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Responses of Nutrients to the Precipitation Variation and Land Use in Subtropical Monsoonal Small Mountainous Rivers:A Case Study of Baixi Watershed

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Journal of Ocean University of China 2024年第2期23卷 383-391页

作者： TIAN Yuan GAO Fei CAO Ke LV Shenghua DUAN Xiaoyong YIN Ping Qingdao Institute of marine {1. China Geological SurveyMinistry of Natural ResourcesQingdao 266237China Laboratory for marine {1. Laoshan LaboratoryQingdao 266237China

Small mountainous rivers are characterized by large instantaneous fluxes and susceptible to extreme weather events,which can rapidly transport materials into the sea and have a significant impact on the ecological environment of estuaries and *** order to investigate the seasonal characteristics of nutrients in small mountainous rivers in the subtropical monsoon region and the output pattern to the sea during heavy precipitation,surveys on the mountainous rivers were carried out in Baixi watershed in August 2020(wet season),March 2021.dry season)and June 2021.Meiyu period).The results showed that the dissolved inorganic nitrogen(DIN)of the rivers has an average concentration of 752μg L^(−1.in the wet season and 1.72μg L^(−1.in the dry *** concentrations of dissolved inorganic phosphorus(DIP)in wet season and dry season were 63μg L^(−1.and 51.g L^(−1.,*** by the changes of land use in sub-watersheds,DIN concentrations in the mainstream increased from 701.g L^(−1.in the upper reaches to 1.84μg L^(−1.in the middle *** rainstorms during the Meiyu period in the watershed caused the pulse runoff in the *** maximum daily runoff reached 70 times that before *** maximum daily fluxes of DIN and DIP were 1.9 and 247 times that before rains,*** view that the watershed experienced several rainstorms in the wet season,the river,with pulse runoff,carries a large amount of nutrients into the sea in a short time,which will have a significant impact on the environment of Sanmen bay and its adjacent sea.

关键词： small mountainous river uneven precipitation rainstorm pulse runoff nitrogen and phosphorus

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Geochronological and geochemical constraints on the petrogenesis and geodynamic process of Hemler,Vlinder,and Il'ichev seamount lavas in NW Pacific

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Science China Earth Sciences 2024年第6期67卷 1856-1871页

作者： Xun WEI Yan ZHANG Xuefa SHI Hui ZHANG Key Laboratory of marine {1. and Metallogeny First Institute of OceanographyMinistry of Natural ResourcesQingdao 266061China Laboratory for marine {1. Qingdao Marine Science and Technology CenterQingdao 266237China Shandong Key Laboratory of Deep Sea Mineral Resources Development(Preparatory) Qingdao 266061China

Oceanic intraplate volcanoes with linear age progressions are usually accepted to be derived from melting of an upwelling mantle *** seamount groups in NW Pacific,however,show complex age-distance relationships that are difficult to explain using the classic“mantle plume hypothesis”,and thus their origins are *** this study,we present ^(40)Ar-^(39)Ar age,geochemical,and Sr-Nd-Pb-Hf isotopic data of lavas from Hemler,Vlinder,and Il’ichev seamounts in NW Pacific,to elucidate their petrogenesis and geodynamic *** lavas from Hemler,Vlinder,and Il’ichev seamounts are classified as alkali basalt,basanite/nephelinite,and *** with Mg O>8 wt.%exhibit high contents of CaO,FeO^(T),and TiO_(2),similar to the composition of melts formed from reaction between carbonated eclogite-derived melts and fertile *** lavas have elevated Zr/Hf ratios(40.6-45.2)and negative Zr and Hf anomalies,indicating the presence of a carbonate component in the mantle *** are enriched in incompatible trace elements and have enriched mantle 1.EM1.-like SrNd-Pb-Hf isotopic *** isotopic compositions of Vlinder,Il’ichev basanite,and Hemler lavas in this study are similar to the Rarotonga *** occurring at the same seamount,the Il’ichev alkali basalts display more depleted SrNd-Hf isotopic compositions compared to Il’ichev *** to plate tectonic reconstruction results,the ages of Hemler(1.0.1.Ma),Vlinder pre-(1.0.2 Ma)and post-shield(87.5 Ma),and Il’ichev(56.4 Ma)lavas clearly deviate from the Macdonald,Arago,Rarotonga,and Samoa hotspot tracks,indicating that they cannot directly originate from mantle *** propose that in the mid-Cretaceous,when the Pacific plate passed over Rarotonga hotspot,melting of Rarotonga plume formed the Vlinder(main-shield stage),Pako,and Ioah *** Rarotonga(and possibly Samoa)plume materials would have been dispersed into the surrounding asthenosphere by mantle conve

关键词： Mantle plume Magellan seamount trail Carbonated mantle component Hotspot Lithosphere extension

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Distribution, burial fluxes and carbon sink effect of sedimentary organic carbon in the eastern China seas

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Science China Earth Sciences 2024年第10期67卷 3062-3082页

作者： Xuefa SHI Bin WU Shuqing QIAO Zhengquan YAO Limin HU Yazhi BAI Shan HU Jie SHENG Yanguang LIU Shengfa LIU Kunshan WANG Jianjun ZOU Key Laboratory of marine {1. and Metallogeny First Institute of OceanographyMinistry of Natural ResourcesQingdao 266061China Laboratory for marine {1. Qingdao Marine Science and Technology CenterQingdao 266237China Key Laboratory of Deep Sea Mineral Resources Development Shandong Province(Preparatory)Qingdao 266061China Key Laboratory of Submarine Geosciences and Technology College of Marine GeosciencesOcean University of ChinaQingdao 266100China

The ocean is the largest active carbon reservoir on Earth. Organic carbon(OC), as the primary species of carbon sequestration in the ocean, plays an important role in the global carbon cycle through its deposition and burial. In this study,sedimentary OC data from 5796 stations, together with relevant geochemical and sedimentological parameters in the Bohai Sea,Yellow Sea, and East China Sea(BYES) were used to summarize and elucidate the distribution and burial patterns of sedimentary OC, and assess carbon sink effect of sedimentary OC burial. The results show that the OC content in the sediments of the BYES ranges from 0.00% to 2.1.%, with an average content of 0.47%±0.26%. OC content is significantly correlated with finegrained sediments, with an average OC content in mud areas being 39% higher than that in non-mud areas. Modern OC buried in the BYES are mainly deposited in 7 major mud areas, with a total sedimentary OC burial flux of approximately 8.20 Mt C yr^(–1..Among them, the burial flux of biospheric OC is 6.92 Mt C yr^(–1., equivalent to the OC consumption amount of silicate weathering of the 9 major river basins in the eastern China. In its natural state, the annually sequestered OC in the sediments of the eastern China seas is equivalent to 25.37 Mt of atmospheric CO_(2), indicating a significant carbon sink effect. The distribution and burial of terrigenous OC in the BYES are mainly influenced by the large river inputs and complex marine hydrodynamic environment,while human activities such as dam construction have significantly altered the OC burial in these coastal mud areas.

关键词： Sedimentary organic carbon Burial flux Carbon sink effect Carbon cycle Eastern China seas

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Hydrocarbon generation potential of Campano-Maastrichtian to Paleogene shales in the Benin Flank of the Anambra Basin,SW Nigeria

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Energy Geoscience 2024年第3期5卷 103-116页

作者： Omabehere Innocent Ejeh Israel Aruoriwo Abiodun Etobro Konstantinos Perleros Jude Etunimonuwa Ogala Ajayi Olugbenga Ehinola Kimon Christanis Stavros Kalaitzidis department of {1. Delta State UniversityAbrakaNigeria Geo-Energy Resources Team Laboratory of Economic GeologyDepartment of GeologyUniversity of PatrasRio-PatrasGreece department of {1. University of IbadanIbadanNigeria

The hydrocarbon generation potential of the Campano-Maastrichtian to Paleogene shales from the Benin Flank(located in SW Nigeria)of the Anambra Basin,has been previously investigated mostly by studying outcrops and by relatively few subsurface data-based ***,it is expedient undertaking an assessment of the hydrocarbon generation potential of this frontier area from subsurface ***-Maastrichtian to Paleogene shale samples obtained from Egoli-1.borehole in the Benin Flank of the Anambra Basin are studied by means of HAWK programmed pyrolysis,organic petrography,and mineralogy(XRD),with the aim to explore the petroleum-generating potential and the thermal *** obtained results display a significant variation of the TOC content ranging from very low(5%),indicating poor to excellent oil potential based on S_(2)values under the condition,of course,the studied formations reached the oil *** shales of the Nsukka and Imo Formations display lower petroleum-generating potential than these of the Mamu *** the studied samples are dominated by gas-prone(type III)and inert(type IV)kerogens,with few displaying mixed II/III(oil-and gas-prone).The organic-petrography observations support partly the results of the HAWK programmed pyrolysis,as they reveal an organic-richer Mamu Formation in comparison to the Nsukka and Imo Formations;huminite/vitrinite particles(both indigenous and recycled)along with variable contents of liptinite(mostly alginite and bituminite)and inertinite macerals(mostly inertodetrinite)are hosted in the *** latter display a typical composition for fine-grained clastic sediments;mostly kaolinite,illite/montmorillonite,quartz,and subordinately,*** terms of thermal maturity,huminite/vitrinite reflectance data points to immature stage;however,the occurrence of solid bitumens,displaying equivalent vitrinite reflectance values within the oil window,points to an active petroleum system in s

关键词： Maceral Mamu Formation Thermal maturity Solid bitumen Source rock Vitrinite reflectance

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Provenance of colorless and brown volcanic glass in late Pleistocene tephra layers in the Western Philippine Sea

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Journal of Oceanology and Limnology 2024年第5期42卷 1438-1449页

作者： Fuqing JIANG Zhishun ZHANG Zhaohui ZHANG Guoliang ZHANG Peng HUANG Xiaojing ZHOU Zhifang XIONG Congying LI Tiegang LI Key Laboratory of Ocean Observation and Forecasting and Key Laboratory of marine {1. and Environment Institute of OceanologyChinese Academy of SciencesQingdao 266071China Laboratory for marine {1. Qingdao Marine Science and Technology CenterQingdao 266237China University of Chinese Academy of Sciences Beijing 100049China Institute of marine Chemistry and Environment Ocean CollegeZhejiang UniversityZhoushan 316021China College of marine Technology and Environment Dalian Ocean UniversityDalian 116023China Key Laboratory of marine Sedimentology and Environmental {1. First Institute of OceanographyMinistry of Natural ResourcesQingdao 266061China

Tephra layers in the western Philippine Sea,characterized by abundant volcanic glass shards,may provide crucial evidence on the eruption history of volcanoes and tectonic evolution of the western Pacific.A 220-ka sediment core from the Benham Rise in the western Philippine Sea offers new insights into the provenance of four intercalated tephra layers(T1.T4,in chronological order)containing either colorless or brown glass *** to primitive mantle,all glass shards are enriched in large-ion lithophile elements,such as Rb,Cs,and Pb,and depleted in high field-strength elements,such as Th,Nb,and Ta,indicating a subduction-related *** colorless glass shards are characterized by high SiO_(2)(>78%)and light rare earth element(LREE)contents as well as high La/Sm ratios(>9),low FeO and MgO contents(1.),low Sr/Y(1.)and high Ba/Th ratios(>1.0),pointing to a rhyolitic composition and a medium-K calc-alkaline serial *** contrast,the brown glass shards are characterized by lower SiO_(2)(1.),indicating derivation from medium to high-K calc-alkaline andesite *** glass shards from layers T3(1.2 ka)and T4(1.2 ka)were correlated with volcanic deposits from the Taal and Laguna Caldera in the Maccolod Corridor,respectively,while the colorless glass shards from layers T1.36.5 ka)and T2(61.2 ka)were likely sourced from the Irosin Caldera in the Bicol *** the provenance of late Pleistocene tephra layers in the western Philippine Sea is helpful to complement a Philippine volcanic history and establish a regional tephrochronostratigraphy.

关键词： volcanic glass provenance chemical composition Philippine Sea late Pleistocene

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Stratigraphy of the Alveolina elliptica group from the Middle Eocene of Iran:Calibration with calcareous nannofossils biozones and description of Alveolina ozcani n. sp.

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Journal of Palaeogeography 2024年第1期13卷 54-79页

作者： Mehdi Hadi Lorenzo Consorti Ali Bahrami Mohammad Parandavar Saeed Khorramdel department of {1. Faculty of SciencesUniversity of IsfahanIsfahanIran Institute of marine Sciences(ISMAR-CNR) Area Science ParkBasovizza34149 TriesteItaly National Iranian Oil Company Exploration DirectorateSheikh Bahaei SquareTehranIran department of {1. Faculty of ScienceFerdowsi University of MashhadMashhadIran

Precise taxonomy and the chronostratigraphic calibration of the Middle Eocene Alveolina from Central Iran is here undertaken from the Chah-Talkh section of the southern Sabzevar region(Central Iran). We have identified Alveolina kieli, Alveolina stercusmuris and Alveolina nuttalli along with the new species Alveolina ozcani n. sp. that we include into the Alveolina elliptica group. We have also found Nummulites uroniensis, Nummulites obesus and Nummulites cf. verneuili and associated calcareous nannofossils that look reliable to make thoughtful correlations with the Shallow Benthic Zones(SBZ). The foraminiferal biostratigraphy suggests an assignment to the upper part of the lower Lutetian-lower part of the middle Lutetian,SBZ1.(Middle Eocene), further strengthened through the identification of the calcareous nannofossil NP1.b-NP1.b or CNE8-CNE1. biozones, providing a solid correlation with the global stratigraphic standards.

关键词： Alveolina Calcareous nannofossil Central neo-tethys Central Iran Middle Eocene Biostratigraphy

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Mineralogy and geochemistry of trachytic rocks from the Lichi Volcanics, Eastern Himalaya: insights into the Kerguelen mantle plume activity in the Eastern Himalayan Region

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Acta Geochimica 2024年第1期43卷 180-197页

作者： Pallabi Basumatary Deepshikha Borah Hiredya Chauhan Tribujjal Prakash Bibhuti Gogoi department of {1. Cotton UniversityGuwahatiAssam 781001India Wadia Institute of Himalayan geology DehradunUttarakhand 248001India

The Lichi volcanics are a suite of mafic-intermediate-felsic rocks and are considered coeval with the Abor volcanics(~1.2 Ma) of the Siang window in the Eastern Himalaya. Here, we present the first report of trachytic rocks from the Lichi volcanics, which are exposed in the Ranga valley, along the Kimin-Yazali road section in the Eastern Himalayan Region, Northeast India. The trachytes occur in close association with sandstones of the Gondwana Group of rocks and are characterised based on field, petrographical, and geochemical *** fine-grained trachytes are composed of alkali feldspar, biotite, plagioclase, sodic-amphibole, apatite, illmenite, and titanite. The REE profiles of the evolved trachytic rocks(higher SiO_(2)content) display fractionated trends. The fractionation of accessory mineral phases, like apatite and titanite, was possibly responsible for the strongly fractionated REE patterns of the evolved *** trachytic rocks demonstrate high apatite saturation temperatures of 988 ± 1. ℃(1., n = 8). The Aluminium Saturation Index(1.1. and binary discrimination diagrams of these peralkaline trachytes define their affinity with A-type granitoids. Elemental ratios like Y/Nb, Nb/U,and Ce/Pb signify that the Lichi trachytes are differentiated products of mantle-derived ocean island basalts. Trace elemental discrimination diagrams Th/Yb versus Nb/Yb, Y versus Nb, and Y + Nb versus Rb reflect a within-plate tectonic regime for the trachytes. From the results presented in this work, we infer that the development of rifting events during the breakup of eastern Gondwana due to the onset of Kerguelen plume activity further led to underplating of basic magma in lower crustal levels. These parental basaltic magmas underwent fractionation processes forming differentiated trachyandesites and *** into consideration the similarities recorded between the Lichi volcanics and Abor volcanics, this study supports the idea that Kerguelen plume ac

关键词： Peralkaline trachytes Trachyandesites A-type granitoids Apatite saturation temperature Abor volcanics Eastern Gondwana

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Provenance and depositional setting of the Late MiocenePleistocene clastic sediments in the eastern Arabian Peninsula and western Iraq using rare earth elements geochemistry

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Acta Geochimica 2024年第2期43卷 399-410页

作者： Salih M.Awadh Zinah S.Al-Ankaz Mohanad R.A.Al-Owaidi John S.Armstrong-Altrin department of {1. College of ScienceUniversity of BaghdadBaghdadIraq department of {1. College of ScienceUniversity of WasitWasit 52011Iraq department of Applied {1. College of ScienceUniversity of BabylonBabylon 51001Iraq Unidad de Procesos Oceanicos y Costeros Instituto de Ciencias del Mar y LimnologíaUniversidad Nacional Autonoma de MexicoCiudad Universitaria04510 Mexico CityCDMXMexico department of {1. Sciences Bharathidasan UniversityTiruchirapalliTamil Nadu 620024India

The sandstones of the Late miocene–Pliocene Dibdibba Formation in the Najaf–Karbala Plateau and Basra were examined to determine their source rocks and origin. The rare earth elements(REE) and trace elements(Sc, Co, V, and Th) concentrations in these sandstones revealed that they likely derived from a single source. The steep light rare earth elements(LREE) and flat, heavy rare earth element(HREE) patterns, negative Eu anomaly, and high ΣREE contents in sandstones suggest its derivation from a suggests that a passive continental margin environment and originated from felsic source rocks. The average concentration of ΣREE is 93.5 ppm, which is lower than that of the average crustal compositions like Upper Continental Crust and Post Archean Australian Shale. The higher proportion of LREE compared to HREE implies that these sandstones were recycled and derived from a distal source. The Th/Co, Th/Sc, La/Sc, La/Co, Eu/Eu*and(La/Lu)cn elemental ratios indicated that these Late Miocene–Pliocene sandstones were derived from felsic rocks located in the marginal region of the Arabian Shield.

关键词： REE Dibdibba formation Clastic sediments Passive continental margin

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Changes in Sediment Sources in the Southern Muddy Area of Weihai,China,Since the Late Pleistocene:A Record from Rare Earth Elements

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Journal of Ocean University of China 2024年第5期23卷 1221-1232页

作者： ZHANG Zhichao LIU Jinqing YIN Ping CAO Ke FENG Xiaokun WANG Shengyu College of Earth Science and Engineering Shandong University of Science and TechnologyQingdao 266590China State Key Laboratory of marine {1. School of Ocean and Earth ScienceTongji UniversityShanghai 200092China Qingdao Institute of marine {1. China Geological SurveyQingdao 266237China

The small muddy areas developed in the southern Shandong Peninsula have attracted increasing attention from researchers because of complex changes in sediment sources driven by sea-level fluctuations and land-sea interactions since the late *** study investigates the evolution of sediment sources and their responses to environmental changes since the late Pleistocene,using core WHZK01.collected from the nearshore muddy area in southern Weihai for rare earth element(REE)*** doing so,this work highlights the changing patterns of material sources and the primary control *** results reveal that the sedimentary deposits in core WHZK01.exhibit distinct terrestrial *** function analysis(F_(D))and source discrimination dia-grams both suggest that the primary sources of these deposits are the Yellow River and adjacent small and medium-sized rivers,although the sources vary among different sedimentary ***,the DU3 layer(1..82-25.1. m)displays typical riverine sedimentation,dominated by terrestrial detrital input,primarily from the local rivers,namely the Huanglei and Muzhu *** material in the DU2 layer(1..91.1..82 m)is mainly influenced by a mixture of the Qinglong and Yellow *** DU1.layer(0-1..91.m)is influenced by sea-level changes during the Holocene,with the Yellow River being the primary source,although there is also some input from local *** changes in sea level during the Holocene and the input of Yellow River material carried by the coastal currents of the Yellow Sea are identified as the main controlling factors for the changes in material sources in the study area since the late Pleistocene,with small and mediumsized rivers also exerting some influence on the material *** above mentioned findings not only contribute to a better understanding of the source-sink systems of the Yellow River and adjacent small and mediumsized rivers but also deepen our understanding of the la

关键词： rare earth element source identification environmental evolution muddy area southern Weihai

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Kink-band Kinematic Analysis and its Implications for Late-stage Deformation in the Internal Parts of the Zagros Collision(Sanandaj–Sirjan Zone) in West Iran

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Acta Geologica Sinica(English Edition) 2024年第4期98卷 921-935页

作者： Maryam HEYDARI Mahdi BEHYARI department of {1. Faculty of SciencesUrmia University57153165 UrmiaIran

In the internal parts of the Zagros collision zone, several deformation phases have been superimposed. The early deformation phase caused the development of a penetrative foliation. The late-stage deformation phase was preferentially accommodated within shear zones and caused the generation of shear bands, implying a non-coaxial component of deformation, the end of this stage deformation was marked by the development of kink-bands. In the vicinity of Zagros suture zone, the kink angle increased from 40° to 60°, and the kink-bands was converted to chevron folds. In this region, the external(α) and internal(β) angular ratio is α/β ≠ 1.and kink angle increased, and deformation occurred with 1.% to 30% volume loss. Farther from the suture zone in the east, α/β = 1.and total volume was constant or increased by 5% to 1.%. Kink-bands kinematic analysis in the study area revealed this structures were sensitive to deformation conditions and components such that, with decreasing distance to the Zagros suture zone, shearing and rotation increased, a high kinematic vorticity dominated, and volume loss occurred during deformation.

关键词： kink-band shear zone strain vorticity Zagros Iran

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