Late Quaternary paleoenvironments and paleoclimatic conditions in the distal Andean piedmont, southern Mendoza, Argentina

2011 ◽  
Vol 76 (2) ◽  
pp. 253-263 ◽  
Author(s):  
Alfonsina Tripaldi ◽  
Marcelo A. Zárate ◽  
George A. Brook ◽  
Guo-Qiang Li
Keyword(s):  
Late Quaternary ◽  
Semiarid Region ◽  
Aeolian Deposits ◽  
Aeolian Activity ◽  
Facies Associations ◽  
Sand Sheet ◽  
Size And Morphology ◽  
Paleoclimatic Significance ◽  
San Rafael ◽  
The Last Glacial

AbstractThe Andean piedmont of Mendoza is a semiarid region covered by extensive and partially vegetated dune fields consisting of mostly inactive aeolian landforms of diverse size and morphology. This paper is focused on the San Rafael plain (SRP) environment, situated in the distal Andean piedmont of Mendoza (34° 30′S), and reports the sedimentology and OSL chronology of two representative exposures of late Quaternary deposits, including their paleoenvironmental and paleoclimatic significance. Eleven facies, including channel, floodplain, fluvio–aeolian interaction, and reworked pyroclastic and aeolian deposits, were described and grouped into two facies associations (FA1 and FA2). FA1 was formed by unconfined sheet flows, minor channelized streams and fluvial–aeolian interaction processes. FA2 was interpreted as aeolian dune and sand-sheet deposits. OSL chronology from the SRP sedimentary record indicates that between ca. 58–39 ka and ca. 36–24 ka (MIS 3), aggradation was governed by ephemeral fluvial processes (FA1) under generally semiarid conditions. During MIS 2, the last glacial maximum (ca. 24–12 ka), a major climatic shift to more arid conditions is documented by significant aeolian activity (FA2) that became the dominant sedimentation process north of the Diamante–Atuel fluvial system. The inferred paleoenvironmental conditions from the SRP sections are in broad agreement with regional evidence.

Late Quaternary aeolian activity in Gonghe Basin, northeastern Qinghai-Tibetan Plateau, China

2013 ◽  
Vol 79 (3) ◽  
pp. 403-412 ◽  
Author(s):  
Mingrui Qiang ◽  
Fahu Chen ◽  
Lei Song ◽  
Xingxing Liu ◽  
Mingzhi Li ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Late Quaternary ◽  
Optically Stimulated Luminescence ◽  
Aeolian Sand ◽  
Aeolian Deposits ◽  
Effective Moisture ◽  
Aeolian Activity ◽  
History Of ◽  
Gonghe Basin ◽  
Semi Arid

AbstractAeolian deposits at four sites in the Gonghe Basin were used to reconstruct the history of aeolian activity over the late Quaternary. These deposits include well-sorted aeolian sand, paleosols and/or loess. Aeolian sand represents dune-field expansion and/or dune buildup, whereas paleosols indicate stabilization of dunes, accompanying ameliorated vegetation cover. On the basis of 25 dates by optically stimulated luminescence (OSL), it appears that aeolian activities occurred episodically at 33.5, 20.3, 13.9, 11.8–11.0, 9.4, 7.8, and 5.7 (5.5) ka, which is largely consistent with the recent findings from the adjacent semi-arid areas. Aeolian sand mobility occurring during the early to mid Holocene conflicts with a climatic optimum inferred from lacustrine records in the northeastern Qinghai-Tibetan Plateau. This inconsistency may be resolved by interpreting aeolian activity as a response to decreased effective moisture due to enhanced evaporation, induced by higher summer insolation at that time, together with local terrain and its effects on moisture. Our results suggest that aeolian sand and paleosol cannot be simply ascribed to regional dry and wet climates, respectively, and they most likely reflect changes in effective moisture.

scholarly journals Timing and Sedimentary Record of Late Quaternary Fluvio-Aeolian Successions of the Tura-Pyshma Interfluve (SW Western Siberia, Russia)

Geosciences ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 396
Author(s):  
Oleg Sizov ◽  
Alexandr Konstantinov ◽  
Anna Volvakh ◽  
Anatoly Molodkov
Keyword(s):  
Western Siberia ◽  
Late Quaternary ◽  
Late Glacial ◽  
Northern Eurasia ◽  
Sedimentary Record ◽  
Aeolian Deposits ◽  
Aeolian Activity ◽  
Geomorphic Features ◽  
Periglacial Zone ◽  
Two Stages

The sedimentary record of aeolian deposits and geomorphic features of the aeolian landforms of Northern Eurasia contain important information that allows us to better understand the climate and environments of the Late Glacial and Early Holocene periods. At the same time, the degree of scientific knowledge about the timing of aeolian activity, as well as the landscapes that existed during these periods, differs significantly for different parts of this vast territory. Data on the sedimentological record and age estimations of aeolian phases are practically absent for the periglacial zone of Western Siberia, in contrast to that of Europe. This paper presents the first data on the Late Quaternary fluvio-aeolian environments of the southwestern part of Western Siberia, using two sections as examples. Our methods included field investigations, analysis of grain-size and chemical composition, quartz grain morphoscopy and infrared optically stimulated luminescence (IR-OSL) and AMS dating. The obtained results show that aeolian sands are common covering deposits within the study area. Two stages of aeolian activity were identified: the first during the Boreal period (9.2–10.2 ka BP), and the second during the Atlantic period, beginning near 7 ka BP.

Paleoclimatic Significance of Late Quaternary Lacustrine and Alluvial Stratigraphy, Animas Valley, New Mexico

1998 ◽  
Vol 50 (3) ◽  
pp. 283-289 ◽  
Author(s):  
P.Reed Krider
Keyword(s):  
New Mexico ◽  
Last Glacial Maximum ◽  
Late Holocene ◽  
Late Quaternary ◽  
Fluvial Systems ◽  
Quaternary Stratigraphy ◽  
Paleoclimatic Significance ◽  
Stratigraphic Sequences ◽  
The Last Glacial Maximum ◽  
The Last Glacial

Lacustrine and alluvial stratigraphic sequences in the southern Animas Valley of New Mexico allow reconstruction of late Quaternary climates. Four separate stands of late Quaternary Lake Cloverdale in the southern Animas Valley are recorded by lacustrine shoreline deposits. Soils and stratigraphic evidence show that three young lake highstands occurred during the Holocene and that a higher lake stand occurred 18,000 to 20,00014C yr B.P. Fluvial systems aggraded the southern Animas Valley during the middle to late Holocene. The late Quaternary stratigraphy shows that several periods during the late Holocene were characterized by higher effective precipitation than at any time since the last glacial maximum.

scholarly journals Environmental conditions and paleowind directions at the end of the Weichselian Late Pleniglacial recorded in aeolian sediments and geomorphology (Twente, Eastern Netherlands)

2001 ◽  
Vol 80 (2) ◽  
pp. 1-18 ◽  
Author(s):  
Ko (J.) van Huissteden ◽  
Jacques C.G. Schwan ◽  
Mark D. Bateman
Keyword(s):  
Permafrost Degradation ◽  
Aeolian Deposits ◽  
Arid Conditions ◽  
Channel Belt ◽  
Aeolian Sediments ◽  
Aeolian Activity ◽  
Sand Sheet ◽  
Late Weichselian ◽  
Active Channel ◽  
Sand Sheets

AbstractThe Late weichselian Pleniglacial wind regime in the eastern Netherlands is reconstructed by means of landform and sedimentological analysis. This analysis involves aeolian and fluvial landforms in the Dinkel river valley in the Twente region. The aeolian deposits considered here date from the Last Glacial Maximum (approximately 22 ka) to the start of the Belling Interstadial at 14.7 ka.A major event in this period is the formation of a cryoturbation level caused by permafrost degradation, overlain by an erosional hiatus dated between 21 and 17 ka. Both features are attributed to a period of warmer and moister climate, causing permafrost degradation and erosion by surficial runoff. Thereafter aeolian activity prevailed under relatively arid conditions. A deflation surface was formed, the Beuningen Gravel Bed. This deflation surface is present in many Weichselian sections in the Netherlands and the adjacent parts of Belgium and Germany. The deflation occurred concurrently with deposition of coversand at other places.The morphology of the coversand-landscape in the Dinkel valley was controlled by the relief of the pre-existing floodplain and the wind pattern. Coversand ridges consisting of low dunes accumulated near the margins of the active channel belt. Relatively thick sand sheets occur in the leesides of the ridges, thin sand sheets are found at greater distance.Mainly westerly sand-transporting winds operated during winter and summer. In winter aeolian deposition occurred by frequent and strong easterly winds also. On the smallest, local scale, the pattern of deposition was determined by the topography and moisture of the receiving surface.Coversand deposition came to an end with the formation of a sand sheet under relatively warm and less arid conditions. Coversand deposition continued into the Belling Interstadial; colonization of the coversand surface by vegetation probably has been delayed by nutrient-poor conditions.

scholarly journals Cryostratigraphy, sedimentology, and the late Quaternary evolution of the Zackenberg River delta, northeast Greenland

2017 ◽  
Vol 11 (3) ◽  
pp. 1265-1282 ◽  
Author(s):  
Graham L. Gilbert ◽  
Stefanie Cable ◽  
Christine Thiel ◽  
Hanne H. Christiansen ◽  
Bo Elberling
Keyword(s):  
Late Quaternary ◽  
Sediment Cores ◽  
River Delta ◽  
Optically Stimulated Luminescence ◽  
Delta Plain ◽  
Valley Fill ◽  
Subaerial Exposure ◽  
Facies Associations ◽  
Delta Progradation ◽  
Ice Content

Abstract. The Zackenberg River delta is located in northeast Greenland (74°30′ N, 20°30′ E) at the outlet of the Zackenberg fjord valley. The fjord-valley fill consists of a series of terraced deltaic deposits (ca. 2 km2) formed during relative sea-level (RSL) fall. We investigated the deposits using sedimentological and cryostratigraphic techniques together with optically stimulated luminescence (OSL) dating. We identify four facies associations in sections (4 to 22 m in height) exposed along the modern Zackenberg River and coast. Facies associations relate to (I) overriding glaciers, (II) retreating glaciers and quiescent glaciomarine conditions, (III) delta progradation in a fjord valley, and (IV) fluvial activity and niveo-aeolian processes. Pore, layered, and suspended cryofacies are identified in two 20 m deep ice-bonded sediment cores. The cryofacies distribution, together with low overall ground-ice content, indicates that permafrost is predominately epigenetic in these deposits. Fourteen OSL ages constrain the deposition of the cored deposits to between approximately 13 and 11 ka, immediately following deglaciation. The timing of permafrost aggradation was closely related to delta progradation and began following the subaerial exposure of the delta plain (ca. 11 ka). Our results reveal information concerning the interplay between deglaciation, RSL change, sedimentation, permafrost aggradation, and the timing of these events. These findings have implications for the timing and mode of permafrost aggradation in other fjord valleys in northeast Greenland.

Late Quaternary Paleotemperatures Derived from a Speleothem from Cango Caves, Cape Province, South Africa

1992 ◽  
Vol 37 (2) ◽  
pp. 203-213 ◽  
Author(s):  
A.S. Talma ◽  
John C. Vogel
Keyword(s):  
South Africa ◽  
Isotopic Composition ◽  
Late Quaternary ◽  
Carbon Isotopic Composition ◽  
Temperature Record ◽  
The Past ◽  
Carbon Isotopic ◽  
Groundwater Aquifer ◽  
Combining Data ◽  
The Last Glacial

AbstractAn oxygen isotope temperature record over a large part of the past 30,000 yr has been obtained for the southern Cape Province of South Africa by combining data on the isotopic composition of a stalagmite from a deep cave with that of a confined groundwater aquifer in the same region. Results show that temperatures during the last glacial maximum were on average about 6°C lower than those today, with peaks up to 7°C lower. A detailed analysis of the past 5000 yr suggests multiple fluctuations, with generally lower temperatures (1–2°C) around 4500 and 3000 yr B.P. The carbon isotopic composition of the stalagmite indicates significant vegetation changes between the late Pleistocene and today, and also during the second half of the Holocene.

scholarly journals Sea level implications from Late Quaternary/Holocene paleosols from the Oujiang Delta, China

Radiocarbon ◽  
2018 ◽  
Vol 61 (1) ◽  
pp. 83-99
Author(s):  
Daidu Fan ◽  
Shuai Shang ◽  
George Burr
Keyword(s):  
Sea Level ◽  
East China Sea ◽  
Late Quaternary ◽  
Sediment Cores ◽  
East China ◽  
The East China Sea ◽  
China Sea ◽  
Mis 3 ◽  
Plant Matter ◽  
The Last Glacial

ABSTRACTWe describe two coastal paleosols recovered in sediment cores from the Oujiang Delta, Southeast China. These provide useful benchmarks for past sea level change on the East China Sea coast. Radiocarbon (14C) dates on charcoal and plant matter show that one formed during Marine Isotope Stage 3 (MIS 3) and was exposed for perhaps 20 ka, during the Last Glacial Maximum. The other formed in the Early Holocene and was briefly exposed, during a period of fluctuating sea level. Similar paleosols have been described from the Changjiang (Yangtze) Delta, and at many other sites from the East China Sea. The MIS 3 paleosol records a regional relative sea level of about –27 m at the end of MIS 3. While this value is consistent with other paleo sea level estimates for the East China Sea region, it is much higher than predicted by eustatic sea level estimates.

scholarly journals Stratigraphy and sedimentology of a late Pleistocene incised valley fill: a depositional and paleogeographic model for “Cancagua” deposits in north-western Patagonia, Chile

2018 ◽  
Vol 45 (2) ◽  
pp. 161
Author(s):  
Rodrigo M. Vega ◽  
Mauricio Mella ◽  
Sven N. Nielsen ◽  
Mario Pino
Keyword(s):  
Late Pleistocene ◽  
Substantial Part ◽  
Glacial Cycle ◽  
Incised Valley ◽  
Last Glacial ◽  
Valley Fill ◽  
Sedimentary Deposits ◽  
Facies Associations ◽  
North Western ◽  
The Last Glacial

Late Pleistocene sedimentary deposits outcropping around Valdivia city, locally known as Cancagua, have been subject of contrasting interpretations, from glacial to interglacial sediments. Opposing views emerge from focusing on upstream or coastal sedimentary controls, within a zone were these potentially overlap through a full glacial cycle. Here we present the first detailed facies analysis and a broad chronological framework, reconciling previous interpretations in a single paleogeographic model that encompasses the last glacial cycle. Seven facies associations are described, interpreted as an estuarine complex developed primarily during the last glacial cycle’s highstand, yet accumulating sediments during a substantial part of the falling stage. These results offer the opportunity to extend paleoenvironmental records through a full glacial cycle in northern Patagonia.

scholarly journals Synoptic climate change as a driver of late Quaternary glaciations in the mid-latitudes of the Southern Hemisphere

2006 ◽  
Vol 2 (1) ◽  
pp. 11-19 ◽  
Author(s):  
H. Rother ◽  
J. Shulmeister
Keyword(s):  
New Zealand ◽  
Southern Hemisphere ◽  
Large Scale ◽  
Late Quaternary ◽  
Synoptic Climatology ◽  
Balance Model ◽  
Last Glacial ◽  
Regional Flow ◽  
Quaternary Glaciations ◽  
The Last Glacial

Abstract. The relative timing of late Quaternary glacial advances in mid-latitude (40-55° S) mountain belts of the Southern Hemisphere (SH) has become a critical focus in the debate on global climate teleconnections. On the basis of glacial data from New Zealand (NZ) and southern South America it has been argued that interhemispheric synchrony or asynchrony of Quaternary glacial events is due to Northern Hemisphere (NH) forcing of SH climate through either the ocean or atmosphere systems. Here we present a glacial snow-mass balance model that demonstrates that large scale glaciation in the temperate and hyperhumid Southern Alps of New Zealand can be generated with moderate cooling. This is because the rapid conversion of precipitation from rainfall to snowfall drives massive ice accumulation at small thermal changes (1-4°C). Our model is consistent with recent paleo-environmental reconstructions showing that glacial advances in New Zealand during the Last Glacial Maximum (LGM) and the Last Glacial Interglacial Transition (LGIT) occurred under very moderate cooling. We suggest that such moderate cooling could be generated by changes in synoptic climatology, specifically through enhanced regional flow of moist westerly air masses. Our results imply that NH climate forcing may not have been the exclusive driver of Quaternary glaciations in New Zealand and that synoptic style climate variations are a better explanation for at least some late Quaternary glacial events, in particular during the LGIT (e.g. Younger Dryas and/or Antarctic Cold Reversal).

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