Palaeogeography, Palaeoclimatology, Palaeoecology最新文献

{"title":"Terrigenous influx from Peninsular Indian Rivers in response to climatic variability since the Last Glacial Maximum","authors":"K.V. Reshma ,&nbsp;Ammoose K. Jayan ,&nbsp;Srinivas Bikkina ,&nbsp;A.V. Sijinkumar ,&nbsp;M. Venkateshwarlu ,&nbsp;Jithin Jose ,&nbsp;A.K. Rafaz ,&nbsp;P.J. Kurian ,&nbsp;Rajveer Sharma ,&nbsp;K. Sandeep","doi":"10.1016/j.palaeo.2025.113233","DOIUrl":"10.1016/j.palaeo.2025.113233","url":null,"abstract":"<div><div>The contribution of rivers from peninsular India to the sediment load of the continental shelf in south-eastern India, the western Bay of Bengal, is relatively less understood. Here, we present a record of a sediment core from the continental margin off Kalpakkam, located in the western Bay of Bengal, inferring detrital influx, palaeo-weathering, and palaeo-monsoonal conditions over the past 23,000 years. We used a multi-proxy approach that included mineral magnetism, particle size, geochemical analyses, stable isotopic (δ¹³C and δ¹⁵N), and diffuse reflectance spectroscopic analyses to decipher the sediment supply from the Palar River and the depositional history of the southeastern continental shelf in response to variations in the monsoon during the late Quaternary. Radiocarbon (¹⁴C) dating of sediment samples was carried out using Accelerator Mass Spectrometry (AMS), based on five sample analyses. Organic carbon samples were collected at different core depths to establish a precise chronology of climatic and sedimentary changes over the last 23,000 years, covering key periods such as the Last Glacial Maximum, the Bølling-Allerød, and the Younger Dryas. The magnetic mineral concentration (SIRM, χ_ARM, χ_lf) and mineralogy (HIRM) varied in response to terrigenous influx, chemical weathering, monsoon strength and shifts in provenance of sediments. The magnetic data is corroborated by other proxies, such as hematite/goethite ratio, particle size distribution (percentages of sand, silt, clay), CaCO₃, C/N ratio, and carbon and nitrogen isotopes. A gradual increase in the northeast monsoon is documented during 22,000–15,000 cal. Years B·P. (Last Glacial Maximum), followed by a slight decline during 15,000–10,000 cal. Years B·P. A brief decline in northeast monsoon rainfall is observed at around ∼13,900 cal. Years B·P. (Bølling-Allerød), with an increase during ∼12,900–11,800 cal. Years B.P. (Younger Dryas). The Early Holocene period was characterized by increased detrital influx to the core site, strong pedogenesis, and chemical weathering in the continental areas in response to high rainfall conditions. A significant increase in terrigenous input, linked to the shifting and upliftment of the Palar River basin, is observed around 4900 cal. Years B.P. These findings provide valuable insights into the Late Quaternary evolution of riverine sediment dynamics of peninsular India and monsoon variability in the western Bay of Bengal.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"678 ","pages":"Article 113233"},"PeriodicalIF":2.7,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144920019","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":"Earlywood blue intensity of Picea purpurea reveals June minimum temperature variability in Eastern Tibetan Plateau since 1671CE","authors":"Na Du ,&nbsp;Shuhua Qiao ,&nbsp;Baolong Ma ,&nbsp;Xinyue Li ,&nbsp;Linhan Si ,&nbsp;Linlin Gao ,&nbsp;Yang Deng","doi":"10.1016/j.palaeo.2025.113220","DOIUrl":"10.1016/j.palaeo.2025.113220","url":null,"abstract":"<div><div>Temperature variations exhibit significant regional and seasonal differences, necessitating comprehensive research on different temperature variables across diverse areas. This study established an Earlywood Blue Intensity (EWBI) chronology of <em>Picea purpurea</em> in the eastern Tibetan Plateau (TP) and reconstructed the regional minimum temperature (Tmin) of June spanning from 1671 to 2007. The reconstruction, which accounted for 65 % of the variance during the calibrated period (1961–2007), revealed a period of relative stability in the 19th century and significant warming since the 1970s. The study indicated that the potential driving factors of the regional Tmin variation were El Niño-Southern Oscillation (ENSO) and tropical volcanism. Furthermore, we highlight that when a tropical volcanic eruption occurred without an El Niño event, the cooling effect on Tmin in the TP was significantly greater than when El Niño events occurred. A comparison between the reconstructed Tmin and mean maximum temperature (Tmax) series for the region revealed that the low-frequency variations of both series were generally consistent prior to 1900, while a pronounced asymmetry appeared in recent decades, with Tmin changes occurring earlier and exhibiting a more substantial warming trend.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"678 ","pages":"Article 113220"},"PeriodicalIF":2.7,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144921952","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":"High resolution Ordovician (Floian-Sandbian) carbon isotope stratigraphy from the Jiangnan slope, South China: The first complete record of the MDICE in δ13Corg and its global significance","authors":"Xiaocong Luan ,&nbsp;Mikael Calner ,&nbsp;Fangyi Gong ,&nbsp;Oliver Lehnert ,&nbsp;Guanzhou Yan ,&nbsp;Yuchen Zhang ,&nbsp;Zhutong Zhang ,&nbsp;Rongchang Wu","doi":"10.1016/j.palaeo.2025.113227","DOIUrl":"10.1016/j.palaeo.2025.113227","url":null,"abstract":"<div><div>The Middle Darriwilian Isotopic Carbon Excursion (MDICE) is one of the globally recognized positive excursions in carbon isotope chemostratigraphy, but mainly documented by δ¹³C_carb data in previous research. In this paper, new stable organic carbon isotope data (δ¹³C_org) are presented from the Hule-1 core from the southern Anhui Province of southern China. The core constitutes an Ordovician siliciclastic succession deposited in the upper Jiangnan slope. The Ordovician graptolite biostratigraphy of this area is already well established, and ranges from the <em>Baltograptus deflexus</em> Zone (Floian) to the <em>Nemagraptus gracilis</em> Zone (Sandbian). Based on the well-constructed graptolite biostratigraphy, a low-amplitude positive excursion of middle–late Darriwilian age within the Hulo Formation is confidently identified as the MDICE. The excursion has an amplitude of ca. 1.1‰ starting from the value of −28.0‰ near the base of this formation, reaching a peak at −26.9‰ in the middle, and decreasing to −28.5‰ in its upper part. Therefore, it reveals to our knowledge the globally best preserved and most complete δ¹³C_org record of MDICE hitherto. Our data elucidate the stratigraphic significance of the MDICE also in deeper depositional environments and as a tool for correlation across different lithofacies belts. The inferred perturbation of the global carbon cycle during this time interval was presumably more pronounced than previously thought, confirming that the Darriwilian was a critical time slice in terms of environmental and biosphere changes.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"679 ","pages":"Article 113227"},"PeriodicalIF":2.7,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145007566","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 largest outburst flood from the Paleo Hutiao Gorge landslide dam, Yangtze River since Late Pleistocene","authors":"Niannian Fan ,&nbsp;Xiaonan Yan ,&nbsp;Hao Xie ,&nbsp;Gongming Yin ,&nbsp;Chengshan Wang ,&nbsp;Xingnian Liu ,&nbsp;Ruihua Nie ,&nbsp;Weilin Xu","doi":"10.1016/j.palaeo.2025.113234","DOIUrl":"10.1016/j.palaeo.2025.113234","url":null,"abstract":"<div><div>Dam outburst floods caused by the breaching of natural landslide dams are highly destructive catastrophes in the world, far exceeding in magnitude of the gauged flood events. However, reconstructing paleo dammed lake outburst floods remains challenging. In this paper, a comprehensive field survey of the lake and flood deposits upstream and downstream of the paleo landslide dam at Hutiao Gorge, Yangtze River, and spanning 2000 km was conducted, and the chronological evidence suggested that the paleoflood occurred around 30 ka BP. The hydrodynamic model simulated the flood propagation throughout the 2000 km downstream reach. The modeled peak discharge of the dam break was about 7.5 × 10⁵ m³/s and dually verified by the field evidence, which was approximately 90 times of the largest gauged floods in the same reach and was the largest flood in the Yangtze River basin since the Late Pleistocene. The peak discharge attenuated to the largest gauged flood 1800 km downstream. Our research methods offered substantial advantages in reducing uncertainty associated with paleo landslide dam outburst flood estimates, thus enhancing our understanding of outburst mechanisms and aiding in the development of risk analysis for outburst flood events.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"678 ","pages":"Article 113234"},"PeriodicalIF":2.7,"publicationDate":"2025-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144933583","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":"Stable Sr isotopes of fossil dental enamel reflect diet and digestive system differences among sympatric herbivores","authors":"Elena Armaroli ,&nbsp;Razika Chelli Cheheb ,&nbsp;Anna Cipriani ,&nbsp;Sara Bernardini ,&nbsp;Jan van der Made ,&nbsp;Isabel Cáceres ,&nbsp;Mohamed Sahnouni ,&nbsp;Federico Lugli","doi":"10.1016/j.palaeo.2025.113226","DOIUrl":"10.1016/j.palaeo.2025.113226","url":null,"abstract":"<div><div>Reconstructing the trophic (paleo)ecology and associated physiological traits of both extinct and extant taxa is essential for understanding the functioning of (past) ecosystems. In this context, novel metal stable isotope proxies offer promising tools for investigating ancient diets and, to some extent, the digestive adaptations of animals. In this study, we analyzed the stable strontium isotope composition (δ⁸⁸Sr), alongside δ¹³C, δ¹⁸O, and ⁸⁷Sr/⁸⁶Sr ratios, in fossil dental remains of herbivorous mammals from the Early Pleistocene site of Tighennif, Algeria (∼1.2–1.0 Ma). Traditional carbon and oxygen isotope data indicate an environment dominated by C₃ vegetation, while the ⁸⁷Sr/⁸⁶Sr ratios suggest either a relatively homogeneous strontium baseline or limited geographic mobility of the animals. Our results demonstrate that δ⁸⁸Sr is sensitive to diagenetic alteration, with enamel samples retaining biogenic signatures comparable to those of modern mammals, whereas dentine exhibits δ⁸⁸Sr values shifted toward positive geogenic end-members. δ⁸⁸Sr patterns may reflect trophic niche differentiation among herbivores and potentially indicate distinct digestive physiologies, offering a novel alternative proxy for dietary and ecological reconstructions in the fossil record.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"678 ","pages":"Article 113226"},"PeriodicalIF":2.7,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144903381","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":"Environmental change on the eastern Arabian shelf during the early Aptian Oceanic Anoxic Event (OAE1a): A chemostratigraphic approach","authors":"Margherita Denaro,&nbsp;Thomas Steuber,&nbsp;Mohammad Alsuwaidi","doi":"10.1016/j.palaeo.2025.113225","DOIUrl":"10.1016/j.palaeo.2025.113225","url":null,"abstract":"<div><div>The effect of the early Aptian Oceanic Anoxic Event (OAE1a) on the southern Tethyan carbonate sedimentation on the eastern Arabian shelf is investigated. Chemostratigraphic platform-to-basin correlation of published and new outcrop and well core data allows for a lateral and temporal investigation of the changes in the depositional environment and reassessing the paleoenvironmental impact of OAE1a. Our results demonstrate that sedimentation rates varied spatially, influenced primarily by accommodation space and sediment redistribution rather than by effects of global carbon-cycle perturbations on carbonate production. Contrary to previous hypotheses, geochemical proxies do not support widespread anoxia on the Arabian shelf; instead, intermittent oxygen depletion was limited to specific basinal settings. Likewise, with the stratigraphic resolution of this study, no evidence of ocean acidification was detected, challenging models linking global carbonate platform demise to ocean acidification. Facies analysis reveals that transgressive-regressive cycles played a dominant role in shaping carbonate deposition. The transition from rudist–coral to orbitolinid–<em>Bacinella</em> assemblages reflects sea-level changes rather than nutrient stress. The spatial variations of δ¹³C_carb indicate hydrodynamic isolation within the platform interior, affecting local carbon budgets. Sediment preservation rates align with other Tethyan carbonate platforms, reinforcing the role of sea-level fluctuations in controlling carbonate production and accumulation.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"679 ","pages":"Article 113225"},"PeriodicalIF":2.7,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145010968","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":"Geochemical evidence indicates that deserts are not the dominant source of loess in Central Asia","authors":"Yue Li ,&nbsp;Yougui Song ,&nbsp;Xiuling Chen ,&nbsp;Dimitris G. Kaskaoutis ,&nbsp;Hamid Gholami ,&nbsp;Xiulan Zong ,&nbsp;Shukhrat Shukurov ,&nbsp;Nosir Shukurov","doi":"10.1016/j.palaeo.2025.113223","DOIUrl":"10.1016/j.palaeo.2025.113223","url":null,"abstract":"<div><div>To what extent are deserts in Central Asia (CA) the dominant source of loess? In this paper, we compare geochemical data for loess deposits and desert sands across CA to address this question. Sr–Nd isotopic data indicate that the sources of loess deposits in northern and southern CA are different. While caution is advised, isotopic data do not strongly support a direct genetic link between deserts and loess for this region. Trace element geochemistry further elucidates this relationship. The source rocks of both loess and desert sands in CA are dominated by felsic components; however, significant differences in the spatial heterogeneity of their trace element compositions were observed using clustering analysis based on the Calinski–Harabasz and Bayesian information criteria, with four clusters identified for loess deposits, and only two clusters determined for desert sands. The difference in optimal cluster numbers challenge the validity of aeolian comminution and abrasion in deserts as sources of silt-sized particles. Principal Component Analysis shows that the &lt;75/63 μm fractions of desert sands are geochemically distinct from the adjacent loess, questioning the deserts as transition zones for the CA loess formation. Therefore, combined with the relative spatial distributions of loess and deserts and the scarcity of silt-sized particles within the deserts, we propose that deserts are unlikely to be the main contributors to loess sedimentation in CA. Instead, alluvial plains and proximal debris fans along mountain foothills are more plausible provenances. Specifically, the northern Central Asian loess is sourced mainly from glacial-fluvial alluvium and frost-shattered debris of the Tianshan Mountains; the southern Central Asian loess derives predominantly from the Afghan foothills and the Panj–Amu Darya floodplains. Loess in the southern Tarim Basin appears to derive primarily from the Kunlun Mountains, a provenance assignment that would benefit from further testing. Although CA deserts are excluded as a dominant loess source based on multi-proxy evidence, uncertainties persist. Specifically, we emphasise the need for improved grain-size-controlled sampling and analysis across a wider spectrum of source regions. Integrating these expanded datasets within Bayesian unmixing models and identifying optimal grain-size windows will constitute a critical frontier for quantitative and nuanced reconstruction of loess provenance in CA.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"678 ","pages":"Article 113223"},"PeriodicalIF":2.7,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144908822","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":"Extreme faunal endemism, super-island faunas, and the Late Ordovician mass extinction","authors":"Jisuo Jin ,&nbsp;David A.T. Harper","doi":"10.1016/j.palaeo.2025.113222","DOIUrl":"10.1016/j.palaeo.2025.113222","url":null,"abstract":"<div><div>The majority of studies on mass extinction events (MEEs) have focused on the various extrinsic or palaeoenvironmental killing mechanisms, most associated with habitat destruction and some of which remain hotly contested. The ‘<em>mass extinction by insularization and kill</em>’ (MEIK) model of this study is proposed as a significant intrinsic cause of the Late Ordovician MEE based on palaeoecological and palaeobiogeographical analyses of Ordovician brachiopod faunas from Laurentia and its adjacent tectonic plates. During the Late Ordovician pulses of a first-order sea-level rise, the MEIK model reveals that biodiversity hotspots shifted from open ocean to epicontinental seas associated with a drastic increase in faunal endemism. Continental-sized ‘island faunas’, exemplified by the Laurentian intracratonic-sea brachiopods, were characterized by high abundance but relatively low diversity, but more critically the eventual loss of their inter-plate dispersal ability. The onset of mass extinction of these highly endemic ‘super-island’ faunas, specialized in living in shallow intracratonic seas for ∼8 million years during the Katian, occurred at the start of the Hirnantian glaciation due to draining of epicontinental seas and loss of their specialized habitats. The data presented here suggest that during a major sea-level rise, global biodiversity epicentres migrated from the ocean to epicontinental seas, becoming genetically isolated, rendering marine shelly benthos intrinsically susceptible to rapid environmental change and subsequent mass extinction.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"677 ","pages":"Article 113222"},"PeriodicalIF":2.7,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144892916","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":"A late Permian palynological assemblage from the Spearfish Formation of South Dakota, United States: Implications for biostratigraphy, paleofloristics, and phytogeography","authors":"Carol L. Hotton ,&nbsp;Antoine Bercovici ,&nbsp;Cindy V. Looy ,&nbsp;Ivo A.P. Duijnstee ,&nbsp;Dan S. Chaney ,&nbsp;Cortland F. Eble ,&nbsp;Isabel P. Montañez ,&nbsp;Sylvie Bourquin ,&nbsp;Blaine Cecil ,&nbsp;John Nelson ,&nbsp;Robert A. Gastaldo ,&nbsp;Johnathan Wingerath ,&nbsp;William A. DiMichele","doi":"10.1016/j.palaeo.2025.113218","DOIUrl":"10.1016/j.palaeo.2025.113218","url":null,"abstract":"<div><div>We report here on a palynoflora from the Spearfish Formation of South Dakota that represents the first definite record of late Permian plant remains in the form of miospores from North America. The assemblage is dominated by taeniate pollen (<em>Lueckisporites virkkiae</em>, <em>Lunatisporites noviaulensis</em>, <em>Corisaccites alutas</em>, <em>Jugasporites</em> spp.) as well as simple saccate pollen taxa (<em>Klausipollenites schaubergeri</em>, <em>Falcisporites</em> spp.), but is highly depauperate in spores. The palynoflora was extracted from a mudstone associated with black fissile shales and carbonates about 30 m above the conformable contact with the underlying Minnekhata Limestone at Cascade Springs. Multiple lines of evidence from organic and carbonate petrology as well as acritarchs indicate that the depositional context was a brackish lagoon or inlet subject to high evaporation rates. Eolian dust, present in all studied units, combined with carbonate and organic petrography, indicates aridity through this interval. Through similarity and ordination analysis, we show that the Spearfish assemblage most closely resembles low paleolatitude palynofloras of late Permian (Lopingian) age in Europe and differs significantly from middle Permian palynofloras of the central United States. The palynoflora also differs from lower Triassic palynofloras, thereby establishing that the lower portion of the Spearfish Formation is late Permian. The similarity in composition of the Spearfish assemblage in the western United States to xeric European assemblages indicates that a near-uniform xerophytic flora dominated by voltzian conifers and peltasperms extended thousands of kilometers across low-latitude Pangaea in late Permian times.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"679 ","pages":"Article 113218"},"PeriodicalIF":2.7,"publicationDate":"2025-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145005049","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":"Palaeoecological studies on the development of the world's southernmost palm-swamp peatland ecosystem in Kosi Bay, South Africa","authors":"Marvin Gabriel ,&nbsp;Jemma Finch ,&nbsp;Klaus-Holger Knorr ,&nbsp;Amanda Khuzwayo ,&nbsp;Graeme T. Swindles ,&nbsp;Mariusz Gałka","doi":"10.1016/j.palaeo.2025.113217","DOIUrl":"10.1016/j.palaeo.2025.113217","url":null,"abstract":"<div><div>Palm-swamps are known as peat forming environments from several tropical regions. The southernmost peat forming palm-swamps lie in Kosi Bay, at the South African East Coast (27° southern latitude), consisting of scattered homogeneous stands of <em>Raphia australis</em> Oberm. and Strey. It is the only <em>Raphia</em> species endemic to southern Africa and red listed. This study investigates the genesis of a <em>R. australis</em> palm-swamp peatland at Kosi Bay. Environmental reconstruction based on plant macrofossils, pollen, elemental composition and peat qualities, supported by AMS radiocarbon dating unveiled that: i) a shallow peat layer (ca. 55 cm) has accumulated since about 1000 CE under a regionally warm and wet climate, with the first peat forming vegetation community composed of sedges, including <em>Pycreus polystachyos</em> and <em>Cyperus</em> sp. Around 1370 CE a shift to swamp forest occurred. <em>R. australis</em> became established around 1550 CE, following a fire and becoming dominant around 1900 CE; ii) peat accumulation occurred since then at a low rate of 0.038 mm yr⁻¹ (19 g m⁻² yr⁻¹), which is especially low for top soil peat layers, yet indicates rather steady hydrologic conditions on the floodplain with currently low peat accumulation potential. <em>Raphia</em> peat is highly decomposed, with high contents of aromatics, aliphatics, and also of amids. Peat forming parts are the roots, leaves become decomposed in the surface layer; iii) the ecological conditions (eutrophic: C/N 14–20; slightly acid: pH 5–6) resemble rather Amazonian <em>Mauritia flexuosa</em> palm-swamps peatlands than <em>Raphia</em> peatlands of the Congo Basin.</div></div>","PeriodicalId":19928,"journal":{"name":"Palaeogeography, Palaeoclimatology, Palaeoecology","volume":"679 ","pages":"Article 113217"},"PeriodicalIF":2.7,"publicationDate":"2025-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145020690","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}