Pub Date : 2024-10-31DOI: 10.1016/j.quascirev.2024.109012
Maximilian Prochnow , Katharina Dulias , Paul Strobel , Marcel Bliedtner , Gerhard Daut , Sönke Szidat , Gary Salazar , Franziska Lechleitner , Sudip Acharya , Rodrigo Martínez-Abarca , Anja Schwarz , Antje Schwalb , Roland Zech
Understanding Holocene hydroclimatic variability in the European Alps is challenging due to spatial and temporal disparities between the northern and southern Alps. In addition, interpreting lake sediment records in terms of paleohydrology is complicated by human presence during Roman and Medieval settlements, which increased soil erosion and lake eutrophication. Here, we present a ∼4440-year long sediment record from Schliersee, Bavaria, where we applied compound-specific δ2H on leaf waxes, geochemical and diatom analyses to reconstruct hydrology and lake productivity. The terrestrial δ2Hn-C31 records the isotopic composition of precipitation and is similar to leaf wax δ2H from Lake Ghirla, southern Alps, and δ18O from Spannagel cave in Austria. This provides evidence that, on millennial time scales, changes in moisture sources associated with shifts in the position of the Westerlies are one potential explanation regarding the isotope signals across the region. However, doubts remain whether the North Atlantic Oscillation as a winter signal can explain variations in summer-sensitive biomarker δ2H records. The aquatic δ2Hn-C25 records the isotopic composition of lake water and its isotopic offset to δ2Hn-C31 (Δaq–terr) is applied as a proxy for lake evaporation. We find increased evaporation during the Medieval Climate Anomaly in line with a drought reported from tree-ring studies, whereas lower evaporation prevailed during the Little Ice Age, likely due to solar forcing. Lake productivity was higher during the Roman period and Middle Ages, concomitant with land use resulting in higher nutrient inputs into the lake. The intensified use of industrial fertilizers and the drainage of untreated wastewater after the Second World War caused eutrophication during the 1950s. Despite its paleoclimatic significance, this study emphasizes that multi-proxy approaches combining assemblages of geochemical and biological proxies allow robust reconstructions of climate–landscape interactions and human impact.
{"title":"Paleohydrology and human driven paleoproductivity during the Late Holocene from Schliersee, Bavaria","authors":"Maximilian Prochnow , Katharina Dulias , Paul Strobel , Marcel Bliedtner , Gerhard Daut , Sönke Szidat , Gary Salazar , Franziska Lechleitner , Sudip Acharya , Rodrigo Martínez-Abarca , Anja Schwarz , Antje Schwalb , Roland Zech","doi":"10.1016/j.quascirev.2024.109012","DOIUrl":"10.1016/j.quascirev.2024.109012","url":null,"abstract":"<div><div>Understanding Holocene hydroclimatic variability in the European Alps is challenging due to spatial and temporal disparities between the northern and southern Alps. In addition, interpreting lake sediment records in terms of paleohydrology is complicated by human presence during Roman and Medieval settlements, which increased soil erosion and lake eutrophication. Here, we present a ∼4440-year long sediment record from Schliersee, Bavaria, where we applied compound-specific δ<sup>2</sup>H on leaf waxes, geochemical and diatom analyses to reconstruct hydrology and lake productivity. The terrestrial δ<sup>2</sup>H<sub><em>n</em>-C31</sub> records the isotopic composition of precipitation and is similar to leaf wax δ<sup>2</sup>H from Lake Ghirla, southern Alps, and δ<sup>18</sup>O from Spannagel cave in Austria. This provides evidence that, on millennial time scales, changes in moisture sources associated with shifts in the position of the Westerlies are one potential explanation regarding the isotope signals across the region. However, doubts remain whether the North Atlantic Oscillation as a winter signal can explain variations in summer-sensitive biomarker δ<sup>2</sup>H records. The aquatic δ<sup>2</sup>H<sub><em>n</em>-C25</sub> records the isotopic composition of lake water and its isotopic offset to δ<sup>2</sup>H<sub><em>n</em>-C31</sub> (Δ<sub>aq–terr</sub>) is applied as a proxy for lake evaporation. We find increased evaporation during the Medieval Climate Anomaly in line with a drought reported from tree-ring studies, whereas lower evaporation prevailed during the Little Ice Age, likely due to solar forcing. Lake productivity was higher during the Roman period and Middle Ages, concomitant with land use resulting in higher nutrient inputs into the lake. The intensified use of industrial fertilizers and the drainage of untreated wastewater after the Second World War caused eutrophication during the 1950s. Despite its paleoclimatic significance, this study emphasizes that multi-proxy approaches combining assemblages of geochemical and biological proxies allow robust reconstructions of climate–landscape interactions and human impact.</div></div>","PeriodicalId":20926,"journal":{"name":"Quaternary Science Reviews","volume":"345 ","pages":"Article 109012"},"PeriodicalIF":3.2,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554709","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-30DOI: 10.1016/j.quascirev.2024.109045
Roseanna J. Mayfield , Dilli P. Rijal , Peter D. Heintzman , Peter G. Langdon , Dirk N. Karger , Antony G. Brown , Inger G. Alsos
Climate-induced ecotonal shifts are expected to occur in the (sub)arctic and boreal zones in the coming decades. Understanding how these ecosystems have previously responded to climate change can provide greater insight into how ecosystems may develop under existing and future pressures. Here we present a Holocene record from Lake Horntjernet, a lake on the northern edge of the boreal forest in Northern Norway. We show vegetation development and landscape dynamics typical for Northern Fennoscandia during the Holocene. A plant sedaDNA record indicates rapid vegetation development following deglaciation with early arrival of Betula trees/shrubs. Pine forest was established by c. 8500 cal yr BP, and subsequent mid- to late Holocene vegetation assemblages are relatively stable. The aquatic ecosystem community is indicative of climatic change during the early Holocene, while strong coupling with changes in the catchment vegetation affects the water quality during the mid- and late Holocene. The chironomid record indicates lake water acidification following the establishment of pine forest and heathland. Different approaches for temperature reconstruction are calculated and the results are compared to better understand ecosystem-climate relationships and ecosystem resilience to climate change. Chironomid-inferred temperatures indicate early Holocene warming and late Holocene cooling, comparable to independent regional temperature trends. However, lake acidification impedes reliable reconstruction of chironomid-inferred temperatures in the mid-Holocene, a trend recognised in other boreal chironomid records. The application of sedaDNA plant-inferred summer temperature reconstruction is inhibited by the persistence of cold and warm tolerant species within the boreal pine forest. However, a trait-based approach reconstructed temperature trends that aligned with independent regional data. Thus, here we demonstrate the value of combined molecular and fossil-based proxies for elucidating the complex response of a boreal catchment to climate change.
{"title":"Holocene summer temperature reconstruction from plant sedaDNA and chironomids from the northern boreal forest","authors":"Roseanna J. Mayfield , Dilli P. Rijal , Peter D. Heintzman , Peter G. Langdon , Dirk N. Karger , Antony G. Brown , Inger G. Alsos","doi":"10.1016/j.quascirev.2024.109045","DOIUrl":"10.1016/j.quascirev.2024.109045","url":null,"abstract":"<div><div>Climate-induced ecotonal shifts are expected to occur in the (sub)arctic and boreal zones in the coming decades. Understanding how these ecosystems have previously responded to climate change can provide greater insight into how ecosystems may develop under existing and future pressures. Here we present a Holocene record from Lake Horntjernet, a lake on the northern edge of the boreal forest in Northern Norway. We show vegetation development and landscape dynamics typical for Northern Fennoscandia during the Holocene. A plant <em>sed</em>aDNA record indicates rapid vegetation development following deglaciation with early arrival of <em>Betula</em> trees/shrubs. Pine forest was established by c. 8500 cal yr BP, and subsequent mid- to late Holocene vegetation assemblages are relatively stable. The aquatic ecosystem community is indicative of climatic change during the early Holocene, while strong coupling with changes in the catchment vegetation affects the water quality during the mid- and late Holocene. The chironomid record indicates lake water acidification following the establishment of pine forest and heathland. Different approaches for temperature reconstruction are calculated and the results are compared to better understand ecosystem-climate relationships and ecosystem resilience to climate change. Chironomid-inferred temperatures indicate early Holocene warming and late Holocene cooling, comparable to independent regional temperature trends. However, lake acidification impedes reliable reconstruction of chironomid-inferred temperatures in the mid-Holocene, a trend recognised in other boreal chironomid records. The application of <em>sed</em>aDNA plant-inferred summer temperature reconstruction is inhibited by the persistence of cold and warm tolerant species within the boreal pine forest. However, a trait-based approach reconstructed temperature trends that aligned with independent regional data. Thus, here we demonstrate the value of combined molecular and fossil-based proxies for elucidating the complex response of a boreal catchment to climate change.</div></div>","PeriodicalId":20926,"journal":{"name":"Quaternary Science Reviews","volume":"345 ","pages":"Article 109045"},"PeriodicalIF":3.2,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-30DOI: 10.1016/j.quascirev.2024.109004
Israel Jesus Jimenez , César Laplana , María Isabel García-Real , Enrique Baquedano , Juan Luis Arsuaga , Nuria Garcia
In this study, we examine patterns for identifying spotted hyena dens in the fossil record through mortality profiles and discuss their ethological significance as a tool for understanding how this taxon occupied cavities in the past. We analysed the age structure of the spotted hyena from the Upper Pleistocene site of Cueva del Camino (Pinilla del Valle, Madrid) and compared it with other sites as well as with a modern hyena population. We interpret the mortality profile obtained at Cueva del Camino as indicative of a spotted hyena den, specifically a communal den, due to the scarcity of neonates and the high percentage of juveniles in the communal denning period. In the comparative analysis, we found a pattern in spotted hyena mortality profiles that can help classify denning behaviour in the fossil record: the composition of communal denning populations should comprise more than seventy percent juveniles, and the proportion of adults should be lower than that of older adults. Furthermore, for the first time, we can also statistically discriminate between den and non-den occupations. However, one of the main issues that arise with statistics is that when the sample size is low, confidence is reduced, which can lead to misinterpretations of the type of occupation. As an alternative approach, we followed the method of Discamps and Costamagno to adapt the ternary diagram demarcation to the spotted hyena, based on species-specific age class boundaries. Based on this method, we propose that: (I) the JOP zone could be associated with sites used as communal dens by hyenas, (II) the JPO zone could be designated for sites where a clan, including cubs, used the cave for living, and (III) the O and P zones could be related to sporadic occupations by hyenas.
在这项研究中，我们通过死亡率剖面图研究了在化石记录中识别斑鬣狗巢穴的模式，并讨论了其作为了解该类群过去如何占据洞穴的工具的伦理意义。我们分析了上更新世 Cueva del Camino（马德里，Pinilla del Valle）遗址中斑鬣狗的年龄结构，并将其与其他遗址以及现代鬣狗种群进行了比较。我们将在 Cueva del Camino 发现的死亡特征解释为斑鬣狗巢穴，特别是群居巢穴，因为在群居巢穴时期，新生鬣狗很少，而幼年鬣狗的比例很高。在比较分析中，我们发现了斑鬣狗的死亡特征，这有助于对化石记录中的穴居行为进行分类：群居穴居种群的构成中，幼年斑鬣狗的比例应超过 70%，成年斑鬣狗的比例应低于老年斑鬣狗。此外，我们还首次可以从统计学角度区分穴居和非穴居。然而，统计中出现的一个主要问题是，当样本量较少时，置信度会降低，从而导致对职业类型的误读。作为一种替代方法，我们采用了 Discamps 和 Costamagno 的方法，根据斑鬣狗物种特有的年龄等级界限，将三元图划分法应用到斑鬣狗身上。根据这种方法，我们建议(I)JOP区可能与鬣狗用作公共巢穴的地点有关，(II)JPO区可能指定为包括幼崽在内的一个氏族使用洞穴生活的地点，(III)O区和P区可能与鬣狗的零星占用有关。
{"title":"“Society of the den”: Identifying patterns of denning behaviour in Upper Pleistocene hyena populations","authors":"Israel Jesus Jimenez , César Laplana , María Isabel García-Real , Enrique Baquedano , Juan Luis Arsuaga , Nuria Garcia","doi":"10.1016/j.quascirev.2024.109004","DOIUrl":"10.1016/j.quascirev.2024.109004","url":null,"abstract":"<div><div>In this study, we examine patterns for identifying spotted hyena dens in the fossil record through mortality profiles and discuss their ethological significance as a tool for understanding how this taxon occupied cavities in the past. We analysed the age structure of the spotted hyena from the Upper Pleistocene site of Cueva del Camino (Pinilla del Valle, Madrid) and compared it with other sites as well as with a modern hyena population. We interpret the mortality profile obtained at Cueva del Camino as indicative of a spotted hyena den, specifically a communal den, due to the scarcity of neonates and the high percentage of juveniles in the communal denning period. In the comparative analysis, we found a pattern in spotted hyena mortality profiles that can help classify denning behaviour in the fossil record: the composition of communal denning populations should comprise more than seventy percent juveniles, and the proportion of adults should be lower than that of older adults. Furthermore, for the first time, we can also statistically discriminate between den and non-den occupations. However, one of the main issues that arise with statistics is that when the sample size is low, confidence is reduced, which can lead to misinterpretations of the type of occupation. As an alternative approach, we followed the method of Discamps and Costamagno to adapt the ternary diagram demarcation to the spotted hyena, based on species-specific age class boundaries. Based on this method, we propose that: (I) the JOP zone could be associated with sites used as communal dens by hyenas, (II) the JPO zone could be designated for sites where a clan, including cubs, used the cave for living, and (III) the O and P zones could be related to sporadic occupations by hyenas.</div></div>","PeriodicalId":20926,"journal":{"name":"Quaternary Science Reviews","volume":"345 ","pages":"Article 109004"},"PeriodicalIF":3.2,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142554758","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The article deals with stable isotopes of oxygen and carbon on current and archaeological semi-aquatic gastropod shell of the Pila wernei from Sudan and reports some new 14C analyses on archaeological Pila specimens. This, with the aim of obtaining new information on climatic and environmental changes in the al-Khiday area during the first phase of Holocene. The Pila shells come from a well-preserved shell midden present at al-Khiday and dated 8700-7000 cal yr BP. The area of al-Khiday was inhabited since at least 10 ka. Pila wernei species has never been studied in detail; this study demonstrates that the O and C isotope composition of aragonite shell is able to record the environmental and diet changes during the gastropod life. The comparison between the isotope data obtained on present-day and archaeological shells show a prevalence of C4 plants and higher rainfall during the Mesolithic. Two climatic fluctuations have been recognised: the first one indicating wetter conditions from 8650-8400 to 8500-8050 cal yr BP (decrease of the δ18O values), the second one pointing less wetter conditions from 8500-8050 to 7850-7600 cal yr BP (increase of δ18O values). Despite the difficulties in studying semi-aquatic gastropods due to their lifestyle habit, the identification of climatic fluctuations in the Early Holocene confirms the reliability of this proxy for climatic reconstructions. Despite the high number of isotopic analyses (1556) used in this work, they were not sufficient to mirror the fast climate changes characterising the studied period and finally obtain a detailed reconstruction for nearly the two millennia considered. Nonetheless, future projects may benefit greatly from unveiling the shell-environment relationship of the species.
{"title":"Stable isotope of Mesolithic remains of Pila wernei of the Nile area, Sudan: A tool for palaeoenvironment reconstruction","authors":"Paola Iacumin , Antonella Macrì , Mattia Rossi , Donatella Usai , Fabio Marzaioli , Sofia Ramigni , Giampiero Venturelli","doi":"10.1016/j.quascirev.2024.109029","DOIUrl":"10.1016/j.quascirev.2024.109029","url":null,"abstract":"<div><div>The article deals with stable isotopes of oxygen and carbon on current and archaeological semi-aquatic gastropod shell of the <em>Pila wernei</em> from Sudan and reports some new <sup>14</sup>C analyses on archaeological <em>Pila</em> specimens. This, with the aim of obtaining new information on climatic and environmental changes in the al-Khiday area during the first phase of Holocene. The <em>Pila</em> shells come from a well-preserved shell midden present at al-Khiday and dated 8700-7000 cal yr BP. The area of al-Khiday was inhabited since at least 10 ka. <em>Pila wernei</em> species has never been studied in detail; this study demonstrates that the O and C isotope composition of aragonite shell is able to record the environmental and diet changes during the gastropod life. The comparison between the isotope data obtained on present-day and archaeological shells show a prevalence of C4 plants and higher rainfall during the Mesolithic. Two climatic fluctuations have been recognised: the first one indicating wetter conditions from 8650-8400 to 8500-8050 cal yr BP (decrease of the δ<sup>18</sup>O values), the second one pointing less wetter conditions from 8500-8050 to 7850-7600 cal yr BP (increase of δ<sup>18</sup>O values). Despite the difficulties in studying semi-aquatic gastropods due to their lifestyle habit, the identification of climatic fluctuations in the Early Holocene confirms the reliability of this proxy for climatic reconstructions. Despite the high number of isotopic analyses (1556) used in this work, they were not sufficient to mirror the fast climate changes characterising the studied period and finally obtain a detailed reconstruction for nearly the two millennia considered. Nonetheless, future projects may benefit greatly from unveiling the shell-environment relationship of the species.</div></div>","PeriodicalId":20926,"journal":{"name":"Quaternary Science Reviews","volume":"345 ","pages":"Article 109029"},"PeriodicalIF":3.2,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142539659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-29DOI: 10.1016/j.quascirev.2024.109020
Attila Çiner , Marc Oliva , Josep Ventura , M. Akif Sarıkaya , Adem Candaş , David Palacios , Onur Altınay , Steven A. Binnie , Natalia Castaneda
The cold and dry Younger Dryas (YD) stadial (ca. 12.9 to 11.7 ka) generated glacial deposits in the Iberian Mountains, often restricted to high altitudes in cirque areas. Contrary to expectations, we encountered well-developed YD moraines at relatively low altitudes on the northern slopes of the Cadí Massif in the Southeastern Pyrenees, Spain. We applied the 36Cl terrestrial cosmogenic nuclides (TCN) surface exposure dating method on 11 limestone boulders collected from three moraines to assess the glacial geochronology and paleoclimate conditions associated with their formation. We report a small but well-preserved moraine at an unusually high altitude for the Southeastern Pyrenees (between 2160 m and 2120 m above sea level; asl) fed by a small hanging glacier that formed at 23.0 ± 1.5 ka during the global Last Glacial Maximum (LGM). Four kilometres west of the LGM moraine, a ca. 2.5 km long glacier originating from one of the largest cirques of the Cadí Massif deposited a ca. 700 m long moraine preserved between 1760 m and 1600 m. As alluvial and periglacial processes heavily modified this moraine, we cautiously attribute its age to 12.9 ± 1.0 ka. This age represents the onset of the YD period following the Bølling-Allerød warming, widespread in the Pyrenees. On the other hand, another ca. 1.7 km long glacier sourced from the adjacent cirques deposited a pair of well-preserved lateral moraines and a terminal moraine ca. 1150 m long. The samples collected from the moraines yielded tightly clustered boulder ages (average age = 12.1 ± 1.1 ka). Although they developed at relatively low elevations (1830–2100 m) with an Equilibrium Line Altitude (ELA) of 2175 m, which is exceptional for the Southeastern Pyrenees, these moraines were formed during the YD stadial. Our study suggests that despite increased glacier retreat in the Mediterranean region, local relief is crucial in preserving ice masses far below the modern glacial belt with ample snow accumulation. We also used the Parallel Ice Sheet Model (PISM) to reconstruct the paleo-ice extents and paleoclimate regime. We propose two equally possible best-fit scenarios for the maximum ice extent of the YD period. The first foresees a 4 °C temperature decline with today's precipitation values, and the second predicts a 5 °C cooling if precipitation were 20% lower than today. Identifying and dating this unexpected YD glaciation on Cadí Massif provides new insights into understanding the Iberian Peninsula's paleoclimate.
{"title":"Late Pleistocene glacial chronology and paleoclimate of the Cadí Massif, SE Pyrenees, Spain: Insights from 36Cl cosmogenic surface exposure dating and glacier modelling","authors":"Attila Çiner , Marc Oliva , Josep Ventura , M. Akif Sarıkaya , Adem Candaş , David Palacios , Onur Altınay , Steven A. Binnie , Natalia Castaneda","doi":"10.1016/j.quascirev.2024.109020","DOIUrl":"10.1016/j.quascirev.2024.109020","url":null,"abstract":"<div><div>The cold and dry Younger Dryas (YD) stadial (<em>ca.</em> 12.9 to 11.7 ka) generated glacial deposits in the Iberian Mountains, often restricted to high altitudes in cirque areas. Contrary to expectations, we encountered well-developed YD moraines at relatively low altitudes on the northern slopes of the Cadí Massif in the Southeastern Pyrenees, Spain. We applied the <sup>36</sup>Cl terrestrial cosmogenic nuclides (TCN) surface exposure dating method on 11 limestone boulders collected from three moraines to assess the glacial geochronology and paleoclimate conditions associated with their formation. We report a small but well-preserved moraine at an unusually high altitude for the Southeastern Pyrenees (between 2160 m and 2120 m above sea level; asl) fed by a small hanging glacier that formed at 23.0 ± 1.5 ka during the global Last Glacial Maximum (LGM). Four kilometres west of the LGM moraine, a <em>ca.</em> 2.5 km long glacier originating from one of the largest cirques of the Cadí Massif deposited a <em>ca.</em> 700 m long moraine preserved between 1760 m and 1600 m. As alluvial and periglacial processes heavily modified this moraine, we cautiously attribute its age to 12.9 ± 1.0 ka. This age represents the onset of the YD period following the Bølling-Allerød warming, widespread in the Pyrenees. On the other hand, another <em>ca.</em> 1.7 km long glacier sourced from the adjacent cirques deposited a pair of well-preserved lateral moraines and a terminal moraine <em>ca.</em> 1150 m long. The samples collected from the moraines yielded tightly clustered boulder ages (average age = 12.1 ± 1.1 ka). Although they developed at relatively low elevations (1830–2100 m) with an Equilibrium Line Altitude (ELA) of 2175 m, which is exceptional for the Southeastern Pyrenees, these moraines were formed during the YD stadial. Our study suggests that despite increased glacier retreat in the Mediterranean region, local relief is crucial in preserving ice masses far below the modern glacial belt with ample snow accumulation. We also used the Parallel Ice Sheet Model (PISM) to reconstruct the paleo-ice extents and paleoclimate regime. We propose two equally possible best-fit scenarios for the maximum ice extent of the YD period. The first foresees a 4 °C temperature decline with today's precipitation values, and the second predicts a 5 °C cooling if precipitation were 20% lower than today. Identifying and dating this unexpected YD glaciation on Cadí Massif provides new insights into understanding the Iberian Peninsula's paleoclimate.</div></div>","PeriodicalId":20926,"journal":{"name":"Quaternary Science Reviews","volume":"345 ","pages":"Article 109020"},"PeriodicalIF":3.2,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142539660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-29DOI: 10.1016/j.quascirev.2024.109030
Duo Wu , Qili Xiao , Shilong Guo , Jinghua Huang , Shuai Shao , Tao Wang , Xuemei Chen , Jiawu Zhang , Aifeng Zhou , Fahu Chen
<div><div>Holocene climate change between different geographic units of the Asian continent exhibits spatiotemporal heterogeneity under the control of different atmospheric circulation systems. Precipitation/moisture variations between the northeastern and southeastern Tibetan Plateau show an out-of-phase pattern on decadal, centennial, and millennial time scales during the Holocene, influenced by interactions between the summer monsoon system and the westerlies. However, conflicting proxies exist in some regions on millennial time scale, and it is vital to detect and evaluate the detailed processes responsible for such a dipolar pattern. Here, we select and summarize well-dated Holocene records of pollen-based vegetation, oxygen isotope composition (δ<sup>18</sup>O) of authigenic carbonates and cellulose, hydrogen isotope composition (δD) of long-chain <em>n</em>-alkanes from leaf wax, and chronology of aeolian activity and soil development from various geological archives, including lake sediments, peat bogs, aeolian deposits, cave speleothems, and tree rings from the eastern margin of the Tibetan Plateau. We find a long-term decreasing trend in summer monsoon precipitation across the eastern Tibetan Plateau during the Holocene, indicated by declining arboreal pollen percentages, enhanced values of δ<sup>18</sup>O from lakes in the southeastern Tibetan Plateau (SETP), speleothems, and tree-ring cellulose, as well as enhanced δD values across the entire eastern margin of the plateau. A summary of the chronology of aeolian sand and paleosol on the northeastern Tibetan Plateau (NETP) reveals enhanced aeolian activity during the early Holocene and increased soil development from the middle Holocene onwards. These data, combined with those indicating increased lake levels and decreased lake-water δ<sup>18</sup>O values in the region, suggest that the effective moisture on the NETP increased throughout the Holocene. Our findings indicate that increased non-monsoon-season precipitation with the strengthening intensity of the westerlies, against a background of possible decreasing summer evaporation, provided increased moisture to the NETP, ultimately resulting in a Holocene dipolar pattern of humidity variations between the northern and southern parts of the eastern margin of the Tibetan Plateau. The inference that the seasonality of precipitation controlled moisture variation in the study region is supported by high-resolution climate proxies and meteorological data on centennial and decadal time scales during the last millennium. Additionally, we propose a conceptual framework of hydroclimatic processes in a land–lake system to reconcile contradictions between different indicators. The present study not only clearly summarizes the Holocene climate change on the eastern margin of the Tibetan Plateau, but it also highlights the critical importance of distinguishing terrestrial and lacustrine signals in paleolimnological studies, and of noting associat
{"title":"Precipitation seasonality in controlling the north‒south dipolar pattern of effective moisture variations on the eastern margin of the Tibetan Plateau during the Holocene","authors":"Duo Wu , Qili Xiao , Shilong Guo , Jinghua Huang , Shuai Shao , Tao Wang , Xuemei Chen , Jiawu Zhang , Aifeng Zhou , Fahu Chen","doi":"10.1016/j.quascirev.2024.109030","DOIUrl":"10.1016/j.quascirev.2024.109030","url":null,"abstract":"<div><div>Holocene climate change between different geographic units of the Asian continent exhibits spatiotemporal heterogeneity under the control of different atmospheric circulation systems. Precipitation/moisture variations between the northeastern and southeastern Tibetan Plateau show an out-of-phase pattern on decadal, centennial, and millennial time scales during the Holocene, influenced by interactions between the summer monsoon system and the westerlies. However, conflicting proxies exist in some regions on millennial time scale, and it is vital to detect and evaluate the detailed processes responsible for such a dipolar pattern. Here, we select and summarize well-dated Holocene records of pollen-based vegetation, oxygen isotope composition (δ<sup>18</sup>O) of authigenic carbonates and cellulose, hydrogen isotope composition (δD) of long-chain <em>n</em>-alkanes from leaf wax, and chronology of aeolian activity and soil development from various geological archives, including lake sediments, peat bogs, aeolian deposits, cave speleothems, and tree rings from the eastern margin of the Tibetan Plateau. We find a long-term decreasing trend in summer monsoon precipitation across the eastern Tibetan Plateau during the Holocene, indicated by declining arboreal pollen percentages, enhanced values of δ<sup>18</sup>O from lakes in the southeastern Tibetan Plateau (SETP), speleothems, and tree-ring cellulose, as well as enhanced δD values across the entire eastern margin of the plateau. A summary of the chronology of aeolian sand and paleosol on the northeastern Tibetan Plateau (NETP) reveals enhanced aeolian activity during the early Holocene and increased soil development from the middle Holocene onwards. These data, combined with those indicating increased lake levels and decreased lake-water δ<sup>18</sup>O values in the region, suggest that the effective moisture on the NETP increased throughout the Holocene. Our findings indicate that increased non-monsoon-season precipitation with the strengthening intensity of the westerlies, against a background of possible decreasing summer evaporation, provided increased moisture to the NETP, ultimately resulting in a Holocene dipolar pattern of humidity variations between the northern and southern parts of the eastern margin of the Tibetan Plateau. The inference that the seasonality of precipitation controlled moisture variation in the study region is supported by high-resolution climate proxies and meteorological data on centennial and decadal time scales during the last millennium. Additionally, we propose a conceptual framework of hydroclimatic processes in a land–lake system to reconcile contradictions between different indicators. The present study not only clearly summarizes the Holocene climate change on the eastern margin of the Tibetan Plateau, but it also highlights the critical importance of distinguishing terrestrial and lacustrine signals in paleolimnological studies, and of noting associat","PeriodicalId":20926,"journal":{"name":"Quaternary Science Reviews","volume":"345 ","pages":"Article 109030"},"PeriodicalIF":3.2,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142539658","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-29DOI: 10.1016/j.quascirev.2024.109016
Pierre Lapellegerie , Laurent Millet , Damien Rius , Fanny Duprat-Oualid , Tomi Luoto , Oliver Heiri
<div><div>The location of Bergsee (382 m a.s.l.), between the Black Forest and northern Alpine glaciers during their maximum extent of the Würm glaciation, makes the sediment record of this lake a unique palaeoenvironmental archive that probably recorded the entire Last Glacial Period. Here we present a chironomid record from Bergsee covering ca. 35 thousands of years (kyr) including the period corresponding to the Last Glacial Maximum in the northern Alpine area. The record is divided into 6 biostratigraphical zones. Between ca. 45.4–30.1 thousand calibrated <sup>14</sup>C years (cal ka BP) taxa typical for the littoral of relatively warm lakes (<em>Parakiefferiella bathophila</em>-type and <em>Paratanytarsus penicillatus</em>-type) are dominating. Then (ca. 30.1–23.3 cal ka BP), <em>Sergentia coracina</em>-type, a profundal and cold indicative taxon, becomes dominant alongside <em>Parakiefferiella bathophila</em>-type. Low diversity and high abundances of <em>Sergentia coracina</em>-type suggest the most severe environmental conditions of the record. The third zone (ca. 23.3–20.6 cal ka BP) is largely dominated by <em>Parakiefferiella bathophila</em>-type and warmer indicative taxa replace <em>Sergentia coracina</em>-type. In the fourth zone (ca. 20.6–16.9 cal ka BP), <em>Paratanytarsus penicillatus</em>-type and <em>Tanytarsus pallidicornis</em>-type dominate and the presence of <em>Chironomus anthracinus</em>-type suggests slightly warmer conditions, more nutrients or organic matter and lower oxygen availability in the lake. In the next zone (ca. 16.9–10.7 cal ka BP), <em>Corynocera ambigua</em>, a taxon with uncertain distribution in respect to temperature, becomes the dominant chironomid. Changing abundances of <em>Corynocera ambigua</em> match the climate variability of the Lateglacial, with high abundances corresponding to the cold phases of the Oldest and Younger Dryas interrupted by the warmer Bølling/Allerød interstadial. However, the high abundances of <em>Corynocera ambigua</em> are not necessarily due to colder temperature but could also be explained by changes in the trophic conditions in the lake or other environmental changes. The last zone (ca. 10.7–8.4 cal ka BP, onset of the Holocene), shows the highest diversity and presence of warm indicative taxa such as <em>Endochironomus tendens</em>-type and <em>Polypedilum nubeculosum</em>-type. The high abundances of <em>Corynocera ambigua</em> make the temperature reconstruction challenging for the Lateglacial since this taxon is restricted to cold lakes in some European chironomid-temperature calibration datasets, whereas it is known that it can also be found in high abundances in warmer lakes in other calibration datasets. A chironomid-temperature transfer function based on a Swiss-Norwegian calibration dataset reconstructed exceptionally cold values in the interval with maximum abundances of <em>Corynocera ambigua</em>, which disagree with reconstructions from other palaeoenvironme
Bergsee湖（海拔382米）位于黑森林和阿尔卑斯山北部冰川之间，在Würm冰川作用的最鼎盛时期，该湖的沉积物记录可能记录了整个末次冰川期，是一个独特的古环境档案。在此，我们展示了来自 Bergsee 的摇蚊记录，该记录涵盖了约 35000 年（kyr），其中包括阿尔卑斯山北部地区末次冰川极盛时期。该记录分为 6 个生物地层区。在大约 45.4-30.1 千校准 14C 年（cal ka BP）之间，以相对温暖湖泊沿岸的典型分类群（Parakiefferiella bathophila 型和 Paratanytarsus penicillatus 型）为主。随后（约 30.1-23.3 cal ka BP），Sergentia coracina-type--一种深层和寒冷指示性分类群---与 Parakiefferiella bathophila-type--一起成为主导。Sergentia coracina-type 的低多样性和高丰度表明当时的环境条件最为恶劣。第三区（约 23.3-20.6 cal ka BP）主要以 Parakiefferiella bathophila 型为主，较暖的指示类群取代了 Sergentia coracina 型。在第四区（约 20.6-16.9 cal ka BP），Paratanytarsus penicillatus-type 和 Tanytarsus pallidicornis-type 占主导地位，Chironomus anthracinus-type 的出现表明湖中的条件略微温暖，营养物质或有机物较多，氧气供应较少。在下一区域（约 16.9-10.7 cal ka BP），Corynocera ambigua（一种与温度相关的分布不确定的类群）成为主要摇蚊。Corynocera ambigua的丰度变化与大冰期的气候变异相吻合，高丰度与最老干纪和小干纪的寒冷阶段相对应，被较暖的博林/阿勒罗德间冰期所打断。不过，Corynocera ambigua 的高丰度并不一定是由于气温较低造成的，也可以用湖泊中营养条件的变化或其他环境变化来解释。最后一个区域（约 10.7-8.4 cal ka BP，全新世开始）显示出最高的多样性和暖指示类群的存在，如 Endochironomus tendens-type 和 Polypedilum nubeculosum-type。Corynocera ambigua 的高丰度使大冰期的温度重建具有挑战性，因为在一些欧洲摇蚊温度校准数据集中，该分类群仅限于寒冷湖泊，而在其他校准数据集中，该分类群在温暖湖泊中的丰度也很高。基于瑞士-挪威校准数据集的摇蚊-温度传递函数重建了 Corynocera ambigua 最高丰度区间的异常寒冷值，这与该地区其他古环境档案的重建结果不符。为了解决这个问题，我们还使用了瑞士-挪威模型（不包括伏毛虫），并将另一个校准数据集（芬兰）应用于 Bergsee 摇蚊记录，对结果进行评估。使用瑞士-挪威校准数据集（不包括Corynocera ambigua）和芬兰校准数据集进行重建后，Bergsee大冰期的温度变化更为真实。基于这些数据集的重建结果表明，45-30.1 cal ka BP 期间的气温约为 11.6 °C，30.1-23.3 cal ka BP 期间是最冷的阶段，7 月气温约为 10.5 °C，在 Bølling interstadial 开始时气温突然升高至约 16 °C，在 Younger Dryas 期间降至 12.2 °C。据估计，在少干世之后，气温又升高了 3.7 °C，重建的气温在全新世早期达到了约 16.4 °C。然而，在这一范围内推断的温度可能已经受到边缘效应的影响，导致低估的温度接近校准数据集所覆盖的最高温度。最冷阶段的时间与阿尔卑斯山北部冰川扩张和最大范围的重建、Bergsee 的花粉记录以及该地区的其他古环境记录相一致。
{"title":"Chironomid-inferred summer temperature during the Last Glacial Maximum in the Southern Black Forest, Central Europe","authors":"Pierre Lapellegerie , Laurent Millet , Damien Rius , Fanny Duprat-Oualid , Tomi Luoto , Oliver Heiri","doi":"10.1016/j.quascirev.2024.109016","DOIUrl":"10.1016/j.quascirev.2024.109016","url":null,"abstract":"<div><div>The location of Bergsee (382 m a.s.l.), between the Black Forest and northern Alpine glaciers during their maximum extent of the Würm glaciation, makes the sediment record of this lake a unique palaeoenvironmental archive that probably recorded the entire Last Glacial Period. Here we present a chironomid record from Bergsee covering ca. 35 thousands of years (kyr) including the period corresponding to the Last Glacial Maximum in the northern Alpine area. The record is divided into 6 biostratigraphical zones. Between ca. 45.4–30.1 thousand calibrated <sup>14</sup>C years (cal ka BP) taxa typical for the littoral of relatively warm lakes (<em>Parakiefferiella bathophila</em>-type and <em>Paratanytarsus penicillatus</em>-type) are dominating. Then (ca. 30.1–23.3 cal ka BP), <em>Sergentia coracina</em>-type, a profundal and cold indicative taxon, becomes dominant alongside <em>Parakiefferiella bathophila</em>-type. Low diversity and high abundances of <em>Sergentia coracina</em>-type suggest the most severe environmental conditions of the record. The third zone (ca. 23.3–20.6 cal ka BP) is largely dominated by <em>Parakiefferiella bathophila</em>-type and warmer indicative taxa replace <em>Sergentia coracina</em>-type. In the fourth zone (ca. 20.6–16.9 cal ka BP), <em>Paratanytarsus penicillatus</em>-type and <em>Tanytarsus pallidicornis</em>-type dominate and the presence of <em>Chironomus anthracinus</em>-type suggests slightly warmer conditions, more nutrients or organic matter and lower oxygen availability in the lake. In the next zone (ca. 16.9–10.7 cal ka BP), <em>Corynocera ambigua</em>, a taxon with uncertain distribution in respect to temperature, becomes the dominant chironomid. Changing abundances of <em>Corynocera ambigua</em> match the climate variability of the Lateglacial, with high abundances corresponding to the cold phases of the Oldest and Younger Dryas interrupted by the warmer Bølling/Allerød interstadial. However, the high abundances of <em>Corynocera ambigua</em> are not necessarily due to colder temperature but could also be explained by changes in the trophic conditions in the lake or other environmental changes. The last zone (ca. 10.7–8.4 cal ka BP, onset of the Holocene), shows the highest diversity and presence of warm indicative taxa such as <em>Endochironomus tendens</em>-type and <em>Polypedilum nubeculosum</em>-type. The high abundances of <em>Corynocera ambigua</em> make the temperature reconstruction challenging for the Lateglacial since this taxon is restricted to cold lakes in some European chironomid-temperature calibration datasets, whereas it is known that it can also be found in high abundances in warmer lakes in other calibration datasets. A chironomid-temperature transfer function based on a Swiss-Norwegian calibration dataset reconstructed exceptionally cold values in the interval with maximum abundances of <em>Corynocera ambigua</em>, which disagree with reconstructions from other palaeoenvironme","PeriodicalId":20926,"journal":{"name":"Quaternary Science Reviews","volume":"345 ","pages":"Article 109016"},"PeriodicalIF":3.2,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142528040","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-29DOI: 10.1016/j.quascirev.2024.109018
Lukas Gegg , Laura Jacob , Olivier Moine , Ellie Nelson , Kirsty E.H. Penkman , Fiona Schwahn , Philipp Stojakowits , Dustin White , Ulrike Wielandt-Schuster , Frank Preusser
The Upper Rhine Graben in Central Europe, and notably its depocentre in the Heidelberg Basin, is an archive of complex and long-lasting deposition throughout the Quaternary. A new drill core, 136 m long, from the southern Heidelberg Basin is investigated by characterising sedimentary facies, sediment provenance, as well as analysing the pollen and mollusc content. The chronological framework is based on post-infrared infrared-stimulated luminescence dating, and complemented with amino acid geochronology. The sediment sequence consists of fluvial, colluvial, and palustrine deposits that represent at least the last ∼500 ka, interrupted by some, major and minor, hiatuses. In the lower part, fluvial gravel and colluvial diamicts of a lateral alluvial fan into the Upper Rhine Graben prevail. The central part of the succession consists of a large-scale fining upward cycle that contains increasing amounts of material from the Alps delivered by the Rhine river. This sequence terminates with palustrine fines with rich mollusc and pollen assemblages that allow for a detailed reconstruction of environmental conditions. The results of pIRIR dating place the palustrine deposits in marine isotope stage 11. However, the pollen profile shares similarities with the Mannheim Interglacial that has previously been assigned to the Cromerian, a correlation that is supported by the amino acid geochronology, which poses a chronostratigraphical problem. In the upper part, Alpine sediments are progressively replaced by a new alluvial fan from the graben margin with striking variations in grain size. Overall, the diverse succession is the result of an interplay of tectonic activity and climatic factors. While subsidence triggers the generation of accommodation space and river deflection, pulses of coarse sediment are probably related to periglacial weathering, mass wasting and short-scale transport during cold periods.
中欧的莱茵河上游地堑，尤其是其海德堡盆地的沉积中心，是整个第四纪复杂而持久的沉积档案。研究人员对海德堡盆地南部一个长 136 米的新钻孔岩芯进行了研究，确定了沉积面的特征、沉积物的来源，并分析了花粉和软体动物的含量。年代学框架基于后红外红外激发发光测年法，并辅以氨基酸地质年代法。沉积序列由至少代表过去 ∼500 ka 年的河流沉积、冲积沉积和河口沉积组成，中间有一些或大或小的间断。在下部，主要是进入上莱茵地堑的侧向冲积扇的砾石和冲积二迭系。演替的中部由大规模的细化上升循环组成，其中包含莱茵河输送的来自阿尔卑斯山的越来越多的物质。该层序的末端是具有丰富的软体动物和花粉组合的河滩细沙，可用于详细重建环境条件。pIRIR 测定的结果将河口沉积物归入海洋同位素阶段 11。然而，花粉剖面与曼海姆间冰期有相似之处，而曼海姆间冰期曾被归入克罗默里期（Cromerian）。在上部，阿尔卑斯山沉积物逐渐被地堑边缘的新冲积扇所取代，其粒度变化显著。总体而言，多样化的演替是构造活动和气候因素相互作用的结果。沉降引发了容纳空间的产生和河流的偏转，而粗沉积物的脉冲则可能与围冰期风化、大规模流失和寒冷时期的短尺度迁移有关。
{"title":"Climatic and tectonic controls on deposition in the Heidelberg Basin, Upper Rhine graben, Germany","authors":"Lukas Gegg , Laura Jacob , Olivier Moine , Ellie Nelson , Kirsty E.H. Penkman , Fiona Schwahn , Philipp Stojakowits , Dustin White , Ulrike Wielandt-Schuster , Frank Preusser","doi":"10.1016/j.quascirev.2024.109018","DOIUrl":"10.1016/j.quascirev.2024.109018","url":null,"abstract":"<div><div>The Upper Rhine Graben in Central Europe, and notably its depocentre in the Heidelberg Basin, is an archive of complex and long-lasting deposition throughout the Quaternary. A new drill core, 136 m long, from the southern Heidelberg Basin is investigated by characterising sedimentary facies, sediment provenance, as well as analysing the pollen and mollusc content. The chronological framework is based on post-infrared infrared-stimulated luminescence dating, and complemented with amino acid geochronology. The sediment sequence consists of fluvial, colluvial, and palustrine deposits that represent at least the last ∼500 ka, interrupted by some, major and minor, hiatuses. In the lower part, fluvial gravel and colluvial diamicts of a lateral alluvial fan into the Upper Rhine Graben prevail. The central part of the succession consists of a large-scale fining upward cycle that contains increasing amounts of material from the Alps delivered by the Rhine river. This sequence terminates with palustrine fines with rich mollusc and pollen assemblages that allow for a detailed reconstruction of environmental conditions. The results of pIRIR dating place the palustrine deposits in marine isotope stage 11. However, the pollen profile shares similarities with the Mannheim Interglacial that has previously been assigned to the Cromerian, a correlation that is supported by the amino acid geochronology, which poses a chronostratigraphical problem. In the upper part, Alpine sediments are progressively replaced by a new alluvial fan from the graben margin with striking variations in grain size. Overall, the diverse succession is the result of an interplay of tectonic activity and climatic factors. While subsidence triggers the generation of accommodation space and river deflection, pulses of coarse sediment are probably related to periglacial weathering, mass wasting and short-scale transport during cold periods.</div></div>","PeriodicalId":20926,"journal":{"name":"Quaternary Science Reviews","volume":"345 ","pages":"Article 109018"},"PeriodicalIF":3.2,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142528127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-10-29DOI: 10.1016/j.quascirev.2024.109026
Xuguang Feng , Jianjun Zou , Xuefa Shi , Zhengquan Yao , Zhi Dong , Jiang Dong , Yonghua Wu , Ruxi Dou , Hualong Jin , Aimei Zhu , Xiaojing Wang , Qingchao Wang , Lingfeng Luo , Sergey A. Gorbarenko , Yuriy P. Vasilenko , Aleksandr A. Bosin
As the main heat and water mass sources, the warm and saline Pacific waters have significant influence on sea ice and intermediate water circulation in the Sea of Okhotsk (SO). However, the long-term history of Pacific warm water intrusion into the SO remains unknown, impeding accurate predictions of its future changes. In this study, provenance proxies (clay mineral assemblages and trace element ratios (<2 μm)) from surface sediments and Site LV87-55-1 were used to investigate the history of Pacific water intrusion into the SO over the past 20 kyr. Provenance analysis indicates that sediments in the central SO primarily originated from the Amur River before 11.7 ka, with a significant rise in sediment input from the Kamchatka Peninsula since that time. By integrating published data on sediment grain size, sea surface temperature (SST), and sea-ice diatoms, we observed that the enhanced inflow of Pacific warm water into the SO led to intensified counterclockwise surface currents and the retreat of sea ice since the early Holocene, which subsequently resulted in a noticeable shift in sediment sources in the central SO. Furthermore, based on modern observation and TraCE-21 model simulations, we deduce that the intensified Aleutian Low (AL) since the early Holocene stimulated the East Kamchatka Current (EKC) through increased Sverdrup transport caused by cyclonic wind patterns. This, in turn, facilitated greater intrusion of Pacific warm water into the SO. Overall, our findings suggest an increase in Pacific warm water intrusion into the SO under future global warming scenarios, potentially posing a significant threat to the marine environment of both the SO and the subarctic Pacific.
作为主要的热量和水团来源，太平洋暖咸水对鄂霍次克海（SO）的海冰和中间水环流有重大影响。然而，太平洋暖流侵入鄂霍次克海的长期历史仍然未知，这阻碍了对其未来变化的准确预测。本研究利用表层沉积物和LV87-55-1站点的原生代用资料（粘土矿物组合和微量元素比（<2 μm））研究了过去20万年太平洋海水侵入鄂霍次克海的历史。来源分析表明，在 11.7 ka 年之前，中部 SO 的沉积物主要来源于阿穆尔河，自那时起，来自堪察加半岛的沉积物输入显著增加。通过整合已发表的沉积物粒度、海面温度（SST）和海冰硅藻数据，我们观察到，自全新世早期以来，太平洋暖流流入南部海域的增加导致逆时针表层流的加强和海冰的退缩，进而导致南部海域中部沉积物来源的明显变化。此外，根据现代观测和 TraCE-21 模型模拟，我们推断自全新世早期以来，阿留申低纬度（Aleutian Low，AL）的加强通过气旋风模式导致的斯维尔德鲁普输送的增加刺激了东堪察加洋流（East Kamchatka Current，EKC）。这反过来又促进了更多的太平洋暖流侵入阿留申群岛。总之，我们的研究结果表明，在未来全球变暖的情况下，太平洋暖流会更多地侵入勘察加洋流，从而可能对勘察加洋流和亚北极太平洋的海洋环境构成重大威胁。
{"title":"Abrupt enhanced Pacific warm water intrusion into the Sea of Okhotsk since the early Holocene","authors":"Xuguang Feng , Jianjun Zou , Xuefa Shi , Zhengquan Yao , Zhi Dong , Jiang Dong , Yonghua Wu , Ruxi Dou , Hualong Jin , Aimei Zhu , Xiaojing Wang , Qingchao Wang , Lingfeng Luo , Sergey A. Gorbarenko , Yuriy P. Vasilenko , Aleksandr A. Bosin","doi":"10.1016/j.quascirev.2024.109026","DOIUrl":"10.1016/j.quascirev.2024.109026","url":null,"abstract":"<div><div>As the main heat and water mass sources, the warm and saline Pacific waters have significant influence on sea ice and intermediate water circulation in the Sea of Okhotsk (SO). However, the long-term history of Pacific warm water intrusion into the SO remains unknown, impeding accurate predictions of its future changes. In this study, provenance proxies (clay mineral assemblages and trace element ratios (<2 μm)) from surface sediments and Site LV87-55-1 were used to investigate the history of Pacific water intrusion into the SO over the past 20 kyr. Provenance analysis indicates that sediments in the central SO primarily originated from the Amur River before 11.7 ka, with a significant rise in sediment input from the Kamchatka Peninsula since that time. By integrating published data on sediment grain size, sea surface temperature (SST), and sea-ice diatoms, we observed that the enhanced inflow of Pacific warm water into the SO led to intensified counterclockwise surface currents and the retreat of sea ice since the early Holocene, which subsequently resulted in a noticeable shift in sediment sources in the central SO. Furthermore, based on modern observation and TraCE-21 model simulations, we deduce that the intensified Aleutian Low (AL) since the early Holocene stimulated the East Kamchatka Current (EKC) through increased Sverdrup transport caused by cyclonic wind patterns. This, in turn, facilitated greater intrusion of Pacific warm water into the SO. Overall, our findings suggest an increase in Pacific warm water intrusion into the SO under future global warming scenarios, potentially posing a significant threat to the marine environment of both the SO and the subarctic Pacific.</div></div>","PeriodicalId":20926,"journal":{"name":"Quaternary Science Reviews","volume":"345 ","pages":"Article 109026"},"PeriodicalIF":3.2,"publicationDate":"2024-10-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142539657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The understanding of the flooding processes in the entire basin of the middle-lower reaches of the Yangtze River (MLRYR) during the Holocene remains elusive. This is primarily attributed to the constraints posed by site-scale data characterized by limited spatiotemporal resolutions, compounded by conflicting results of the reconstructed Holocene paleoflood records in some of the previous studies. In this study, by synthesizing 114 paleoflood data with robust evidence of flood occurrence (including timing and location of flood occurrence), we comprehensively reconstructed the first continuous Holocene paleoflood record that cover the entire basin of the MLRYR. The results show that at the onset of the Holocene, flood frequency peaked notably in the middle reaches of the Yangtze River (MRYR), with no corresponding peak observed in the lower reaches of the Yangtze River (LRYR). However, in both the MRYR and LRYR, a significant flood frequency peak emerged around 8.0 ± 0.5 ka BP, and scarce flood occurrences appeared approximately 7.5–5.0 ka BP. This scarcity shifted abruptly to a surge in flood frequency from 5.0–4.0 ka BP. Following this, the MRYR witnessed three successive peaks in flood frequency, occurring at approximately 3.0 ka BP, 1.8 ka BP, and 1.0 ka BP, respectively. In contrast, flood events in the LRYR were infrequent during the 3.0–2.0 ka BP period, followed by a surge in frequency from 2.0 ka BP onwards. We further explored the driving mechanisms of paleofloods in the MLRYR and found that floods were more likely to occur during periods of weakened EASM, characterized by wet and unstable climate conditions in the MLRYR. Marine erosion may be also a key factor in the lack of geological evidence for palaeofloods during the early Holocene. Additionally, variations in the ISM and human activities during the late Holocene have significantly influenced the occurrence of floods in the MLRYR. By comparing the paleoflood frequency with the spatial distribution and number of archaeological sites in the MLRYR, respectively, we propose that the period of flood scarcity during the middle Holocene may have facilitated the development of rice agriculture and the prosperity of ancient settlements. In contrast, during flood-prone period, ancient societies adapted and coped with floods by migrating to higher terrain during the early Holocene and implementing simple hydraulic engineering techniques during the late Holocene.
人们对全新世长江中下游全流域洪水过程的认识仍然模糊不清。这主要是由于时空分辨率有限的遗址尺度数据所造成的限制，以及以往一些研究中重建全新世古洪水记录的结果相互矛盾。在本研究中，我们综合了 114 个具有可靠洪水发生证据（包括洪水发生的时间和地点）的古洪水数据，全面重建了第一个连续的全新世古洪水记录，该记录覆盖了整个多伦多河谷盆地。结果表明，在全新世开始时，长江中游（MRYR）的洪水频率明显达到峰值，而长江下游（LRYR）则没有观测到相应的峰值。然而，在长江中游和长江下游，大约在 8.0 ± 0.5 ka BP 出现了一个显著的洪水频率峰值，大约在 7.5-5.0 ka BP 出现了稀少的洪水。在 5.0-4.0 ka BP 期间，这种稀少的洪水频率突然转变为洪水频率的激增。在此之后，MRYR 的洪水频率连续出现了三次高峰，分别发生在大约 3.0 ka BP、1.8 ka BP 和 1.0 ka BP。相比之下，在 3.0-2.0 ka BP 期间，低海拔地区的洪水事件并不频繁，而从 2.0 ka BP 开始，洪水事件的频率急剧上升。我们进一步探讨了大洋中游地区古洪水的驱动机制，发现在大洋中游地区以潮湿和不稳定的气候条件为特征的EASM减弱时期更容易发生洪水。海洋侵蚀也可能是全新世早期缺乏古洪水地质证据的一个关键因素。此外，全新世晚期 ISM 的变化和人类活动也极大地影响了河套地区洪水的发生。通过比较古洪水发生频率与河套地区考古遗址的空间分布和数量，我们认为全新世中期洪水稀少时期可能促进了稻作农业的发展和古代聚落的繁荣。相反，在洪水多发期，古代社会通过在全新世早期向地势较高的地区迁移和在全新世晚期实施简单的水利工程技术来适应和应对洪水。
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