Geomorphological, chronological, and paleoenvironmental context of the Mousterian site at Roca San Miguel (Arén, Huesca, Spain) from the penultimate to the last glacial cycle

2021 ◽  
pp. 1-20
Author(s):  
José Luis Peña-Monné ◽  
Lourdes Montes Ramírez ◽  
María Marta Sampietro-Vattuone ◽  
Rafael Domingo Martínez ◽  
Alicia Medialdea ◽  
...  
Keyword(s):  
Evolutionary Model ◽  
Archaeological Site ◽  
Optically Stimulated Luminescence ◽  
Marine Isotope Stage ◽  
Paleoenvironmental Reconstruction ◽  
Glacial Period ◽  
Glacial Cycle ◽  
Last Glacial ◽  
The Last Glacial

Abstract The Roca San Miguel (RSM) archaeological site was occupied during Mousterian times. Here we present a geoarchaeological and paleoenvironmental reconstruction of the site. Five stratigraphic units (A to E) formed by different archaeological levels are identified. Three optically stimulated luminescence (OSL) ages show that Unit A dates to between 169.6 ± 9.1 and 151.9 ± 11.1 ka, during the penultimate glacial period (PGP), and contains numerous signs of recurring hearths. Unit B is unexcavated. Unit C dates to between 118.9 ± 11.5 and 103.4 ± 6.9 ka (late Eemian–marine isotope stage (MIS) 5d) and shows an abundance of lithic remains as well as some faunal elements. Unit C is covered by Unit D, which incorporates materials moved downslope, and is dated at 81.2 ± 4.7 ka. These OSL ages concur with U/Th ages (129.3 ± 1.5 and 123.6 ± 0.6 ka) derived from a flowstone covered by both -C and D- post-flowstone units. Finally, Unit E covers the archaeological site, which was partially eroded during MIS2. The robust and well-constrained chronology of the RSM site and surroundings enables the establishment of its evolutionary model from the PGP to the last glacial cycle. The RSM site is the oldest Neanderthal occupation accurately dated in the Pre-Pyrenean region.

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.

CLIMATE@COA project: Climate and human adaptation during the Last Glacial Period in the Côa Valley region (Portugal)

2021 ◽  
Author(s):  
Luca Dimuccio ◽  
Thierry Aubry ◽  
Lúcio Cunha ◽  
Nelson Rodrigues
Keyword(s):  
Late Pleistocene ◽  
Interdisciplinary Approach ◽  
Evolutionary Model ◽  
Depositional Environments ◽  
Glacial Period ◽  
Upper Palaeolithic ◽  
Last Glacial Period ◽  
Last Glacial ◽  
North East ◽  
The Last Glacial

&lt;p&gt;In Portugal, climate fluctuations of Late Pleistocene are well-known from marine record on the western Iberian continental margin, particularly of Marine Isotope Stages 4, 3 and 2, and they include various events of secular abrupt climate changes. During cooling phases the Heinrich Events (HE) occurred, corresponding to episodes of massive ice-discharges from Northern Hemisphere ice sheets. Furthermore, several climate phases with relatively warmer conditions, known as Dansgaard-Oeschger (D-O) cycles, characterized by an abrupt warming (D-O event) followed by a more gradual cooling, took place in-between HE. This pronounced climate instability that characterizes the Last Glacial Period between ca. 80-12 ka is recorded in a variety of marine and terrestrial archives worldwide. It had a recognized impact on the bioclimatic zones and, possibly, on the Neanderthal and Anatomically Modern Human (AMH) settlements of Iberia.&lt;/p&gt;&lt;p&gt;Based mainly on the study of geoarchaeological records preserved in caves and rock-shelters of Iberia, a correlation framework with climate shifts has been proposed to explain the observed discontinuities between sequences containing late Middle and early Upper Palaeolithic remains. Moreover, a climate driven model has been advanced to explain the chronological differences between northern and southern Pyrenean data by a later dispersion of AMH and the persistence of last Neanderthals in Southern Iberia, which were interpreted as a direct impact of HE4 (40-38 ka) in the distribution of large ungulate populations.&lt;/p&gt;&lt;p&gt;Despite all these data, the exact impact of HE on terrestrial systems, the evaluation of the latitudinal differentiation of their impact and time-gap, as well as the correlation between periods of relative stabilization/soil formation and the D-O events remain to be clearly established. In addition, the whole framework relating to the Middle-to-Upper Palaeolithic transition has been excessively dependent on karst archives and it should be investigated in other geomorphological settings - among these the fluvial and Iberian plateau (&amp;#8220;Meseta&amp;#8221;), both present in the C&amp;#244;a Valley region (Douro Basin, north-east of Portugal). Alluvial and colluvial deposits preserved in the C&amp;#244;a Valley (e.g. at the Cardina-Salto do Boi, Quinta da Barca Sul, Penascosa, Fariseu, Olga de Ervamoira sites) have demonstrated to be a valuable record of information about Late Pleistocene sedimentary processes, depositional environments, and hunter-gatherer&amp;#8217;s behaviour at local and regional scales.&lt;/p&gt;&lt;p&gt;In this context, the CLIMATE@COA project (COA/CAC/0031/2019), funded by the Funda&amp;#231;&amp;#227;o para a Ci&amp;#234;ncia e Tecnologia (FCT), proposes an integrated multi/interdisciplinary approach based on the stratigraphical, sedimentological, geochemical, geomorphological, geoarchaeological, and geochronological analyses of terrestrial record (natural and cultural) preserved in the C&amp;#244;a Valley and surrounding plateau areas, with the aim to develop an evolutionary model for the region and to deduce the environmental forcing factors for such evolution - namely climate and ecosystem changes. In addition, the project&amp;#8217;s data will allow to define better the chronology of the transition between Neanderthal and AMH and to infer on land use and social organization in its environmental context.&lt;/p&gt;

scholarly journals Ice-sheet models as tools for palaeoclimatic analysis: the example of the European ice sheet through the last glacial cycle

1995 ◽  
Vol 21 ◽  
pp. 103-110 ◽  
Author(s):  
G. S. Boulton ◽  
N. Hulton ◽  
M. Vautravers
Keyword(s):  
Numerical Model ◽  
Ice Sheets ◽  
Ice Sheet ◽  
Early Holocene ◽  
Climate Forcing ◽  
Glacial Period ◽  
Glacial Cycle ◽  
Last Glacial ◽  
Sheet Surface ◽  
The Last Glacial

A numerical model is used to simulate ice-sheet behaviour in Europe through the last glacial cycle. It is used in two modes: a forward mode, in which the model is driven by a proxy palaeoclimate record and the output compared with a geological reconstruction of ice-sheet fluctuation; and an inverse mode, in which we determine the climate function that would be required to simulate geologically reconstructed ice-sheet fluctuations. From these simulations it is concluded that extra-glacial climates may be poor predictors of ice-sheet surface climates, and that climatic transitions during the glacial period may have been much more rapid and the intensity of warming during the early Holocene much greater than hitherto supposed. Stronger climate forcing is required to drive ice-sheet expansion when sliding occurs at the bed compared with a non-sliding bed. Sliding ice sheets grow more slowly and decay more rapidly than non-sliding ice sheets with the same climate forcing.

scholarly journals Ice-sheet models as tools for palaeoclimatic analysis: the example of the European ice sheet through the last glacial cycle

1995 ◽  
Vol 21 ◽  
pp. 103-110
Author(s):  
G. S. Boulton ◽  
N. Hulton ◽  
M. Vautravers
Keyword(s):  
Numerical Model ◽  
Ice Sheets ◽  
Ice Sheet ◽  
Early Holocene ◽  
Climate Forcing ◽  
Glacial Period ◽  
Glacial Cycle ◽  
Last Glacial ◽  
Sheet Surface ◽  
The Last Glacial

A numerical model is used to simulate ice-sheet behaviour in Europe through the last glacial cycle. It is used in two modes: a forward mode, in which the model is driven by a proxy palaeoclimate record and the output compared with a geological reconstruction of ice-sheet fluctuation; and an inverse mode, in which we determine the climate function that would be required to simulate geologically reconstructed ice-sheet fluctuations.From these simulations it is concluded that extra-glacial climates may be poor predictors of ice-sheet surface climates, and that climatic transitions during the glacial period may have been much more rapid and the intensity of warming during the early Holocene much greater than hitherto supposed. Stronger climate forcing is required to drive ice-sheet expansion when sliding occurs at the bed compared with a non-sliding bed. Sliding ice sheets grow more slowly and decay more rapidly than non-sliding ice sheets with the same climate forcing.

scholarly journals Dansgaard–Oeschger-like events of the penultimate climate cycle: the loess point of view

2020 ◽  
Vol 16 (2) ◽  
pp. 713-727 ◽  
Author(s):  
Denis-Didier Rousseau ◽  
Pierre Antoine ◽  
Niklas Boers ◽  
France Lagroix ◽  
Michael Ghil ◽  
...  
Keyword(s):  
Ice Core ◽  
Spatial Coherence ◽  
Point Of View ◽  
Optically Stimulated Luminescence ◽  
Glacial Cycle ◽  
Last Glacial ◽  
Climate Cycle ◽  
Statistical Similarity ◽  
The Last Glacial ◽  
Millennial Scale

Abstract. The global character of the millennial-scale climate variability associated with the Dansgaard–Oeschger (DO) events in Greenland has been well-established for the last glacial cycle. Mainly due to the sparsity of reliable data, however, the spatial coherence of corresponding variability during the penultimate cycle is less clear. New investigations of European loess records from Marine Isotope Stage (MIS) 6 reveal the occurrence of alternating loess intervals and paleosols (incipient soil horizons), similar to those from the last climatic cycle. These paleosols are correlated, based on their stratigraphical position and numbers as well as available optically stimulated luminescence (OSL) dates, with interstadials described in various Northern Hemisphere records and in GLt_syn, the synthetic 800 kyr record of Greenland ice core δ18O. Therefore, referring to the interstadials described in the record of the last climate cycle in European loess sequences, the four MIS 6 interstadials can confidently be interpreted as DO-like events of the penultimate climate cycle. Six more interstadials are identified from proxy measurements performed on the same interval, leading to a total of 10 interstadials with a DO-like event status. The statistical similarity between the millennial-scale loess–paleosol oscillations during the last and penultimate climate cycle provides direct empirical evidence that the cycles of the penultimate cycle are indeed of the same nature as the DO cycles originally discovered for the last glacial cycle. Our results thus imply that their underlying cause and global imprint were characteristic of at least the last two climate cycles.

scholarly journals DO-like events of the penultimate climate cycle: the loess point of view

2019 ◽  
Author(s):  
Denis-Didier Rousseau ◽  
Pierre Antoine ◽  
Niklas Boers ◽  
France Lagroix ◽  
Michael Ghil ◽  
...  
Keyword(s):  
Ice Core ◽  
Spatial Coherence ◽  
Point Of View ◽  
Optically Stimulated Luminescence ◽  
Glacial Cycle ◽  
Last Glacial ◽  
Climate Cycle ◽  
Statistical Similarity ◽  
The Last Glacial ◽  
Millennial Scale

Abstract. The global character of the millennial-scale climate variability associated with the Dansgaard-Oeschger (DO) events in Greenland has been well-established for the last glacial cycle. Mainly due to the sparsity of reliable data, however, the spatial coherence of corresponding variability during the penultimate cycle is less clear. New investigations of European loess records from MIS 6 reveal the occurrence of alternating loess intervals and paleosols (incipient soil horizons), similar to those from the last climatic cycle. These paleosols are correlated based on their stratigraphical position and numbers, and available optically stimulated luminescence (OSL) dates with interstadials described in various Northern Hemisphere records as well as in GLt_syn, the synthetic 800-kyr record of Greenland ice core δ18O. Therefore, referring to the interstadials described in the record of the last climate cycle in European loess sequences, the MIS 6 interstadials can confidently be interpreted as DO-like events of the penultimate climate cycle. The statistical similarity between the millennial-scale loess-paleosol oscillations during the last and penultimate climate cycle provides direct empirical evidence that the cycles of the penultimate cycle are indeed of the same nature as the DO cycles originally discovered for the last glacial cycle. Our results thus imply that their underlying cause and global imprint was characteristic of at least the last two climate cycles.

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 Chronology and provenance of last-glacial (peoria) loess in western iowa and paleoclimatic implications

2013 ◽  
Vol 80 (3) ◽  
pp. 468-481 ◽  
Author(s):  
Daniel R. Muhs ◽  
E. Arthur Bettis III ◽  
Helen M. Roberts ◽  
Stephen S. Harlan ◽  
James B. Paces ◽  
...  
Keyword(s):  
Grain Size ◽  
Missouri River ◽  
Optically Stimulated Luminescence ◽  
Laurentide Ice Sheet ◽  
Glacial Period ◽  
Accumulation Rates ◽  
Last Glacial Period ◽  
Last Glacial ◽  
The Earth ◽  
The Last Glacial

Geologic archives show that the Earth was dustier during the last glacial period. One model suggests that increased gustiness (stronger, more frequent winds) enhanced dustiness. We tested this at Loveland, Iowa, one of the thickest deposits of last-glacial-age (Peoria) loess in the world. Based on K/Rb and Ba/Rb, loess was derived not only from glaciogenic sources of the Missouri River, but also distal loess from non-glacial sources in Nebraska. Optically stimulated luminescence (OSL) ages provide the first detailed chronology of Peoria Loess at Loveland. Deposition began after ~ 27 ka and continued until ~ 17 ka. OSL ages also indicate that mass accumulation rates (MARs) of loess were not constant. MARs were highest and grain size was coarsest during the time of middle Peoria Loess accretion, ~ 23 ka, when ~ 10 m of loess accumulated in no more than ~ 2000 yr and possibly much less. The timing of coarsest grain size and highest MAR, indicating strongest winds, coincides with a summer-insolation minimum at high latitudes in North America and the maximum southward extent of the Laurentide ice sheet. These observations suggest that increased dustiness during the last glacial period was driven largely by enhanced gustiness, forced by a steepened meridional temperature gradient.

Effects of glaciation on karst hydrology and sedimentology during the Last Glacial Cycle: The case of Granito cave, Central Pyrenees (Spain)

CATENA ◽  
2021 ◽  
Vol 206 ◽  
pp. 105252
Author(s):  
Miguel Bartolomé ◽  
Carlos Sancho ◽  
Gerardo Benito ◽  
Alicia Medialdea ◽  
Mikel Calle ◽  
...  
Keyword(s):  
Karst Hydrology ◽  
Glacial Cycle ◽  
Last Glacial ◽  
Central Pyrenees ◽  
The Last Glacial
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