Haizhou Bay (Jiangsu, eastern China) is a major land-sea transition zone, yet long-term sedimentary records of organic contaminants and their anthropogenic drivers remain poorly constrained, limiting a process-based understanding of regional pollution trajectories and their links to shifts in the energy mix. We quantified 16 priority polycyclic aromatic hydrocarbons (PAHs) and four sterols in four intertidal sediment cores using GC–MS. Spatial variability was evaluated across all cores, whereas centennial-scale (~150-year) temporal changes were interpreted primarily from the representative core HZ02, based on its published ²¹⁰Pbex–¹³⁷Cs chronology, for which PAH diagnostic ratios were also assessed. Source patterns were further constrained using bivariate correlations together with principal component analysis and hierarchical clustering. PAH concentrations decreased seaward, whereas sterols were strongly enriched near the Linhong River estuary. In the dated HZ02 record, low-molecular-weight PAHs dominated before 1950, followed by episodic increases in high-molecular-weight PAHs and sterols during the 1950s-1960s and the 1980s-1990s, and a decline in sterols in the early 2000s, consistent with reduced domestic wastewater-related inputs. Multivariate fingerprints indicate two dominant mixed sources: local inputs linked to agricultural biomass burning and household sewage, and an industrial–transport component associated with coal and petroleum combustion and traffic emissions. Contaminant histories covary with population density and energy consumption, supporting a transition from a pre-1950 biomass–sewage-dominated regime to a post-1950 industrial-transport mixture. These century-scale records provide a baseline for reconstructing coastal pollution histories and for evaluating how changes in energy use and emission controls shape organic contamination in eastern China.

Marginal basins provide sensitive yet incomplete records of climate and tectonic forcing, and the southern North China Basin provides an ideal setting to decode these interactions since the late Pliocene. A 135.6-m borehole sequence, the XiaoQian (XQ) core, recovered from the Fuyang region, was dated using AMS 14C, OSL, and ESR, supplemented by magnetostratigraphic correlations to the parallel WLB core. Integrated analyses of physical and geochemical proxies were then employed to reconstruct the depositional evolution over the past similar to 3 million years. The succession records three main stages. Stage I (similar to 3-1.6 Ma) comprises sandy delta-front deposits, indicating active progradation into a lacustrine basin. Stage II (similar to 1.6-0.128 Ma) consists of rhythmically bedded silty clays, recording hydrological instability on a delta plain. Stage III (similar to 0.128 Ma to present) is dominated by floodplain muds, reflecting low-energy alluviation under stable tectonic conditions. Variations in sediment continuity and thickness reflect the combined influence of tectonic segmentation and autogenic reworking, which modulated the completeness of the stratigraphic record. Within well-preserved intervals, elemental and magnetic proxies show coherent trends that parallel regional and global reference curves, indicating that monsoon hydroclimate and base-level fluctuations were the primary external controls, while local tectonic setting and depositional dynamics influenced how these environmental signals were recorded.

Discrepancies among fire proxies have long hindered integrated reconstructions of prehistoric anthropogenic burning and its climatic feedbacks. We analyzed a 490-cm terrestrial sedimentary profile from Guangrao, Shandong Province (GR section; 4000-0 yr BP) within the East Asian monsoon domain. By integrating fecal stanols with black carbon, polycyclic aromatic hydrocarbons (PAHs), and paleoecological proxies, we reconstruct fire regime dynamics and human responses to monsoon variability over the past four millennia. Spectral analysis of char and 5-ring PAHs concentrations, combined with Redfit and Multi-Taper Method (MTM) analyses, delineates a three-phase evolution of anthropogenic fire regimes over the past 4000 years:(1) 4000-2500 yr BP (Yueshi Culture to Warring States), characterized by low-intensity smoldering with similar to 500-year quasi-periodicity linked to agricultural clearance; (2) 2500-300 yr BP (Warring States to late Ming-early Qing), dominated by high-intensity flaming with similar to 280-year quasi-periodicity associated with warfare-related burning; and (3) the past 300 years (Qing to present), marked by pervasive biomass burning under anthropogenic climate influence at centennial-to-decadal scales. Cross-Wavelet Transform (XWT) and Wavelet Transform Coherence (WTC) analyses indicate that the periodic changes in the fire regime are significantly correlated with the quasi-periods of the East Asian Summer Monsoon (EASM) at the centennial scale (similar to 500 years) and (similar to 200-300 years), respectively. XGBoost-SHAP analyses show that the contribution of anthropogenic burning to fire regimes has increased progressively over the past 4000 years, rising from similar to 23 % to more than 51 %. These shifts in fire regime periodicity were mainly governed by seasonal hydrothermal changes induced by the weakening of the EASM, together with increasing spatial heterogeneity in anthropogenic fire patterns. Concurrently, in the mid-to-late Holocene, the use of different biomass-burning practices by ancient human progressively altered the regional ecological landscape. Therefore, Over 4000 years, anthropogenic fire practices have both mirrored centennial-scale monsoon variability and reflected adaptive shifts in production systems and social structures. In the lower Yellow River, sustained land reclamation promoted persistent smoldering fires, leading to landscape fragmentation, ecological degradation, and marking a critical threshold in anthropogenic mediated climate transformation.

The Paleolithic sites in South China have caused controversy regarding human behav-iors in response to the rapidly shifting environment of the Late Pleistocene.However,chronometric and high-resolution proxies are absent from interpreting the paleoenvironmental evolution.Here we present the chronology,grain size parameters,and geochemical elements records from the Hejialing(HJL)site in South China to reveal the crucial aspects of environmental evolution,and hu-man occupation.The geochemical record shows that during MIS 5e-5a,northern Hunan experi-enced the influence of the summer monsoon and maintained a warm and humid climate.The later-ite layer began to develop.During MIS 4,the climate transitioned to a dry and cold state,leading to the attraction of hominins to the HJL area due to the abundant water and lithic raw material resourc-es,resulting in their establishment of a short-term camp.The HJL site was primarily inhabited by hunter-gatherer societies within a forested environment.From MIS 4 to MIS 2,Hunan experienced a prolonged period of dry and cold climatic conditions,with a brief rainfall recovery occurring in late MIS 3.Diminished vegetation and resource availability compelled human populations to broaden their activities and undertake migrations.The HJL site was abandoned amid the arid phase of MIS 2.The HJL area gradually became buried beneath eolian dust deposition(EM1)from distant sourc-es and riverine dust from nearby sources(EM2),and the site was informed.In MIS 1,During MIS 1,the climate shifted to a warm and humid state,marking the emergence of early agricultural prac-tices.As an essential part of South China,the environmental evolution process and diverse survival strategies employed by hominins in Hunan are vital for explaining how the paleoenvironment drove human occupation during the Late Pleistocene.

Resolving the complex interplay between natural and anthropogenic fire drivers remains a critical challenge in paleoenvironmental studies. This investigation employs an innovative multi-proxy approach integrating fecal stanol biomarkers with high-resolution records of charcoal and black carbon to reconstruct Holocene biomass burning dynamics and human-environment interactions at two key prehistoric profiles: the Yangguancun (YGC) loess profile (Shaanxi Province, the middle reaches of the Yellow River Drainage Basin) and Changyi (CY) terrestrial sequence (Shandong Province, the lower reaches of the Yellow River Basin). Our analysis reveals three distinct fire regime phases across the basin: 1) Early Holocene monsoon-controlled infrequent wildfires (8700-8500 yr BP), 2) Mid-late Holocene localized anthropogenic high biomass burning (6000-1000 yr BP), and 3) Recent millennium-scale regional anthropogenic combustion dominance. Between 6200 and 5300 yr BP, highintensity biomass burning in the middle reaches of the Yellow River was primarily driven by frequent slash-andburn practices for forest clearance for millet cultivation and daily subsistence activities during the late Miaodigou and Banpo IV Cultures. Contrastingly, between 4000 and 3500 yr BP, low-intensity smoldering fires in the lower reaches of the Yellow River were associated with persistent aridity and deforestation during the Longshan and Yueshi Cultures. These contrasting fire regimes reflect the complex interplay between monsoon-driven climate variability and anthropogenic land-use practices, leading to significant landscape changes in the region during the mid-to-late Holocene. Meanwhile, the region underwent a vegetation evolution, transitioning from fireresilient natural forests and grasslands to fire-prone secondary shrub lands and cultivated lands. It was noted that long-term deforestation and vegetation fragmentation, exacerbated by persistent drought, has triggered smoldering biomass burning pattern, which have become a primary driver of future wildfires and vegetation degradation in the middle and lower reaches of the Yellow River. Combining fecal stanol molecular biomarkers with sedimentary charcoal and black carbon records, we clarify the distinctions between natural and humaninduced fires, providing a deeper understanding of the impact of anthropogenic biomass burning on regional and global warming.

Deciphering Neolithic settlement environmental selection strategies is vital for understanding prehistoric human-environment relationships. This study employs a multi-classification XGBoost model and SHAP analysis to accurately classify 432 Neolithic archaeological sites in Zhejiang Province (AUC = 0.93), effectively distinguishing environmental selection patterns across different cultural phases. The model's feature importance ranking indicates that elevation, surface relief, slope, and water buffer zones are main factors influencing settlement site selection, though their impact intensity and mechanisms vary significantly across different cultural phases. Early Neolithic settlements (11.0-7.0 ka BP) favored high-altitude, vegetated river valleys supporting hunting-gathering economies, while mid-Neolithic communities (7.0-4.3 ka BP) shifted to lowland alluvial plains promoting rice agriculture. Late Neolithic settlements (4.3 ka BP-) expanded to higher elevations to mitigate flooding risks, coinciding with revived hunting-gathering practices. This study highlights the interplay between environmental and socio-economic factors in shaping settlement patterns and demonstrates the value of machine learning for archaeological research.

Understanding the sources and dynamics of past biomass burning remain a significant challenge due to variations in paleofire combustion patterns across different temporal and spatial scales. This study integrates black carbon and polycyclic aromatic hydrocarbon (PAH) records from the Lubei Plain in the Shandong Peninsula, Lower Yellow River, to reconstruct Holocene fire regimes and their relationship with climatic shifts and human activities over the past 5000 years. During the mid-to-late Holocene (5000–3000 year BP. (calendar years before 1950)), a biomass burning levels were generally low, with a pronounced peak in low-molecular-weight PAHs (3-ring PAHs) and charcoal fluxes between 5000 and 4500 year BP, indicating increased fire activity likely driven by a short-term cold-dry event around 5000 year BP. From 3500 to 1000 year BP, three distinct episodes of low-temperature smoldering fires are identified, coinciding with deforestation and persistent droughts during the Shang Dynasty (3600–3046 year BP), the Qin and Western Han Dynasties (2200–2000 year BP), and the Sui and Tang Dynasties (1400–1100 year BP). In contrast, high-temperature flaming fires are associated with periods of intensified warfare and social upheaval, compounded by cold, arid climates during the Warring States period (2500–2400 year BP), the Eastern Han Dynasty (2000–1800 year BP), and the Wei, Jin, and Southern-Northern Dynasties (1800–1400 year BP). Over the past millennium, anthropogenic biomass burning remained elevated, reflecting sustained human influence on fire regimes. Meanwhile, Pollen and n-alkane records reveal a transition from primary forests to secondary shrubland during the late Holocene, driven by declining seasonal precipitation linked to a weakening East Asian monsoon and increased anthropogenic burning. Principal component analysis indicates that long-term deforestation primarily drove low-temperature smoldering fires, whereas high-temperature fires were more closely linked to periods of conflict. Seasonal precipitation variability, regulated by monsoonal dynamics, emerged as a fundamental control on fire regimes. This integrated analysis of PAHs, black carbon, and charcoal, coupled with multivariate statistical approaches, offers a robust framework for reconstructing fire-climate-human interactions in East Asia. The findings provide new insights into the mechanisms driving fire regimes and their long-term ecological and societal impacts.

Geomorphological research at archaeological sites reveals that environmental factors, such as geomorphology and hydrology, play a crucial role in understanding changes in site layout and cultural processes. However, due to the lack of reliable chronologies, there is limited understanding of environmental factors in relation to archaeological site. This study focuses on the sedimentary records from the southern moat of the Fenghuangzui (FHZ) site, a representative site in the middle Yangtze River region, integrating a chronological framework and climate proxies such as elemental geochemistry. It reconstructs the evolution of the regional sedimentary environment and the hydrogeomorphology during the mid-late Holocene at the FHZ site, elucidating its interplay with human activities. Key findings include: (1) From 5.6-4.5 ka BP, elevated chemical index of alteration (CIA), Rb/Sr, and Mn/Ti values indicate a warm and humid climate. The Qujialing culture unified the middle Yangtze River and established regional central settlements such as Shijiahe site, and then expanded to the north. The FHZ site was built in the Nanyang Basin at this time to prevent the invasion of northern culture. (2) During 4.5-4 ka BP, decreased CIA and Rb/Sr values alongside rising secondary aluminum factor (Saf) and dealkalization coefficient (Bc) values signify reduced weathering and a transition to cooler, drier conditions. A flood event of 4-3.9 ka BP caused the moat of the FHZ site to lose its defensive function. (3) During 4-2.7 ka BP, declining CIA and Rb/Sr values with slight increases in Saf and Bc suggest ongoing dry and cool environmental conditions. The FHZ site was abandoned at the end of the Meishan culture. (4) Between 2.7-1.6 ka BP, rising CIA and Rb/Sr values indicate a return to warmer and more humid conditions. The FHZ site was built to expand the influence of Qujialing culture and protect the Shijiahe settlement. Taking into account the location of the water system and farming area, the south-facing direction was chosen. In general, our findings suggest that changes in regional hydrology in the context of climate change can trigger upheaval and even collapse of prehistoric societies.

Due to the differences in paleofire combustion patterns, the sources of biomass burning remains uncertain. This study examines the sediments from the Lubei Plain in the Shandong Peninsula, Lower Yellow River, integrating black carbon analysis and polycyclic aromatic hydrocarbons (PAHs) to reveal the evolution of fire ecology and human activities in this region over the past 5000 years. During the mid-to-late Holocene (5000 − 3500 year BP), the findings reveal that biomass burning levels in this region were generally low. However, between 3500 and 3000 year BP, smoldering biomass combustion pattern was prevalent, driven by extensive deforestation and prolonged droughts during the Shang Dynasty (3600 − 3046 year BP). During the late Holocene. three intensified-fire episodes (2600 − 2400 year BP, 2100 − 1900 year BP, and 1600 − 1400 year BP) may be a consequence of the population growth, deforestation to reclaim land, and/or the frequent wars during the periods of the Spring and Autumn & Warring States, Eastern Han, Wei, Jin, Southern & Northern Dynasties in China with cold and dry climatic condition. Conversely, two distinct periods of reduced fire activity are related to a significant decrease in anthropogenic biomass burning, likely due to population migration and farming activities decreased in the study area. Meanwhile, n-alkane and pollen records indicate a shift from primary forests to secondary artificial forests during the late Holocene, which were attributed to a decrease in the seasonal precipitation controlled by the weakening East Asian monsoon and increased anthropogenic biomass burning. In the past 300 years, the climate has become more arid, and the local biomass burning in this study area has increased significantly. According to principal component analysis, warfare was a potential factor in the high-intensity pyrogenic fires in the past 5000 years, and the low-intensity fire pattern induced by long-term and frequent deforestation activities of human beings is an important factor that cannot be ignored, which leads to the decrease of vegetation and land degradation in this region.

The ocean is the ultimate sink for all pollutants, rivers are important channels for land-based pollutants to enter the oceans. Riverine transport of polycyclic aromatic hydrocarbons (PAHs) to coastal seas in China poses environmental threats. This study examined the spatial and temporal distribution of PAHs in coastal rivers in Yancheng City in Jiangsu Province of China, with the aim of identifying their likely sources, concentrations, and influencing factors. Surface sediments were taken from the Xinyanggang River (XYR) and the Sheyang River (SYR). The concentrations of Ʃ16PAHs in river sediments were measured on average 477.05 ng/g dry weight (dw), with values varying from 2.18 to 6351.42 ng/g, indicating a moderate pollution level, with a dominance of high molecular weight (HMW) PAHs. The XYR exhibited significantly higher PAHs concentrations compared to the SYR. The key sources of PAHs were vehicle emissions (47.87%), coal and natural gas combustion (35.07%). Geographically weighted regression and redundancy analysis linked PAHs pollution to distinct land use patterns and socioeconomic indicators, highlighting urban land as the major contributor, driven by high urbanization and industrialization (70.91%). In XYR, industrial activities and transport emissions were major contributors, while in SYR, agricultural activities predominantly influenced PAHs pollution. Urgent mitigation strategies are needed to reduce PAHs pollution in river sediments, mitigating ecological and human risks associated with these contaminants.

Potential risks to people's health should receive much more attention with an increasing compound pollution in urban river ecological landscape. In this paper, the concentrations of 8 heavy metals (HMs, V, Cr, Mn, Co, Ni, Zn, As and Pb), black carbon (BC, char and soot) and polycyclic aromatic hydrocarbons (PAHs) were determined in soils and river sediments collected from 72 sampling sites along the Chan-Ba River, and also were evaluated, concerning source analysis and health risks. The results indicate that the concentrations of BC and PAHs varied seasonally, and the concentration of HMs showed little seasonal variation. The concentration of BC was higher in winter than in summer, while that of PAHs was higher in summer than in winter. These pollutants were spatial heterogeneity. The concentrations of these pollutants in the middle reaches of the Ba River were much higher than those in the upper and lower reaches. These changes are attributed to the spatial-temporal distribution of local pollutant emissions and the characteristics of regional pollutant transportation and deposition. Source and cluster analysis revealed that BC, HMs and PAHs were pyrogenic (including coal and biomass combustions, vehicular emissions). The evaluation of health risk of PAHs and HMs revealed that the cancer risk for adults and children was higher than the 10-6 and lower than 10-4 implying low to moderate risk, and it is noted that there are higher potential risks of Phe and Flu at the middle reaches in summer and As at the lower reaches in Autumn. Therefore, pollution prevention and monitoring, classification management and control mechanisms in designated river basins are necessary to ensure the quality and safety of the ecological environment in the Chan & Ba River basin.

江汉地区的石家河是长江中游地区迄今发现面积最大、持续时间最长的新石器时代聚落.本文以史前的石家河聚落作为研究对象,从区域、流域和遗址三个尺度,通过实地考察、遥感影像分析,并结合区域环境考古学的研究进展,探讨了石家河聚落形成的地貌背景.以此为基础,对相关人地关系问题进行了讨论.

新石器时代中期,中国先民将制陶技术运用于房屋建筑中,发展了一系列强度与耐水性能显著提升的烧土建筑材料,极大地改善了居住环境.长江中下游地区新石器时代房屋建筑发展脉络清晰,广泛利用红烧土材料.采用XRD法、XRF法、磁化率法和色度法从物相组成、元素成分、磁化率、色度等方面对湖南七星墩遗址出土的不同文化时期的烧土样品进行综合分析.结果表明,6 件红烧土样品应均为就地取土,并在泥料中加入了稻壳和稻草等植物残骸作为羼和料,经人工烘烤而成的建筑材料,等效烧成温度区间为550～700℃.研究结果可丰富史前建筑史的研究,磁化率测温法为未烧制黏土考古材料的烧成温度研究提供了一种科学有效的方法,进一步可尝试应用于早期陶器(尤其低温陶器)的烧成温度研究.

沿海地区经济的快速发展导致污染物排放量不断增大,对近岸海域生态环境造成一定威胁.其中,重金属是主要污染物之一.本文采用富集系数法与潜在生态风险指数法对海州湾沉积物柱状样中重金属元素(V、Cr、Mn、Ni、Zn、Sr和Pb)进行污染生态风险评估,运用多变量分析方法(相关性分析和因子分析)、APCS-MLR和PMF模型定性、定量解析重金属污染来源.结果表明:海州湾沉积物柱状样中重金属含量普遍高于背景值,且其在1980年以前变化不大,1980年以后呈上升趋势,这与1980年以后连云港的工业经济迅速发展有关.海州湾沉积物柱状样中重金属属于轻度-中度富集水平和低潜在生态风险水平.多变量分析结果表明,V、Mn、Zn和Sr主要来源于农业源与自然源的混合源;Cr和Ni主要由工业源控制;Pb以交通源为主.APCS-MLR与PMF模型分析结果与多变量分析结果基本一致.结果表明,APCS-MLR模型和PMF模型中,农业源与 自然源的混合源、工业源、交通源对重金属污染的贡献率分别是39.81％和45.75％、48.49％和35.08％、11.67％和19.17％,该研究结果可以为海州湾重金属污染防治提供重要依据.

The Bohai Sea is influenced by numerous extreme oceanic wave events in history. However, it is often difficult to determine the types of these events due to the lack of detailed historical records, causing uncertainty in the reconstruction of historical coastal disasters. We investigated an anomalous sand layer in the Xiliyu Village by the coast of Laizhou Bay, Shandong, from which an extreme event deposit was identified using a multi-proxy approach including grain size distribution, geochemistry, and magnetic susceptibility. This event was dated 2 700–3 100 a bp, and caused inundation of a large coastal area of Laizhou Bay. By comparing historical records with instrumental data, we believe that the event deposit was generated by a severe storm surge with wind speed of >34.9 m/s.

The Xinyanggang River in Yancheng City, one of the essential rivers entering the Yellow sea, has imported abundant pollutants to the coast of Jiangsu Province. Trace elements (Cr, Ni, Cu, Zn, As, Rb, Sr, Mo, Pb, Th, U, Sc, Ga, Se, Zr, Nb, and Sn) in surface sediments in the Xinyanggang River were measured to analyze the spatial distribution, risk assessment, and source appointment. The results showed that the parts of 17 trace elements presented high average values in river sediments, such as Zr (309.19 mg/kg), Sr (182.72 mg/kg), Zn (77.67 mg/ kg), and Cr (70.63 mg/kg). Compared with some coastal rivers, the Xinyanggang River was polluted by certain trace elements, such as Cr, Zn, and As. Based on the analysis of the enrichment factor (EF), the contamination factor (CF), the pollution load index (PLI), and the geoaccumulation index (Igeo), trace elements in sediments showed unpolluted to moderate contamination and mild to moderate enrichment. Among them, Zn, Pb, and Sn were highly polluted. The multivariate analysis, the principal component analysis-multiple linear regression (APCS-MLR) model, and the Unmix model identified four contributing trace element sources. Cr, Th, U, Se, Zr, and Nb originated from manufacturing industries and hydrodynamic transport erosion. Ni, Rb, Sc, and Ga were attributed to natural source. Cu, Zn, Mo, Pb, and Sn were contributed from mixed sources including industrial wastewater and transportation emissions. As and Sr were associated mainly with mixed sources of agriculture and combustion. These four sources of metals accounted for 22.5 %, 5.7 %, 15.3 %, and 11.1 % by using the APCS-MLR model, whereas 22.9 %, 39.7 %, 17.5 %, and 19.9 % by using the Unmix model, respectively.

以盐城市新洋港河表层沉积物为研究对象,运用富集系数法和潜在生态风险指数法对6种重金属进行污染评价,结合多变量分析方法和正定矩阵因子分解模型(PMF)进行来源解析.研究结果表明,新洋港河表层沉积物重金属Cr、Ni、Cu、Zn、As、Pb的平均浓度分别为70.63、27.73、21.60、21.60、9.01、20.38 mg/kg,其平均浓度顺序为Zn>Cr>Ni>Cu>Pb>As,多数表层沉积物样品中6种重金属数样点处于轻度?中度富集水平,潜在生态风险指数评价结果表明研究区域整体处于轻度生态风险.重金属按照来源大致分为3类:①第1类为Cu、Zn和Pb,主要来自工业废水、城市生活污水和城市交通(贡献率占44.60％);②第2类为Cr和Ni,主要来自城市制造业(贡献率占34.50％);③第3类为As,主要来源农业污染和养殖(贡献率占20.90％).

使用HR-ICPMS对长沙铜官窑遗址石渚坪(SZP)剖面的地球化学元素进行测定,分析了遗址剖面地球化学含量变化特征,揭示其沉积环境演变及其物源变化.结果表明,元素的含量变化特征显著,元素Ti、Cr、Co、V、Ni等在80～230 cm逐渐升高出现峰值,230～310 cm逐渐降低至谷值.Pb、Zr、Mn等分布趋势与其相反.其中,Ti含量最高,平均值达5 405.8 μg/g;最低的是Mo,平均值为0.9 μg/g.含量均值由大到小为:Ti>Mn>Ba>Zr>Rb>Zn>Li>Cr>V>Pb>Sr>Cu>Y>Ni>Th>Cs>Co>Sc>Sn>Hf>U>Be>Mo.SZP剖面记录了一个近1 300年来的沉积环境变化过程:风尘堆积—石渚湖形成—河漫滩沉积—石渚湖再次形成—石渚坪.物质来源也发生相应变化:310 cm以下来源为末次冰期风尘堆积;310～230 cm(年代为1 288～1 094 a B.P.)地层中含大量瓷片,物源主要是铜官窑瓷器煅烧过程中金属矿物开采及冶炼产生的废料;230～80 cm(年代为1 094～380 a B.P.),下层物源是湘江输入的泥沙,主要是上游的石灰岩沉积,上层是中下游地区砂岩的风化侵蚀和水流搬运沉积;80 cm以上(年代为380 a B.P.以来)与人类活动有关,主要为人工垫土和坡地周边风化侵蚀堆积.

Several studies have documented that during ‘green tide’ events, comprising green macroalgae blooms in aquatic ecosystems, dissolved inorganic phosphorus (DIP) levels remain relatively steady despite the absorption of a large amount of DIP. In this study, surface sediment samples and a sediment core were extracted using a modified sequential extraction scheme, and water and surface sediment samples were analyzed in April 2017 to better understand phosphorus (P) cycling and replenishment in Subei shoal. We used a simple model on equilibrium of adsorption-desorption to present the buffering capacity of phosphate. The total P (TP) in the surface sediments ranged from 12.2 to 28.4 µmol g−1 (average 15.5 µmol g−1) and was dominated by inorganic P. TP, exchangeable P, reactive and reductive Fe/Al bound P, and authigenic apatite P significantly decreased northward and eastward from Subei shoal, contrary to the detrital P and organic P results. Dissolved and particulate inorganic P in the water samples ranged from 0.01 to 0.54 µmol L−1 (average 0.19 µmol L−1) and 0.9 to 19.6 µmol g−1 (average 4.9 µmol g−1), respectively. The applied model showed that suspended particulate matter is an important regulator of DIP behavior. Thus, modification of SPM can alter the DIP buffering capacity. The calculated buffering capacity in the surface layer of the sea water was > 60 within Subei shoal and always > 10 along the path of floating Ulva prolifera, providing a reasonable explanation for the steady concentration of DIP and its replenishment during the blooming of this green macroalgae.