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Sedimentation rates and sediment budgets are important agents to understand the source-to-sink dynamics in marginal seas. As a classical representative of mega-river dominated marginal seas globally, the South China Sea (SCS) receives huge amounts of fluvial input from mega rivers covering different climate zones. Despite its well-documented prevalence, quantifying the spatial distribution of sedimentation rate and sediment budget over the entire SCS remains a challenge due to limited data availability. In this study, we employed a comprehensive approach to quantify the modern sedimentation rates and sediment budget in the SCS. This approach combined 210Pb measurements from 409 cores, AMS14C data from 112 cores, and 33 sediment trap observations. Our results show that higher sedimentation rates >0.3 cm/a mainly occur in deltas, shelf mud areas, and upper continental slope that connects the submarine canyon. In the subaqueous Mekong Delta, for example, the sedimentation rates can exceed 10 cm/a. In contrast, there is no substantial modern sedimentation in sandy and gravelly areas of the shelf due to strong erosion by a combination of waves, tides and ocean currents. We further compare these results with the eastern China seas including the Bohai Sea, Yellow Sea and East China Sea. A similar spatial distribution of sedimentation rates can be observed in the continental shelf of the eastern China seas. The Holocene sedimentation rates in the deep-water regions of the SCS are generally <100 cm/ka. The basin floor experiences the slowest accumulation, with rates below 3 cm/ka. In contrast, sedimentation rates on the eastern island slopes range from 3 to 8 cm/ka, while the northern, western, and southern continental slopes accumulate sediment most rapidly, exceeding 25 cm/ka. Approximately 1191.1 × 106 t of fine-grained sediment is deposited annually in the continental mud areas of the SCS, with a comparable amount of 1185.4 × 106 t/a deposited on the continental shelf of the eastern China seas. The continental slope accumulates sediment at a significantly higher rate (∼161.0–239.4 × 106 t/a) compared to the deep-water basin (∼16.5–20.1 × 106 t/a) in the SCS. Most of the modern sediments (>98%) are deposited on the continental shelf and slope. In the SCS, fluvial inputs dominates modern sediment sources, contributing over 80% of the total. Coastal/seabed erosion and biogenic deposition account for approximately ∼18%, with eolian dust contributing less than <2%. The findings presented here are critical for elucidating the sources, transport pathways, and deposition patterns of modern sediments in marginal seas. • Distribution of modern sedimentation rates in the South China Sea was illustrated at the basin scale. • The sediment budget and mass balance from a source–to–sink perspective was constructed. • Comparison of sedimentation rates and sediment budgets of the South China Sea and east China seas was conducted. [ABSTRACT FROM AUTHOR]

Geothermal resources exist in complex and comprehensive geological settings. In the current study, we proposed a CPU/GPU collaborative parallel prestack time migration methodology for geothermal resource exploration. First, seismic geological conditions in Xian County were obtained based on an analysis of drill cores for further seismic evaluation. Then, combined with the analysis of two‐dimensional seismic data in the adjacent area, a test section with three seismic survey lines were designed to explore the geological structure of the study area. In the study area, the seismic data were derived through the multiple coverage reflection wave exploration method with explosive ignition in deep wells and high coverage frequency observations. Finally, we employed CPU/GPU collaborative parallel prestack time migration technology to analyze the obtained seismic data for geothermal resource evaluation. The favorable areas of karst fissure heat storage in Middle–Upper Proterozoic Jixianian and Paleozoic Cambrian–Ordovician rocks were inferred together with two preferred recommended exploration holes. [ABSTRACT FROM AUTHOR]

Neogloboquadrina pachyderma (sinistral), the dominant planktonic foraminiferal species in the mid-to-high latitude oceans, represents a major component of local calcium carbonate (CaCO3) production. However, the predominant factors, governing the calcification of this species and its potential response to the future marine environmental changes, are poorly understood. The present study utilized an improved cleaning method for the size-normalized weight (SNW) measurement to estimate the SNW of N. pachyderma (sin.) in surface sediments from the Amundsen Sea, the Ross Sea, and the Prydz Bay in the Antarctic Zone of the Southern Ocean. It was found that SNW of N. pachyderma (sin.) is not controlled by deep-water carbonate dissolution post-mortem, and can be therefore, used to reflect the degree of calcification. The comparison between N. pachyderma (sin.) SNW and environmental parameters (temperature, salinity, nutrient concentration, and carbonate system) in the calcification depth revealed that N. pachyderma (sin.) SNWs in the size ranges of 200–250, 250–300, and 300–355 µm are significantly and positively correlated with seawater temperature. Moreover, SNW would increase by ∼30% per degree increase in temperature, thereby suggesting that the calcification of N. pachyderma (sin.) in the modern Antarctic Zone of the Southern Ocean is mainly controlled by temperature, rather than by other environmental parameters such as ocean acidification. Importantly, a potential increase in calcification of N. pachyderma (sin.) in the Antarctic Zone to produce CaCO3 will release CO2 into the atmosphere. In turn, the future ocean warming will weaken the ocean carbon sink, thereby generating positive feedback for global warming. [ABSTRACT FROM AUTHOR]

Evidence of meltwater and ice rafted debris from the Tenji and Detroit seamounts in the northwestern corner of the North Pacific are key to understanding ice sheet dynamics across the Kamchatka Region. Marine isotopic stages 6.5–1 were established in this study for the Tenji Seamount sediment core based on accelerator mass spectrometry (AMS) 14C data, benthic foraminifera δ18O stratigraphy, and relative paleointensity excursions. Records of planktic foraminifera δ18O and ice rafted debris (IRD) in sediment cores pertaining to the last 190 kyr were used to outline several periods of surface water freshening and increased accumulation of coarse terrigenous grains induced by iceberg supply and melting in the northwest Pacific. Iceberg discharge events (IDEs) were reconstructed over the last and penultimate glacial periods in the central and eastern parts of the Okhotsk Sea and southwestern part of the Bering Sea using relevant published proxies. Similar reconstructions of IDEs were also performed for two published sediment cores from the Detroit Seamount. Synthesis of planktic foraminifera δ18O and IRD records along with other related proxies from the studied areas concordantly revealed five IDEs in the northwest Pacific and its marginal seas during the last 190 kyr: IDE 1 (42–29 ka), IDE 2 (76–57 ka), IDE 3 (118–110 ka), IDE 4 (152–141 ka), and IDE 5 (179–160 ka). Data showed that IDEs 4–1 occurred at low values of Earth obliquity and under a weak Aleutian Low, facilitating snowfall precipitation and enhancing glacier formation at Kamchatka, which is a priority area for capturing atmospheric moisture transferred into northeast Asia. Compared with the other IDEs, IDEs 2 and 5 were more pronounced and prolonged events over the last 190 kyr. In addition, IDE 2 was also characterised by a catastrophic and short IRD peak that was probably forced by the influx of lake water from the Central Kamchatka Depression. It is likely that IDEs 2 and 1 occurred during phases I (more extensive) and II (less extensive) of the published Kamchatka glaciations during the Late Pleistocene. • Planktic δ18O and ice rafted debris as tools for iceberg discharge in the NW Pacific. • Dated records of iceberg evidences in sediments of NW Pacific and marginal Seas. • Five dated iceberg discharge events (IDE) in NW Pacific inferred by data synthesis. • Five periods of Kamchatka glaciations related with NW Pacific IDEs over last 190 ka. [ABSTRACT FROM AUTHOR]

The Quaternary history of the Arctic Ocean reflects pronounced periodic changes in marine and glacial environments. This variability is an important component of the Arctic paleoclimatic system. For more insight, we use isotopic measurements on the detrital (Nd-Sr-Pb) and authigenic (Nd) phases of the Quaternary sediments from the central Arctic Ocean. We analyze core ICE4 from ∼3 km water depth off the Lomonosov Ridge. This core was previously studied for other sedimentary proxies (Dong et al., 2022). The analyzed record is estimated to cover major Late Pleistocene Weichselian/Wisconsinian glaciations occurring over the last ∼100–200 ka. Our results provide new evidence that glacially-derived waters from the glaciated margins reached the bottom of the deep Arctic basins. We infer that these waters were delivered to the deep basins by hyperpycnal flows originating from subglacial outbursts accompanying overflow meltwater and iceberg discharge during glacial/deglacial events. Voluminous outbursts during the older, presumed Early/Middle Weichselian glaciation, ca. 115-35 ka, are traced to the West Siberian margin impacted by the Eurasian Ice Sheet. Similar sedimentary layers are found in longer records from the central Arctic Ocean at older stratigraphic intervals. Sediments constrained to the Last Glacial Maximum have less pronounced glacigenic inputs with a stronger Laurentide Ice Sheet signature. The circulation patterns were likely dependent on the interplay of the timing and extent of the Laurentide and Eurasian ice sheets. • Late Pleistocene sediment record from Eurasia Basin, Arctic Ocean. • Isotope proxies in the detrital (Nd, Sr, Pb) and authigenic (Nd) phases. • Eurasian Ice Sheet waters transported to deep basins via hyperpycnal flows. • Less glacigenic inputs with a stronger Laurentide signature during LGM. [ABSTRACT FROM AUTHOR]

Knowledge of thermo-hydro-mechanical (THM) coupling process is important for rock hydrofracturing of enhanced geothermal systems (EGS). The THM coupling parameters (e.g. thermal conductivity, water permeability and Biot's coefficient, etc) of granite undergoing treatment with heating and water cooling (HWC) were measured using laboratory tests. A large number of cracks inside the granite are caused by the uncoordinated deformation of minerals and the tensile stress induced by the treatment of HWC were clearly observed by scanning electron microscope (SEM), resulting in degradations of physico-mechanical behavior and capacity of heat transmission, and increases of effective stress and connectivity of transport path. Compared with the treatments of heating and natural cooling or heating in real-time in previous studies, the temperature threshold of THM coupling parameters are advanced for HWC treated granite, especially for thermal conductivity, water permeability, Biot's coefficient and brittle–plastic transition. Prediction models for THM coupling parameters are established based on the correlation analysis. The predictions are in good agreement with the experimental observations. The results are likely to provide an outlet for understanding the characteristics of dry hot rock undergoing hydraulic fracturing or thermal stimulation, especially for the variations and predictions in THM coupling parameters. • Treatment of heating and water cooling could exacerbate thermal cracking. • Reduction of thermal conductivity, increases of effective stress and transport path. • Temperature threshold of thermo-hydro-mechanical coupling parameters are advanced. • Establishing prediction model for thermo-hydro-mechanical coupling parameters. [ABSTRACT FROM AUTHOR]

The Okhotsk Sea, located between the Asian continent and the western Pacific, is a natural laboratory for investigating sediments source-to-sink influenced by atmosphere–ocean–land–sea ice interactions. However, despite their paleoenvironmental significance, changes in sediment provenance within the Okhotsk Sea are still debated due to the diversity of sediment sources and transport processes. Here, we investigate Sr and Nd isotope compositions in surface sediment samples from regions across the Okhotsk Sea, as well as Sr and Nd isotope compositions and elemental abundances in the sediments of core LV55‐40-1, collected from the southwestern Okhotsk Sea. Our results reveal an increasing trend of εNd values over the past ∼110 kyr, with an abrupt increase during the transition into the last deglacial/early Holocene (MIS 1). We also observed minor variations characterized by less radiogenic εNd during the glacial/stadial (G/S) periods (MIS 5d, MIS 5b, MIS 4, MIS 2), and more radiogenic εNd during the interglacial/interstadial (I/I) periods (MIS 5c, MIS 5a, MIS 3). The major terrigenous sediment sources in the northwestern Okhotsk Sea are via the Amur River and from Sakhalin Island (∼60–80%), with a minor volcanic contribution (∼20–40%) from the Okhotsk-Chukotka volcanic belt and the southern Kuril Islands/Hokkaido. Provenance variations are primarily controlled by the interplay of sea-ice drifting and ocean circulation, reflecting a dominant transport mode shift from sea ice to surface current dominance since the early Holocene. During the G/S periods with severe sea-ice condition, terrigenous materials from the Amur River and Sakhalin Island were transported to the study site, due to the southeastward drift of sea ice driven by the prevailing northwesterly winds and enhanced Okhotsk Sea Intermediate Water circulation. In contrast, during the I/I periods with moderate sea-ice conditions, an increased contribution from the Okhotsk-Chukotka volcanic belt was caused by sea-ice drifting southwestwards under the prevailing northerly and northeasterly winds, supplemented by surface currents. This study provides the first Sr-Nd isotopes record spanning the last glacial cycle in the Okhotsk Sea and it offers new insights into the relationship between sediment provenance and the interplay of sea ice and ocean currents in this region. • First record of Sr-Nd isotopes in the Okhotsk Sea over the last glacial cycle. • The Amur River and Sakhalin Island were primary sediments sources in this region. • Volcanic materials increased during the interglacial/interstadial periods. • Shift of sediments provenance was driven by sea-ice drifting and ocean currents. [ABSTRACT FROM AUTHOR]

Understanding past changes in oceanic circulation and the corresponding heat, salt delivery variations are essential for assessing the climatic roles of ocean dynamic processes since the last glacial period. Unravelling salinity budget variation in the North Pacific and its controls is important to better understand the North Pacific Intermediate/Deep Water formation and associated climate impacts. The Tsushima Warm Current (TWC), the northernmost Kuroshio branch entering the semi-closed Japan Sea through the shallow strait, is regarded as a fundamental component for oceanographic changes in the Japan Sea. To obtain a comprehensive history of the Japan Sea salinity budget, this study reconstructed the evolution history of the TWC inflow by compiling paleo-hydrographic records in the Japan Sea. Following a persistent but weakened TWC inflow during Marine Isotope Stage 3, radiolarian assemblage data revealed that the TWC taxa disappeared since ∼30 thousand years ago (ka). The synchronous onset of the low salinity anomaly event was in response to the cutoff of saline TWC inflow due to the rapid fall in global sea level at 30 ka. Extreme restriction of seawater exchange caused a persistent freshening of the glacial Japan Sea and formed a low-salinity water mass in the upper ocean. The compiled paleodata confirmed that the Japan Sea accumulated excess freshwater during the glacial sea-level lowstands and the low-salinity pool extended downward to ∼900 m depths. Coinciding with the peak of the low salinity anomaly event, re-emerging TWC inflow after 19 ka reflected the reconnection of the open ocean to the Japan Sea. The persistent TWC inflow mainly drove the reduction in magnitude of the deep low-salinity pool during the last deglaciation. As a large and isolated freshwater sink for the glacial North Pacific, the deep low-salinity pool evolution could potentially have strong impacts on the North Pacific salinity budget and subsequent large-scale circulation. • Radiolarian reconstruction indicates a persistent but weakened influence of the TWC inflow in the Japan Sea during MIS 3. • The low-salinity pool extended downward to ∼900 m depths in the Japan Sea during the LGM. • The link between global sea-level change and deep low-salinity pool evolution is sought. [ABSTRACT FROM AUTHOR]

The Western Subarctic Gyre (WSG) in the North Pacific represents the termination of the Atlantic Meridional Overturning Circulation (AMOC). It has been strongly influenced by periodic glaciations of adjacent landmasses, orbital- and millennial-scale variability of its environment, and ventilation, which, to date, have been poorly studied. In this study, we investigated sediment core LV76-21 recovered from the Detroit Seamount using several productivity and lithological proxies, δ18O records of planktic and benthic foraminifera (δ18Opf and δ18Obf), AMS 14C data. We also used the published results from three well-dated cores from the Detroit and Tenji Seamounts. Comparison of the δ18Opf and δ18Obf records allowed us to establish iceberg discharge events 1 and 1' at 39–36.8 and 42–40 ka, respectively, in the WSG over the last 43 kyr. This was accompanied by considerable lightning of δ18Opf relative to the coeval δ18Obf values. The lithological results have also shown variable sea-ice influence on the regional environment during Marine Isotope Stage 3 and particularly 2, with sea ice extensions at 28.5–25.5 ka and 17.6–16.6 ka, and its significant loss since the Bølling–Allerød warming. We used high resolution δ18Obf records from studied cores as a subtle proxy of contribution of North Atlantic Deep Water (NADW) to Lower Circumpolar Deep Water (LCDW), which originating from around Antarctica and have slightly different δ18Obf values, in order to reconstruction of its spatial variability in the context of regional deep-water ventilation. The contribution of NADW to LCDW in the ventilation of the western flank of Detroit Seamount significantly increased during the interglacial and long-lasting Dansgaard–Oeschger interstadials, which was synchronous with the AMOC intensification. Over the last 43 kyr, the deep water of its eastern flank has been constantly ventilated by the LCDW with low contribution of NADW. • ●Sediment core LV76-21 recovered from the Detroit Seamount is analyzed. • ●Productivity and lithological proxies, δ18O records, and 14C data are derived. • ●Iceberg discharge and sea-ice influences are identified over the last 43 kya. • ●NADW inputs into deep-water ventilation are synchronous with AMOC intensification. • ●The eastern flank of the Detroit Seamount has been constantly ventilated by ABW. [ABSTRACT FROM AUTHOR]

The role of the Southern Ocean in releasing CO 2 (sequestered in the global ocean during the Last Glacial Maximum) into the atmosphere during deglaciation is an important topic for investigation of Earth's climate. Changes in global deep water circulation associated with upwelling of Circumpolar Deep Water (CDW) around Antarctica may have played a part in the CO 2 release, but remain poorly studied. The potential response of the Pacific Ocean, including the North Pacific, to upwelling of CDW with its vast reservoir of CO 2 remains unresolved. Here we combine productivity proxies, oxygen and carbon isotope values in benthic and planktic foraminifera, data on the occurrence and abundance of ice-rafted debris, and benthic foraminiferal species composition in three sediment cores with published data for three cores from the Northern Emperor Rise for the Last Glacial Maximum, deglaciation and Holocene in order to elucidate the North Pacific role in CO 2 redistribution in the past. Age models of the cores are based on radiocarbon data calibrated by 14C atmospheric plateau tuning. The calcium carbonate content in all cores increased abruptly around 14.5 ka, indicating an influx of relatively young water enriched in carbonate ion, oxygen and nutrients, and sourced in the Southern Oceans. A decrease in the extent of sea ice at the NER area during early deglaciation is reflected in sharp increases in the productivity of siliceous phytoplankton near the onset of Bølling/Allerød warming, possibly facilitated by the influx of Southern Ocean-sourced nutrient-rich waters. • Stable isotope, lithological and micropaleontological proxies of 6 cores from the Western Subarctic Gyre (WSG) were studied. • Age models of cores over the last 25kyr were modified by radiocarbon data calibrated by 14C atmospheric plateau tuning. • Multiple lines of evidences support abrupt flushing of Southern Ocean origin water into the deep WSG since 14.5 ± 0.2 ka. [ABSTRACT FROM AUTHOR]

Sediment accumulation in continental margins during the Quaternary Period was substantially influenced by both sea-level fluctuations and climate changes. However, the response of sediment accumulation to these changes on an orbital timescale, remains poorly understood, for two main reasons: the scarcity of sedimentary records with a high-resolution chronology, and the difficulty in distinguishing the role of sea-level from regional climate signals. Here we present the results of sediment color reflectance (c*), grain size and total organic carbon (TOC) content of core BH08 (212.4 m in length, spanning the last ~1 Myr) recovered from the Bohai Sea, China. The chronology of core BH08 on the orbital timescale is constrained by both magnetostratigraphy and astronomical tuning. Sedimentary facies analysis suggests that the sedimentary sequence is dominated by the alternation of a deltaic system and floodplain deposition. Principal components analysis of the grain-size data reveals two principal components (PCs), including PC1, reflecting the 31–500 μm fraction, and PC2, reflecting the 18–66 μm fraction. Comparison of sample scores on PC1, PC2 and c* with the alternation of sedimentary environments reveals that PC1 and c* reflect cycles of deltaic and floodplain deposition at ~100-kyr and ~40-kyr periodicities, while PC2 exhibits a ~20-kyr periodicity, in addition to the ~100-kyr and ~40-kyr cycles. We infer that PC1 and c* are mainly sea-level dependent, whereas PC2 is controlled by the combination of changes in monsoon climate and sea level. We suggest that Milankovitch-scale monsoon climate fluctuations controlled the sediments supply to the Bohai Sea during the last ~1 Myr, while the redistribution of sediments by marine processes (e.g., tidal currents) has partially obscured the monsoonal signal in the grain-size proxy (e.g., PC1) which instead is sensitive to sea-level change. Our results provide an example of the influence of climate and sea-level on sediment accumulation in a shallow continental margin setting influenced by monsoonal climate in an icehouse world. • A 1-Myr record of orbitally-forced continental margin deposits is presented. • Principal components analysis of grain size reveals sea-level and climate signals. • Sedimentation in the Bohai Sea is influenced by sea level and monsoonal climate. • Monsoon signal could be obscured by marine process (e.g., tidal currents). [ABSTRACT FROM AUTHOR]

The Mariana Trough, a relatively simple intra-oceanic back-arc basin, is ideal for investigating magmatic processes and mantle-crust interaction in a subduction setting. We present new major- and trace element compositions for 31 basaltic lava and glass samples from the Mariana Trough back-arc spreading center. The studied lavas include phenocrysts of plagioclase, olivine and pyroxene. Major element compositions show that these lavas range from tholeiitic basalt to basaltic andesite, and belong to a sub-alkali tholeiitic series produced by fluid-influenced fractional crystallization of primary basaltic melts. Trace element compositions show that these lavas are transitional between typical normal mid-ocean ridge basalts (MORB) and island arc basalt (IAB), and are enriched in large ion lithophile elements (LILEs) and light rare earth elements (LREEs). Trace element ratios, e.g., Ba/Th, Pb/Ce, Th/Nd, La/Sm, Th/Nb, Ba/Nb and Th/Nb, indicate that the mantle from which these lavas were derived underwent modification resulting from the addition of multiple subduction components. Some typical trace element ratios (e.g., Ba/Nb- total subduction component, Ba/Th- shallow subduction, and Th/Nb-deep subduction component) from our new data and the literature suggest that a latitudinal variation exists in addition to subduction components, and indicates a more complex and heterogeneous distribution of subduction components in the Mariana back-arc region. We suggest that, (1) compared to back-arc locations at 18° N and 15.5° N, lavas from back-arc locations at 17° N indicate higher levels of modification by hydrous fluid released from the subducted slab, and (2) compared to back-arc locations at 17° N and 15.5° N, petrogenesis of lavas from back-arc locations at 18° N indicates a greater influence of sediment melt. [ABSTRACT FROM AUTHOR]

This study aims to investigate seismic reflection characteristics and controlling factors of gas within the East China Sea clinoform based on seismic profiles and borehole core data, including organic geochemistry and lithology. The seismic profiles reveal distinct gas-related seismic reflection characteristics along the coast, extending from the Yangtze Estuary southward to the elongated inner shelf. In the northern region, specifically the northern part off the Yangtze Estuary, widespread acoustic blanking is topped by a shallow gas front reflector parallel to seabed. In the middle region, spanning the southern part off the Yangtze Estuary and the adjacent northern inner shelf, widespread acoustic blanking is topped by a gas front reflector following the clinoform stratigraphy. In the southern region, off the Oujiang Estuary, there are widespread acoustic turbidities that are topped by a severely undulated gas front reflector. Based on the combined seismic-core data, it is suggested that the seismic reflection in the northern region, characterized by the gas front reflector parallel to the seabed, is controlled by the combination of anaerobic oxidation of methane and active gas diffusion triggered by seabed erosion. In the middle region, the obstructive effects of clinoform stratification on gas diffusion contribute to the seismic reflection characterized by the gas front reflector following the clinoform stratigraphy. In the southern region, the seismic reflection of low-concentration gas characterized by widespread acoustic turbidities is primarily influenced by the interplay between abundant gas source supplies due to the clinoform depocenter and elevated hydrostatic pressure in deeper water conditions. Furthermore, local gas seepage is observed in the northern region, likely due to seabed erosion and lower hydrostatic pressure in coastal zones. Additionally, the coastal zones and seaward slope break sites along the rest of the clinoform sections are also identified as having higher potentials for gas seepage. • The clinoform exhibits distinct seismic reflection characteristics of gas. • Seabed erosion near Yangtze Estuary leads to shallower gas front parallel to seabed. • Sealing of clinoform layers contributes to gas front following stratigraphy. • Local gas seepage off the Yangtze Estuary is primarily caused by seabed erosion. [ABSTRACT FROM AUTHOR]

Abstract An efficient numerical model, which can simulate the coupled fluid flow and heat transfer processes in geothermal fields, is essentially required to evaluate the fate of geothermal wells and the temperature and pressure evolutions of geothermal reservoirs in response to the long-term well operations. Due to the scale disparity between wells and geothermal reservoirs (∼dm vs. ∼km), very fine mesh is required to accurately represent the highly-dynamic zones near geothermal wells, and thus the conventional geothermal reservoir model including geothermal wells is usually time consuming. To improve the computational efficiency without losing accuracy, a simplified one-dimensional geothermal well model considering heat convection and conduction along well axis and heat transfer between geothermal fluid and rocks in the radial direction is proposed and incorporated into the geothermal reservoir model. Both a bench-mark example and a case study of Beijing city geothermal field are presented to demonstrate the reasonability and efficiency of the proposed reservoir modeling method. The computational time are significantly reduced because of avoiding mesh refinement near geothermal wells. The multiple wells effects, interactions between different reservoirs, and the role of faults in reservoir performance are also discussed based on the case study of Beijing city geothermal field. Graphical abstract Image 1 Highlights • Simplified model for geothermal well based on equivalent heat transfer coefficient. • An integrated reservoir-well model for geothermal field including multiple wells. • Robust prediction of the fate of geothermal wells in Beijing urban geothermal field. [ABSTRACT FROM AUTHOR]

Abstract Production water reinjection plays an important role in geothermal reservoir management. Heterogeneous porous geothermal reservoir models considering the spatial distributions of permeability and rock heat capacity are generated. In total, 200 realizations with different permeability fields were considered. A fully coupled modeling of reservoir deformation, fluid flow, and heat transport was performed on each realization using the finite element method. The results showed that heterogeneity induced channeling appears in the geothermal reservoirs with increasing heterogeneity of permeability, through which the injected production can quickly reach the production well. This causes the shorter thermal breakthrough time at production wells, and the lower reservoir surface settlement. In geothermal reservoir models considering the correlation between heat capacity and permeability, the thermal breakthrough curves and the reservoir surface settlement were the same as the reservoir models of the constant heat capacity. With increasing correlation length, the possibility of flow channels appearing in well pair system increases, causing a short average thermal breakthrough time and a lower surface settlement around the injection well. The existence of preferential flow channels between injection and production wells indicates that an equivalent flow channel model can be approximately simulate geothermal doublets in heterogeneous reservoirs. Highlights • Heterogeneity induced channeling appears in geothermal reservoirs. • The short thermal breakthrough time occurs in heterogeneous geothermal reservoirs. • The low surface settlement occurs in heterogeneous geothermal reservoirs. • The existence of preferential flow channels verifies the equivalent channel models. [ABSTRACT FROM AUTHOR]

Abstract Taiwan is particularly sensitive to changes in monsoonal precipitation and to typhoon-induced heavy precipitation events, however, rainfall variability in Taiwan on centennial and millennial time scales during the Holocene has not been well understood. This study describes mid-Holocene rainfall features of Taiwan based on pollen, total organic carbon (TOC), total nitrogen (TN), and C/N ratio records of core MD05-2908. The step-wise increase in sedimentation rate, fern spore percentage and concentration, TOC content, and C/N ratio suggests an increasing terrestrial material supply due to the intensified rainfall in Taiwan since 6800 cal. yr BP. This rainfall pattern shows an inverse pattern to the decreasing East Asian summer monsoon (EASM) strength represented by the multi-proxy records from North China. Variation of the East Asian summer circulation and associated moisture transport may account for the long-term rainfall changes in Taiwan. Superimposed on this trend, we interpreted three prominent rainfall changes, which focus on the periods of 6800–6600, 1090–880 and 490–190 cal. yr BP. These centennial time scale rainfall variations in our records are linked to the intensity of El-Niño Southern Oscillations. Highlights • Pollen evidence enabled to trace the sources of sediments in South Okinawa Trough. • The rainfall variation of Taiwan during the past 6800 years is reconstructed by multi-proxies. • The result leads an improved understanding of the interplay between East Asian Monsoon and ENSO since mid-Holocene. [ABSTRACT FROM AUTHOR]

Abstract Glaciers, one of basic elements of climate system, play a crucial role in shaping global climate and regional environment. Combined with the published δ18O of Neogloboquadrina pachyderma (sin) (Nps) , the data in this study show the impact of glacier decay on surface hydrography. Light peaks in δ18O Nps of one sediment core retrieved from the NW Pacific, after ice volume correction for water oxygen isotopic composition (δ18O Nps gwc), are referred to correspond to the melting-pulse events during the decay of Kamchatka glaciers. These events are synchronous with the sub-millennial scale warming in the Northern Hemisphere during the Greenland Interstadial 1. On the other hand, the influence of the Kamchatka Glacier decay on surface hydrography is limited to the adjoined area of the Kamchatka River Estuary. In contrast, the δ18O Nps gwc data from the North Pacific show that the effect of Cordilleran Ice Sheet (CIS) decay are remarkable in the Gulf of Alaska, the NE Pacific and the Bering Sea. Specifically, the CIS melting water results in a stronger surface stratification and thus the salinity and density decrease in the surface water of NE Pacific and the eastern Bering Sea. Moreover, this process causes an expansion of the oxygen minimum zone by limiting the ventilation down to intermediate depths, and acts also to give an explanation for the coeval formation of laminated sediments. Here, our data indicate the main role of the CIS melting water in controlling the North Pacific surface and intermediate hydrographic conditions by changing vertical ocean stratification. Highlights • δ18O Nps records as indicator of surface hydrology changes in the subarctic Pacific • δ18O Nps gwc , corrected for global water oxygen changes, depend from local T-S changes • δ18O Nps gwc records off Kamchatka cores indicate timing of peninsula glaciers decay • CIS decay was recorded by δ18O Nps gwc changes of NE Pacific and Bering Sea cores • land glaciers decay led to changes in surface and deep hydrology of the N. Pacific [ABSTRACT FROM AUTHOR]

The Bering Sea and the Chukchi Sea are important regions for marine ecosystems and climate change. However, the historical deposition and sources of metals in these regions are poorly understood. In this study, we utilized Pb isotopes and multi-element concentrations (Ni, Cu, Fe, Mn, Zn, Cd, Pb) coupled with Pb-210 dating to investigate the historical deposition and source identification of metals in sediment cores collected from the Bering Sea and the Chukchi Sea. Our findings reveal that the transport of organic matter was mainly transported by marine and terrestrial sources in the Bering and Chukchi Sea, respectively. Historical variations of metals were similar in both seas, showing an increasing trend of metals (excluding Mn) from the 1960s to the 1990s, followed by a gradual decrease after the 1990s, which can be attributed to the development of industrial and gasoline emission. The results of the geo-accumulation index indicated that sediment in both seas was relatively unpolluted with metals. Additionally, Pb isotopic ratios suggested that natural weathering was the primary source of Pb in the area, but the use and phase-out of gasoline were also well-reconstructed. This study provides valuable information for assessing environmental changes and human activities over the past century in the Arctic and subarctic Ocean. • Characterized multi-element concentrations (Ni, Cu, Fe, Mn, Zn, Cd, Pb) in two sediment cores from the Bering-Chukchi margin. • Historical variations of metals can be attributed to the development of industrial and gasoline emission. • The geo-accumulation index indicated that sediment in both seas was relatively unpolluted with metals. • Pb isotopic ratios suggested that natural weathering was the primary source of Pb in the area. [ABSTRACT FROM AUTHOR]

During the 6th (2014) and 7th (2016) Chinese Arctic Expedition (CHINARE), samples of suspended particulate matter (SPM) were collected from both surface (depth: <1.0 m) and subsurface (depth: approximately between 10 and 150 m) waters over the northern shelf of the Bering Sea and in the western Arctic Ocean. To investigate the distribution and sources of organic matter in both the surface water and the vertical profile, the concentration and stable carbon isotopic composition of SPM, particulate organic carbon (POC), and particulate nitrogen (only in surface water samples) were determined, and some particle samples were selected for examination using scanning electron microscopy. Results showed apparent geographical partitioning and temporal variation in both the concentration and the composition of SPM. Higher SPM concentrations were observed in nearshore, shelf break, and sea ice edge areas; the distribution of POC concentration displayed a similar pattern, with higher values found from the northern part of the Bering Shelf to southern parts of the Chukchi Shelf. In surface water, SPM mainly comprised clay and detrital minerals with higher POC contents, lighter δ13C values, and higher POC/PN ratios, indicating organic matter predominantly derived from terrestrial sources in areas south of St. Lawrence Island and north of 73°N. The downward trend of heavier δ13C values, together with reduction in clay and detrital minerals, suggests that vertical transport of SPM is hindered by stratification, resulting in transport of terrestrial materials toward northern basin areas. In the Chukchi Slope and Canada Basin areas, extremely light δ13C values (as low as −33.41‰ PDB) were mainly observed at depths of 20–60 m, where the Polar Mixed Layer (PML) intersects with the Upper Halocline Layer (UHL). Under the condition of low sea ice extent in 2016, the POC-δ13C values were heavier in the PML than in the UHL in the Chukchi Slope and Canada Basin areas. These findings provide insights into the sources, transport, and fate of organic matter in the Pacific Arctic region, which have important implications for understanding the biogeochemical cycles and ecosystem dynamics in this remote and rapidly changing environment. • Significant geographical partition and temporal variation in suspended particles. • Extremely negative POC-δ13C values at high latitudes. • Links between POC concentration and composition. [ABSTRACT FROM AUTHOR]

Current-use Organoamine Pesticides (CUOAPs) are a growing concern as emerging pesticide pollutants that were initially discovered on a large scale in Chinese Marginal Seas (CMSs). The highest level was detected in the East China Sea in the late spring and decreased in the following order: East China Sea (early spring) > the South China Sea > the Bohai Sea. The crucial role played by the Yangtze and Yellow rivers as significant terrestrial sources were established. The fluctuations in the land application and riverine input led to variations in the source, distribution, and seasonal patterns of CUOAPs. Terrestrial-exported CUOAPs were transported and redistributed spatially by the surface ocean currents, resulting in significant regional disparities. The results displayed a pronounced terrestrial source signature and a cross-regional impact. By the ocean current transport, CMSs will likely become a secondary source region for the surrounding seas. [Display omitted] • Detailed investigation on CUOAPs exhibited a high level in the East China Sea. • Terrestrial riverine export and land use variability resulted in seasonal variations. • Massive CUOAPs cross-regionally affected surrounding seas as a secondary source. [ABSTRACT FROM AUTHOR]

Deciphering the origin of sedimentary material in the Arctic can contribute to a deeper understanding of modern transport and sedimentation processes. Here, the application of rare earth elements (REEs) is particularly promising, as they can serve as indicators of sources as well as chemical and physical conditions and processes. This study aimed to determine the distribution of REE sources in the bottom sediments and the forms of their occurrence on the East Siberian Arctic Shelf. The concentrations and distributions of the REEs and major and trace metals, grain size, and mineral composition of 72 surficial sediment samples and two sediment cores that were collected from the Laptev and East Siberian seas were studied. Increasing REE content, the predominance of light REE, and close correlation with Zr, Nb, Y, Sc, and Ti were revealed in the Laptev and western East Siberian sea sediments in the zone of influence of the Lena River runoff. The source of the REEs was the eroded Yedoma complex along the coast. The REE content in the sub-colloidal fraction of the sediments was comparable to the REE concentration of the bulk bottom sediments and varied in the East Siberian Sea from 104 to 220 mg kg−1, with the maximum content around the submarine valley of the Indigirka River, in the Laptev Sea, ranging from 124 to 197 mg kg−1. The findings could be used to study ice dynamics and to conduct lithostratigraphic and paleoceanographical reconstructions of the Central Arctic. • Sediment from the two Arctic seas were analyzed for major and trace elements. • Rare earth element content is increasing in Laptev and East Siberian Sea sediments. • Source of the rare earth elements was the eroded Yedoma complex along the coast. • Findings can inform lithostratigraphic and paleoceanographical reconstructions. [ABSTRACT FROM AUTHOR]

The origin and expansion of millennial-scale climate changes in the Earth's climate system, widely presented in different paleo records, remain important issues in the scientific community. In this study, we present a highly resolved record of the East Asian monsoon (EAM) over 123 to 30 ka, obtained from a new archive of millennial/centennial climate variability in the mid-latitudes of the Northern Hemisphere. We used sediments from the semi-enclosed Sea of Japan, which is a region with unique land, ocean, and atmospherice interactions. We obtained color lightness (CL) records of a sediment core recovered from the northwestern part of the Sea of Japan with a high temporal resolution comparable to that of the Chinese EAM records using the original photocolorimeter. The chronology of the studied core was established by correlating the Heinrich events with the measured CL, magnetic susceptibility, and chlorin content with color L* and magnetic susceptibility records of the well-dated Sea of Japan core MD01–2407 and subsequently by correlating the abrupt drops in CL with well-dated Greenland and Chinese interstadials within the established Heinrich events. To infer a new record of EAM evolution, we used the CL record of the studied core over 30–123 ka, when the sea level dropped below the present sea level <90 m, the deep-water ventilation did not change profoundly relative to the present and sediment geochemistry was mainly controlled by millennial-timescale climate changes, such as the Dansgaard–Oeschger (DO) cycles. By comparing the DO cycles inferred from different natural archives, such as δ18O records of Greenland ice core and Chinese caves and CL record of the Sea of Japan sediments, we discussed similarities and some peculiarities of the DO cycles evolution and its millennial scale variabilities recorded in the high, middle, and low latitudes of the Northern Hemisphere over 30–123 ka. • High resolution record of sediment color from the Japan Sea (JS) over last 120 ka. • Correlation of Dansgaard-Oeschger cycles between JS, Greenland and Asia monsoon. • DO cycles 17–5 recorded in three archives show oscillation typical for Greenland. • DO cycle 23 and 25 show different changes between records of three archives. • Such differences were likely ruled by special Pacific responses to N Atlantic changes. [ABSTRACT FROM AUTHOR]

Pronounced Quaternary circulation and depositional changes in the Arctic Ocean basins remain poorly understood. We investigate sediment core ARC5-ICE4 (ICE4) in the Eurasian (Amundsen) Basin off the Lomonosov Ridge to reconstruct glacial-interglacial variability in sediment sources and circulation. The ICE4 record features variable lithologies including distinct glacigenic deposits with Ice Rafted Debris (IRD). The sediment age is constrained by a combination of the organic carbon 14C with paleomagnetic data and correlation to earlier developed stratigraphies. The derived sedimentation rates constitute several cm/kyr (6.5 cm/kyr average) consistent with estimates from regional geophysical data. The developed age model covers the time interval from ca. 10 to 75 ka including Late and Middle Weichselian/Wisconsinian glaciations. Respective glacigenic sediments were primarily deposited by pulsed iceberg discharge. The Last Glacial Maximum and deglaciation is expressed in sharp IRD peaks including mineral proxies of the Laurentide Ice Sheet with an apparent millennial-scale variability. The older glacigenic sedimentary unit with abundant IRD of predominantly Siberian provenance was deposited during deglaciation of the Middle Weichselian (MIS 4/3) Eurasian Ice Sheet. These sedimentary differences indicate diverging impacts of the two glaciations on the Arctic Ocean, including ice-sheet sizes/geometries and oceanic circulation. • Continuous 75-ka Arctic Ocean sediment record from Eurasia Basin off Lomonosov Ridge. • New stratigraphic constraints including 14C OC and paleomagnetic inclination data. • Different circum-Arctic ice sheet extent and circulation inferred for MIS 2 and 4. [ABSTRACT FROM AUTHOR]

The source, amount, and trajectory of icebergs discharged into the western Arctic Ocean provide essential clues to Arctic ice sheet development and its feedback on Atlantic meridional overturning circulation (AMOC). Nd and Sr isotopes, ice-rafted debris, and mineral components were used to trace the icebergs that were first discharged into the western Arctic Ocean and then exported to the North Atlantic Ocean. The records indicated that the iceberg outburst (large-scale iceberg export via the Fram Strait) since the Late Pleistocene does not entirely depend on the iceberg discharge from the Laurentide ice sheet (LIS), which is mainly the result of multi-source ice interactions over the western Arctic Ocean. In marine isotope stage 5 (MIS5) and the MIS3a (39–29 ka), the LIS did not reach its maximum extent, discharging its most massive icebergs into the western Arctic Ocean. However, most icebergs were trapped in the western Arctic Ocean, instead of being exported to the North Atlantic Ocean. Different scenarios occurred in the MIS4 and MIS2, when the East Siberian ice sheet (ESIS) emerged and icebergs in the western Arctic Ocean began to accumulate robustly. Ice streams from the LIS or Eurasian ice sheet (EAIS) were finally deflected and pushed to the Fram Strait by the ice streams from the ESIS. The ESIS expansion may thus play a more positive role than the LIS-iceberg discharge in triggering Laurentide-source iceberg outbursts in the western Arctic Ocean. Our findings shed new light on the origin of icebergs in the North Atlantic Ocean and mechanisms of AMOC instability. • Complete sequence of Laurentide iceberg discharge was studied. • Nd & Sr isotope distributions provide new evidence for East Siberian ice sheet. • East Siberian ice streams triggered iceberg outbursts in Arctic Ocean. • Iceberg outbursts weakened the Atlantic meridional overturning circulation. [ABSTRACT FROM AUTHOR]

The TEX 86 paleothermometer was applied for reconstructing sea surface temperature (SST) from glycerol dialkyl glycerol tetraethers (GDGTs) in marine sediments. It has become clear that GDGT-producing archaea live throughout the water column, with maximum concentration usually well below the surface mixed layer of the ocean. Why the TEX 86 parameter correlates well with SST remains poorly understood. Here we evaluate the fidelity of the TEX 86 thermometer using surface sediments and suspended particles from the Yellow Sea (YS), a shallow marginal sea between China and the Korean peninsula. The highest concentration of GDGTs in the water column at a site (A02) from the middle of the YS occurred in the bottom layer, at 70 m. This contrasts with phytoplankton lipids, which were most abundant near the surface. Consistent with the maximum abundance of GDGTs in bottom water, TEX 86 values in surface sediments correlated better with mean annual bottom water temperature (BWT, R 2 0.81) than with mean annual SST ( R 2 0.74). Moreover, TEX H 86 temperature derived from a global core top calibration gave values 0.1–9.4 °C colder than mean annual SST but much closer to mean annual BWT (2.7–4 °C). Lastly, TEX 86 and U 37 K ′ paleotemperature values displayed distinctly different trends over the last 12 kyr for sediments from the shelf between the YS and the East China Sea (ECS), consistent with the notion that TEX 86 and U 37 K ′ reflect different temperature signals. This preponderance of evidence supports the use of TEX 86 as a proxy for BWT in the YS. Therefore, we propose a local calibration of TEX L 86 for reconstructing mean annual BWT (TEX L 86 = 0.03 BWT-0.94; R 2 0.86, n = 22, P < 0.0001). The combination of alkenone ( U 37 K ′ ) derived SST with TEX L 86 BWT yielded a quantitative reconstruction of the vertical thermal gradient in the YS, and an insight into understanding the impact of the Kuroshio Current and East Asian monsoon on the YS. [ABSTRACT FROM AUTHOR]

High-resolution lithological and isotope-geochemical analyses were made on a well age constrained sediment from the northeastern Japan (East) Sea which recorded 10 dark layers (DL) over the last 40 ka BP. Pollen analysis of the core allows us to reconstruct the history of surrounding landmass vegetation and to determine pronounced vegetation/climate changes. We found that DL 10 which correlated with a DO/Chinese interstadial 8 was forced by increased East Asian humidity and influx of the nutrient-rich water into the sea. DL 5 formed during the cold Heinrich event 3 (HE), at 30–31 ka BP, was most likely to be initiated by the global sea level descent and reduction of seawater exchange with the North Pacific. High resolution of δ 18 O pf records reflects a unique sensitivity of the Japan (East) Sea to input of the North Pacific water through the shallow Tsushima and Tsugaru Straits. This led us to the important evidence of the eustatic-sea level changes during the last 40 ka BP. Since 29 ka BP, δ 18 O pf curve shows a continuous descending sea level interrupted by sharp drops of HE 2 with a following rise of DO interstadial 2. A sharp δ 18 O pf increase since 18.6 ka BP is consistent with coral results which indicate abrupt termination of LGM low stand by a rapid sea level rise initiated at 19.0 ka BP. [ABSTRACT FROM AUTHOR]

The Sea of Japan, located in the humid zone, was subjected to significant freshening of surface waters and a decrease in ventilation of deep waters during the glacial eustatic drop in relative sea level (RSL) and a decrease in water exchange with Pacific due to the shallowness of its straits. As a result, the δ18O values of planktic foraminifera (δ18O pf) decreased by several ppm, in contrast to the increase of ones in the Red Sea, depending on the degree of RSL drop. The good preservation of planktic foraminifera in the sediments of the Sea of Japan during the Last Glacial Maximum (LGM) and deglaciation allows us to significantly refine and supplement the available evidences of the global sea level changes over the 33–15 ka. Based on the obtained and published records of δ18O pf of five cores from different parts of the sea and the general chronology of the accumulation of dark layers in the sediments of the Sea of Japan, we calculated the δ18O pf stacks with high and low resolution (0.13 kyr for two cores and 0.5 kyr for other three cores) for the time 33–15 ka. Both stacks showed significant RSL falls at the onset of LGM (32–29 ka), during 21.8–20.3 ka, and an abrupt rise at 17 ka consistently with previously published data. The higher resolution stack additionally showed two phases of RSL falls at the onset of the LGM followed by a slow decrease until 22 ka, with a short and abrupt descent at around 25 ka. According to both stacks the lowest sea level around 18.5–17.5 ka was preceded by a short rise just before 19 ka. A significant RSL rise at 17 ka was followed by an abrupt and short fall at nearly 16.5 ka and then prolonged rise since around 16.2 ka. • Two stacks of planktic foraminifera δ18O records were calculated over the 33-15 ka with a higher and lower resolution. • Chronology was based on synchronicity of dark layers formation ruled by surface water salinity and ventilation changes. • Both stacks showed significant relative sea level (RSL) falls at 32–29 ka, during 21.8-20.3 ka, and abrupt rise at 17 ka. • A higher resolution stack additionally showed millennial-centennial RSL changes over Last Glacial Maximum and since 17 ka. [ABSTRACT FROM AUTHOR]

The flux of low-salinity Pacific water (PW) through Bering Strait (BS) weights on the freshwater budget of the Arctic Ocean, which, in turn, impacts the Atlantic Meridional Overturning Circulation (AMOC). Through time, this PW flux has been tightly controlled by the bathymetry of the Strait (~50 m water depth at present), thus by sea-level (SL) changes, as documented in several papers based on a large array of sedimentological and geochemical tracers. The present study aimed at reassessing the robustness of these tracers of the PW-flux, based on five surface samples collected along a south–north transect from BS to the Chukchi Plateau, within the bathymetric range of the PW-mass dispersal. We also estimated their variation in relation to the post-glacial SL-rise in a sedimentary core (ARC4-R09), from the Chukchi shelf, spanning the last ~10 cal kyr. Potential indicators of PW-flux include sortable silt, clay minerals, and the particulate and exchangeable Nd-isotope composition of specific grain-size fractions. The results indicate that ɛNd-values in leachates, and to a lesser extent, the smectite abundance, both relating to volcanic rocks of the Bering Sea, are sensitive indicators of the PW-flux, whereas sortable silts and other clay minerals relative abundances are also influenced by other processes (e.g., west–east shelf currents, sea-ice rafting). The modern distributions of ɛNd-value and smectite abundance illustrate mixing between two endmembers: i) a northern Bering Sea endmember, characterized by ~14% of smectite (vs all clay minerals) and a ɛNd-value of the exchangeable fraction of ~ −2; ii) a Chukchi Sea endmember, characterized by ~8% of smectite and a ɛNd-value ranging from −7 to −8. The Holocene sedimentary record from the study core indicates a progressive increase in Bering Sea supplies through time, linked to an enhanced inflow of PW, which we associate with the deepening of the Strait due to the rising SL. Following a major reorganization of the Arctic Ocean circulation at ~8 cal kyr BP, a steady increase in PW flux prevailed until ~4 cal kyr BP. A tenuous but continuous positive trend towards modern εNd values followed during the late Holocene. The middle Holocene steep increase of warm, low salinity PW-flux through BS, led to important changes in the Arctic Ocean, in particular of its salinity budget. Assuming that the BS bathymetry is the main parameter governing the PW-flux towards the Arctic Ocean, a first-order estimate of PW-flux under a higher than modern SL can be made using the SL-elevation-ɛNd relationship of the major middle Holocene shift. • Assessment of the reliability of clay minerals and Nd-isotopes as tracers of PW-fluxes through Bering Strait. • Recording of Holocene PW-fluxes through Bering Strait by exchangeable ɛNd-values in a gravity core from the Chukchi Shelf. • Estimation of past changes in PW-fluxes towards the Arctic in relation with SL changes. [ABSTRACT FROM AUTHOR]

[Display omitted] • The Qianlishan granite complex last for 38.8–57.4 Ma. • The duration of the QGC has positive correlation with the volumetric heat production. • Mineralization events well accord with the protracted hydrothermal lifespan. The Dongpo ore field, containing a series of W-Sn-Mo-Bi-Pb-Zn granite-related deposits, is a typical reduced intrusion-related system centered with the causative zoned Qianlishan granite complex (QGC). The QGC comprises porphyritic granite, equigranular granite and granite porphyry. According to zircon U-Pb age data, the emplacement timing of the QGC was constrained to 155–151.7 Ma. Here, we conducted a set of geochronological analyses with different closure temperatures (including monazite, apatite U-Pb, biotite and muscovite Ar-Ar and zircon fission track dating) on the QGC, revealing that the QGC experienced a protracted magmatic-hydrothermal timespan of 38.8–53.8 my. The protracted lifespan is probably due to radiogenic heat supplied by highly enriched high-heat-producing elements. The mineralizing blossom time (149–154.2 Ma) in the Dongpo ore field is in accordance with the prolonged lifespan (5.7 my: from 149.3 Ma to 155 Ma) of the magmatic-hydrothermal process caused by the QGC over the temperature range of 300–800 °C. This result implies that successive inputs of magma with high heat-producing elements (U, Th, K) play a fundamental role in the metal enrichment process of intrusion-related deposits and the formation of large economic ore fields. [ABSTRACT FROM AUTHOR]

Sediment core ARC5-ICE6 from the Makarov Basin was used to reconstruct circum-Arctic glaciation and surface-ocean circulation history for the Middle to Late Pleistocene, ∼0.5–0.7 Ma. Sedimentary proxies include elemental composition, coarse grain content, clay mineralogy, and radiogenic isotopes (Sr-Nd-Pb). Earlier studied records from the central Arctic Ocean were compared with ICE6 for a broader paleoceanographic context. Results indicate predominant sediment delivery from the Eurasian shelves and glaciated mainland with intermittent glacial inputs from North America. Low proxy variability prior to Marine Isotope Stage (MIS) 6 (∼0.2 Ma) suggests persistent sediment transport by sea ice via the Transpolar Drift and limited glaciation at the Eurasian margin. Since MIS 6, sediment inputs and provenance exhibit large shifts between glacial- and interglacial-type environments. The overall northern Eurasian Ice Sheet (EAIS) expansion was possibly related to climatic cooling and growth of a perennial sea ice in the Arctic Ocean. Provenance indicators from MIS 6, 5b and 4/3 reflect EAIS expansions followed by deglacial meltwater discharge from west Siberia. This provenance indicates a strong cyclonic circulation in the Arctic Ocean characterized by a significantly eastward-extended Transpolar Drift. Different glaciogenic sourcing and attendant circulation are proposed for several events within MIS 5 and 3, where proxies indicate increased sediment inputs from North America rather than Eurasian ice sheets. Overall limited glacial influence inferred for MIS 3 is consistent with relatively high sea level reconstructed for this interstadial. The Last Glacial Maximum is barely identifiable in the ICE6 record due to low glacial inputs and/or depositional hiatus. • Predominant sediment delivery from the Eurasian shelves to the southern Makarov Basin during the mid-late Pleistocene. • Intensified glaciation on Eurasian continent since MIS 6 and heterogeneous development of the ice sheets. • Strong cyclonic circulation during intensive glacial/stadials MIS 6, 5b and 4/3. [ABSTRACT FROM AUTHOR]

We investigated the petrographic composition of coarse-grained clasts (>250 μm) in 117 core-top sediment samples from the western Arctic Ocean (the Amerasian Basin, Chukchi Sea, Alaskan/Beaufort margin and East Siberian Sea). Combined with analyses of bulk sediment mineralogy and grain size, we use the results to elucidate the terrigenous clastic sediment distribution patterns and transport modes in four different regions: (1) In the Chukchi Sea, the Bering Strait Inflow (BSI) contributes most of the sediments, with an additional terrigenous clastic contribution from Northern Alaska and Eastern Siberia. The highest coarse clastic content and a northward-fining of the grain-size distributions are attributed to the winnowing by the BSI. (2) In the Alaskan margin, terrigenous clasts are enriched in sea ice/anchor ice-transported quartz-rich sediments from Northern Alaska, and in addition the Alaska Coastal Current (ACC) contributes sediments originating from the Yukon River. Coarse-grained sediments accumulate near offshore Alaska with the finer fractions being transported further into the Chukchi Sea Shelf. (3) In the East Siberian Sea, coarse clasts are sparse and even absent in most study sites. Combined with the results of previous studies, we conclude that the terrigenous components are derived from the Laptev Sea and the adjacent Siberian Platform. They are transported by the Siberian Coastal Current and sea ice. (4) In the Canada Basin, terrigenous clasts are characterized by carbonate and quartz-rich sediments derived from the Canadian Arctic Archipelago (CAA). Sediments incorporated in sea ice/anchor ice drift from the CAA to the Beaufort Sea, where they combine with sediments from the Mackenzie River and are then transported into the Canada Basin by the Beaufort Gyre. Sediments and grain size in northern and southern Canada Basin also involve the early Holocene iceberg-entrained IRD from CAA and winnowing/nepheloid transported mica from marginal areas, respectively. • Terrigenous surficial sediments in the Amerasian Arctic Ocean were extensively investigated. • Comprehensive provenance study for coarse fraction lithology and bulk sediment mineralogy. • Modern sediment transport modes are illustrated by sediment provenances. • This study provides a robust basis for reconstructing Arctic changes in geological time. [ABSTRACT FROM AUTHOR]

The Japan Sea is ideal for investigating deep water formation due to its unique topography and hydrography. However, because of the scarcity of reliable indicator and high-resolution ventilation records, the driving mechanisms behind ventilation changes in the entire Japan Sea since the Last Glacial Maximum (LGM) remain elusive. In this study, we analyze the radiolarian assemblage in three sediment cores from the southwestern, central, and northwestern Japan Sea to reveal ventilation variations over the last 25 ka. Our results suggest that weak ventilation was a widespread phenomenon in the Japan Sea during the LGM. This is inferred by the low relative abundances of species belonging into the Japan Sea Proper Water (JSPW) Assemblage, which are indicative of deep water ventilation in the Japan Sea. The JSPW Assemblage have gradually become the predominant species in studied cores from the last deglaciation to the early Holocene, suggesting an abrupt transition from oxygen poorer to oxygen richer conditions. All investigated regions show re-ventilation during the deglaciation, albeit at different times. The JSPW ventilation in the central Japan Sea started during the 19 ka Melt-water Pulse (MWP) and remained in an interglacial mode after MWP-1A (~14.7 ka), presumably due to the opening of the Tsushima Strait and intrusion of the Tsushima Warm Current (TWC). An abrupt increase in productive shallow water export during the Bølling-Allerød (B/A) was likely the key factor causing poorly oxygenated deep-water conditions in the southwestern Japan Sea. In contrast, the weakening ventilation in the northwestern Japan Sea during the B/A and Younger Dryas was probably caused by the blocking effect of the sea ice. • New 25 ka-long radiolarian assemblage records along a meridional transect offer a comprehensive history of deep-water ventilation in the Japan Sea. • The JSPW ventilation underwent drastic changes from suboxic to oxic conditions during the last deglaciation. • The drastic changes in the deep ventilation in the Japan Sea were sensitive to eustatic sea-level. [ABSTRACT FROM AUTHOR]

Sediment cores from the Northwind Ridge north of the Arctic Chukchi-Alaskan margin were analyzed for a suite of stratigraphic and provenance proxies. Based on the correlation to previously studied regional records, cores under study present sedimentary environments of Marine Isotope Stages (MIS) 1–11 (∼0.4 Ma) on millennial time scales. Contrasting glacial-interglacial conditions and provenance were characterized by means of clay-mineral and geochemical (elemental and isotopic) proxies along with grain size. Interglacial environments are interpreted as sea-ice dominated, with pre-Holocene sediment transported mostly from the East Siberian to Chukchi-Alaskan margin. In comparison with the recent conditions, this pattern suggests a stronger Transpolar Drift expanding into the Canada Basin at the expense of the Beaufort Gyre, or stronger along-shelf currents. Glacial intervals prior to MIS4 have a predominantly North American signature with carbonaceous or terrigenous source rocks. Carbonaceous inputs marked by Ca peaks are tracked to the western Canadian Arctic Archipelago eroded by the Laurentide Ice Sheet (LIS). Terrigenous sources (Zr peaks) are likely related to areas impacted by the Innuitian Ice Sheet and/or the LIS Mackenzie ice stream. MIS 4 and 2 intervals have a different composition with the Siberian/Chukchi rather than North American provenance. A stronger winnowing indicated by grain size in the glacial intervals suggests a stronger mid-depth circulation. Study results provide new boundary conditions for modeling paleocirculation and glaciations in the western Arctic Ocean. • Contrasting glacial-interglacial conditions and provenance were characterized. • Pre-Holocene interglacials have sea-ice dominated depositional environment, margin provenance and a stronger TPD. • Glacial intervals prior to MIS4 have a predominantly North American signature with carbonaceous or terrigenous rocks. • MIS4 and 2 intervals have more interglacial compositions with the Siberian/Chukchi rather than North American source. [ABSTRACT FROM AUTHOR]

Millennial scale variations of terrigenous provenance in marine realm are closely related to regional environment and climate changes. Therefore, a wealth of information of past environment and climate can be constrained via fingerprinting sediment provenance. The Sea of Japan is a unique marginal sea in the North Pacific due to its high sill and distinct thermohaline circulation. The modern hydrography in the Sea of Japan is mainly affected by the East Asian Monsoon and Tsushima Warm Current, one branch of the Kuroshio Current. The Sea of Japan communicates with neighboring seas through four shallow and narrow straits, indicating great effects of global eustatic sea level change on its environment over glacial-interglacial cycles. Here we examine the terrigenous provenance in fine-grained fraction (<63 μm) of core KCES1, located near one end of the Tsushima Strait of the Sea of Japan over the last 48 ka, using radiogenic isotopes of strontium (Sr) and neodymium (Nd). Our data suggest that the terrigenous provenance in core KCES1 was mainly derived from the Yangtze River after 7 ka and a mixture of Yangtze and Yellow Rivers during the last glacial and deglacial periods. Notably, pronounced negative excursions of εNd values at HS1 were attributed to minor additions of unradiogenic Nd contribution from China-Korea cratonic hinterland. A binary mixing model further reveals that >85% terrigenous material is derived from the Yangtze and Yellow Rivers over the last 48 ka. Moreover, abrupt variations in sediment provenance occurred at ~18 ka and ~ 7 ka, which coincide with variations in oceanic surface circulation and deep ventilation recorded in the Sea of Japan. We suggest that paleo-Tsushima Warm Current invaded into the Sea of Japan with reopening of the Tsushima Strait at HS1 and the Tsushima Warm Current substantially entered the Sea of Japan after 7 ka due to intensified Kuroshio Current and rising eustatic sea level. The inflow of Tsushima Warm Current gives rise to a range of changes in surface hydrography, deep ventilation, ecological communities and productivity and sediment texture. The combination of fluxes of paleo-rivers and the intensity of Kuroshio Current, which are closely tied to the eustatic sea level and the East Asian Monsoon, plays a key role in controlling the variations in sediment provenance in the Ulleung Basin. Our study provides unique insight into the tight coupling between changes in sediment provenance and oceanic environment over the last 48 ka in the Sea of Japan. • Radiogenic Sr and Nd isotopes reveal the main provenance of terrigenous materials in the Ulleung Basin over the last 48 ka • Abrupt shift in terrigenous provenance at ~18 ka and ~ 7 ka indicates intrusions of Tsushima Current into the Sea of Japan • Main mechanisms controlling variations in terrigenous provenance in the Ulleung Basin are revealed [ABSTRACT FROM AUTHOR]

This study investigates Holocene sedimentary evolution and hypoxia development using borehole cores CJK06 and CJK09, in combination with other published core data. Based on lithology and microfossil (benthic foraminifera) characteristics, seven types of sedimentary facies were identified from the base upward: river, tidal flat, tide-influenced river, transgressive lag, estuary, inner-shelf, and prodelta. Isochronous correlation among the cores was established relying on accelerator mass spectrometry 14C dates. Facies succession indicates that a weak progradation occurred in coastal environments (12–10 ka BP) due to the Younger Dryas-induced deceleration of sea-level rise; rapid deposition locally occurred in the southern marginal area of tide-dominated estuary environments (10–8 ka BP), likely due to the junction of the Yangtze and Qiantangjiang River currents; and marine current-induced fluid mudflows prevailed in the shallow marine environments (8–1 ka BP), with the cooling climates of 5–1 ka BP. Furthermore, prodelta and shallow marine environments co-occurred with an uneven progradation of the delta within the last 1 ka, while deposition occurred just inside the more southern, delta-influenced area. The occurrence of euryhaline benthic foraminifera suggests that an enhanced freshwater discharge of the mid-Holocene (8–5 ka BP) was followed by a sharp decline in the late Holocene (5–1 ka BP) with climate change. The occurrence of cold-water benthic foraminifera indicates a severe cold-water condition during the mid-Holocene due to the intrusion of upwelling currents triggered by the propelling force of warm currents and summer monsoon winds. In addition, the occurrence of low-oxygen foraminiferal assemblages reveals that hypoxia has developed since 10 ka BP in stages consistent with the sedimentary evolution: localized hypoxia formation coincident with the southern depocenter during the early Holocene (10–8 ka BP); severe hypoxia with enhanced freshwater discharge and upwelling current intrusion during the mid-Holocene; and weakened hypoxia of the late Holocene, mainly due to the sharp decline in freshwater discharge. Within 1 ka BP, freshwater discharge from the approaching river mouth and increased nutrient inputs from enhanced human activities on land have contributed to the prevalence of hypoxia, especially in the southern deltaic area. Overall, it was revealed that the freshwater discharge modulated with climate variations and delta progradation plays a primary role in controlling the sedimentary evolution and hypoxia development during the mid-late Holocene. • Gravity flows (fluid mudflow) prevailed during the late Holocene (5–1 ka BP). • Holocene freshwater discharge was enhanced (8–5 ka BP) and then sharply declined. • Severe upwelling current intrusion occurred during the mid-Holocene (8–5 ka BP). • Hypoxia boomed during the mid-Holocene (8–5 ka BP). [ABSTRACT FROM AUTHOR]

Assessing modern radiolarian distribution in the marginal seas is essential for understanding its relationship to hydrographic and environmental variables, upon which subsequent interpretation of past radiolarian records can be made reliably. Here, we combine published radiolarian assemblages in 69 surface sediments from the Japan Sea with those obtained from 15 new surface sediments in this study to determine the modern distribution of radiolarians. The Tsushima Warm Current (TWC) taxa are only found in the south of the Subpolar Front. The results of redundancy analysis confirm that the temperature at 10 m depth (temperature 10m) is the main factor controlling the spatial variability of TWC taxa. The water depth plays a key role in affecting the abundances of Japan Sea Proper Water (JSPW) Assemblage including Larcopyle buetschlii Dreyer (adult), Cycladophora davisiana Ehrenberg, and Actinomma group. The JSPW Assemblage can be used as a reliable indicator of ventilation changes in the Japan Sea. Based on the newly developed TWC taxa and JSPW Assemblage, we further reconstructed the water column structure in the central Japan Sea over the past 25 ka. There was weak ventilation in the central Japan Sea even during the Last Glacial Maximum (LGM), although a distinct decrease in the TWC inflow resulted in surface-water freshening and water column stratification. After the LGM, the TWC taxa together with JSPW Assemblage resumed in the central Japan Sea at the 19 ka meltwater pulse (MWP). The MWP-1A was clearly marked by an enhanced intrusion of the TWC. Synchronously, JSPW was ventilated deeply down after ~14.6 ka attaining to the similar level of the Holocene as a result of changing sea surface conditions. Along with the continuing sea-level rise, the matured TWC entered the Japan Sea at 7 ka and since then the modern hydrographic condition has been established. We suggest that the changes in the sea level and TWC strength predominantly determined the surface hydrography and deep ventilation in the central Japan Sea since 25 ka, and the TWC might have notably affected the Japan Sea since the Bølling-Allerød. • Radiolarian distribution patterns in the surface sediments are correlated well with water column environmental variables. • The water structure of the Japan Sea since the last deglaciation is reconstructed based on radiolarian assemblages. • Inflow of the TWC into the central Japan Sea resumed at around 19 ka, earlier than previously thought. • The modern-like deep water ventilation in the central Japan Sea has been established during the B/A. [ABSTRACT FROM AUTHOR]

In recent years the method proposed by Scherer (1994) and its update (Warnock and Scherer, 2015) have been widely applied. These methods use sediment samples in milligrams and yield reproducible estimates of diatom abundance. Given that this small amount of sediment represents only a small proportion of the original sample, it is debatable whether or not it is truly representative of the original sample. An orbital shaking method is proposed in the present study for the determination of absolute diatom abundance (ADA) in deep-sea fine-grained sediments. Accuracy of the new method has been verified not only by statistical analyses but also by comparing the results of the new method with the two other methods. Pervasive influences of sediment micro-heterogeneity on results of ADA are presumed because ADA estimates vary by up to two- to threefold in replicate sub-samples. If this holds true, then methods using small amounts of sediment to determine ADA will still need to be improved. • A new method using an orbital shaking technology for determination of diatom abundance in sediments is proposed. • Results from this study demonstrate that influences of sediment micro-heterogeneity on ADA estimates might be apparent [ABSTRACT FROM AUTHOR]

The East China Sea (ECS) is a vast river-dominated depositional basin because of its broad shelf and extensive river sediment supply. This study investigated the mid–late Quaternary stratigraphic framework and evolution of the outer ECS shelf based on a borehole core (DH02) and seismic profiles. Seven sedimentary facies were recognized in the core sediments according to lithology, grain-size composition, sediment structure, and microfossil assemblages, while eight unconformity-bounded major stratigraphic units were identified in the seismic profiles. Based on seismic–core correlations, dating data (radiocarbon and optically stimulated luminescence), and comparison between sedimentary cycles and sea-level curves, the 100 m thick strata below the seafloor were divided into three sequences corresponding to glacial–interglacial sea-level cycles of marine isotope stage (MIS) 1–2, MIS 3–6, and MIS 7–8 (Sq1–Sq3 from top to bottom). In particular, Sq1 is developing in the present sea-level highstand and consists mainly of deposits of transgressive systems tract (TST), including tide-influenced river, tidal flat, and tide-dominated estuarine facies. Sq2 and Sq3 consist mainly of prodelta and related inner-shelf facies of forced regressive systems tract (FRST) and transgressive deposits similar to those of Sq1. For all three sequences, a thin-sand sheet layer of open-shelf facies represents deposits of highstand systems tract (HST). Deposits of lowstand systems tract (LST) were typically represented by river facies. In addition, comprehensive analyses of seabed sand ridge distribution, core sediment characteristics, and ridge deposition mechanism suggest that the occurrence of a paleoestuary with transgression determined the development of a tidal sand ridge field. Based on all these results, a conceptual stratigraphic sequence model in association with the deposition of LST, TST, HST, and FRST was constructed. Overall, our stratigraphic framework, along with a comparison of the sequence stratigraphy to that of other shelves, suggested that glacial–interglacial sea-level fluctuations, huge amounts of river sediment supply, active subsidence, gentle shelf topography, and marine erosion processes (transgression and regression) controlled the mid–late Quaternary stratigraphic development of the ECS shelf. • A mid-late Quaternary stratigraphic framework (since MIS8) was established. • Three sequences were geochronologically corresponded to the recent three glacial/interglacial sea-level cycles. • The paleoestuary retreated with post-LGM transgression, yielding modern seabed tidal sand ridge field. • Comparison of the sequence stratigraphy to other shelves suggested controlling factors of stratigraphic development. [ABSTRACT FROM AUTHOR]

Motivation: It is difficult to generate new molecules with desirable bioactivity through ligand-based de novo drug design, and receptor-based de novo drug design is constrained by disease target information availability. The combination of artificial intelligence and phenotype-based de novo drug design can generate new bioactive molecules, independent from disease target information. Gene expression profiles can be used to characterize biological phenotypes. The Transformer model can be utilized to capture the associations between gene expression profiles and molecular structures due to its remarkable ability in processing contextual information., Results: We propose TransGEM (Transformer-based model from gene expression to molecules), which is a phenotype-based de novo drug design model. A specialized gene expression encoder is used to embed gene expression difference values between diseased cell lines and their corresponding normal tissue cells into TransGEM model. The results demonstrate that the TransGEM model can generate molecules with desirable evaluation metrics and property distributions. Case studies illustrate that TransGEM model can generate structurally novel molecules with good binding affinity to disease target proteins. The majority of genes with high attention scores obtained from TransGEM model are associated with the onset of the disease, indicating the potential of these genes as disease targets. Therefore, this study provides a new paradigm for de novo drug design, and it will promote phenotype-based drug discovery., Availability and Implementation: The code is available at https://github.com/hzauzqy/TransGEM., (© The Author(s) 2024. Published by Oxford University Press.)

The polar oceans play a vital role in regulating atmospheric CO 2 concentrations (pCO 2 ) during the Pleistocene glacial cycles. However, despite being the largest modern reservoir of respired carbon, the impact of the subarctic Pacific remains poorly understood due to limited records. Here, we present high-resolution, 230 Th-normalized export productivity records from the subarctic northwestern Pacific covering the last five glacial cycles. Our records display pronounced, glacial-interglacial cyclicity superimposed with precessional-driven variability, with warm interglacial climate and high boreal summer insolation providing favorable conditions to sustain upwelling of nutrient-rich subsurface waters and hence increased export productivity. Our transient model simulations consistently show that ice sheets and to a lesser degree, precession are the main drivers that control the strength and latitudinal position of the westerlies. Enhanced upwelling of nutrient/carbon-rich water caused by the intensification and poleward migration of the northern westerlies during warmer climate intervals would have led to the release of previously sequestered CO 2 from the subarctic Pacific to the atmosphere. Our results also highlight the significant role of the subarctic Pacific in modulating pCO 2 changes during the Pleistocene climate cycles, especially on precession timescale ( ~ 20 kyr)., (© 2024. The Author(s).)

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) poses a mortal threat to human health. The elucidation of the relationship between peripheral immune cells and the development of inflammation is essential for revealing the pathogenic mechanism of COVID-19 and developing related antiviral drugs. The immune cell metabolism-targeting therapies exhibit a desirable anti-inflammatory effect in some treatment cases. In this study, based on differentially expressed gene (DEG) analysis, a genome-scale metabolic model (GSMM) was reconstructed by integrating transcriptome data to characterize the adaptive metabolic changes in peripheral blood mononuclear cells (PBMCs) in severe COVID-19 patients. Differential flux analysis revealed that metabolic changes such as enhanced aerobic glycolysis, impaired oxidative phosphorylation, fluctuating biogenesis of lipids, vitamins (folate and retinol), and nucleotides played important roles in the inflammation adaptation of PBMCs. Moreover, the main metabolic enzymes such as the solute carrier (SLC) family 2 member 3 (SLC2A3) and fatty acid synthase (FASN), responsible for the reactions with large differential fluxes, were identified as potential therapeutic targets. Our results revealed the inflammation regulation potentials of partial metabolic reactions with differential fluxes and their metabolites. This study provides a reference for developing potential PBMC metabolism-targeting therapy strategies against COVID-19.

In this study, we aimed to construct a non-replication mRNA platform and explore the side effects of electroporation-mediated delivery of mRNA on the mice as well as the expression features of the mRNA. With luciferase gene as a marker, in vitro transcription with T7 RNA polymerase was carried out for the synthesis of luciferase-expressed mRNA, followed by enzymatic capping and tailing. The mRNA was delivered in vivo by electroporation via an in vivo gene delivery system, and the expression intensity and duration of luciferase in mice were observed via an in vivo imaging system. The results demonstrated that the mRNA transcripts were successfully expressed both in vitro and in vivo . The electroporation-mediated delivery of mRNA had no obvious side effects on the mice. Luciferase was expressed successfully in all the mRNA-transduced mice, while the expression intensity and duration varied among individuals. Overall, the expression level peaked on the first day after electroporation and rapidly declined on the fourth day. This study is of great importance for the construction of non-replication mRNAs and their application in vaccine or antitumor drug development.