Increasing lines of evidence suggest the existence of rainfall heterogeneity over southwestern China, yet the multi-scale patterns of this heterogeneity and its causal links to early civilizations remain elusive. Here we reconstruct hydroclimatic changes over the past ∼15,500 years based on high-resolution elemental records from a ∼ 10 m sediment core collected in Lake Chenghai, Yunnan Province, southwestern China. Results suggest that the sedimentary elemental ratios, e.g., the Fe/Mn ratios, can effectively indicate lake-level variations in Lake Chenghai and further reflect regional hydroclimatic changes. Variations in the Fe/Mn ratios show humid conditions during ∼11.2–8.7 ka BP, arid conditions during ∼8.2–4.2 ka BP, and subsequent wetting trends after ∼4.2 ka BP, which are clearly anti-phase or out-of-phase with the Northern Hemisphere summer solar insolation and Asian summer monsoon (ASM) intensity. A series of millennial abrupt events were identified in the study area, among which, those from the early- to mid-Holocene (11.2–5.0 ka BP) correlate well with the cold-dry abrupt events across the ASM region, whereas those during the late Holocene exhibit considerable heterogeneity. We contend that the heterogeneous rainfall trend and the abrupt events in southwestern China are likely linked to variations in solar activity and the long-term behavior of the Western Pacific Subtropical High, and that such changes could have affected the development of regional early civilizations differently. This study shows heterogeneous hydroclimatic patterns across different timescales, thus highlighting the need to regulate the human-nature relationship at various timescales to maintain the sustainability of regional natural-social systems.

Global climate warming profoundly affects the physiological metabolism and adaptive capacity of forest trees. However, the responses of photosynthetic and carbon metabolic traits in coniferous species to long-term experimental warming simulating future climate scenarios remain poorly understood. In the present study, 3-year-old Pinus tabuliformis seedlings were subjected to ambient air temperature (CK) and elevated temperature (ET, ambient +2 °C) in open-top chambers over two consecutive growing seasons. The growth parameters, photosynthetic gas exchange, photosynthetic pigment contents, photosynthetic enzyme activities, photosynthetic product accumulation, and carbon metabolism-related enzyme activities of P. tabuliformis seedlings were determined to explore the growth and photosynthetic physiological adaptive strategies under warming. The results showed that warming significantly increased needle length and needle relative water content (RWC), whereas plant height, basal diameter, and seedling biomass exhibited no significant treatment differences. Additionally, warming enhanced maximum carboxylation rate (Vcmax), maximum electron transport rate (Jmax), respiration rate (Rd), net photosynthetic rate (Pn), water use efficiency (WUE), and photosynthetic pigment contents. Sucrose, soluble sugar, and non-structural carbohydrate (NSC) concentrations were consistently enhanced under warming, accompanied by altered activities of sucrose synthase (SUS), acid invertase (AI), and neutral invertase (NI). Principal component and correlation analyses revealed close interrelationships among growth, gas exchange, photosynthetic pigments, and carbon metabolism under warming. These findings indicate that such physiological adjustments collectively strengthen seedling thermal adaptability under moderate warming, driven by coordinated changes in needle morphology, carbon assimilation, carbohydrate allocation, and related metabolic processes. This study improves our understanding of the physiological adaptation mechanisms of coniferous species to climate warming and provides a scientific reference for forest management under future climate scenarios.

Methane (CH4) is both a major energy resource and a key greenhouse gas in the Earth's carbon cycle. The clumped isotope geochemistry of methane (Δ13CH3D and Δ12CH2D2) offers a unique and effective tool for understanding methane sources and sinks. In this work, we comprehensively compiled a global methane clumped isotopes dataset (n = 1061). Combined with our own measured data (n = 26) and machine learning predictions, we discuss the efficacy of clumped isotope analyses of CH4 to infer methane origin mechanisms and to constrain post-generation processes. Insights gleaned through field observations, laboratory-controlled experiments and geochemical modelling allow an isotopologue-scale reconstruction of the biogeochemical methane cycle and its evolution through transformation (or gas migration) fractionation. The most up-to-date evidence suggests that equilibrated and disequilibrium clumped isotope compositions record reservoir geothermal events and subsequent microbial alteration, as well as kinetically-driven methane metabolism, in the low-temperature surface Earth environment. Modern estimates of the atmospheric methane budget, incorporating source and sink contributions through both forward and reverse constraints, are essential for leveraging clumped isotopes to gain a deeper understanding of Earth system dynamics. Future research that expands the observation of methane clumped isotope data on a broader scale and integrates these findings into methane cycle modelling could provide crucial insights into the potential impacts of anthropogenic influences on the global carbon cycle and climate change.

As a powerful analytical technique for radiocarbon detection, accelerator mass spectrometry (AMS) has revolutionized 14C measurement across interdisciplinary researches. The Tianjin University AMS (TJUAMS) facility, a multi-nuclide analytical platform, has accumulated seven years of operational experience, and processed more than 6,000 14C samples. Through comprehensive 14C-AMS measurements and systematic data analyses, multiple critical factors affecting analytical accuracy have been identified, including: (1) precise cathode alignment, (2) optimal ion beam current intensity, (3) accurate delta 13C correction implementation, and (4) proper ratio normalization protocols. This study presents comprehensive comprehensively experimental data sets which express these effects, and evaluates their systematic effects on the measurement outcomes, and provides methodological insights relevant to the broader AMS community.

Aerobic composting is an effective technology for organic waste recycling; however, it is often hindered by substantial carbon loss, mainly in the form of CO2 and CH4, and slow humification. To address these challenges, this study evaluated the effects of nitric acid (HNO3)-modified co-pyrolyzed biochar derived from gentamicin mycelial residue, food waste, and wheat straw on the composting of cattle manure. The results showed that, compared with the control, unmodified co-pyrolyzed biochar group (GBC) increased cumulative CO2 emissions by 24.85%, but reduced cumulative CH4 emissions by 45.90%. In contrast, the HNO3-modified co-pyrolyzed biochar group (NGBC) demonstrated a comprehensive mitigation effect, reducing cumulative CO2 and CH4 emissions by 2.38% and 60.46%, respectively. Furthermore, NGBC achieved the highest increase in humic acid content (22.72%). The enhanced performance is attributed to the improved specific surface area and surface functionality of the modified biochar, which optimized the composting microenvironment by prolonging the thermophilic period and enriching key bacterial taxa (e.g., Actinobacteria and Firmicutes) crucial for lignocellulose degradation. Metabolic prediction further revealed that HNO3 modification redirected microbial carbon metabolism from mineralization towards humification, facilitating the conversion of organic carbon into stable humus. This study provides a technological approach for the efficient treatment of organic solid waste.

The Xianshuihe fault zone, an active continental strike-slip system located in the eastern Tibetan Plateau, exhibits intense seismicity and widespread geothermal activity. However, the mechanisms by which hydrochemical changes in geothermal systems respond to earthquakes remain poorly constrained. Here we present a time series dataset of hydrochemical and isotopic parameters (e.g., major ions, trace elements, δ18OH2O, δDH2O, δ13CTDIC, and Δ14CTDIC) from five thermal springs located near the epicenters of the 2022 Ms 6.8 Luding earthquake. The stability of most major ions, δ18OH2O, and δDH2O values suggests that post-seismic change is primarily governed by internal aquifer processes. Thermal waters are primarily recharged by meteoric precipitation and affected by minor water–rock interaction. The variation in the δ13CTDIC following the mainshock indicates the input of deep CO2 into the geothermal system through the opening of a deep fault driven by subsequent stress redistribution. Combining geochemical with geophysical evidence suggests that vigorous deep-sourced CO2 (Cdeep) originates from crustal metamorphic decarbonation, likely associated with the ascending mantle materials and the crustal channel flow driven by the Indo-Eurasian collision. The continuous accumulation of deep CO2 in the crust generated over-pressurized reservoirs at depths and enhanced the mechanical weakening of faults. Our findings demonstrate the sensitivity of deep carbon release in geothermal systems to seismic activity, highlighting the potential of hydrogeochemical monitoring for earthquake predictability and providing insights into the complex interactions between deep fluids and seismicity in active tectonic settings.

Volcanic degassing is a critical natural carbon source to the atmosphere, with significant implications for global carbon cycling and climate dynamics. The assimilation of 14C-depleted deep carbon by vegetation provides a biological proxy for deep carbon emissions. In this study, we investigated the carbon isotopic compositions (delta 13C and O14C) of annual herbaceous plants from the geothermal areas in the Changbaishan volcanic area to assess their potential as proxies for monitoring deep carbon emissions. Our results revealed pronounced isotopic anomalies in plants from geothermal areas, with delta 13C values ranging from -31.5 %o to -26.4 %o and O14C spanning -590 %o to +9 %o, indicating significant dilution by 14C-free deep carbon. The Jinjiang geothermal area exhibited the lowest O14C value (-590 %o), reflecting localized hyperactive degassing. The observed carbon isotopic compositions were primarily influenced by deep carbon emissions, with additional effects from interspecific metabolic fractionation among plant species. We estimated deep CO2 concentrations at the sampling sites and observed a clear trend of increasing deep CO2 concentrations closer to emission sources (hot springs). Anomalously elevated deep carbon signals at distal sites (e.g., JL1) were correlated with root-mediated uptake of dissolved deep CO2, as evidenced by isotopic disparities in riparian plants. This study highlighted the feasibility of using annual herbaceous plants as alternative biological proxies for monitoring deep carbon emissions, offering a novel methodology for tracking volcanic activity.

Tectonic degassing along active fault zones in continental collisional orogens has attracted increasing attention due to its critical role as a major pathway for the release of deeply sourced CO2 to Earth’s surface. Active faults are generally characterized by three forms of deep CO2 emissions (i.e., dissolved inorganic carbon (DIC) in spring water, bubbling gases, and diffuse soil micro-seepage), but their fluxes were rarely estimated simultaneously in a single study area. Here, we focus on the Sangri-Cona rift (SCR) in the southern Tibetan Plateau, carrying out the estimation of three forms of deep carbon fluxes based on field observations and geochemical analysis of carbon sources. The calculated percentages of deeply sourced CO2 in the DIC of spring water, CO2 of bubbling gases, and diffuse soil CO2 degassing are 75.8

Carbon(C)sequestered in the mantle and crust over geological timescales accounts for more than 99％of all carbon in the bulk sil-icate Earth and plays a fundamental role in driving surface biogeo-chemical cycles,which involve only a tiny fraction of Earth's total carbon inventory[1].In addition to CO2 released through near sur-face weathering of sedimentary rocks[2],a substantial,but still poorly quantified,amount of carbon in the deeper crust and mantle(hereafter referred to as deeply-sourced carbon)could be mobi-lized by magmatism and metamorphism and then outgassed in volcanic and non-volcanic settings,exerting non-neglectable impact on the atmospheric CO2 budget over million-year time-scales[1].

Reservoir systems serve as critical conduits for terrestrial carbon transfer to aquatic ecosystems. However, research on the dynamics and sources of dissolved organic carbon (DOC) in river-reservoir systems within plateau regions remains incomplete. This study centered on the upper Yellow River's terraced hydropower section (Longyangxia-Lijiaxia-Liujiaxia) and employed spectral analysis and stable carbon isotope techniques to examine DOC's spatial-temporal distribution and source allocation. Results showed: (1) DOC concentrations exhibited significant spatial heterogeneity and seasonal variations, lowest in fall and highest in summer. This variation is likely closely related to precipitation patterns; spatially, the DOC concentration decreases and then increases along the course, with downstream DOC transport patterns altered due to the dam's blocking effect. (2) UV-Vis and EEM-PARAFAC analysis revealed low dissolved organic matter (DOM) humification, with endogenous sources predominating. Four types of fluorescent components were identified within the watershed: humic-like (C1, C2), fulvic-like (C3), and tryptophan-like (C4). (3) MixSIAR modeling results indicate that endogenous sources (e.g., algae) dominate contributions at 49.4 %, supplemented by exogenous terrestrial C3/C4 plant inputs at 29.3 %. Notably, the contribution from endogenous sources is more pronounced in summer, fall, and winter. This study elucidates the biogeochemical behavior of DOC in plateau rivers, providing evidence for carbon cycle research and the promotion of the "spectrum-isotope" combined method.

Understanding the processes of non-steady state denudation and sediment recycling is crucial for interpreting landscape evolution and sedimentary records, yet its quantification remains challenging. This study integrates field observations, cosmogenic nuclide analyses, topographic data, and modeling to unravel these processes from regolith to catchment scales. Depth profile models were used to estimate denudation rates in regolith within non-steady landscapes, revealing that abrupt surface denudation events—such as those driven by climate change, landslides, or human activities—can be recorded by cosmogenic nuclides in regolith. Our findings also show that denudation rates derived from non-steady state region with strong tectonic activity are often overestimated by assuming steady state. Through measurements of both 10Be and 26Al in riverine sediments, we identified evidence of sediment recycling in the central Tibetan Plateau, with a consistent burial age of 0.54 ± 0.16 Ma. By combining these results and paleoclimate records, we interpret this "Great Burial" as most likely resulting from climate-controlled deglaciation and denudation at the termination of Naynayxungla glaciation during the MIS 13–15 period. This event likely marks the first widespread deglaciation on the Tibetan Plateau.

Understanding the species diversity distribution of lycophytes and ferns is crucial for identifying biodiversity hotspots and conservation planning. Northeast China, a biodiversity-sensitive area affected by climate change, lacks comprehensive information on diversity and distribution patterns of these plants. To address this gap, we sorted out all naturally distributed lycophyte and fern species recorded in the region, analyzed their diversity, frequency, and threatened status. Correlation and regression analyses were also conducted with geographic gradients at the county level. Our study identified a total of 143 taxa (species and intraspecific taxa) belonging to 48 genera of 19 families of lycophytes and ferns in Northeast China, with terrestrial (85 spp.) and epilithic (55 spp.) life forms dominating. Species with frequencies below 10.00% comprised 75.52% of the total. Notably, five species were listed as threatened in the Red List of China’s Biodiversity, highlighting the urgency for conservation measures. Overall, species diversity decreased from low to high latitudes, but increased with maximum elevation and elevation range. High diversity areas were concentrated mainly in Da Hinggan Mountains, Xiao Hinggan Mountains, and Changbai Mountains, which correspond to the main mountainous terrain of Northeast China. Changbai Mountains exhibited the highest diversity, establishing itself as a pivotal diversity center for lycophytes and ferns in the region. Exploring the diversity and distribution of lycophytes and ferns is crucial for understanding their interactions with environmental gradients, and thereby supporting significant biodiversity conservation efforts in Northeast China.

A glacial trimline at high elevations in West Antarctica informs on previous warm-based glaciation that occurred during an earlier stage of Antarctic Ice Sheet evolution. A multi-million-year history of theses landscapes has previously been evidenced in a few disparate locations. Here we present new cosmogenic nuclide analyses (Be-10 and Al-26) from a total of 60 samples (clasts and bedrock) at high elevations in several hard-to-access locations across the interior of West Antarctica. In the Sentinel Range of the Ellsworth Mountains this trimline occurs at the highest elevations of any sites in West Antarctica (similar to 3000 m asl). These new data reveal that clasts and bedrock, both above and below the trimline, have long exposure histories with minimum exposure-burial histories of 0.9-2.6 Ma. Accounting for low rates of erosion extends these exposure-burial histories to 2.7-4.8 Ma. Under the assumption of cyclical exposure-burial for proportions of glacial-interglacial cycles we show that some of our samples have exposure-burial histories extending back to the Miocene. We also present new data from the nearby Heritage Range where our new data supports previous work potentially extends the inferred persistence of the location of the West Antarctic ice sheet divide to >2.1 Ma. Finally, we present new data from two isolated nunataks (Mount Woollard and Mount Johns) located deep in the interior of the West Antarctic Ice Sheet near the main ice divide. Paired nuclide analyses of samples from these nunataks also shows long exposure histories and unambiguous evidence of past burial within the last similar to 100 ka. Such a thickening is not currently represented in ice-sheet models.

Coalbed methane (CBM) is an unconventional natural gas resource that supports low-carbon energy demand and mitigates greenhouse gas emissions during coal mining. It is a key natural gas resource in China. Understanding how CBM is produced and accumulates is critical for exploration. Qinshui Basin is the largest and most productive CBM basin in China. This study uses the light noble gas compositions (He, Ne and Ar) of CBM from five blocks in the Qinshui Basin to provide a comprehensive view of gas accumulation history. The noble gases are derived from air and deep crustal sources. Gases from these sources were mixed in formation water prior to methane extraction. Subsequent degassing followed open-system Rayleigh fractionation, enabling the crustal 4He and 40Ar accumulation ages and the gas-water interaction volume to be determined, as well as the proportion of desorbed methane released during production. The coal seams have incorporated the flux of 4He and 40Ar from the deep crust. Despite this, the crustal 4He and 40Ar accumulation ages are considerably younger than the Permo-Carboniferous coal deposition age, revealing widespread gas loss. Adsorbed methane was released during gas extraction. The proportion of desorbed methane in the produced gas shows a strong relationship with crustal 40Ar accumulation ages, indicating that the noble gases serve as a proxy for the preservation of adsorbed methane. The interacted gas/water ratios derived from air-sourced noble gases reflect the extent of gas extraction. Low extraction efficiency is indicated by low gas/water ratios, high dilution ratios and low gas production rates, while prolonged high extraction rates lead to a decline in the dilution ratio. These findings demonstrate the value of measuring trace noble gases for understanding gas accumulation and guiding CBM production strategies.

Regolith, widely distributed on the Earth's surface, constitutes a significant compartment of the Critical Zone, resulting from intricate interactions among the atmosphere, lithosphere, hydrosphere, and biosphere. Regolith formation critically influences nutrient release, soil production, and long-term climate regulation. Regolith development is governed by two primary processes: production and denudation. An urgent need exists to comprehensively understand these processes to refine our understanding of Critical Zone functions. This study investigates an in-situ regolith profile developed on granitic bedrock from a tropical region (Sanya, China). We conducted geochemical analyses, encompassing major, trace elements and mineralogical compositions as well as U-series isotopes, and applied the U-series disequilibrium method to investigate the formation history of this profile. Alternatively, dividing the regolith profile into sub-weathering zones provides a better explanation for the geochemical results, and a multi-stage model based on this subdivision effectively interprets the evolution of deep regolith. Utilizing this multi-stage model, regolith production rates is derived from the "gain and loss" model, ranging from 1.27 +/- 0.03 to 42.42 +/- 24.24 m/Ma. The production rates first increase from surface until a maximum rate is reached at the depth of similar to 160 cm and then decrease at further deeper horizons along the depth profile, and the variation of production rates follows a so-called "humped function". This pioneering investigation into regolith production rates in the Chinese tropical region indicates that (1) the studied profile deviates from a steady state compared to the denudation rate derived from cosmogenic nuclides (10Be_in-situ); (2) subdividing the deep profile based on geochemical data and U-series isotopic activity ratios is imperative for accurately determining regolith production rates; and (3) the combination of U-series disequilibrium and cosmogenic nuclides robustly evaluates the quantitative evolution state of regolith over long time scales. (c) 2025 China University of Geosciences (Beijing) and Peking University. Published by Elsevier B.V. on behalf of China University of Geosciences (Beijing). This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

In this paper, we examine whether outdoor air pollution has a causal effect on body weight. To address the potential endogeneity, we exploit exogenous variation in PM2.5 concentrations generated by China's coal-fired winter heating policy, using regression discontinuity designs to estimate the impact of winter heating on air pollution and body weight in adults. We find that high outdoor air pollution exposure increases body mass index and the corresponding risk of obesity with a 1 mu g/m3 increase in annual average PM2.5 concentrations in the past ten years increasing body mass index by 0.014 units and increasing the rate of adult obesity, by 0.3 percentage points. Our results are robust to using different specifications. Furthermore, the rising risk of obesity caused by air pollution is mainly through channels such as increased intake of energy-dense foods and less physical exercise. The findings imply that low pollution exposure can be an effective way to improve dietary and physical activity patterns and reduce the risk of becoming overweight.

Estuaries significantly affect the transport of dissolved organic matter (DOM) from land to ocean. While the transport and composition of estuarine DOM have been extensively studied, the direct link between DOM chemistry and its age remains unclear, limiting a comprehensive understanding of the dynamics and fate of estuarine DOM under severe conditions (e.g., floods). This study applied radiocarbon and ultrahigh-resolution mass spectrometry analysis to investigate the correlation between DOM chemistry and apparent radiocarbon age of 102 samples collected from the Yangtze River Estuary during both non-flood and flood periods. The results showed that young estuarine DOM are characterized by low-molecular-weight, unsaturated molecules, while aged estuarine DOM are relatively saturated with high-molecular-weight molecules. Phosphorus and nitrogen-containing compounds were key to DOM aging, potentially increasing the lability of aged DOM. Floods significantly impact DOM by introducing more labile aged DOM and young terrestrial DOM. Furthermore, floods enhanced the flux of aged DOM transported to the East China Sea by approximately 1.4 times. Our findings contribute to the study of estuarine DOM and its response during severe floods. Additionally, incorporating apparent radiocarbon age evidence improves the understanding of terrigenous DOM and its fate in large river estuaries before it contributes to the ocean carbon reservoir.

Deciphering Earth's surface denudation-encompassing both physical erosion and chemical weathering-is essential for understanding sediment flux and its impact on long-term carbon cycle. However, quantifying denudation and chemical weathering across different timescales remains challenging. Here, we combine the covariation of different fluxes derived from in-situ Be-10(in) (quartz, 250-500 mu m), the ratio of meteoric Be-10(met) to mineral-weathered Be-9 (fine grains, < 63 mu m), and water chemistry in granitic catchments from the northeastern China to identify the contribution of chemical weathering to overall denudation. Millennial-scale chemical weathering fluxes (W-bulk) derived from the Be-10(met)/Be-9 ratio in authigenic phase capture signals from both the dissolved phase and the reactive phase (adsorbed onto or precipitated in secondary weathering products), ranging from 7.7 to 12.2 mm/kyr. Modern water chemical weathering fluxes (W-water, 2.1-4.0 mm/kyr), which represent only the dissolved phase flux, are positively correlated with W-bulk (R-2 = 0.38) but are consistently lower. Assuming constant weathering fluxes over time, this correlation suggests that only one-third of the bulk weathering products are removed through water discharge. The weathering intensity, defined as the ratio of W-bulk to in-situ Be-10(in) denudation flux (D-in), spans a wide range of 0.14-0.39, in contrast to the relatively narrow range of W-bulk. This highlights the dominant influence of physical erosion in these catchments, likely reflecting a "kinetic limitation" on regional silicate chemical weathering. By integrating previously published global data on D-in and W-bulk, we find that W-bulk scales linearly with D-in in log-log space over three orders of magnitude (10-10(4) t/km(2)/yr). This relationship contrasts with the relationship between W-water and D-in, which shows highly limited weathering flux in uplands with high D-in. The faster decline of W-water compared to W-bulk as D-in increases suggests that W-water is sensitive not only to D-in but also to water discharge. To expand the application of Be-10(met)/Be-9 to any fine-grain Earth surface sample, unlike the strong dependence of Be-10(in)-derived denudation fluxes on the presence of quartz minerals, we also estimate potential weathering intensity proxies such as the mobilized Be-9 fraction in dissolved and reactive phases (freacBe9+fdissBe9) and the chemical depletion factor (CDF). We find that freacBe9+fdissBe9 exhibits a much narrower range (0.22-0.32) compared to W-bulk/D-in. Its insensitivity to weathering intensity is likely due to its strong dependence on particle sorting. Although the CDF is also grain-size dependent and overall higher by 0.29 (< 63 mu m) than W-bulk/D-in, we find that the CDF derived from grain sizes of 250-500 mu m is roughly consistent with W-bulk/D-in. Therefore, the CDF shows promise as a potential weathering intensity proxy for quantifying catchment-wide denudation fluxes through Be-10(met)/Be-9-derived chemical weathering fluxes.

The fluvial development in the Sichuan Basin of southwestern China plays a significant role in the drainage evolution of the Yangtze River. The assumed initially west-flowing middle Yangtze River in the basin was reversed through gradual headward erosion by the lower Yangtze River via the Three Gorges area, resulting in a significant reorganization of the East Asian fluvial system. However, fluvial terrace chronology in the Sichuan Basin is poorly constrained, and the related drainage network development of the middle Yangtze River remains vague. Five distinct terrace levels of the Yangtze River were identified in the field, which could be efficiently correlated with terrace sequences from three major tributaries in the basin: Jialing Jiang, Tuo Jiang, and Min Jiang. This study presents in-situ cosmogenic nuclide 26Al and 10Be ages from these terraces to construct a robust chronology among different rivers, and more importantly, to build a reliable fluvial evolution relationship in the basin. Temporal and spatial variations in the terrace formation ages indicate that: (1) Five terrace levels from the Yangtze River in the southern basin were dated between 1.68 (+1.18/-0.56) Ma and 20.84 (+4.30/-5.03) ka. (2) The formation age of five terrace levels derived from the Jialing Jiang in the eastern basin is concentrated between 0.61 (+0.14/-0.13) Ma and 0.22 +/- 0.20 Ma. (3) The highest terrace T5 of the Tuo Jiang in the middle basin was deposited at 1.24 (+2.86/-0.22) Ma. (4) Three terrace levels from the lower Min Jiang in the western basin were deposited between 0.81(+0.28/-0.26) Ma and 15.24 +/- 1.21 ka. Our new cosmogenic nuclide chronologies provide the first evidence for the Yangtze drainage network evolution in the Sichuan Basin. The Yangtze River and Min Jiang had been aggraded during 1.02-0.14 Ma in the western basin margin with an accumulation rate of 125 m/Ma and then incised after 0.14 Ma. The aggradation in front of the mountain may be attributed to both the active tectonics of the eastern Tibetan Plateau and climate cooling during the Middle Pleistocene Transition. Conversely, the Yangtze River and Jialing Jiang in the eastern basin and the Tuo Jiang in the middle basin cut down into bedrock more than 100 m since 1.68 Ma. The average incision rate of Jialing Jiang (360 m/Ma) in the last 0.6 Ma is higher than those of the Yangtze River (67 m/Ma) and Tuo Jiang (74 m/Ma) over longer timescales. Moreover, we conclude that the present-day eastward-flowing Yangtze River was established in the Sichuan Basin before 1.68 Ma, which further suggests that the downstream Three Gorges connection should have occurred before this point in time.