Palaeogeography, Palaeoclimatology, Palaeoecology最新文献

{"title":"Extensive Oceanic Anoxia during the early Cambrian: Evidence from Mn-Carbonate and Alabandite Deposition in the Northwestern Yangtze margin, South China","authors":"Yi Zhang ,&nbsp;Zhiwei Liao ,&nbsp;Qin Huang ,&nbsp;Zhijie Xu ,&nbsp;Lidan Lei ,&nbsp;Jinjiang Pan","doi":"10.1016/j.palaeo.2024.112549","DOIUrl":"10.1016/j.palaeo.2024.112549","url":null,"abstract":"<div><div>The Cambrian Explosion, which is characterized by complex organisms radiation after ∼521 Ma, has led to speculation about low levels of ocean oxygenation during the Early Cambrian (∼541–521 Ma). Recently, the genesis of sedimentary Mn-deposits has provided a new perspective for understanding the redox status of ancient oceans. The present study reevaluates the redox conditions of the Early Cambrian Ocean in South China using sedimentary records of Mn-deposits. The Mn-deposits developed in the Lower Cambrian Qiujiahe Formation on the northwestern Yangtze margin, covering slope/basin-to-shelf environments. The combined sedimentological, mineralogical, and geochemical evidence indicates that Mn-deposits lack of Mn-oxide precursors and exhibited hydrothermal-type REE patterns and δ¹³C distributions. Mn‑carbonates and partially alabandite (MnS) were directly precipitated in Mn-rich anoxic waters. The Mn-bearing rocks exhibited high total organic matter content (TOC, average 3.96 %), and pyrite layers developed, indicating active anaerobic sulfate reduction with the removal of Fe before Mn-deposition. The increased of the pH and sulfurization degree, promoting the Mn-minerals precipitation in water columns. The widespread Mn deposition across slope/basin-to-shelf areas represents the sedimentary response to the extensive ocean anoxia during the Early Cambrian. Such a scenario aids in elucidating the evolution of early life, suggesting that extensive ocean anoxia likely contributed to delaying the radiation of complex animals during the Cambrian Explosion.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"655 ","pages":"Article 112549"},"PeriodicalIF":2.6,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142434491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Climate-driven peatlands development and vegetation dynamics in Northeastern China since the mid-Holocene: New evidence from Huanan peatlands","authors":"Yutong Qian ,&nbsp;Dongmei Jie ,&nbsp;Honghao Niu ,&nbsp;Guizai Gao ,&nbsp;Frank M. Chambers ,&nbsp;Ziping Liu","doi":"10.1016/j.palaeo.2024.112544","DOIUrl":"10.1016/j.palaeo.2024.112544","url":null,"abstract":"<div><div>Studying peatland evolution and vegetation patterns in response to climate change provides valuable insights into future ecosystem trends. This study focuses on the Huanan peatland located in Changbai Mountain regions in Northeast China, utilizing phytolith analysis and stable carbon isotope composition (δ¹³C) to reconstruct late Holocene vegetation dynamics. Additionally, grain size, total organic carbon (TOC), and total nitrogen (TN) analyses were conducted to understand peatland development and paleoclimate since the late Holocene. The research identifies three distinct climate periods since 5500 cal yr BP: an initial warm, humid phase (5500–4000 cal yr BP) characterized by high river levels that formed lacustrine sediments; a subsequent transition to cold, dry conditions (4000–1500 cal yr BP) that initiated peat formation; and continued dry, cold conditions (1500 cal yr BP to the present) with sustained peat growth. Phytolith data reveal a dominant forest vegetation type since 2000 cal yr BP, further divided into three periods: 2000–1300 cal yr BP, marked by diverse and dense vegetation; 1300–750 cal yr BP, with declining plant cover; and 750 cal yr BP to the present, characterized by an increase in woody plants but a reduction in local grass cover.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"655 ","pages":"Article 112544"},"PeriodicalIF":2.6,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142416848","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Confirmation of Mg/Ca ratios as palaeothermometers in Atlantic limpet shells","authors":"Niklas Hausmann ,&nbsp;Donna Surge ,&nbsp;Ivan Briz i Godino","doi":"10.1016/j.palaeo.2024.112538","DOIUrl":"10.1016/j.palaeo.2024.112538","url":null,"abstract":"<div><div>This study provides a reassessment of magnesium to calcium (Mg/Ca) ratios in Atlantic limpet shells to determine past sea surface temperatures (SST). While <em>Patella depressa</em> along the Spanish shoreline and <em>Patella caerulea</em> in the Mediterranean have repeatedly produced reliable correlations between SST and Mg/Ca ratios, this relationship is not the case for other patelloid species. Particularly, <em>Patella vulgata</em> but also <em>Nacella deaurata</em> have been studied using Mg/Ca ratios with mixed or contrary results. In this study, we present elemental maps of these two species as well as <em>Nacella magellanica</em> together with oxygen isotope ratios (<span><math><mi>δ</mi></math></span>¹⁸O) that confirm a good relationship with SST. Our dataset also reassesses a specimen which was previously unsuccessful in providing significant correlations between <span><math><mi>δ</mi></math></span>¹⁸O values and Mg/Ca ratios. By reassessing these species and including modern and archaeological specimens (<em>n</em> = 12) from three patelloid species (<em>P. vulgata</em>, <em>N. deaurata</em>, and <em>N. magellanica</em>) we further add to the growing set of evidence for the reliable use of Mg/Ca ratios to detect palaeotemperature change. As a result, these species can in the future serve to determine ontogenetic age and season of capture as well as to reveal locations of interest within the growth record (i.e. annual temperature minima and maxima) for targeted <span><math><mi>δ</mi></math></span>¹⁸O and clumped isotope analysis.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"655 ","pages":"Article 112538"},"PeriodicalIF":2.6,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142416072","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Organic carbon burial dynamics at the Chukchi Shelf margin: Implications for the Arctic Ocean carbon sink","authors":"Liming Ye ,&nbsp;Xiaoguo Yu ,&nbsp;Yanguang Liu ,&nbsp;Anatolii S. Astakhov ,&nbsp;Alexander Bosin ,&nbsp;Yeping Bian ,&nbsp;Linsen Dong ,&nbsp;Weijia Fan ,&nbsp;Haili Yang","doi":"10.1016/j.palaeo.2024.112534","DOIUrl":"10.1016/j.palaeo.2024.112534","url":null,"abstract":"<div><div>Organic carbon (OC) burial plays a crucial role in regulating the Arctic Ocean's capacity to uptake atmospheric CO₂. In this study, we demonstrate the transport, deposition, and degradation patterns of different sources of OC to reveal burial dynamics at the Chukchi Shelf margin, a region with the highest primary production in the Arctic Ocean currently affected by dramatic sea ice retreat. Observations of suspended particulate material show a pronounced separation of terrestrial and marine OC in the water column, which subsequently influences OC lateral transport and differential deposition. Easily suspendable terrestrial OC is concentrated in the upper 10 m of water or sea ice and transported to the Canada Basin, where it undergoes severe degradation of fresh carbon in the water column and uppermost sediments. In contrast, faster-settling marine OC is more likely to be buried in the canyons and at the Chukchi Shelf margin, with ice algae contributing about 14 % and 55 % of OC burial in areas south and north of 73°N, respectively, leading to higher initial burial efficiency. Increasing Arctic marine primary production could thus enhance the region's role as a carbon sink over millennial timescales, although the burial efficiency of terrestrial OC will eventually exceed that of marine OC with prolonged burial time. Our findings highlight the importance of lateral transport, differential deposition, and selective degradation in Arctic carbon burial, providing a basis for objectively assessing the future capacity of the Arctic carbon sink and its feedback to climate change.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"655 ","pages":"Article 112534"},"PeriodicalIF":2.6,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142434490","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The collapse of the Ming Dynasty actually began with the Wanli megadrought: Insights from a hydroclimate reconstruction based on tree-ring δ18O over the past 460 years","authors":"Meng Ren ,&nbsp;Yu Liu ,&nbsp;Qiufang Cai ,&nbsp;Qiang Li ,&nbsp;Huiming Song ,&nbsp;Changfeng Sun","doi":"10.1016/j.palaeo.2024.112548","DOIUrl":"10.1016/j.palaeo.2024.112548","url":null,"abstract":"<div><div>Climate change has played a pivotal role in shaping Chinese history, especially during the Ming Dynasty. Previous studies have focused primarily on the Chongzhen megadrought, which is widely considered as the primary climatic perturbation behind the demise of the Ming Dynasty. However, relatively little is known about other severe drought events and their potential impact on the dynasty collapse. Additionally, the characteristics of an exceptional climatic anomaly termed the “Late Ming Weak Monsoon Period” are unclear. In this study, we reconstructed the historical variations of Palmer Drought Severity Index for July–September based on tree-ring stable oxygen isotopes (δ¹⁸O) from 1556 CE to 2015 CE in southwest Chinese Loess Plateau. Our study reveals a significant weakening of the Asian summer monsoon between 1561 CE and 1661 CE, consistent with the Late Ming Weak Monsoon Period, and unravels its structural characteristics in detail. Our reconstruction also captures a distinct humidification trend over northwest China since the early 2000s. Notably, in addition to the well-known Chongzhen megadrought, our study records the severe Wanli megdrought (1585–1590 CE) during the late Ming Dynasty, an event that rarely featured in earlier studies, exhibiting comparable duration and severity to the Chongzhen megadrought. Further analysis indicates that Wanli megadrought may have served as an early trigger for the collapse of the Ming Dynasty. Furthermore, our analysis implicates the El Niño–Southern Oscillation as a contributing factor in both the Wanli and Chongzhen megadroughts, and thus to the ultimate collapse of the Ming Dynasty by affecting the Asian summer monsoon intensity.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"655 ","pages":"Article 112548"},"PeriodicalIF":2.6,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142438125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Melanoides tuberculata and Zootecus insularis gastropod shells provide a snapshot into past hydroclimatic conditions of arid environments: New perspectives from Oman","authors":"Katharina E. Schmitt ,&nbsp;Tara Beuzen-Waller ,&nbsp;Conrad Schmidt ,&nbsp;Lucas Proctor ,&nbsp;Susanne Lindauer ,&nbsp;Christoph J. Gey ,&nbsp;Dana Pietsch ,&nbsp;Bernd R. Schöne","doi":"10.1016/j.palaeo.2024.112542","DOIUrl":"10.1016/j.palaeo.2024.112542","url":null,"abstract":"<div><div>Shells of the aquatic gastropod <em>Melanoides tuberculata</em> and the terrestrial gastropod <em>Zootecus insularis</em> were analysed using high-resolution isotope sampling (up to 274 samples per shell) to assess their potential use as a proxy for hydroclimatic and palaeoenvironmental reconstruction in drylands. A total of 169 snails (fossil and modern) were collected from 37 sites in Northern Oman and Dhofar, with each site selected for its specific geomorphological, archaeological or ecological context. This included fluvial terraces, playa environments, modern oasis gardens, irrigation channels and archaeological sites from the Neolithic (6,000–3,200 BCE) and Early Bronze Age (3,200–2,000 BCE) periods. The δ¹⁸O data obtained from these gastropods could be classified into eight different patterns, three for the aquatic snails (Type 1 A–C) and five for the terrestrial snails (Type 2 A–E), which were linked to the environmental context of their habitat. Furthermore, the use of the aquatic snails enabled us to distinguish between groundwater and surface water signals, whereas the terrestrial snails were employed to reconstruct changes in rainfall origin, humidity, evaporation, regular wet-dry cycles, and meteorological events. According to the results, gastropods can be used to elucidate the long-term, local evolution of rain-fed floodplain ecosystems in drylands and to identify the hydrological resources present in the vicinity of archaeological sites, particularly with regard to type 1 A-C (e.g.<em>,</em> surface water vs groundwater).</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"655 ","pages":"Article 112542"},"PeriodicalIF":2.6,"publicationDate":"2024-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142552785","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microbial mediated hardening of a Central Mediterranean upper shelf seafloor during the MIS 5.5; a possible post global warming scenario?","authors":"Edoardo Perri,&nbsp;Pierluigi Santagati,&nbsp;Mario Borrelli,&nbsp;Salvatore Guerrieri","doi":"10.1016/j.palaeo.2024.112539","DOIUrl":"10.1016/j.palaeo.2024.112539","url":null,"abstract":"<div><div>Higher sea level and sea surface temperature than at present have been inferred for the Last Interglacial (MIS 5.5, 135–116 ka), making it a good analogue for modeling the climate response of the environment to global warming in the near future. With the aim of predicting the possible evolution of some central Mediterranean shallow sandy seabeds, a MIS 5.5 biocalcarenite was investigated (Gulf of Taranto, Italy). Limited post-depositional diagenesis affected this deposit, which represents an infralittoral sandy seabed, with local vegetation and relatively high energy conditions. Medium-coarse sand sized bioclasts, with a negligible quantity of siliciclastic, compose the sediment that also hosts large shells of mollusks. Micritic cements are widespread, often in continuum with the micritized part of the shells, showing non-isopachous aphanitic and filamentous rims, aphanitic micro-mounds, vacuolar peloidal menisci, and aphanitic pore-filling matrix. All these cements consist of submicrometer anhedral or nanospheroidal crystals of low-Mg calcite, mixed with a smaller amount of irregular plate-like crystals of saponite. Micritic cements are also rich in mineralized filamentous, tubular, and subspherical bacterial bodies. This highlights the occurrence of an epilithic and endolithic microbial community forming a biofilm that stabilized the mobile sediment as consequence of the microbial mediated early cement precipitation. This led the synsedimentary hardening of some parts the mobile sandy substrate, the settlement of sessile taxa - such as <em>Spondylus gaederopus</em>, oysters, serpulids and barnacles, together with endofaunal organisms. Early micritic cementation is common in modern tropical climate, whereas is substantially absent in the modern Mediterranean. Consequently, its presence in the MIS 5.5 deposit confirms warmer sea water temperature compared to today (estimated at ca +2 °C) and suggests that similar hardening of mobile substrates may occur in the near future as a response to global warming.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"655 ","pages":"Article 112539"},"PeriodicalIF":2.6,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142416837","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Late Pleistocene to early Holocene vegetation and environmental changes in the tropical Leizhou Peninsula, South China: New evidence from the n-alkane record","authors":"Jia Huo,&nbsp;Jibin Xue,&nbsp;Jingqiang Chen,&nbsp;Yanting Li,&nbsp;Mingyi Chen,&nbsp;Zhenzhen Zhao,&nbsp;Yuxin Liu","doi":"10.1016/j.palaeo.2024.112541","DOIUrl":"10.1016/j.palaeo.2024.112541","url":null,"abstract":"<div><div>Understanding past long-term vegetation responses to regional or even global climate change and forcing mechanisms is essential to future climate change projections. However, due to the lack of long-term terrestrial sedimentary records, there are few studies focusing on vegetation changes in tropical southern China since the last glacial period, especially from the perspective of peat <em>n</em>-alkane records. Here, we have presented a peat core record from the Xialu peatland in the northern Leizhou Peninsula, and <em>n</em>-alkanes were investigated in conjunction with multiple proxy indicators. Our results showed that the organic matter sources were mainly a mixture of aquatic and terrestrial vegetation, with terrestrial vegetation accounting for most of the bulk organic matter composition. From ∼44.1 to 29 cal kyr BP, the organic matter source was mainly dominated by terrestrial vegetation, which corresponds to warm and humid conditions. From 29 to 14 cal kyr BP, the input of the terrestrial vegetation was reduced, the aquatic vegetation input increased, implying cool and dry conditions. From 14 to 9.3 cal kyr BP, the climate gradually became warmer and wetter, and terrestrial vegetation dominated in this area. Overall, the climatic conditions from the Xialu peatland were generally consistent with other records from adjacent areas. Our results suggest that, during the Last Glacial Maximum (LGM), a substantial drop in regional and global sea levels may have been the main cause of drought in tropical southern China on orbital timescales. Meanwhile, several climatic fluctuations on millennial timescales could have been influenced by the variability of the North Atlantic Meridional Overturning Circulation (AMOC) and migration of the Intertropical Convergence Zone (ITCZ).</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"655 ","pages":"Article 112541"},"PeriodicalIF":2.6,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142416825","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"From paleolake to peatland: Paleo environmental changes over glacial and interglacial cycles (Mid-Pleistocene) in the Colônia Basin, Brazil","authors":"Gisele C. Marquardt ,&nbsp;Denise C. Bicudo ,&nbsp;Jaques E. Zanon ,&nbsp;Carlos E.M. Bicudo ,&nbsp;Ingrid Horák-Terra ,&nbsp;Marie-Pierre Ledru","doi":"10.1016/j.palaeo.2024.112528","DOIUrl":"10.1016/j.palaeo.2024.112528","url":null,"abstract":"<div><div>Diatom and geochemical elements were used to analyze the transition from lake to peatland in the Colônia basin, São Paulo, Brazil; local versus regional driving factors were examined. Sediment core COL17–1, section 1470–800 cm depth shows five distinct diatom intervals offering insights into environmental changes and ecological characteristics based on sediment sources, diatom productivity, and bog wetness. Colônia basin evolution exhibited a progressive transition from mineral elements, associated with catchment instability during the lake stage, to higher levels of organic-rich sediments towards the uppermost section of the core. This shift was accompanied by the increasing presence of elements reflecting redox/productivity dynamics under changing conditions. Simultaneously, Br concentrations increased during peat formation indicating alterations in organic matter were influenced by atmospheric circulation and precipitation. During the transition from lake to peatland, the paleolake shallowing process showed successive colonization by benthic acidophilus diatom taxa, indicating a broader littoral zone and subsequent disappearance of diatoms under dry conditions. After a benthic stage, the diatom content shifted to one of planktonic dominance characterized by <em>Aulacoseira</em> sp., marking the return to cold-wet conditions and a moderately deep, flooded environment. Subsequently, the basin evolved into a completely flooded, turbulent peatland dominated by the <em>Aulacoseira granulata</em> complex. An uppermost layer sterile in diatom was associated with warmer and drier conditions and decrease in the concentration of mineral elements. Present results compared with core CO14 and Lake Titicaca showed benthic-rich levels during the penultimate glacial period and low benthic abundances. This differed the glacial-interglacial transition from those of COL17–1, which was dominated by planktonic-rich levels, suggesting the need for either a reassessment of our age model or the influence of local factors on diatom content. These findings highlight the sensitivity of diatoms to climate shifts, particularly in tropical regions, across different glacial-interglacial cycles.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"655 ","pages":"Article 112528"},"PeriodicalIF":2.6,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142434489","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sedimentary record of primary productivity changes in a crater lake in Northeast China since the Last Glacial Maximum","authors":"Yao Wang ,&nbsp;Weiwei Sun ,&nbsp;Enlou Zhang ,&nbsp;Enfeng Liu ,&nbsp;Xianqiang Meng ,&nbsp;Zhenyu Ni ,&nbsp;Wenfang Zhang","doi":"10.1016/j.palaeo.2024.112543","DOIUrl":"10.1016/j.palaeo.2024.112543","url":null,"abstract":"<div><div>High-resolution primary productivity records are valuable for identifying lacustrine ecosystem degradation in the context of long-term climatic variability. In this paper, we analyse primary productivity changes in a seasonally ice-covered crater lake (Lake Tuofengling) in northeast China since the Last Glacial Maximum using biogenic silica content and the carbon preference index of short-chain <em>n</em>-alkanes as proxies. Results show that primary productivity was lower during the cold and dry glacial period, whereas it was higher during the warm and humid Holocene. During the last deglaciation, primary productivity experienced a ∼ 1.5-kyr lagged response to Bølling-Allerød warming, and multiple oscillations during the Younger Dryas. Additionally, the peak productivity of the entire profile also occurred during this period. These fluctuations and the highest primary productivity are suggested to be the result of the combined influences of increased summer temperatures and regional permafrost melting. The current state of primary productivity in Lake Tuofengling is moderate but has been increasing since the abrupt increase in diatom productivity after ∼3 ka B.P. This stage is associated with increased dust deposition and longer ice-free periods under winter-warming conditions. We suggest that longer seasonal stratification under the current warmer winters and increased nutrient concentrations caused by decreased lake level will increase the risk of lake ecosystem degradation in the future.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"655 ","pages":"Article 112543"},"PeriodicalIF":2.6,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142416168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}