Accretional soil formation in northern hemisphere loess regions - evidence from OSL-dating of the P/H climatic transition from China, Europe and North America

2021 ◽  
Author(s):  
Daniela Constantin ◽  
Joseph Mason ◽  
Ulrich Hambach ◽  
Daniel Veres ◽  
Cristian Panaiotu ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
High Resolution ◽  
Northern Hemisphere ◽  
Weighted Average ◽  
Luminescence Dating ◽  
Chinese Loess Plateau ◽  
The Holocene ◽  
Last Glacial ◽  
Climatic Transition ◽  
The Last Glacial

<p>Here we investigate the timing of Pleistocene-Holocene climatic transition as reflected in nine luminescence dated loess-palaeosol sequences across the northern hemisphere, from the Chinese Loess Plateau, the southeastern European loess belt and the central Great Plains, Nebraska, USA.<br>First, logs of high-resolution magnetic susceptibility and its frequency dependence were used as palaeoclimatic proxies to define the environmental transition from the last glacial loess to the current interglacial soil. Second, the onset of increase in their values above typical loess values was used to assess the onset of, and developments during, the Pleistocene-Holocene climatic transition. The variability seen in the magnetic susceptibility records are interpreted based on high-resolution luminescence dating applied on multiple grain-sizes (4-11 µm, 63-90 µm, 90-125 µm) of quartz extracts from the same sample. In order to increase the overall precision of the luminescence based chronology we rely on weighted average ages. Based on these, Bayesian modeling allowed the determination of age-depth models and mean sedimentation rates for each investigated site.<br>The magnetic susceptibility signal shows a smooth and gradual increase for the majority of the sites from the typical low loess values to the interglacial ones. At all but one site, this increase, associated to the onset of the Pleistocene-Holocene boundary (ie., 11.7 ka) was dated to 14 ka or even earlier. Our results highlight the need of combining palaeoclimatic proxies (magnetic susceptibility) with absolute dating when placing the Pleistocene-Holocene climatic transition as reflected by the evolution of this proxy in order to avoid misinterpretations in loess-paleosol records caused by simple pattern correlation. These results indicate diverse environmental dynamics recorded in the different North Hemisphere loess regions during the major global climatic shift from the last glacial to the Holocene.<br>The detailed luminescence chronology coupled with magnetic susceptibility records indicate the formation of accretional Holocene soils in the sites investigated. Modeled accumulation rates for the Holocene soil are similar for European, Chinese and American loess sites investigated and vary from 0.02 m/ka to 0.09 m/ka.</p>

Luminescence age constraints on the Pleistocene-Holocene transition recorded in loess sequences

2020 ◽  
Author(s):  
Daniela Constantin ◽  
Stefana-Madalina Sacaciu ◽  
Viorica Tecsa ◽  
Anca Avram ◽  
Robert Begy ◽  
...  
Keyword(s):  
Magnetic Susceptibility ◽  
North Atlantic ◽  
Ice Core ◽  
Soil Formation ◽  
Luminescence Dating ◽  
The Holocene ◽  
The Past ◽  
The North ◽  
The North Atlantic ◽  
The Last Glacial

<p>Here we investigate the timing of the last glacial loess - Holocene soil transition recorded in loess-paleosol sequences across the Chinese Loess Plateau, the SE European loess belt and the Central Great Plains, Nebraska, USA by applying comparative luminescence dating techniques on quartz and feldspars. Equivalent dose measurements were carried out using the single-aliquot regenerative-dose (SAR) protocol on silt (4–11 μm) and sand-sized (63–90 μm and coarser fraction when available) quartz. Feldspar infrared stimulated luminescence (IRSL) emitted by 4–11 μm polymineral grains was measured using the post IR-IRSL<sub>290</sub> technique.</p><p>The paleoenvironmental transition from the last glacial loess to the current interglacial soil was characterized using magnetic susceptibility and its frequency dependence. Based on the OSL ages and the threshold of the magnetic signal enhancement the onset of soil formation started around Termination 1 (~17 ka in the North Atlantic) as observed in radiocarbon-dated regional benthic δ<sup>18</sup>O stacks (Stern and Lisiecki, 2014) but before the stratigraphic Pleistocene/Holocene transition dated at 11.7 ka in ice core records (Svensson et al., 2008).</p><p>No major hiatuses in ages are identified in the investigated sites. A change in the sedimentation rate is generally observed at the Pleistocene-Holocene transition and no significant sedimentation change during the Holocene. Sedimentation rates of around 6 cm/ka are determined for the Holocene soil in most of the sites investigated.</p><p>The magnetic susceptibility indicates a gradual increase in pedogenesis after Termination 1 (∼17 ka in the North Atlantic). Based on this, we infer that the upbuilding soil formation prevailed over topdown soil formation during the Pleistocene-Holocene transition in the investigated sites (Roberts, 2008).</p><p> </p><p>References</p><p>Roberts, H.M., 2008. The development and application of luminescence dating to loess deposits: a perspective on the past, present and future. Boreas 37, 483-507.</p><p>Svensson, A., Andersen, K.K., Bigler, M., Clausen, H.B., Dahl-Jensen, D., Davies, S.M., Johnsen, S.J., Muscheler, R., Parrenin, F., Rasmussen, S.O., Röthlisberger, R., Seierstad, I., Steffensen, J.P., Vinther, B.M., 2008.A 60 000 year Greenland stratigraphic ice core chronology. Climate of the Past 4, 47-57.</p><p>Stern, J.V., Lisiecki, L.E., 2014. Termination 1 timing in radiocarbon-dated regional benthic δ18O stacks. Paleoceanography 29, 1127-1142.</p><p> </p><p>This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme ERC-2015-STG (grant agreement No [678106]).</p>

Northern Hemisphere temperature to precipitation relationships during the last Glacial from pollen records and climate simulations

2020 ◽  
Author(s):  
Anna Sommani ◽  
Nils Weitzel ◽  
Kira Rehfeld
Keyword(s):  
Northern Hemisphere ◽  
Negative Correlation ◽  
Climate Models ◽  
Seasonal Rainfall ◽  
The Holocene ◽  
Last Glacial ◽  
Temperature And Precipitation ◽  
Climate Simulations ◽  
Pollen Records ◽  
The Last Glacial

<p>The hydrological response to radiative forcing is less understood than the thermal one: many climate models have difficulties in simulating seasonal rainfall and its variability. Indeed, future precipitation projections are much more uncertain than those of temperature. However, confident projections of precipitation are of crucial importance, particularly for highly populated regions where agriculture strongly relies on seasonal rainfall, such as South and Central Asia.</p><p>Instrumental data from Eurasia show a negative correlation between temperature and precipitation on short timescales (10<sup>-3</sup> to 10<sup>0</sup> years). However, on longer timescales (10<sup>1</sup> to 10<sup>3</sup> years), proxy data covering the Holocene show a positive correlation between temperature and precipitation. Climate models in contrast simulate a negative correlation on all timescales. To extend previous estimates to longer time scales, we focus on the last Glacial period, characterized by colder temperature than the Holocene as well as pronounced millennial-scale climate fluctuations in the Northern Hemisphere.</p><p>We reconstruct temperature and precipitation from four high resolution pollen records at mid-latitudes in the Northern Hemisphere. The estimates are compared with climate simulations. The chosen proxy sites cover the East and West coasts of both the Eurasian and North American continent. We employ four different statistical reconstruction methods to assess validity and biases of each method. The differences between reconstructed and simulated temperature-precipitation relationships as well as the zonal structure of orbital- and millennial-scale variations are examined. In particular, we explore the thermodynamic and dynamic contributions to the inferred relationships between temperature and precipitation.</p>

scholarly journals High-resolution summer precipitation variations in the western Chinese Loess Plateau during the last glacial

2013 ◽  
Vol 3 (1) ◽  
Author(s):  
Zhiguo Rao ◽  
Fahu Chen ◽  
Hai Cheng ◽  
Weiguo Liu ◽  
Guo'an Wang ◽  
...  
Keyword(s):  
High Resolution ◽  
Loess Plateau ◽  
Summer Precipitation ◽  
Chinese Loess Plateau ◽  
Chinese Loess ◽  
Last Glacial ◽  
The Last Glacial

scholarly journals Millennial-scale atmospheric CO<sub>2</sub> variations during the Marine Isotope Stage 6 period (190–135 ka)

2020 ◽  
Vol 16 (6) ◽  
pp. 2203-2219
Author(s):  
Jinhwa Shin ◽  
Christoph Nehrbass-Ahles ◽  
Roberto Grilli ◽  
Jai Chowdhry Beeman ◽  
Frédéric Parrenin ◽  
...  
Keyword(s):  
High Resolution ◽  
Northern Hemisphere ◽  
Marine Isotope Stage ◽  
Atmospheric Co2 ◽  
Temperature Record ◽  
Glacial Period ◽  
Glacial Cycle ◽  
High Resolution Data ◽  
Last Glacial ◽  
The Last Glacial

Abstract. Using new and previously published CO2 data from the EPICA Dome C ice core (EDC), we reconstruct a new high-resolution record of atmospheric CO2 during Marine Isotope Stage (MIS) 6 (190 to 135 ka)  the penultimate glacial period. Similar to the last glacial cycle, where high-resolution data already exists, our record shows that during longer North Atlantic (NA) stadials, millennial CO2 variations during MIS 6 are clearly coincident with the bipolar seesaw signal in the Antarctic temperature record. However, during one short stadial in the NA, atmospheric CO2 variation is small (∼5 ppm) and the relationship between temperature variations in EDC and atmospheric CO2 is unclear. The magnitude of CO2 increase during Carbon Dioxide Maxima (CDM) is closely related to the NA stadial duration in both MIS 6 and MIS 3 (60–27 ka). This observation implies that during the last two glacials the overall bipolar seesaw coupling of climate and atmospheric CO2 operated similarly. In addition, similar to the last glacial period, CDM during the earliest MIS 6 show different lags with respect to the corresponding abrupt CH4 rises, the latter reflecting rapid warming in the Northern Hemisphere (NH). During MIS 6i at around 181.5±0.3 ka, CDM 6i lags the abrupt warming in the NH by only 240±320 years. However, during CDM 6iv (171.1±0.2 ka) and CDM 6iii (175.4±0.4 ka) the lag is much longer: 1290±540 years on average. We speculate that the size of this lag may be related to a larger expansion of carbon-rich, southern-sourced waters into the Northern Hemisphere in MIS 6, providing a larger carbon reservoir that requires more time to be depleted.

Southern Chilean continent-ocean interaction over the last glacial cycle

2020 ◽  
Author(s):  
Julia Rieke Hagemann ◽  
Frank Lamy ◽  
Kana Nagashima ◽  
Naomi Harada ◽  
Shinya Iwasaki ◽  
...  
Keyword(s):  
High Resolution ◽  
Ice Sheet ◽  
Water Masses ◽  
Marine Isotope Stage ◽  
Glacial Period ◽  
The Holocene ◽  
Last Glacial ◽  
Subsurface Temperatures ◽  
Chilean Margin ◽  
The Last Glacial

&lt;p&gt;Available sea surface temperature (SST) records from the subantarctic SE Pacific reveal large amplitude changes at orbital time-scales. High sedimentation rates along the southern Chilean margin provided higher resolution records back to ~70 ka showing millennial-scale SST variations paralleling temperatures reconstructed in Antarctic ice-cores.&lt;/p&gt;&lt;p&gt;Here we present high-resolution millennial-scale SST and subsurface temperature records based on core MR16-09 PC03 covering a complete glacial/interglacial cycle back to Marine Isotope Stage 6, including a high-resolution record of the Eemian. Located on the Chilean margin at the bifurcation of the Antarctic Circumpolar Current into the Peru-Chile Current to the North and the Cape Horn Current to the South, core MR16-09 PC03 is in an ideal position to study the continent-ocean interactions, including changes in water masses, ice sheet formation, precipitation and vegetation.&lt;/p&gt;&lt;p&gt;We used alkenones and GDGTs to determine SST (U&lt;sup&gt;K&amp;#8217;&lt;/sup&gt;&lt;sub&gt;37&lt;/sub&gt;) and subsurface temperatures (TEX&lt;sup&gt;H&lt;/sup&gt;&lt;sub&gt;86&lt;/sub&gt;; 0 - 200 m), and integrated these results with XRF core scanner and planktic &amp;#948;&lt;sup&gt;18&lt;/sup&gt;O data (&lt;em&gt;G. &lt;/em&gt;&lt;em&gt;bulloides&lt;/em&gt;). During the Eemian, SSTs and subsurface temperatures were ~2&amp;#176; C and ~4&amp;#176; C, higher than during the Holocene, respectively. The high Eemian temperatures at our site are roughly consistent with the few available subantarctic SST records. The large temperature difference in the subsurface water masses between the Eemian and the Holocene could be explained by a deeper thermocline during the Eemian. During the last glacial period, the strongly fluctuating temperatures averaged ~8&amp;#176; C at the surface and ~6&amp;#176; C in the subsurface. The relative amount of C&lt;sub&gt;37:4&lt;/sub&gt; alkenone (%C&lt;sub&gt;37:4&lt;/sub&gt;) show a drastic increase during the glacial period, especially in Marine Isotope Stage 3 in concentration. High %C&lt;sub&gt;37:4&lt;/sub&gt; values suggest increased freshwater supply, which could be related to fluctuations of the Patagonian Ice sheet and/ or precipitation on the adjacent land. The sedimentation rate and other terrigenous proxies, e.g. Titanium, BIT, Iron and Alkanes, confirm such increased and highly variable terrestrial inputs.&lt;/p&gt;

scholarly journals Paleoenvironments from robust loess stratigraphy using high-resolution color and grain-size data of the last glacial Krems-Wachtberg record (NE Austria)

2020 ◽  
Vol 248 ◽  
pp. 106602
Author(s):  
Tobias Sprafke ◽  
Philipp Schulte ◽  
Simon Meyer-Heintze ◽  
Marc Händel ◽  
Thomas Einwögerer ◽  
...  
Keyword(s):  
Grain Size ◽  
High Resolution ◽  
Last Glacial ◽  
Size Data ◽  
The Last Glacial

scholarly journals Investigating the evolution of major Northern Hemisphere ice sheets during the last glacial-interglacial cycle

2009 ◽  
Vol 5 (3) ◽  
pp. 329-345 ◽  
Author(s):  
S. Bonelli ◽  
S. Charbit ◽  
M. Kageyama ◽  
M.-N. Woillez ◽  
G. Ramstein ◽  
...  
Keyword(s):  
Northern Hemisphere ◽  
Climate Model ◽  
Ice Sheets ◽  
Ice Sheet ◽  
Co2 Concentration ◽  
Atmospheric Co2 ◽  
Glacial Cycle ◽  
Last Glacial ◽  
Atmospheric Co2 Concentration ◽  
The Last Glacial

Abstract. A 2.5-dimensional climate model of intermediate complexity, CLIMBER-2, fully coupled with the GREMLINS 3-D thermo-mechanical ice sheet model is used to simulate the evolution of major Northern Hemisphere ice sheets during the last glacial-interglacial cycle and to investigate the ice sheets responses to both insolation and atmospheric CO2 concentration. This model reproduces the main phases of advance and retreat of Northern Hemisphere ice sheets during the last glacial cycle, although the amplitude of these variations is less pronounced than those based on sea level reconstructions. At the last glacial maximum, the simulated ice volume is 52.5×1015 m3 and the spatial distribution of both the American and Eurasian ice complexes is in reasonable agreement with observations, with the exception of the marine parts of these former ice sheets. A set of sensitivity studies has also been performed to assess the sensitivity of the Northern Hemisphere ice sheets to both insolation and atmospheric CO2. Our results suggest that the decrease of summer insolation is the main factor responsible for the early build up of the North American ice sheet around 120 kyr BP, in agreement with benthic foraminifera δ18O signals. In contrast, low insolation and low atmospheric CO2 concentration are both necessary to trigger a long-lasting glaciation over Eurasia.

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