Journal of Earth System Science最新文献

{"title":"Application of GPS PWV for rainfall detection using ERA5 datasets over the Indian IGS locations","authors":"Ashutosh Srivastava","doi":"10.1007/s12040-024-02286-3","DOIUrl":"https://doi.org/10.1007/s12040-024-02286-3","url":null,"abstract":"<p>Precipitable water vapour (PWV) available in the lower atmosphere plays a very crucial role in the determination of potential rainfall over an area and its early detection is very important for predicting heavy rainfall events. Hence, precise estimation of PWV is necessary for weather forecasting and other atmospheric analysis. In the present study, global positioning system (GPS) derived PWV is used for the prediction of short-term rainfall. The GPS observations acquired from the HYDE (Hyderabad) and IISc (Bengaluru) IGS stations and meteorological observations obtained from weather stations are used for the retrieval of PWV. Thereafter, estimated PWV values are used in a rain prediction algorithm. A relationship is established between hourly estimated PWV values and ERA5 reanalysis rainfall data to forecast the rainfall event. The validation of estimated results is carried out at different levels. Estimated zenith tropospheric delay (ZTD) results are compared with IGS results which show a good agreement with RMS errors close to 5 mm in different cases. Further estimated PWVs are compared with the ERA5 PWVs, which show a difference of 2–4 mm considering all the datasets. Subsequently, this validated PWV is used in rainfall detection analysis and results show that 56.6% of the rain events can be forecasted with a false alarm rate of 42.3% in the region around IISc and 52.2% of the rain events can be forecasted with a false alarm rate of 43.9% in the region around HYDE. A good prediction is observed for IISc as compared to HYDE. Considering different threshold values of different years, it is observed that 70% and 60% rain events can be forecasted for IISc and HYDE, respectively. The analysis shows that by using GPS PWV, an accurate prediction of rainfall is possible and this can be used further for weather prediction analyses over the region.</p>","PeriodicalId":15609,"journal":{"name":"Journal of Earth System Science","volume":"15 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140324971","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Potential variability of discharge and suspended sediment load in the Sone River basin, Bihar","authors":"Ankit Ranjan, Thendiyath Roshni","doi":"10.1007/s12040-024-02292-5","DOIUrl":"https://doi.org/10.1007/s12040-024-02292-5","url":null,"abstract":"<p>Suspended sediment load (SSL) and discharge are closely related concepts that characterise the sediment movement and quantity within water bodies and play a crucial role in evaluating the impact of erosion, sedimentation, and land management practices on riverine ecosystems. Despite numerous studies on SSL and discharge assessments, a site-specific understanding remains essential for effective riverine ecosystem protection. This study integrates daily sediment and discharge data from the Koelwar station spanning June 2010 to May 2015, with a primary focus on analysing SSL variability relative to Sone River discharge in Bihar. SSL–discharge rating curves were computed to assess concentration shifts during low flow season (LFS), high flow season (HFS), and the annual period. Results indicate a nearly linear dependence of SSL on discharge, with <i>r</i>² values of 0.72, 0.94, and 0.84 for LFS, HFS, and the annual period, respectively. The study unveils the underlying mechanics driving catchment erosion and sediment transport during lean and peak flows through hysteresis loops. Findings reveal that 50% of events are influenced by shear stress and hydraulic forces from the channel bed, 20% by sediment depletion in the channel bed due to repeated peak flows, and the remaining 30% by a combination of shear stress and sediment reduction. Additionally, MATLAB-utilized wavelet analysis explains the time-frequency variability of discharge and SSL. Cross-wavelet analysis shows the outflow of SSL closely following discharge, indicating synchronisation across all scales. The study underscores the importance of effectively managing runoff events to mitigate SSL. The proposed methodology and results offer valuable insights for water management and policymakers, aiding in the formulation of guidelines to minimise anthropogenic activities and sustain aquatic ecosystems.</p>","PeriodicalId":15609,"journal":{"name":"Journal of Earth System Science","volume":"15 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140324797","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cyclonic wind loads and structural mitigation measures – vulnerability assessment of traditional housings in Odisha","authors":"","doi":"10.1007/s12040-024-02255-w","DOIUrl":"https://doi.org/10.1007/s12040-024-02255-w","url":null,"abstract":"&lt;h3&gt;Abstract&lt;/h3&gt; &lt;p&gt;As global temperatures rise in response to global warming and climate change, the sea-surface temperature of Bay of Bengal shows a rise of 1–2.5ºC during the months of May–August. This has led to a change in the pattern of cyclones, occurring specifically in the Bay of Bengal, along with the increased frequency of cyclone occurrences. The cyclones in 2018–2022 have been found to intensify rapidly from a low-pressure disturbance to severe cyclonic storm within 48–54 hours. While meteorological forecasting predicts the onset and wind speed, the holistic wind profile for an intensifying cyclone changes rapidly with time and interference from nearby structures. The damage to life and property depends on the structural integrity of structures. With modernization, the number of concrete masonry structures has increased. The coastal-rural zones of Odisha are known to consist of traditional housing made of different materials like rammed earth, wooden rafters with thatched roofs made of paddy stubble and wooden frames, stone with mud and in few cases, a mix of cement, wood and stones. Although the materials vary, the shape of traditional houses, schools and temples were found to be either gabble roofed or hip-roofed. Studies done in the past highlight the increased vulnerability of gabble-roofed structures to severe destruction levels. Most of the previous research focuses on cyclone forecasting, zonation, and vulnerability analysis based on socio-economic parameters. A thorough structural vulnerability analysis and ranking of traditional housing is a must, considering the fact that the number and intensity of cyclones are rising. And also, the fact that as per the Economic Survey of 2018, 45% of coastal-rural households fall below the poverty line and rely on traditional modes of construction. The authors carried out a thorough on-field post-damage assessment of 2019 cyclone Fani and compared it with the historical data of damage caused to traditional structures due to past cyclones. Based on the time histories, recurrence period and intensity of cyclonic winds, different levels of vulnerability were assigned to the traditional structures of houses, schools and temples. A fragility function was designed to quantify the vulnerability levels. A detailed scientific interpretation of destruction/failure mechanisms is also presented. Further, to quantify the structural behaviour under cyclonic wind load, the cyclonic wind profile was modelled numerically, and validated with wind tunnel testing and finite element analysis was done on various structural members of a traditional gabble roof structure to study the loads and reactions of members. The consequences received showcased novel findings, such as temples being found to be structurally more stable to cyclonic wind loads. Based on the structural analysis and vulnerability levels, economically viable strengthening measures are provided for both, existing traditional structures and struc","PeriodicalId":15609,"journal":{"name":"Journal of Earth System Science","volume":"27 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140154852","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the possible primary sources of Koh-i-Noor and other Golkonda diamonds","authors":"Hero Kalra, Ashish Dongre, Swapnil Vyas","doi":"10.1007/s12040-024-02260-z","DOIUrl":"https://doi.org/10.1007/s12040-024-02260-z","url":null,"abstract":"<p>Koh-i-Noor and other world-famous diamonds such as Hope, Orloff, Great Mogul, Nizam, and Pitt, well-known in the industry as ‘Golkonda Diamonds’ are very well recognised for their rare colours, large carat sizes, and because of the paucity of nitrogen atoms majority of them have been classified as Type IIa diamonds. These renowned Golkonda diamonds were recovered from placers mined on the banks of the Krishna River in southern India; however, their primary source rocks (either kimberlites or lamproites) remain questioned and untraced. Precise identification of the primary sources of such large-sized, dominantly Type IIa diamonds (i.e., CLIPPIRS) is crucial for understanding their deep mantle origin, nature and timing of magmatism carrying them and essential from economic and geological perspectives. We employed a multidisciplinary approach incorporating xenocrystic mineral composition and bulk-rock geochemistry, field geological and remote sensing (GIS) studies to locate the probable primary sources of these renowned diamonds, know the origin of Type IIa Golkonda diamonds in southern India, and to understand the mechanism and timing of diamond transport and dispersal as placers in the Krishna River basin. Our study rules out the possibility of various lamproite occurrences of the Eastern Dharwar Craton and Banganapalle conglomerates as being sources of Koh-i-Noor and other Golkonda diamonds. The absence of Type IIa diamonds in the highly diamondiferous Late Cretaceous kimberlites of Wajrakarur likewise excludes them as source of Golkonda diamonds. Among southern India's two significant kimberlite fields, i.e., Wajrakarur and Narayanpet, compositions of indicator minerals from the Wajrakarur Kimberlite Field (WKF) reveal their ultimate diamond preservation potential, presence of strong diamondiferous mantle roots and deeper source regions, hence recognising them to be the potential sources of Golkonda diamonds. GIS and remote sensing tools were used to calculate moisture content, vegetation indices, and to locate paleo-channel of the Penner River, which was primarily responsible for the transportation of diamonds from their Mesoproterozoic (ca. 1.1 Ga) source rocks at Wajrakarur to their final sites of recovery, i.e., Kolluru and other mines situated on the banks of the Krishna River. The occurrence of alluvial placer deposits in Krishna River drainage system is analogous to the Orange River drainage system in South Africa. Both areas have diamonds sourced from primary kimberlite pipes, transported by rivers, and deposited in specific areas. Similarities in the origin, mechanism of diamond transport, dispersal and deposition have played a crucial role in significant diamond production from alluvial deposits in Krishna and Orange Rivers.</p>","PeriodicalId":15609,"journal":{"name":"Journal of Earth System Science","volume":"24 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140154913","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An exhaustive investigation of changes in projected extreme precipitation indices and streamflow using CMIP6 climate models: A case study","authors":"Suram Anil, P Anand Raj","doi":"10.1007/s12040-024-02267-6","DOIUrl":"https://doi.org/10.1007/s12040-024-02267-6","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>This study draws attention to the better comprehension of spatio-temporal analysis of climate changes based on precipitation extremes and projection of future streamflow for efficient management of water resources in the Krishna River Basin (KRB), India. The concept of symmetric uncertainty (SU) is employed to select the top five Global Climate Models (GCMs) from the Coupled Model Intercomparison Project Phase 6 (CMIP6) to project future precipitation extreme indices under different Shared Socio-economic Pathways (SSPs). Grid-wise trend analysis reveals that there is more number of decreasing trends in extreme precipitation indices than increasing trends. From the results, it is observed that the percentage contributions of maximum one-day (RX1day) and five-day (RX5day) precipitation indices to the annual total precipitation indices are more important. In future periods, the precipitation extremes are expected to increase, especially the heavy precipitation indices such as R95p, R99p, RX1day, and RX5day, which are increasing significantly along with R50. The projection of future streamflow in the KRB is done using a Support Vector Machine (SVM) and is expected to increase under different SSPs. These precipitation extremes may increase the chance of hydrological calamities across the basin in the future.</p><h3 data-test=\"abstract-sub-heading\">Research highlights</h3>\u0000<ul>\u0000<li>\u0000<p>Spatio-temporal analysis of extreme precipitation indices is carried out using CMIP6 climate model simulations over KRB.</p>\u0000</li>\u0000<li>\u0000<p>One of the most efficient algorithm, symmetric uncertainty is employed to select best-performing GCMs to reduce the uncertainty in GCM selection.</p>\u0000</li>\u0000<li>\u0000<p>The association between the extreme indices and discharge is carried out using Pearson correlation.</p>\u0000</li>\u0000<li>\u0000<p>A significant increase is observed in projected extreme indices, especially very extreme indices such as 95th and 99th percentiles, RX1day and RX5day.</p>\u0000</li>\u0000<li>\u0000<p>SVM regression is established between TOTPR and mean daily discharge to predict the future annual average streamflow under different SSP scenarios.</p>\u0000</li>\u0000</ul>","PeriodicalId":15609,"journal":{"name":"Journal of Earth System Science","volume":"22 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140155217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Extreme value analysis of annual precipitation in districts of Maharashtra, India","authors":"Nikhilesh Gandhre, Saha Dauji, Shreenivas Londhe","doi":"10.1007/s12040-023-02243-6","DOIUrl":"https://doi.org/10.1007/s12040-023-02243-6","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>India is dependent on rainfall for agriculture, food security and economic advancements. Spatial and temporal variability of rainfall is well reported, as well as the recent upsurge of extremes due to climate change. In Maharashtra, rainfall intensity varies widely from very high (coasts) to low (west-interior). Extreme value analysis (EVA) of heavy annual rainfall for the various districts of Maharashtra was conducted to ascertain the following for each district: suitable extreme value distribution; extreme (high) annual rainfall; efficacy of gap-filling for missing annual record/s. The suitability of various statistical distributions for representing high annual rainfall values was evaluated using Anderson–Darling test (quantitative), quantile and probability plots (qualitative). The gap-filling exercise resulted in minor variations (&lt;10%) in the estimated extremes, positive as well as negative, for different cases. Therefore, the results of EVA on the actual records are advocated. The suitable distributions for 35 districts are presented in maps and Frechet distribution was adjudged suitable for almost 60% of districts. The estimated extremes for all districts are listed for different return periods for ready reference. These values would be useful for the planning and construction of hydraulic structures, water resources and reservoir management, design and planning of irrigation.</p><h3 data-test=\"abstract-sub-heading\">Research highlights</h3>\u0000<ul>\u0000<li>\u0000<p>Suitable probability distribution functions for modelling the extremes of annual rainfall in each district of Maharashtra have been identified and the parameters have been provided.</p>\u0000</li>\u0000<li>\u0000<p>Extreme values of annual rainfall for each district in Maharashtra for selected return periods have been presented.</p>\u0000</li>\u0000<li>\u0000<p>Evaluation was performed on whether the gaps in the annual rainfall records would affect EVA of the annual rainfall in the districts of Maharashtra.</p>\u0000</li>\u0000</ul>","PeriodicalId":15609,"journal":{"name":"Journal of Earth System Science","volume":"31 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140154847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lithofacies and geochemical analysis of intertrappeans of the Ninama Basin, Saurashtra, Western India: An integrated approach for paleolake depositional system","authors":"Nishi H Shah, Satish J Patel","doi":"10.1007/s12040-024-02265-8","DOIUrl":"https://doi.org/10.1007/s12040-024-02265-8","url":null,"abstract":"&lt;h3 data-test=\"abstract-sub-heading\"&gt;Abstract&lt;/h3&gt;&lt;p&gt;The sedimentary sequence of the Ninama Basin is associated with the latest phase of the continental Deccan volcanism of the Indian peninsula. It occurs as inter-, intratrappeans with a 39-m thick sequence comprising Sukhbhadar Formation and Ninama Limestone. The investigation aims to reconstruct its depositional setting based on the lithofacies and inorganic geochemistry to understand the influence of paleosalinity, paleoredox, paleodepth, provenance and paleoclimate on the sedimentation pattern. It is characterized by clastic and chemically formed rocks, including shale, mudstone, siltstone, sandstone and limestone. Facies analysis has revealed seven lithofacies, amongst which four are clastic facies, shale (SH), calcareous shale (CSH), silty mudstone (SM) and lithic greywacke (LGW), and three are carbonate facies, namely, grey-black limestone (GBL), cherty limestone (CL) and marlite (ML). Using geochemical analysis of major oxides and trace elements, ratios of Ca/(Ca+Fe), Sr/Ba, V/(V+Ni), V/Cr, Fe/(Ca+Mg), Ti/Al, Na/K, K/(Fe+Mg), CIA-K and MAP were determined and used to interpret and note the changes in the depositional system. The combined results of the lithofacies and geochemistry indicate that the deposition occurred in three phases. Phase 1 is characterized by high energy conditions in the shallow to moderate depth brackish-saline lake with oxic to dysoxic conditions; Phase 2 is characterized by anoxic deep fresh to the brackish water basin; and Phase 3 is characterized by semiarid conditions, saline, anoxic waters, high evaporation leading to shallowing of the lake, and low to moderate terrestrial input. This lacustrine basin in the paleotopographic low of the Deccan Volcanic Province is characterized by distinct lithology governed by various depositional parameters. A composite depositional model is constructed for the Ninama Basin, reflecting three phases of evolution that are dominantly controlled by the paleoenvironment.&lt;/p&gt;&lt;h3 data-test=\"abstract-sub-heading\"&gt;Research highlights&lt;/h3&gt;&lt;p&gt;The present study focuses on lithofacies and inorganic geochemical analysis of Ninama paleolake sediments, Saurashtra intertrappeans, to interpret their paleosalinity, paleoredox, water depth, provenance, detrital influx, and paleoclimate.&lt;/p&gt;&lt;ol&gt;\u0000&lt;li&gt;\u0000&lt;span&gt;1.&lt;/span&gt;\u0000&lt;p&gt;Phase 1 deposition was initiated in paleotopographic low of Deccan Traps, in an oxic–dysoxic, high-energy turbulent brackish water environment, in humid conditions.&lt;/p&gt;\u0000&lt;/li&gt;\u0000&lt;li&gt;\u0000&lt;span&gt;2.&lt;/span&gt;\u0000&lt;p&gt;Phase 2 characterizes fine-grained clastic facies deposited in anoxic, fresh-brackish, deep lake waters in humid conditions.&lt;/p&gt;\u0000&lt;/li&gt;\u0000&lt;li&gt;\u0000&lt;span&gt;3.&lt;/span&gt;\u0000&lt;p&gt;Phase 3 marks the shallowing, evident by carbonate facies with low-moderate terrestrial input deposited in saline and anoxic paleolake in semiarid conditions with high evaporation and low-moderate precipitation.&lt;/p&gt;\u0000&lt;/li&gt;\u0000&lt;/ol&gt;&lt;p&gt;The Deccan Traps have influenced the paleolake inter","PeriodicalId":15609,"journal":{"name":"Journal of Earth System Science","volume":"144 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140154923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"How well does MPAS simulate the West African Monsoon?","authors":"","doi":"10.1007/s12040-023-02245-4","DOIUrl":"https://doi.org/10.1007/s12040-023-02245-4","url":null,"abstract":"<span> <h3>Abstract</h3> <p>The West African Monsoon (WAM) system plays a crucial role in the West African climate system because it transports moisture from the Atlantic Ocean into the subcontinent in summer. This study evaluates the capability of the Model for Prediction Across Scales-Atmosphere (MPAS-A) to simulate the characteristic reproduce the WAM system and the associated rainfall-producing features. The MPAS model was used to perform a 30-year global climate simulation (1981–2010) at a regular grid (uniform resolution of 60 km). The simulation was initialized with the Climate Forecast System Reanalysis (CSFR) dataset. The results showed that MPAS simulate well the rainfall pattern over West Africa and reproduces the different phases of the monsoon dynamics system (i.e., the northward progression, the peak period, and the southward retreat). The model also reasonably replicates the pattern of the zonal components of wind and the vertical velocity. However, MPAS underestimates the orographic rainfall over the Guinea Coast, Jos Plateau, and Mount Cameroon. It also underestimates the vertical velocity and zonal wind magnitudes over the region. In addition, the model features a weaker temperature gradient than in the reanalysis. Understanding and correcting the sources of these model biases will enhance the suitability of MPAS for weather and seasonal forecasts over West Africa.</p> </span> <span> <h3>Research highlights</h3> <p>In this study, we investigated the ability of the Model for Prediction Across Scales (MPAS) to simulate the West African monsoon rainfall, the associated atmospheric features controlling the variability of the seasonal and annual cycle, and the thermal wind conditions. First, the model is initialized using the CSFR reanalysis. Then, we run the model simulation for 30 years, from 1981 to 2010, using a regular grid (uniform resolution of 60 km). We showed that the model realistically simulated the spatial pattern of rainfall over West Africa. However, it has some problems when it comes to capturing the monsoon features.</p> </span>","PeriodicalId":15609,"journal":{"name":"Journal of Earth System Science","volume":"50 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140154848","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microstructural and compositional variations of allanite in hydrothermal veins: Implications for REE mobilization in Chhotanagpur Granite Gneiss Complex, Purulia district, West Bengal, India","authors":"Prithwiraj Maiti, Aparajita Datta, Trisrota Chaudhury, Sujit Kumar Tripathy, Monotrisha Dey, Shilpa V Khandolkar, Anjana Ritu Ekka","doi":"10.1007/s12040-024-02259-6","DOIUrl":"https://doi.org/10.1007/s12040-024-02259-6","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>This study employs a combination of texture and composition of allanite to investigate the chemical evolution of rare earth elements (REEs) in the hydrothermal veins within the Chhotanagpur Granite Gneiss Complex around Kalapathar area, Purulia district, West Bengal, India. Allanite occurs as pockets and lumps in the hydrothermal veins. Locally, the allanite pockets/lumps have high concentrations of REEs (∑REEs ~9.8 wt.%), Th (up to 1427.2 ppm) and U (up to 642.1 ppm). Three hydrothermal fluids and associated REE mobilization have been distinguished and characterized. The hydrothermal fluid₁ causes metasomatic addition of REEs that leads to the formation of early REE-enriched allanite. Hydrothermal fluid₂ imposed changes in the texture and composition of the allanite where the early allanite was replaced by relatively REE-depleted allanite following the substitution scheme REE⁺³ + (Fe⁺², Mg⁺²) → Ca⁺² + (Al, Fe⁺³). The hydrothermal fluid₃ is marked by the alteration of allanites to the bastnaesite and monazite. REEs have been transported mainly in aqueous chloro-complexes with high to moderate salinity and low homogenization temperature (257°–361°C). The timing of the hydrothermal event is established through U–Th–total Pb dating of monazite, yielding at around 875 ± 43 Ma.</p><h3 data-test=\"abstract-sub-heading\">Research highlights</h3><ol>\u0000<li>\u0000<span>1.</span>\u0000<p>The allanite clots and lumps in hydrothermal veins within CGGC around Kalapathar, Purulia District, West Bengal display high ∑REEs up to 9.8 wt.% along with Th and U up to 1427.22 and 642.14 ppm, respectively.</p>\u0000</li>\u0000<li>\u0000<span>2.</span>\u0000<p>The hydrothermal event has been characterized linked with two distinct varieties of allanite growth.</p>\u0000</li>\u0000<li>\u0000<span>3.</span>\u0000<p>The transportation of REEs occurs in aqueous chloro-complexes during the hydrothermal event.</p>\u0000</li>\u0000<li>\u0000<span>4.</span>\u0000<p>The timing of hydrothermal events and growth of the allanites has been determined.</p>\u0000</li>\u0000<li>\u0000<span>5.</span>\u0000<p>REE-enriched magmatic intrusion.</p>\u0000</li>\u0000</ol>","PeriodicalId":15609,"journal":{"name":"Journal of Earth System Science","volume":"31 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-03-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140154925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Estimation of burial depth using stylolite roughness from the Neoproterozoic Narji Limestone, Cuddapah Basin, India","authors":"Damayanti Choudhury, Tridib Kumar Mondal, Sourav Mondal, Arijit Debnath, Pramita Majumder, Amlan Banerjee","doi":"10.1007/s12040-023-02247-2","DOIUrl":"https://doi.org/10.1007/s12040-023-02247-2","url":null,"abstract":"<p>We use the stylolite roughness inversion technique (SRIT) to decipher the principal vertical stress and corresponding burial depth of the Narji Limestone, Cuddapah Basin, India. The method is applied to bedding parallel stylolites (BPS), which are present in carbonate rocks and originated due to pressure dissolution along the contact points between layers and are caused by compaction and deformation of sedimentary rocks. In this study, we analyse the surface roughness of a set of 25 stylolites that run parallel to the sedimentary bedding. The study area is replete with Class 2 (seismogram pinning type) and Class 3 (suture and sharp peak) types of BPS, of which Class 3 is more appropriate for determining the burial depth, which is the dominant type. The results confirm that there are two self-affine scaling regimes in the stylolite morphology, with cross-over lengths (<i>L</i>_c) varying from 0.32 to 0.95. The calculated vertical stress varies from 19.0 to 43.6 MPa, estimating the range of burial depth of the Narji Limestone between 718 m and 1649 m, with a median of 923 ± 92 m.</p>","PeriodicalId":15609,"journal":{"name":"Journal of Earth System Science","volume":"2 1","pages":""},"PeriodicalIF":1.9,"publicationDate":"2024-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140155114","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}