Geosystems and Geoenvironment最新文献

{"title":"Assessing the effects of human interventions on the morphodynamics and health of a lowland tropical river: A case study of the river Dwarkeswar, India","authors":"Biman Ghosh","doi":"10.1016/j.geogeo.2023.100234","DOIUrl":"https://doi.org/10.1016/j.geogeo.2023.100234","url":null,"abstract":"<div><p>The present study tries to analyze the impact of human activities on the physical and chemical health of the Dwarkeswar River. The river flows through a densely populated area. As a result, nearly 4000 t of sand are being extracted per day from the four segments of the river. Moreover, huge materials are extracted from the river to supply the raw materials of 97 brick kilns developed along the banks of the river. An industrial plant extracts 2,200,000 L d⁻¹ of water from the Dwarkeswar River, besides nearly 80 water lifting pumps. Similarly, a number of bridges are constructed across the river, and embankments are made along the banks. Per day 15.10 million liters of untreated sewage drain into the Dwarkeswar River from Bankura Town. The town also generates 63,111 kg/d of solid waste, some parts of which are disposed on the bank of the river. Intensive field surveys, analysis of multi-dated satellite images, and water quality parameters of the last ten years (2011–2020) were carried out in the present study to assess the impact of these interventions on river morphology, hydrology, and water quality. The comprehensive pollution index (CPI) was used to assess water quality. Results reveal that the Dwarkeswar River is highly affected, including the planform change, reduction of mean discharge and increase in the concentration of pollutants in the river water. The CPI value increased from 0.72 (2011) to 2.81 (2020), which indicates a severe increase in the level of pollution.</p></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"3 1","pages":"Article 100234"},"PeriodicalIF":0.0,"publicationDate":"2023-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49747089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Estimation of MFFPI for flood hazards assessment using geospatial technology in the Tawi Basin, India","authors":"Ajay Kumar Taloor ,&nbsp;Savati Sharma ,&nbsp;Divanshu Sharma ,&nbsp;Rajesh Chib ,&nbsp;Rakesh Jasrotia ,&nbsp;Surbhi Gupta ,&nbsp;Girish Ch Kothyari ,&nbsp;Pankaj Mehta ,&nbsp;Ravindra Vitthal Kale","doi":"10.1016/j.geogeo.2023.100233","DOIUrl":"https://doi.org/10.1016/j.geogeo.2023.100233","url":null,"abstract":"<div><p>&gt;Flash flood in the Himalayan River has made some catastrophic effects on the life people residing in its river banks mainly associated with extreme rainfall events/cloud bursts/the collapse of moraine-dammed lakes which significantly leads to rapid flooding and subsequently disaster in low laying areas. In the present study, we used different equations to determine the flash flood potential index(FFPI) and further, an improved Modified Flash Flood Potential Index (MFFPI) equation has been used to estimate the area with a predisposition to water accumulation. Various thematic layers prepared in the Geographic Information System (GIS) environment and integrated by providing proper weightage to each thematic layer i.e., slope, profile curvature, soil texture, geology and Land Use Land Cover (LULC), flow accumulation, slope, and profile curvature, etc. The MFFPI equation-derived map of Tawi Basin is classified into five zones such as very high hazard (100.40 km²), high hazard (971.60 km²), medium hazard (92.78 km²), low hazard (634.03 km²) and the very low hazard (254.61 km²) areas. Further, the results of the MFFPI were validated with the Analytical Hierarchy Process (AHP) based flood hazard zonation results which shows a very high correlation and similar trends of spatial and areal distribution with the MFFPI. The results of this study are quite useful for the local administration for futuristic planning and management of flood hazards in the Tawi River Basin and many other basins of similar terrain around the world.</p></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"3 1","pages":"Article 100233"},"PeriodicalIF":0.0,"publicationDate":"2023-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49746503","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment of groundwater potential zones using remote sensing and GIS-based fuzzy analytical hierarchy process (F-AHP) in Mpwapwa District, Dodoma, Tanzania","authors":"Ally Mgelwa Ally ,&nbsp;Jianguo Yan ,&nbsp;George Bennett ,&nbsp;Neema Nicodemus Lyimo ,&nbsp;Selassie David Mayunga","doi":"10.1016/j.geogeo.2023.100232","DOIUrl":"https://doi.org/10.1016/j.geogeo.2023.100232","url":null,"abstract":"<div><p>Groundwater is a very important resource for socio-economic development. The uncertainty of where potential groundwater resources is located often causes some groundwater development projects to fail. It is common for water resources development projects hitting dry wells after heavy investments of resources. In Mpwapwa District, borehole drilling locations are uncertain, determined by trial-and-error techniques based on geophysical survey methods that involve the study of the behaviour of rock and soil types in specific geological locations. To reduce such uncertainty, this study used remote sensing and GIS-based Fuzzy Analytical Hierarchical Process (F-AHP) to simulate groundwater potential zones (GWPZ) in Mpwapwa District, Dodoma region, Tanzania. The F-AHP model was used to reclassify, weight, and rank various thematic maps, including lithology, soil types, drainage density, lineament, magnetic intensity, slope and elevation. The overall GWPZ map was created by combining the seven (7) ranking thematic map layers in a GIS environment. The resulting GWPZ map that was then validated using two methods: overlaying method and area under the curve (AUC) method. The resulting GWPZ map shows that 19%, 31%, 28% and 22% of the area are classified as very good, good, moderate, poor and very poor zones, respectively. The accuracy of the generated map is 72% using the overlaying method and 93% using the AUC method.</p></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"3 1","pages":"Article 100232"},"PeriodicalIF":0.0,"publicationDate":"2023-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49747169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geospatial-based tectono-morphometric analyses of the drainage system in the Chengi and Myinee River basins in the Chittagong Hill Tracts, Bangladesh","authors":"Abdul Mohaimen,&nbsp;Biswajit Nath,&nbsp;Md. Ragib Hasan","doi":"10.1016/j.geogeo.2023.100224","DOIUrl":"https://doi.org/10.1016/j.geogeo.2023.100224","url":null,"abstract":"<div><p>Neotectonics is a major factor for controlling landform development in tectonically active Chittagong Tripura Fold Belt (CTFB) region, along the western flank of the Indo-Burma ranges. Morphotectonic parameters are excellent indicators for landscape morphology evaluation to highlight past and ongoing tectonic processes in a region. To investigate the matter, different morphometric indices such as linear, areal, and relief parameters were quantified using the Digital Elevation Model (DEM) data and its attributes of Chengi River Basin (CRB) and Myinee River Basin (MRB) in CTBF. All the computations for morphometric characteristics and visualization were performed in the Geographical Information System (GIS) and statistical platforms. The CRB and MRB are identified as fifth and fourth-order basins with a total area of 503.53 km² and 267.28 km², respectively which have low drainage frequency. The Bifurcation ratio (Rb) value of both these basins is indicative of structural control. TSI controls the upper course of the rivers and the variations have been observed in year-wise Topographic Sinuosity Index (TSI) distribution. The Asymmetry Factor (AF) in both these basins indicates that CRB is tilting towards the western side, whereas the MRB is tilting towards the eastern side. Moreover, these two rivers are elongated in nature indicates tectonic activity along with Google earth (GE) seamless mosaic image-based longitudinal profiles indicates significant deformation along their courses. In addition, the moderate Hypsometric Integral (HI) value shows a convex shape in the lower portion, which might be related to the upliftment along a fault or perhaps an upliftment associated with recent folding. The overall results in both these basins indicate the presence of tectonic activity. Therefore, morphotectonic analyses using DEM, Landsat satellite data, and GE seamless data are found useful in this study and could be considered an ideal tool for any complex basin morphotectonic study.</p></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"3 1","pages":"Article 100224"},"PeriodicalIF":0.0,"publicationDate":"2023-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49746933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cenozoic tectonic subsidence in the Upper Assam Basin, NE India","authors":"Priyadarshi Chinmoy Kumar ,&nbsp;Jitender Kumar ,&nbsp;Kalachand Sain","doi":"10.1016/j.geogeo.2023.100223","DOIUrl":"https://doi.org/10.1016/j.geogeo.2023.100223","url":null,"abstract":"<div><p>The Upper Assam Basin is an intermontane foreland basin surrounded by gigantic mountain belts in NE India. The structural geometry of the basin is controlled by the tectonic interactions of the Himalayan orogenic belt in the north, Mishmi thrusts in the east, and the Assam-Arakan fold-and-thrust belts in the south. The basin has received significant attention not only because of its complex geological set-up but also due to its petroliferous nature for hosting significant hydrocarbon resources. The present study attempts to explore the tectonic subsidence history of the Cenozoic succession using subsurface stratigraphic details of ten (10) boreholes drilled within the upper shelf of the basin. Subsidence analysis is carried out using the backstripping technique. It is observed that the tectonic subsidence in the basin developed through four different stages. During the Paleocene-Eocene epoch, the basin witnessed slow subsidence. It increased gradually through Oligocene and attained rapid speed in the Miocene. Further, during the deposition of post-Miocene sediments (Plio-Pleistocene epoch), the tectonic subsidence in the basin remained accelerated. Subsidence curves obtained from the studied borehole depict a convex-upward profile, indicating that the basin attained a foreland configuration over time and is presently a SE dipping shelf bounded by opposite verging fold-and-thrust belts. Overall, the basin experienced tectonic subsidence of ∼2 km throughout its lifespan with an average subsidence rate of ∼30 m/Ma. This case study prominently elucidates the tectonic history of the basin, which underwent during the Cenozoic time. Our findings stress the importance of subsidence analysis through the backstripping technique as a potential approach for untangling the geohistory of sedimentary basins worldwide.</p></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"3 1","pages":"Article 100223"},"PeriodicalIF":0.0,"publicationDate":"2023-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49758283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Palaeoproterozoic rift-related alkaline magmatism in Bari area, Son valley, Central India","authors":"G. Mageswarii ,&nbsp;Meenal Mishra ,&nbsp;Vaibhava Srivastava ,&nbsp;Hari B. Srivastava ,&nbsp;M. Satyanarayanan ,&nbsp;J.P. Shrivastava","doi":"10.1016/j.geogeo.2023.100222","DOIUrl":"https://doi.org/10.1016/j.geogeo.2023.100222","url":null,"abstract":"<div><p>Earlier studies on Palaeoproterozoic (∼1800 Ma) alkaline (shoshonitic) rocks comprised of limited petrochemical data on the Bari syenite and other contiguous felsic rocks emplaced in anorogenic rift setting along the Son-Narmada North Fault (SNNF). Using new major and trace element data-sets, this study offers means of study of origin, source of magma, tectonic settings and geodynamic implications. The major oxide chemistry grouped Bari rocks into high alkali, but low CaO bearing peraluminous alkaline rocks. These rocks represent high abundance of HREE, Zr, Nb, Ga, Y, Eu, Ba and Sr. Primitive mantle normalized REE and trace elemental patterns correspond to A-type suite, suggesting origin of the magma mainly from the mantle. Significantly, anomalous Th/U and Rb/Cs values revealed crustal contamination of the melt, derived from partial melting of the mantle. Moreover, binary data plots between La vs. La/Sm and La vs. La/Yb are pointing towards crustal assimilation which was concomitant with the fractional crystallization of the mantle derived melt. Thus, crustal contamination coupled with the fractional crystallization of the melt mainly contributed to the formation of syenite melt. But, a high degree of partial melting of the lower crust was primarily responsible for the formation of Bari granite. The enrichment of incompatible elements in the syenite rocks suggests involvement of mantle metasomatism in their genesis. The magmatic processes related to the formation of syenite, lamprophyre, ultramafics, mafic and granite bodies were operative in the diverse magmatic realm and initiated earlier at the waning stage of the Mahakoshal orogeny and continental rifting, but magma emplaced later during Post-Mahakoshal orogeny and Pre-Vindhyan sedimentation that also in a rifted basement of the Bundelkhand craton at ∼1800 Ma during the amalgamation of the Columbian Supercontinent.</p></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"3 1","pages":"Article 100222"},"PeriodicalIF":0.0,"publicationDate":"2023-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49758285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of microseism noise sources in Indian Ocean due to ocean atmospheric dynamics","authors":"Gyanasmita Pradhan,&nbsp;Ramakrushna Reddy,&nbsp;Paresh Nath Singha Roy","doi":"10.1016/j.geogeo.2023.100220","DOIUrl":"https://doi.org/10.1016/j.geogeo.2023.100220","url":null,"abstract":"<div><p>Microseism noise, which occurs in the period range of 2–20 s, is the most energetic band in the earth's background spectra. In the present study, we examined the amplitude spectra and directional characteristics of microseism in the Indian Ocean. We use the data from ten openly accessible land stations located all around the Indian Ocean. The probability power spectral density was used to characterize the microseism. To characterize the microseism, we employ the frequency dependent polarization approach, which is governed by the Eigen value decomposition of the 3 × 3 spectral covariance matrix. The spatial and temporal variation of microseism was investigated in order to better understand its distribution in the Indian Ocean region, which is regarded as a global source of microseism. For some stations, we observe the splitting of double frequency microseism into short period (2–5 s) and long period (6–10 s) microseism. The polarization analysis reveals the dominant sources of the microseism are located in the Southern Ocean. We also correlated the spatio-temporal variation of significant wave heights (swh) with the power spectral densities at each station. We observe a remarkable correlation between power spectral density with the significant wave height (swh) in both spatially and temporally in secondary microseism band. We also characterize the dominant surface wave types in the microseism band. In long period band Rayleigh waves are dominant and Love waves are prominent in the short period band.</p></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"3 1","pages":"Article 100220"},"PeriodicalIF":0.0,"publicationDate":"2023-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49764637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Petrogenesis of ultramafic rocks with abyssal peridotite affinity from the Central Bundelkhand Craton, India","authors":"Abinash Sahu ,&nbsp;Neeraj Vishwakarma ,&nbsp;M. Santosh ,&nbsp;Yamuna Singh ,&nbsp;K.R. Hari","doi":"10.1016/j.geogeo.2023.100221","DOIUrl":"10.1016/j.geogeo.2023.100221","url":null,"abstract":"<div><p>The Bundelkhand craton in India preserves important records of archean geological evolution, where several ultramafic rocks belonging to the Babina Greenstone Belt (BGB) occur as isolated and oval shaped bodies. These rocks are composed of olivine, orthopyroxene, amphiboles, and serpentine along with accessory mineral phases like chromian spinel and ilmenite. Here we present the major and trace element geochemistry of these ultramafic rocks that are characterised by low SiO₂ (45.16–49.00 wt%), high MgO (24.41–29.15 wt%) and moderate Fe₂O₃ (5.82–9.95 wt%) with high Ni (1164–1674 ppm), Cr (1532–3477 ppm) and Cu (14.7–39.5 ppm) suggesting primary magmatic nature. The rocks show low rare earth element (REE) content (ΣREE 2.1–3.5 ppm) with depleted LREE pattern and flat to slightly fractionated HREE pattern similar to abyssal peridotite signature. The Nb/Yb ratio ranges between 0.01 to 0.20 (average = 0.03), similar to that of N-MORB, suggesting magma derivation from a depleted mantle source, further substantiated by the Th/Yb vs. Ta/Yb plot. Trace elements like Ta and Pb show positive spikes, whereas La, Nb, Pr and Ce show depleted nature. The rocks generally have low platinum group elements (PGE) content (&lt;150 ppb) except one sample where it goes up to 388 ppb. The ΣPPGE concentration is higher than ΣIPGE for all the samples and the high Pd/Ir ratio (7.55–20.98) indicating the derivation of these ultramafic rocks from low degree of partial melting. Our data suggest that the ultramafic rocks were derived from a depleted mantle source at a shallow depth with affinity towards abyssal peridotite. These rocks might represent residue after extraction of low degree melt (∼2–10%) in a mid-oceanic ridge (MOR) setting, which were captured and brought to shallow levels and subsequently exposed on the surface.</p></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"3 1","pages":"Article 100221"},"PeriodicalIF":0.0,"publicationDate":"2023-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2772883823000444/pdfft?md5=7a199a527ff887b696cf4f74bb5f67ac&pid=1-s2.0-S2772883823000444-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78075602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diagenetic characteristics and their implications on the reservoir potential of Bajocian Sandstone, Jaisalmer Basin, western Rajasthan, India","authors":"Aashna Javed,&nbsp;K.F. Khan,&nbsp;M.A. Quasim,&nbsp;Shaikh Asjad","doi":"10.1016/j.geogeo.2023.100219","DOIUrl":"https://doi.org/10.1016/j.geogeo.2023.100219","url":null,"abstract":"<div><p>Petrography and scanning electron microscopy (SEM) investigations aided by energy dispersive X-ray (EDX) analysis and quantitative measurement of reservoir properties were used to extensively examine the physical and diagenetic characteristics of the Joyan Member Sandstone of Jaisalmer Formation. The Joyan Member Sandstone is fine- to medium-grained, moderate to well sorted, sublitharenite to litharenite. Mechanical compaction, precipitation of calcareous, ferruginous and silica cements, clay minerals, dissolution and alteration of unstable clastic grains such as feldspar and rock fragments, and grain fracturing are the identified diagenetic features. Feldspar and rock fragments underwent significant changes to kaolinite and chlorite while silica cement primarily originated from the dissolution and alteration of these grains and pressure solution. Mechanical compaction and the authigenic cements like calcareous, ferruginous, and silica reduced primary porosity, while secondary porosity was created by dissolution of clastic grains and cements. Compaction reduced porosity from an anticipated original 40% to around 13.4%. Porosity was reduced by cementation to 20.8%. Cementation reduced the porosity of the Joyan Member Sandstone somewhat more than compaction. Calcareous cementation played a major role in the porosity evolution of Joyan Member Sandstone. During early burial, the early calcareous cement occupied most of the pore spaces, leading to a significant reduction in porosity. However, incomplete filling or scattered patches of calcareous cement helped to preserve some primary porosity. In addition to calcareous cement, clay minerals like kaolinite and chlorite also acted as pore-filling and pore-lining cements. Kaolinite had a booklet-like or lamellar pattern contributing to minor porosity loss through pore-occlusion, while pore lining chlorite helped to retain porosity by preventing syntaxial silica overgrowth. Extensive dissolution of calcareous cement significantly increased the secondary porosity. Diagenesis affects reservoir quality by reducing initial porosity through cementation and compaction, and then increasing it through dissolution of early calcareous cement and unstable grains. The diagenesis of the studied sandstone is closely linked to its potential as a reservoir.</p></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"2 4","pages":"Article 100219"},"PeriodicalIF":0.0,"publicationDate":"2023-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49747187","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Flux melting of subducting carbonated sediments: An experimental study","authors":"Wei Chen ,&nbsp;Guoliang Zhang ,&nbsp;Takahashi Eiichi ,&nbsp;Li Li","doi":"10.1016/j.geogeo.2023.100218","DOIUrl":"https://doi.org/10.1016/j.geogeo.2023.100218","url":null,"abstract":"<div><p>Subduction zones play a critical role in the global carbon cycle by regulating carbon exchange between the Earth's surface and interior. Processes that are known to release carbon from the slab, including metamorphic decarbonation and carbonate dissolution, cannot explain the high CO₂ flux in magmatic arcs. Slab melting is the least considered mechanism for carbon mobilization at subarc depths based on the high solidus temperatures of carbonated lithologies, which were experimentally determined under dry or H₂O-absent conditions. Subducted sediments are major carbon carriers, however, their melting behaviour with excess H₂O remains largely unexplored. Here, we perform fluid-present melting, high-pressure experiments at 750–1100 °C and 2.5–4 GPa using starting compositions similar to global average subducted sediments to determine the solidus, melting relations and carbonate stability fields. The onset of melting is between 750 and 800 °C at 2.5 GPa and between 850 and 900 °C at 4 GPa. Dolomite melts out on or close to the solidus, whereas crystalline aragonite persists &gt;150 °C above the solidus. Flux melting of carbonated sediment at moderately hot subduction zones is examined to be feasible in the framework of the previously constructed dehydration history of the underlying serpentinites, providing a pathway to transfer carbon from the slab to the subarc mantle. However, complete breakdown of refractory aragonite requires at least 50 °C higher than that predicted for the hottest slab P‒T paths. Thus, even in the presence of H₂O, partial subducted carbon may survive the melting event occurring at shallow regions and reach considerable mantle depths.</p></div>","PeriodicalId":100582,"journal":{"name":"Geosystems and Geoenvironment","volume":"2 4","pages":"Article 100218"},"PeriodicalIF":0.0,"publicationDate":"2023-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49747186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}