transition that is different from the present humid climate. The eolian sands form long chains of linear dunes bordering the Rio Negro River and some tributaries. Here, we present thermoluminescence (TL) ages spanning the period 32,000–8000 yr B.P. The final dune stabilization took place after 8,000 yr B.P. and now the bases of the dunes are fixed by vegetation. Clustering of the TL dates suggests that the dry climate in the Amazon Basin occurred in distinct episodes and argues against current opinions that drastic ecological changes did not affect in the Amazon during the last global glaciation.

CHRONOLOGY OF THE MIS 3 MEGAFAUNA IN SOUTHEASTERN WEST SIBERIA AND THE POSSIBILITY OF LATE SURVIVAL OF THE KHOZARIAN STEPPE MAMMOTH (MAMMUTHUS TROGONTHERII CHOSARICUS)

Radiocarbon ◽  
2021 ◽  
pp. 1-10
Author(s):  
Andrei V Shpansky ◽  
Yaroslav V Kuzmin
Keyword(s):  
Late Pleistocene ◽  
West Siberia ◽  
Mis 3 ◽  
Woolly Rhinoceros ◽  
Mis 5E ◽  
Late Survival ◽  
Woolly Mammoth

ABSTRACT We report a new series of radiocarbon (14C) dates on the MIS 3 megafauna for a previously poorly studied region of southeastern West Siberia. Some species, like woolly mammoth and woolly rhinoceros, and Pleistocene bison and horse, existed throughout the MIS 3 (ca. 29–59 ka cal BP); cave hyaena is dated to ca. 46,400 cal BP. The very late 14C dates on Khozarian steppe elephant (Mammuthus trogontherii chosaricus), ca. 45,100–45,400 cal BP, may indicate the survival of this species in Siberia up to MIS 3. More work is needed to confirm or reject this suggestion. Previously, Khozarian steppe elephant was known in Siberia only at the beginning of the Late Pleistocene (MIS 5e).

scholarly journals Paudorf locus typicus (Lower Austria) revisited: The potential of the classic loess outcrop for Middle to Late Pleistocene landscape reconstructions

2013 ◽  
Vol 62 (1) ◽  
pp. 59-72 ◽  
Author(s):  
Tobias Sprafke ◽  
Birgit Terhorst ◽  
Robert Peticzka ◽  
Christine Thiel
Keyword(s):  
Late Pleistocene ◽  
Mis 5E ◽  
Locus Typicus

Abstract. Die über 12 m mächtige Löss-Paläoboden-Sequenz in Paudorf (Niederösterreich), ist seit Jahrzehnten bekannt als locus typicus für die „Paudorfer Bodenbildung“. Dieser 1 m mächtige Pedokomplex im obersten Profilabschnitt entwickelte sich eem- bis frühwürmzeitlich. Das differenzierte Lösssediment im Liegenden, mit einem über 2 m mächtigen Pedokomplex im basalen Bereich, stellt ein außergewöhnliches Archiv mittelpleistozäner Landschaftsentwicklung dar. Die paläopedologischen und sedimentologischen Untersuchungen sowie erste mikromorphologische Analysen widmen sich erstmals der Gesamtabfolge und den Prozessen, die zu ihrer Entstehung beitrugen. Farb- und Karbonatanalysen in hoher Auflösung sowie detaillierte Korngrößenanalysen dienen dabei als hilfreiche Datenbasis. Die Untersuchungen zeigen zum einen, dass die Lösssedimente einer komplexen Genese unter periglazialen Bedingungen unterlagen. Neben äolischer Akkumulation spielten (zumeist solifluidale) Umlagerungsprozesse unter Einmischung von lokalem Material ebenso wie in situ Prozesse eine Rolle. Morphodynamisch stabile Phasen sind insbesondere in den beiden Pedokomplexen nachweisbar. In Bereichen, in denen Datierungen vorliegen, können Entwicklungsphasen mit jenen anderer Sequenzen korreliert werden und als klimatische Signale interpretiert werden. Die „Paudorfer Bodenbildung“ ist vermutlich eine frühglaziale Humuszone (MIS 5c[–a?]), die sich in einer solifluidal umgelagerten (MIS 5d) eemzeitliche Braunerde (MIS 5e) gebildet hat. Im Lösssediment konnten Nassböden nachgewiesen werden, wie sie typisch für spätrisszeitliche (MIS 6) Sequenzen sind. Der untere Pedokomplex wurde offenbar über mehrere Warmphasen verschiedener Intensitäten hinweg gebildet und wiederholt von Umlagerungsprozessen und äolischer Sedimentation während Kaltphasen unterbrochen.

Pliocene and late Pleistocene (MIS 5e) decapod crustaceans from Santa Maria Island (Azores Archipelago: Central Atlantic): systematics, palaeoecology and palaeobiogeography

2020 ◽  
Vol 36 (1) ◽  
pp. 91-109
Author(s):  
Matúš Hyžný ◽  
Carlos S. Melo ◽  
Ricardo S. Ramalho ◽  
Ricardo Cordeiro ◽  
Patrícia Madeira ◽  
...  
Keyword(s):  
Late Pleistocene ◽  
Decapod Crustaceans ◽  
Azores Archipelago ◽  
Mis 5E ◽  
Central Atlantic ◽  
Santa Maria
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