Estuaries mediate global land-ocean biogeochemical cycles, but few studies quantify how shelf depocenters regulate estuarine carbon-nitrogen dynamics, limiting source-to-sink and blue-carbon models.Here, we integrate bulk sedimentary organic carbon and nitrogen abundances, stable isotopes, and a Bayesian mixing model across a fluvial-estuarine continuum in southeastern China and the adjacent East China Sea inner-shelf mud belt. Our results reveal a striking spatial bifurcation in organic matter provenance. Non-tidal reaches are dominated by terrestrial signatures, primarily sewage and catchment-derived eroded soil (36.3% and 34.5%). Conversely, tidally influenced reaches shift to a dual dominance of autochthonous marine inputs (12.2%) and anthropogenic waste (25.7%), regulated by tidal hydrodynamic sorting, estuarine mixing, and authigenic accretion. Crucially, inner-shelf mud sediments act as a major estuarine end-member (28.6%), fundamentally reshaping the architecture of the estuarine carbon reservoir. Mass-balance calculations indicate that tidal pumping drives a substantial landward flux of ~0.90 to 2.39 Mt C/yr from the shelf mud belt back into the estuarine reaches. Challenging the traditional view that shelf sediments are passive carbon sinks, macro-tidal mud belts serve as active carbon suppliers. This neglected backward carbon flux needs incorporating into coastal carbon budgets for climate‑ and human‑induced disturbance assessments.

Our study was designed to unravel the provenance signals of sediments from various sediment source-to-sink processes. To achieve this, we systematically collected samples from river basins, estuaries, and offshore waters of the Oujiang River estuary. Analyses of clay minerals and trace geochemical elements (Cr, Th, Sc) were then conducted. Our findings revealed a dynamic pattern of sediment distribution, with the predominant clay minerals in the surface sediment of the offshore area being illite, followed by kaolinite and chlorite, with a minor smectite content. Notably, we observed a gradual increase in the proportions of illite and smectite from the upstream to the estuary, while kaolinite decreased accordingly. The ratios of Cr/Th and Sc/Th in the small mountain rivers also showed a gradual increase, indicating a rising influence of fine-grained sediment from the Yangtze River. Furthermore, we utilized a robust nonlinear mathematical model to determine and quantify the sources and provenance contributions of the clay fraction sediment in the Oujiang River estuary. Our model results revealed that the majority (64%) of the clay fraction sediment in the offshore region of the estuary originates from the Yangtze River. In contrast, sediments from small mountain rivers, including the Oujiang River, contribute an average of 29%, but this can increase to 40% within the Oujiang River estuary and its southern areas. Coastal currents and tides influence the sediment distribution in coastal areas. The Zhe-Min Coastal Current plays a significant role in transporting sediments from the Yangtze River to the estuaries of Zhejiang Province, where they settle in the downstream areas of the current. Moreover, sediment from the Oujiang River is carried southward by the coastal current, most of which is deposited in the estuary and the nearby coastal waters to the south. In conclusion, our study underscores the significant influence of sediments from the Yangtze River on the surface sediments in small mountain rivers and offshore regions near the Zhejiang coastline.

Coastal processes, including riverine inputs, alongshore currents, tidal currents, and estuarine circulation, are crucial in shaping the Earth's landscape and regulating land-ocean material cycling. The Changjiang (Yangtze River), the largest river in Asia, has greatly influenced coastal sedimentation and environmental evolution in the East China Sea during the Holocene. However, its interactions with smaller mountainous rivers and their estuaries in southeastern China, as well as the impact of post-glacial sea-level rise on sediment source-to-sink dynamics in this region, remain poorly constrained. Here, we present a comprehensive analysis of the sedimentary characteristics, elemental composition, and Sr-Nd isotopic ratios of Core MLX-S obtained from the Mulanxi River estuary. By comparing these findings with literature data from the Changjiang and other coastal estuaries in SE China, we provide new insights into the source-to-sink dynamics in this region. Our results indicate that the postglacial maximum flooding event occurred at similar to 4.8 kyr BP in the southern Taiwan Strait and at similar to 7.0 kyr BP in the northern Taiwan Strait. The terrigenous sediment mixing between the Changjiang and coastal mountainous rivers can be traced back to the early Holocene, coinciding with the postglacial sea levels rise. As the depositional environment shifted from low-stand fluvial to inner shelf settings, sediment provenances also changed from the dominance of local source (e.g., Mulanxi) to a mixture of sediments from the Changjiang and local rivers. The average proportion of Changjiang-sourced sediments in Core MLX-S was about 14.2 % during early Holocene (before 9.5 kyr BP), 25.0 % during the early-middle Holocene accompanied by rising sea level (9.5-7.7 kyr BP), 38.5 % during high sea-level period (7.7-0.3 kyr BP), and 29.9 % during the late Holocene with present sea level (after 0.3 kyr BP). These findings suggest that the initial influence of Changjiang sediments on the estuaries of the southeastern coastal rivers occurred prior to the formation of a large-scale mud belt on the inner shelf at similar to 8.0 kyr BP. This study underscores the sensitivity of coastal sediment routing to sea-level and climate forcings, demonstrating how large river systems interact with regional smaller rivers to shape marginal marine stratigraphy.

Over the past two decades, a large number of zircon U‐Pb ages from the Yangtze and Yellow River Basins have been published, yet distinguishing the sources of sediment between these regions remains challenging. Issues related to sampling, analytical methods, and biases complicate the interpretation of detrital zircon geochronology. In this study, we leveraged machine learning techniques to analyze a data set of over 33,000 zircon U‐Pb ages, refining the data to 28,082 ages for our analysis. We employed two characterization strategies: tectonic classification and kernel density estimation, and optimized our models through hyperparameter tuning. Our results demonstrated that the machine learning algorithm, eXtreme Gradient Boosting (XGBoost), significantly improved the accuracy of predicting sediment sources when compared to conventional methods (e.g., multidimensional scaling diagram). Additionally, we found that the most informative age populations were associated with the orogenic events (e.g., Jinning, 800–1,000 Ma, Tianshan, 260–394 Ma, and Nanhua, 680–800 Ma) rather than the movements of Lvliang (1,800–2,500 Ma) and Wutai (2,500–2,800 Ma), as suggested in previous studies. Finally, we tested the optimized models on several case studies, illustrating the effectiveness in identifying provenance signals for modern and quaternary sediments in East China Seas and the Yangtze Delta. While this machine learning approach shows great potential for improving sediment provenance analysis in these case studies, it is still limited by the availability and quality of detrital zircon age data for more detailed provenance analysis on sub‐basin scales.

Silicate weathering regulates climate as a critical carbon sink, yet understanding its role in the carbon cycle is challenging because of limited knowledge about the impact of temperature and rainfall on weathering during glacial-interglacial cycles. Here we investigated the orbital scale of silicate weathering variations and their role in atmospheric carbon dioxide sequestration using reconstructions, model simulations, and modern river sediment geochemical data. Results show that silicate weathering intensity in subtropical and tropical monsoon regions follows the precession cycle and is mainly controlled by rainfall. During glacial periods, global carbon dioxide consumption by silicate weathering was lower than interglacials but remained stable at similar to 2.47 Teramoles per year. We propose that ice sheet expansion confined intense weathering to the subtropics and tropics during glacial times. As insolation patterns shifted with the precession cycle, rainfall belts oscillated between hemispheres, maintaining a constant weathering area and stable carbon dioxide consumption. Our study provides insights into silicate weathering's role in the global carbon cycle, both historically and in future projections.

Continental silicate weathering acts as a crucial negative feedback mechanism for removing atmospheric CO2 and maintaining Earth’s long-term climate stability. However, quantifying continental silicate weathering rates and fluxes continues to pose a fundamental challenge in Earth system science. This study utilizes the GEOCLIM carbon cycle model, which integrates modern high-resolution (0.1° × 0.1°) datasets on surface temperature, runoff, topography, and lithology to model the spatial distribution of global silicate weathering fluxes. Results indicate a strong correlation between modeled basin-scale outputs and hydrological observations, with weathering rates falling within consistent error margins. Silicate weathering fluxes exhibit distinct latitudinal patterns, with the highest values concentrated within 30° of the equator, accounting for 76.9

Deforestation and technical innovation have changed the natural fire regimes, topography and carbon reservoirs during the history of human evolution. Recognition of the timing, scope, and magnitude of wildfire events in large river basins such as the Changjiang (Yangtze River) is essential for understanding the impacts of climate forcing and human perturbation on Earth surface processes. Here, we present a multi-proxy study based on the pollen and black carbon (BC) abundance in sediments of Core CM97 taken from the Changjiang Delta, aiming to reconstruct the paleo-fire history in the Changjiang River Basin and further disentangle anthropogenic and climatic influences on fire regimes during the Holocene. Our results show that the average BC abundance increased from 0.88 %o at 12-8 cal kyr BP to 1.17 %o at 8-5 cal kyr BP, well corresponding to the evolution of the Asian Summer Monsoon (ASM). This suggests the wildfire occurrences were dominated by hydroclimatic conditions during 12-5 cal kyr BP. After the early Bronze Age (similar to 5 cal kyr BP), the sustained high anomaly of BC abundance (average 1.30 %o), however, was decoupled from the weakened monsoon climate. We propose that this might be associated with anthropogenic destruction of natural forests through fire-assisted agriculture and bronze smelting. Especially, with the prosperity of the Han Dynasty (202 BCE - 220 CE), a rapid increase in population promoted the transition of ecosystem (vegetation type) from forests to permanent farmlands in the drainage basin. Human intervention has overwhelmed the long-term climate control over wildfire, plant diversity, soil erosion, and sediment source-to-sink processes, suggesting the dominance of anthropogenic activities on nature over the last 2 kyrs. Our study provides deep insight on the enhancing perturbation of human activities on Earth's surface at a continental scale and provides more constraints on the Anthropocene epoch.

The Yangtze (Changjiang) Delta serves as a prominent depocenter for siliciclastic sediments from the Tibetan Plateau and Yangtze Craton, providing essential data on sediment source-to-sink dynamics and geomorphological evolution of large river drainage systems. This study presents the detrital zircon geochronology of Plio-Pleistocene sediments in the Yangtze Delta, alongside the data from modern river sediments, to elucidate provenance evolution since the Pliocene. The zircon geochronology reveals a considerable shift in sediment provenance during the Pliocene-Pleistocene transition. The Pliocene sediments exhibit a straightforward and predominant zircon age spectrum characterized by a typical peak age of 100-200 Ma. This spectrum markedly differs from the modern upper-middle Yangtze River sediments but closely resembles those of local rivers in the lower Yangtze River region. This demonstrates that the Pliocene sediments originated from local mountainous rivers, indicating the paleo-Yangtze River channelization prior to the Quaternary. In contrast, the zircon age spectra of Pleistocene sediments in the present-day delta reveal several dominant age groups ranging from 11.9 +/- 1 to 3643 +/- 30 Ma, similar to those found in present-day upper-middle Yangtze River sediments. This implies that the Pleistocene sediments were mainly derived from the upper-middle Yangtze River, showing a diversity of source rocks with varying geological ages and origins. The presence of the upper Yangtze River provenance signal, characterized by Cenozoic (<65 Ma) zircons, in early Pleistocene strata (ca. 1.6 Ma) of the delta suggests that the paleo-Yangtze River transported Tibet-sourced sediments into the modern delta area no later than that time. These findings indicate the geomorphological evolution of the Yangtze River Delta from an intermontane basin in the Pliocene to an alluvial-fluvial plain during the Quaternary. This geomorphological and geographic evolution, along with changes in sediment source, directly reflect extensive tectonic subsidence in eastern China since the late Cenozoic.

Some of the earliest bio-sedimentary records of life on Earth are represented by microbial carbonates, which are also critical geochemical archives of ancient seawater chemistry and the environmental circumstances in which they precipitated. Reconstructing paleo-microbial environments on Earth and potentially other planets requires precise determination of the depositional ages of these materials. The (abiogenic) carbonate geochemistry communities can now use developments in in-situ laser ablation U-Pb dating using inductively coupled plasma mass spectrometry (LA-ICP-MS). Due to the effects of impurity mixing and diagenesis, microbial carbonates have received little geochronological study despite their broad relevance for understanding ancient seawater's environmental conditions and geochemical compositions. This study demonstrates using time-of-flight mass spectrometry (TOF-MS) to perform quick, quantitative elemental mapping before U-Pb spot dating to improve experiment success rates and data reliability and offers four practical application examples.

Silicate weathering has long been considered to maintain the Earth's climate stability, yet how the weathering responds to the late Cenozoic cooling remains unclear, partly because of the complicated factors which obscure the weathering records. Large rivers in East Asia integrate continental weathering history, but how the source-tosink system evolution affected the weathering signals need to be clarified. We compile proxy data of Nd isotopes, zircon ages and Chemical Index of Alteration (CIA) in East Asian margin and source terranes, along with new proxy data from core CSDP-2 in the shelf region, to understand the large river evolution and assess their influence on weathering proxy records. The median epsilon Nd values of East Asian marginal sediments increased from -18.8 in pre-3.6 Ma period to -11.3 since the 1.0 Ma, corresponding to the isotopic signatures in North China Craton and Northeastern (NE) Tibetan Plateau/Loess Plateau terranes, respectively. The zircon ages further confirmed the provenance shift, hinting that the modern-like Huanghe (Yellow River) system has been fully integrated during early Pleistocene, no later than similar to 1.0 Ma. This integration facilitated the sediment transportation from plateaus into the continental margin. Consequently, the CIA records in marginal regions show a more significant decrease than other Asian regions, within the context of Plio-Pleistocene cooling. Our study found that the upland expansion of large river system and global cooling jointly controlled the decline in the weathering intensity records, highlighting the importance to understand the evolution of source-to-sink system before interpreting the weathering signals from the continental margin sediments.

Secondary weathering of exposed continental shelf sediment at low-latitudes may play a significant role in atmospheric CO2 consumption during glacial periods, which is negative feedback for climate stability. However, more lines of evidences are required to verify the link of glacial weathering with climate. This study presents a comprehensive analysis of geochemical proxies that indicate the silicate weathering intensity in the northern South China Sea (SCS) over orbital timescales since ∼244 ka. Provenance discrimination results, based on the Sr-Nd isotopes values and the patterns of rare earth elements (REEs), suggest that the terrigenous sediment was primarily derived from Taiwan Island. The silicate weathering records revealed two different weathering regimes during glacial periods in the northern SCS, corresponding to changes in monsoon climate and sea-level. During the early period of Marine Isotope Stage 6 (MIS 6), the increase in weathering intensity was in response to climate variability, and the rapid delivery of terrigenous sediment through contour currents allowed for the preservation of climate signals in the continental margin. In contrast, the significant increase in weathering intensity during the glacial periods at late MIS 2 and late MIS 6, was a result of the sedimentary recycling process dominated by sea-level rises. In this case, the marginal sea weathering records did not truly reflect climate changes, due to secondary weathering processes on the exposed continental shelf. Our new geochemical results emphasize the dynamic coupling effects of climate and sea-level changes in transmitting and preserving silicate weathering signals at low-latitude during glacial periods. When using marginal sea sediments for paleoclimatic and paleo-weathering reconstruction, one should be cautious of the complex influence of sediment source-to-sink processes on sediment composition, and a holistic approach may provide more robust constraints.

The Late Triassic was a key period for the evolution of the western Sichuan Basin from marine to continental sedimentation. However, the provenance of the earliest terrigenous sediments during this period remains debated, hindering our understanding of the tectonic events that ruled the evolution of the basin at that time. Herein, samples of fine sandstone from the Upper Triassic Ma'antang and Xiaotangzi formations in the western Sichuan Basin were collected for petrology, heavy mineral analysis, bulk rock geochemistry, and detrital U-Pb dating. In addition, corresponding data from potential source areas were collected for comparison. The sedi-mentological, geochronological, and geochemical characteristics of terrigenous sediments suggest that the clastic materials were mainly sourced from the Qinling orogenic belt and Yangtze Craton (including the northern and western margin). The Longmen Shan thrust belt likely provided clastics since the Early Norian. Siliciclastic deposits of the Late Triassic sedimentary succession of the western Sichuan Basin (Ma'antang and Xiaotangzi formations) yielded young zircon U-Pb ages of 214-245 Ma, suggesting that these zircons were likely sourced from the magmatic activities in the South Qinling orogenic belt or Yidun Island Arc. Combined with previous research, this study predates the transformation of the western Sichuan Basin from marine to continental sedi-mentation in the Late Carnian/Early Norian period.

The supplementary data of the manuscript: Tectonic and magmatic evolution of NE Cathaysia Block controls sediment geochemical heterogeneity of rivers in SE China

Sediment source-to-sink processes of river systems have significant impacts on depositional environments in coastal and shelf seas and on long-term climate change. Typically, sediments at the outlets of small mountainous rivers (SMRs) are considered to represent the average composition of particles eroded from the entire river basin due to the fast sediment transfer rate and short residence time in the basins. However, this assumption may be challenged by the significant heterogeneity in sediment erosion and transport processes within the SMRs catchments. In this study, we compare the geochemical and provenance heterogeneity of two typical mountainous rivers in subtropical East Asia, the Mulanxi in Mainland China and the Zhuoshuixi in Taiwan. These two SMRs have similar monsoon climate regimes but different tectonic, geomorphic, and hydrological settings, as well as sediment routing processes. Neodymium isotopes (εNd) and stable elemental ratios of Cr/Th and Sc/Th demonstrate the remarkable intra-catchment geochemical heterogeneity of both rivers. The εNd decreases from −7.1 to −10.0 from non-tidal to tidal reaches in the Mulanxi, while it changes from −11.5 in the upper reaches to −14.1 in the lower reaches of Zhuoshuixi. Apart from the general controls of provenance lithology and weathering processes on sediment geochemical heterogeneities between these two SMRs, the intra-catchment heterogeneity of the Zhuoshuixi is mainly induced by uneven sediment mixing in the flat and low connectivity areas (accounting for ∼36.5% of the downstream area). Meanwhile, the strong tidal influence is the primary control for the intra-catchment geochemical heterogeneity of the Mulanxi sediment, and relatively long sediment residence time in the catchment also plays some role. Our study suggests that samples collected at the river mouths cannot be simply treated as representative of the basin average or fluvial end-member to the sea. The compositional heterogeneity of the SMRs and its environmental effects and responses to rapid climate change require more in-depth investigations.

Silicate weathering plays a key role in maintaining a habitable climate on Earth. Although the climate-weathering link has been verified by observations on river geochemistry and weathering profiles, it remains a big challenge to quantify this link in the geological past mainly because sedimentary records of weathering intensity are complicated by other factors such as tectonics, sediment provenance and sorting effects. To clarify the climate dependence of weathering on different spatial and temporal scales, 4 Myr weathering intensity records determined by Chemical Index of Alteration (CIA), are compiled from 12 sites along the East and Southeast Asian margins ranging from ca. 10 degrees N to 40 degrees N. All the CIA records show overall decreasing trends, corresponding to global cooling. The CIA stacks that indicate regional and continental-scale weathering intensity are produced by binning and averaging the CIA data from each site. To explore the weathering intensity-temperature relationship, literature data on sea surface temperature (SST) anomaly are presented for the paleo-temperature changes at comparable latitudes. The results show that the decrease in CIA stack since 4 Ma is larger in East Asia (71-82 in Pliocene down to ca. 62 in late Quaternary) than in Southeast Asia (73-75 in Pliocene to ca. 72 in late Quaternary), in part due to the amplified midlatitude cooling. The correlation analyses indicate the temperature sensitivity of stacked CIA record in Southeast Asia (ca. 0.8 CIA units/degrees C) is consistent with modern observations of surface soils and river sediments. In comparison, the response of weathering intensity to temperature change is more sensitive in East Asia, with a magnitude of ca. 2.4 CIA units/degrees C, which may relate to dynamic source-to-sink processes and weathering regime changes. This study provides the first observation on silicate weathering responses to temperature changes at various latitudes since the Pliocene, showing the similar responses, but with different magnitudes. Our findings provide new insights on continental weathering mechanism and late Cenozoic cooling. (C) 2021 Elsevier B.V. All rights reserved.

碎屑锆石U-Pb年代学是识别沉积物来源和确定地层最大沉积年龄的重要工具.利用激光剥蚀电感耦合等离子体质谱(LA-ICP-MS)进行物源分析的碎屑锆石测试数量为60～120颗,在这个范围内,年龄组分通常不能从样本中识别出来.近年来,为提高物源分析的可靠性,LA-ICP-MS测试要求有更多数量的锆石颗粒(n≥300),甚至大于1000颗的大样本量(large-n)试验.大样本量碎屑锆石U-Pb年代学的出现对数据测试方法、处理和评估都提出了挑战.本文通过对国内外大样本量文献进行梳理,总结了大样本量碎屑锆石U-Pb年代学在测试方法、数据处理以及数据评估方面的进展.首先,单颗粒测试需要对U、Pb同位素信号进行快速获取,这可以通过改进气溶胶传输效率实现,"峰值"信号模式代替"平顶"信号接收也可实现快速测试.其次,大样本量产生的数据,需要高效的数据处理协议和强大的软件(如Iolite)进行处理,以减少实验室间比较的误差;针对U-Pb数据处理流程,介绍了同位素分馏校正以及不确定度传播等方面的方法优化;此外,还引入了累积计数法和线性回归校正法两种处理方法专门处理"峰形"信号.在数据评估方面,新的U-Pb和Pb-Pb年龄不谐和度计算方法的提出,如采用Aitchison谐和距离,使数据过滤更加合理.基于上述新进展,对仪器和处理软件的选取进行了讨论,并对未来大样本量碎屑锆石U-Pb年代学分析的自动化、规范化提出了展望.基于已有研究,未来大样本量碎屑锆石U-Pb年代学的发展具有广阔前景,在物源示踪及确定地层年代等研究中将发挥更大的作用.

The Neoproterozoic witnessed several low latitude glaciations (i.e., the Sturtian, Marinoan and Gaskiers glaciations) and the geodynamic reorganization of cratonic blocks after the breakup of Rodinia. Trace element and stable isotope geochemistry from approximately coeval carbonate deposits on continental marginal sea and foreland basins (Yangtze Platform, China; Otavi and Nama Groups, Namibia) have shown fluctuating oxygen increase on the marine shelves. To gain an increasingly global picture of the bio-geochemical conditions in late Neoproterozoic seawater, we here present new redox-sensitive trace element, stable (C, O) and radiogenic (Nd, Sr) isotope records of carbonates from the Cryogenian Blaubeker and Court, and the Ediacaran Buschmannsklippe Formations (Witvlei Group, Namibia). Shale-normalised REE + Y patterns of post-Sturtian and post-Marinoan carbonates parallel modern seawater showing positive La, Gd and Y anomalies. Negative Ce anomalies argue for their preservation in increasingly more oxidising sea/porewater conditions in the Witvlei Basin from the Ediacaran on. While Cryogenian carbonates underwent radiogenic basin-fluid type overprinting, Ediacaran carbonates upsection record pristine Sr isotopic compositions that match the global Neoproterozoic seawater curve. Partly coupled negative correlations between Sr and Nd suggest long-term shifts in continental weathering and short-term changes in ocean circulation patterns. The delta C-13(carb) values range from -7.2 to +3.5 parts per thousand and record a negative isotope excursion in the upper part of the Witvlei stratigraphy. This excursion might be equivalent to the 'Shuram' carbon isotope excursion (CIE). However, the causes, global extent and correlation of the Shuram CIE are still debated. Typical for carbonates of the putative Shuram excursion are less pronounced Ce anomalies, lower Y/Ho ratios, and lower bio-essential and redox-sensitive trace metal concentrations, arguing for periodic redoxcline oscillations in a redox-stratified late Neoproterozoic shelf environment. The overall long-term decrease in redoxsensitive element enrichments throughout the Witvlei Group argues for a progressively increasing, presumably biologically-driven metal cycling towards values typical for Phanerozoic carbonates. The combination of changes in local weathering flux and ambient redox conditions in the late Neoproterozoic ocean may have caused dynamic (bio)geochemical metal cycling, predating (and possibly promoting) the metazoan radiation documented in the overlying Nama Group.

The Cenozoic sediments in marginal basins of East Asia ultimately reflected coupling between the tectonics, landscape evolution, and drainage reorganization. Recently, the provenance of Miocene sediments in the East China Sea Basin (ECSB) and Taiwan has been in hot debate, and several models were proposed to interpret the provenance changes. Most of them are related to river reorganization in East Asia and highly relied on detrital zircon U-Pb dating. In this study, a large number of detrital zircon U-Pb ages of Miocene sediments from the ECSB, Taiwan region, and the potential source areas have been compiled for quantitative provenance analysis. The results suggested that all the early–middle Miocene sediments in Taiwan and the ECSB were closely linked to North China and the Korean Peninsula. Over 80% sediments in Taiwan were delivered from the ECSB whose sediments were predominantly contributed by North China and the Korean Peninsula (70%). However, for the late Miocene to Quaternary sediments in the ECSB, the contribution of the Yangtze River system was 72%, which indicates distinct reorganization of river networks and initial formation of the Yangtze River in the late Miocene. The quantitative provenance analysis together with southward environmental changes from dominantly fluvial sediments in the northern and middle ECSB to shallow marine sediments in Taiwan region suggested that the early–middle Miocene sediments of Taiwan were mainly sourced from the North China and the Korean Peninsula by passing the ECSB. Thus, these sediments in Taiwan region would experience the river–delta–shallow marine route from the ECSB to Taiwan region.

The terrigenous sediment source-to-sink processes in continental margins are determined by complex interactions among climate, sediment discharge, sea level and oceanic circulations on various temporal and spatial scales. The northeastern South China Sea (NSCS) margin is a natural laboratory to catch a glimpse of these processes due to large amounts of terrigenous sediment inputs and continuous sedimentations during the late Quaternary. Based on a 35 m-long sedimentary sequence (core MD12-3429) retrieved from the NSCS upper continental slope, we distinguished sediment sources based on geochemical compositions, and then linked sedimentary responses to sea level change and Kuroshio intrusion over the past 244 kyrs via various sedimentary records including mass accumulation rates (MAR), foraminifera data, grain-size end-member modeling (EMM) and spectral analysis. Geochemical proxies including major element ratios and fractionation parameters of rare earth elements suggest that the detrital sediment in the core was derived primarily from the Taiwan. The MAR of terrigenous sediment yields an average 9.6 g/cm(2)/kyr, and high MAR values are both observed in glacial and interglacial intervals. The results of EMM reveal three end-members with dominant modal grain sizes of 6.6 mu m (EM1), 26.3 mu m (EM2) and 49 mu m (EM3), respectively. The temporal variations of the finest end-member (EM1) and the coarsest end-member (EM3) demonstrate clearly glacial-interglacial cyclicity, and the spectral analysis indicates the dominance of 100-kyr eccentricity, which suggests that sea level changes are the first-order control for the NSCS continental margin sedimentation. In addition, the temporal variations in hydrodynamic sensitive component (EM2) and its MAR display gradually increasing trends with weakening East Asian monsoon. Combing with modern observation and modeling results, we suggest that enhanced Kuroshio intrusion might account for the transport of Taiwan-derived sediment during the late Quaternary. As indicated by a 31 kyr periodicity in EM2, we infer that the development of El Nino-like condition strengthened the intrusion of oligotrophic Kuroshio from the Luzon Strait, resulting in the obvious increase of Taiwan terrigenous MAR but decreases of the primary productivity in the northeastern South China Sea. This study provides deep insight into the complex terrigenous sediment source-to-sink processes in a fast-changing marginal sea environment during the late Quaternary. (C) 2022 Elsevier Ltd. All rights reserved.