Multiproxy Evidence for Natrojarosite–Natroalunite Solid Solutions in Western Kutch: Jarosite Formation, Preservation, and Martian Implications Sayantan Guha, Shiba Shankar Acharya, Mruganka Kumar Panigrahi Journal of Geophysical Research Planets, 2026 The western Kutch basin, India, provides a unique window into aqueous alteration under extreme acid‐sulfate conditions. While previous research focused primarily on the Matanomadh Formation, this study presents a systematic investigation of hydroxy‐sulfate minerals‐including jarosite, alunite, minamiite, gypsum‐across several chronostratigraphic units, spanning the pre‐Deccan Ghuneri Member (Late Cretaceous) through post‐Deccan formations (Matanomadh, Naredi, Harudi). Using a comprehensive analytical suite (XRD, XRF, FTIR, Raman, SEM‐EDS, δ 34 S) and laboratory‐synthesized potassium jarosite dissolution experiments, this work provides a complete solution to the source, formation, and preservation of these minerals. Isotopic data identify the primary source of iron and sulfur as the oxidation of precursor pyrite by meteoric water. A significant finding is the documentation of a natural natrojarosite–natroalunite solid solution, where Al‐substitution enhances structural stability, making Na‐jarosite more abundant than K‐jarosite. Notably, field associations and geochemical data indicate that host‐rock composition exerts only a minor influence on the formation of these jarosites. Crucially, our data reveal that the formation of these hydroxy‐sulfate phases cannot be attributed to a single geological event or a specific past timeframe. Instead, we demonstrate that these minerals are geologically recent and continue to form as an ongoing process under current environmental conditions. The long‐term preservation of these assemblages is primarily governed by the region's prevailing aridity and localized mineral buffering associated with their mode of occurrence along the fractures of host rock. The discovery of the natrojarosite–natroalunite solid solution provides key insights into acid‐sulfate system evolution on both Earth and Mars.
Natural Sources and Anthropogenic Influences on the River Water and Groundwater Chemistry of the Lower Mahanadi Basin: Insights From Radiogenic Sr Isotopes and Major Ion Chemistry Shiba Shankar Acharya, Valens Hishamunda, Ramananda Chakrabarti Frontiers in Water, 2022 The Mahanadi River ranks second among the rivers in the peninsular India in terms of water potential and flows through a geologically heterogeneous terrain. The present study uses a multiproxy approach, involving concentrations of major ions, and 87Sr/86Sr of the dissolved phases in seasonally collected river water and groundwater samples from the Lower Mahanadi Basin to investigate the sources of ions, the Cl-enrichment in the river water, the influences of the man-made structures like the Naraj Barrage, and the role of fertilizers on the chemistry of the river water. This study also provides the first estimate of the radiogenic Sr-flux of the Mahanadi River to the Bay of Bengal. Both inverse and forward models were used to evaluate the contributions of different sources to the dissolved ions of the Mahanadi River over different seasons. The results suggest that even in the predominantly silicate watershed of the Lower Mahanadi River, the riverine chemistry is modulated primarily by carbonate dissolution farther upstream followed by silicate weathering although, the contributions vary seasonally. The Naraj Barrage, which divides the main channel of the Lower Mahanadi River into several distributaries marks a divide between the less polluted upstream and the more polluted downstream. The radiogenic 87Sr/86Sr of the Mahanadi River water can be explained by mixing of four endmembers: Proterozoic carbonates, Archean silicates, rainwater, and fertilizers. The dominance of agricultural input during monsoon is consistent with high loadings of nitrates and phosphates used as fertilizers in the Mahanadi River basin along with a strong positive relationship between phosphate concentrations and 87Sr/86Sr of the river water samples. The flux-weighted averages of Sr concentration and 87Sr/86Sr to the Bay of Bengal were found to be 1.03 μmol/l and 0.72154, respectively. The groundwater composition of the Lower Mahanadi Basin is modulated by the mixing of four endmembers, viz. weathering of silicate and carbonate rocks, Bay of Bengal seawater, and fertilizer inputs. The groundwater samples of the Mahanadi basin show an average Sr concentration of 5.45 μmol/l and an average 87Sr/86Sr of 0.71772.
Submarine groundwater discharge derived strontium from the Bengal Basin traced in Bay of Bengal water samples Ramananda Chakrabarti, Surajit Mondal, Shiba Shankar Acharya, J. Sree Lekha, Debasis Sengupta Scientific Reports, 2018 Abstract Evaluating the submarine groundwater discharge (SGD) derived strontium (Sr) flux from the Bengal Basin to the Bay of Bengal (BoB) and determining its isotopic composition is crucial for understanding the marine Sr isotopic evolution over time. Measurements of spatially and temporally distributed water samples collected from the BoB show radiogenic 87 Sr/ 86 Sr, high Sr, calcium (Ca) concentrations and high salinity in samples collected dominantly from 100–120 m depth, which can be explained only by the contribution of saline groundwater from the Bengal Basin. These results provide a direct evidence of the SGD-Sr flux to the BoB. This SGD-Sr flux is however, spatially heterogeneous and using conservative hydrological estimates of the SGD flux to the BoB, we suggest a SGD Sr flux of 13.5–40.5 × 10 5 mol/yr to the BoB. Mass balance calculations using Sr concentrations and 87 Sr/ 86 Sr suggest up to 7% contribution of SGD to the 100–120 m BoB water samples. The identification of SGD at 100–120 m depth also provides an explanation for the anomalous variations in barium (Ba) concentrations and the δ 18 O-salinity relationship in intermediate depths of the BoB.
Multiproxy evidence for natrojarosite–natroalunite solid solutions in western Kutch: Jarosite formation, preservation, and Martian implications S Guha, SS Acharya, MK Panigrahi Journal of Geophysical Research: Planets 131 (5), e2025JE009601 , 2026 2026
Multiproxy Evidence for Natrojarosite-Natroalunite Solid Solutions in Western Kutch: Jarosite Formation, Preservation, and Martian Implications S Guha, SS Acharya, MK Panigrahi Authorea Preprints , 2025 2025
Deciphering the mechanisms of Jarosite Formation and Preservation in Western Kutch, India: A Multiproxy Approach with Martian Insights S Guha, SS Acharya AGU25 , 2025 2025
Weathering Trends Unveil K-Metasomatism in Bundelkhand Granitoids: Resolving the Pink–Grey Granitoid Paradox SS Acharya, A Sain, P Behera, A Basak, GK Deb EarthArXiv , 2025 2025
Chemical Weathering Pathways of Basalt: Mineral Transformation and Element Mobility L Biswal, SS Acharya AGU Fall Meeting Abstracts 2024, EP01-44 , 2024 2024
Geochemical insights into the 5.4 ka event in the eastern Arabian Shelf SS Acharya, P Dey Journal of Earth System Science 133 (2), 106 , 2024 2024 Citations: 3
Mobilization of rare earth elements during extreme weathering of basalt S Roy, SS Acharya, R Chakrabarti Geochemistry 84 (1), 126086 , 2024 2024 Citations: 11
Formation and preservation mechanisms of jarosite on the earth’s surface: A coupled theoretical and experimental approach S Guha, SS Acharya ACS Spring 2023 , 2023 2023
Evaluation of the efficacy of water-rock interaction in granitic & basaltic terrains in the present and past climate change episodes as a potential negative feedback on … A Basu, SS Acharya ACS SPRING 2023 , 2023 2023
Stable Strontium Isotopic Variability in River Water and Groundwater Samples from the Mahanadi River Basin, India-Implications for Carbonate Precipitation and Clay Formation S Ganguly, SS Acharya, R Chakrabarti AGU Fall Meeting Abstracts 2022, EP45C-1672 , 2022 2022
Natural sources and anthropogenic influences on the river water and groundwater chemistry of the Lower Mahanadi Basin: Insights from radiogenic Sr isotopes and major ion chemistry SS Acharya, V Hishamunda, R Chakrabarti Frontiers in Water, 38 , 2022 2022 Citations: 6
Variations in trace metal concentrations and Sr, Nd isotopic compositions in sediments from two contrasting settings in the Eastern Arabian Shelf: Implications for provenance … SS Acharya, R Chakrabarti Chemical Geology 509, 134-151 , 2019 2019 Citations: 12
Large Stable Ca Isotopic (δ⁴⁴/⁴⁰Ca) Variation in Open Ocean Samples from the Bay of Bengal R Chakrabarti, SS Acharya, S Mondal Twenty-eighth Annual Goldschmidt Conference, 359 , 2018 2018
Submarine groundwater discharge derived strontium from the Bengal Basin traced in Bay of Bengal water samples R Chakrabarti, S Mondal, SS Acharya, JS Lekha, D Sengupta Scientific reports 8 (1), 4383 , 2018 2018 Citations: 51
Large Stable Ca Isotopic (δ44/40Ca) Variation in Open Ocean Samples from the Bay of Bengal R Chakrabarti, SS Acharya, &, S Mondal Goldschmidt Annual Conference , 2018 2018 Citations: 4
Strontium Isotopic Evidence for Submarine Groundwater Discharge (SGD) in Bay of Bengal Water R CHAKRABARTI, S MONDAL, SS ACHARYA, J SREELEKHA, ... Goldschmidt Annual Conference , 2017 2017
Evaluation of factors controlling the distribution of organic matter and phosphorus in the Eastern Arabian Shelf: A geostatistical reappraisal SS Acharya, MK Panigrahi Continental Shelf Research 126, 79-88 , 2016 2016 Citations: 8
Eastward shift and maintenance of Arabian Sea oxygen minimum zone: Understanding the paradox SS Acharya, MK Panigrahi Deep Sea Research Part I: Oceanographic Research Papers 115, 240-252 , 2016 2016 Citations: 79
Speciation of phosphorus in the continental shelf sediments in the Eastern Arabian Sea SS Acharya, MK Panigrahi, J Kurian, AK Gupta, S Tripathy Continental Shelf Research 115, 65-75 , 2016 2016 Citations: 33
Oxygen Minimum Zone Vis-À-Vis distribution of carbon and phosphorus in the eastern Arabian Shelf: A geochemical reappraisal SS Acharya IIT, Kharagpur , 2016 2016 Citations: 2
MOST CITED SCHOLAR PUBLICATIONS
Eastward shift and maintenance of Arabian Sea oxygen minimum zone: Understanding the paradox SS Acharya, MK Panigrahi Deep Sea Research Part I: Oceanographic Research Papers 115, 240-252 , 2016 2016 Citations: 79
Submarine groundwater discharge derived strontium from the Bengal Basin traced in Bay of Bengal water samples R Chakrabarti, S Mondal, SS Acharya, JS Lekha, D Sengupta Scientific reports 8 (1), 4383 , 2018 2018 Citations: 51
Response of trace metal redox proxies in continental shelf environment: The Eastern Arabian Sea scenario SS Acharya, MK Panigrahi, AK Gupta, S Tripathy Continental Shelf Research 106, 70-84 , 2015 2015 Citations: 46
Speciation of phosphorus in the continental shelf sediments in the Eastern Arabian Sea SS Acharya, MK Panigrahi, J Kurian, AK Gupta, S Tripathy Continental Shelf Research 115, 65-75 , 2016 2016 Citations: 33
Variations in trace metal concentrations and Sr, Nd isotopic compositions in sediments from two contrasting settings in the Eastern Arabian Shelf: Implications for provenance … SS Acharya, R Chakrabarti Chemical Geology 509, 134-151 , 2019 2019 Citations: 12
Mobilization of rare earth elements during extreme weathering of basalt S Roy, SS Acharya, R Chakrabarti Geochemistry 84 (1), 126086 , 2024 2024 Citations: 11
Evaluation of factors controlling the distribution of organic matter and phosphorus in the Eastern Arabian Shelf: A geostatistical reappraisal SS Acharya, MK Panigrahi Continental Shelf Research 126, 79-88 , 2016 2016 Citations: 8
Natural sources and anthropogenic influences on the river water and groundwater chemistry of the Lower Mahanadi Basin: Insights from radiogenic Sr isotopes and major ion chemistry SS Acharya, V Hishamunda, R Chakrabarti Frontiers in Water, 38 , 2022 2022 Citations: 6
Large Stable Ca Isotopic (δ44/40Ca) Variation in Open Ocean Samples from the Bay of Bengal R Chakrabarti, SS Acharya, &, S Mondal Goldschmidt Annual Conference , 2018 2018 Citations: 4
Geochemical insights into the 5.4 ka event in the eastern Arabian Shelf SS Acharya, P Dey Journal of Earth System Science 133 (2), 106 , 2024 2024 Citations: 3
Oxygen Minimum Zone Vis-À-Vis distribution of carbon and phosphorus in the eastern Arabian Shelf: A geochemical reappraisal SS Acharya IIT, Kharagpur , 2016 2016 Citations: 2
Multiproxy evidence for natrojarosite–natroalunite solid solutions in western Kutch: Jarosite formation, preservation, and Martian implications S Guha, SS Acharya, MK Panigrahi Journal of Geophysical Research: Planets 131 (5), e2025JE009601 , 2026 2026
Multiproxy Evidence for Natrojarosite-Natroalunite Solid Solutions in Western Kutch: Jarosite Formation, Preservation, and Martian Implications S Guha, SS Acharya, MK Panigrahi Authorea Preprints , 2025 2025
Deciphering the mechanisms of Jarosite Formation and Preservation in Western Kutch, India: A Multiproxy Approach with Martian Insights S Guha, SS Acharya AGU25 , 2025 2025
Weathering Trends Unveil K-Metasomatism in Bundelkhand Granitoids: Resolving the Pink–Grey Granitoid Paradox SS Acharya, A Sain, P Behera, A Basak, GK Deb EarthArXiv , 2025 2025
Chemical Weathering Pathways of Basalt: Mineral Transformation and Element Mobility L Biswal, SS Acharya AGU Fall Meeting Abstracts 2024, EP01-44 , 2024 2024
Formation and preservation mechanisms of jarosite on the earth’s surface: A coupled theoretical and experimental approach S Guha, SS Acharya ACS Spring 2023 , 2023 2023
Evaluation of the efficacy of water-rock interaction in granitic & basaltic terrains in the present and past climate change episodes as a potential negative feedback on … A Basu, SS Acharya ACS SPRING 2023 , 2023 2023
Stable Strontium Isotopic Variability in River Water and Groundwater Samples from the Mahanadi River Basin, India-Implications for Carbonate Precipitation and Clay Formation S Ganguly, SS Acharya, R Chakrabarti AGU Fall Meeting Abstracts 2022, EP45C-1672 , 2022 2022
Large Stable Ca Isotopic (δ⁴⁴/⁴⁰Ca) Variation in Open Ocean Samples from the Bay of Bengal R Chakrabarti, SS Acharya, S Mondal Twenty-eighth Annual Goldschmidt Conference, 359 , 2018 2018
