GEOCHEMICAL AND Sr–Nd ISOTOPE CLUES TO THE WIDESPREAD SUBAERIAL DISPERSAL OF SANDY DESERT SEDIMENTS INFLUENCED BY SPATIALLY VARIABLE SORTING AND WEATHERING PROCESSES Rohan Bhattacharyya, Satinder Pal Singh, Shivam Sahu, Sudesh Yadav, Jayant K. Tripathi, Anupam Sharma Journal of Sedimentary Research, 2026 Understanding the subaerial dispersal of desert sediments along a downwind aridity gradient is challenging but crucial for promising sustainability in habitable semiarid boundary regions. The Thar Desert of Rajasthan (India) emits copious fine dust towards the Himalayas before the onset of the Indian Summer Monsoon every year. However, the climatic influence (especially of eolian processes and aridity conditions) on the provenance characteristics, downwind dispersal, and postdepositional alteration of sandy sediments across the desert is poorly understood. This knowledge is essential for reliable provenance tracing in arid and semiarid environments. For this purpose, 52 surface sediment samples, spanning the hyperarid southwestern area to the semiarid eastern and northeastern fringes of Rajasthan, have been characterized for geochemical, isotope, mineralogical, and grain-size data. The measured properties reveal a consistent upwind provenance of sandy sediments across the desert, as well as the variable impacts of wind forcing, elevation, and aridity conditions. The Thar sediment signatures from upwind Jaisalmer and Barmer districts can be reliably traced at downwind locations in the Jhunjhunu, Churu, and Jaipur districts. The dune-profile sediments from Jhunjhunu and Rajgarh (Churu), located in the northeastern semiarid fringes, are more weathered chemically and show higher Zr abundances and lower εNd than the other samples. Notably, higher 87Sr/86Sr and quartz enrichment are found in fine sand, especially from the Aravalli highlands. The plausible reason for the grain-size variability of Sr isotopes seems to be K-feldspar or mica preferentially retained in fine sand delivered to highlands under stormy conditions. This study highlights the widespread eolian transport of sandy Thar sediments to downwind locations at distances of ∼ 400–500 km. The widespread Thar sediment dispersal is also accompanied by spatially variable grain size, mineral sorting, and postdepositional chemical weathering under favorable conditions. The modification in geochemical and isotope compositions of widespread desert sediments owing to spatially varying sedimentary processes needs to be accounted for in future provenance studies of downwind eolian sediments.
Geochemical and Radiogenic Sr-Nd Isotope Characterization of Widespread Sandy Surface Sediments in the Great Indian Desert, Thar: Implications for Provenance Studies Rohan Bhattacharyya, Satinder Pal Singh, Abul Qasim, Azad Kashyap Chandrashekhar Journal of Geophysical Research Earth Surface, 2024 Understanding large desert formation/evolution contributing to regional‐to‐global dust cycles remains a challenge. This study presents the geochemical and Sr‐Nd isotope compositions of 51 surface sediment samples collected from the widespread hyper‐arid Thar Desert in northwestern India. The major objective is to determine sediment provenance for a better understanding of the formation/evolution mechanism of this Great Indian Desert as well as downwind dust contributions toward the Himalayas. The compositionally immature sandy Thar sediments (CIA ∼50 ± 4, WIP ∼49 ± 12, and EuN/Eu* ∼0.80 ± 0.13) are recycled materials derived from the Himalayan orogen and later modified by quartz addition and heavy mineral depletion/sorting processes. The 87Sr/86Sr (0.7259 ± 0.0012 and εNd (−12.5 ± 2.7) in the bulk of these Thar sediments are different from the earlier published compositions of the eolian sand deposits in northwestern India. The subcategories of Thar materials collected from different dune types exposed over different lithologies (Quaternary alluvium vs. Tertiary and Mesozoic sedimentary formations) are geochemically and isotopically indistinguishable, which indicates their cogenetic sources and/or sediment reworking. Thar sediments collected in this study have a predominant Indus origin along with significant contributions from the upwind Ghaggar‐Hakra paleochannels. The Indus sediments are most likely wind‐eroded from the shelf region exposed during the low sea stand of LGM and afterward deglaciation. Considering the new and published data sets, the Sr‐Nd isotope budget of dust deposited in the Himalayan frontal glaciers indicates that atmospheric mineral dust contribution from the upwind Indo‐Gangetic Plain proximal to the Himalayas is at par with dust parcels from distant natural deserts.
Characterization of Saharan and Sahelian dust sources based on geochemical and radiogenic isotope signatures D. Guinoiseau, S.P. Singh, S.J.G. Galer, W. Abouchami, R. Bhattacharyya, K. Kandler, C. Bristow, M.O. Andreae Quaternary Science Reviews, 2022 Mineral dust can significantly impact climate and biogeochemical cycles on Earth. To understand dust provenance, an accurate characterization of dust sources and emission regions is required. In this study, we combine rare-earth element patterns, elemental ratios, and radiogenic Sr-Nd-Pb isotopes to discriminate dust sources from key regions in North Africa responsible for ∼55% of the total dust load emitted annually on Earth. This new dataset, based on fifty-nine analyses of deflatable fine soil material, improves our current knowledge about North African dust sources, especially those underrepresented in Saharan-Sahelian regions. Six potential source areas (PSA) – Libya-Algeria-Mali (PSALAM), Libya-Egypt (PSALE), Bodélé Depression (PSABD), Mali Center (PSAMC), West African Coast (PSAWAC) and Mauritania (PSAMa) – are defined based on several lithogenic tracers as well as on the geological subdivision of North African geological provinces, providing a unique chemical and isotope fingerprint for each PSA. For example, the PSABD – the main dust activation area in North Africa – is clearly distinguished from western African sources using Pb isotopes. Major elements show a large variability within each PSA and are not alone diagnostically useful. Comparison of the newly defined PSA with aerosols collected in remote locations over the North Atlantic shows that their sources are predominantly from western African regions (PSALAM and PSAWAC). Bodélé-derived dust has a limited impact on the bulk dust transported over the tropical North Atlantic, regardless of the season and altitude of dust transport. The low impact of the Bodélé Depression can be explained by a high deposition rate (wet and dry) of aerosols along its southwestward trajectory. A detailed analysis of dust collected over South America during winter will be essential to confirm this observation at a global scale. The present dataset can be efficiently used to track modern dust emissions as well as their changes at the scale of glacial/interglacial cycles or during the development of African Humid Periods as stored in sedimentary archives.
Geochemical and Sr–Nd isotope clues to the widespread subaerial dispersal of sandy desert sediments influenced by spatially variable sorting and weathering processes R Bhattacharyyaa, SP Singh, S Sahu, S Yadav, JK Tripathi, A Sharma Journal of Sedimentary Research 96 (3), 437-451 , 2026 2026
Seasonal and inter-estuarine Sr cycling controlled by water mixing and hydrogenous sediments: Low 87Sr/86Sr in groundwater loss via the Gulf of Cambay A Qasim, SP Singh Chemical Geology 703, 1-16 , 2026 2026
Terrane-specific REE composition in the bulk materials of modern soils and aquatic sediments as a reliable provenance tracer in a progressive weathering scenario S Sahu, SP Singh, A Qasim, N Ahmad, R Bhattacharyya Catena 262, 1-16 , 2026 2026 Citations: 1
Plant Biomarkers in Arid Ecosystems: Molecular and Isotopic Insights from the Thar Desert DK Jha, N Miyash, P Gupta, R Rudd, SP Singh, P Roberts European Geophysical Union (EGU) General Assembly, 10135 , 2025 2025
Radiogenic Sr isotope behavior during tropical basalt weathering S Sahu, SP Singh, KB Joshi Goldschmidt, 28852 , 2025 2025
Radiogenic Pb and Nd isotopic variability of fine lithic materials in weathering profiles of Deccan Trap, India S Sahu, SP Singh, KB Joshi European Geophysical Union (EGU) General Assembly, 764 , 2025 2025
Consistent provenance and physicochemical reworking of sandy surface sediments in Rajasthan, India R Bhattacharyyaa, SP Singh, S Yadav Frontiers in Geosciences Research Conference (FGRC), PRL , 2025 2025
Consistent provenance and physicochemical reworking of sandy surface sediments in Rajasthan, India R Bhattacharyyaa, SP Singh, S Yadav Frontiers in Geosciences Research Conference (FGRC), PRL , 2025 2025
Radiogenic Sr-Nd-Pb isotope behavior in different grain-sized fine lithic materials during basalt weathering S Sahu, SP Singh, KB Joshi, Y Kadlag EarthArXiv , 2025 2025
Geochemical and Radiogenic Sr-Nd Isotope Characterization of Widespread Sandy Surface Sediments in the Great Indian Desert, Thar: Implications for Provenance Studies R Bhattacharyya, SP Singh, A Qasim, AK Chandrashekhar Journal of Geophysical Research: Earth Surface 129 (8), 1-22 , 2024 2024 Citations: 5
Isotopic evidence of autochthonous organic matter acting as a major sink of anthropogenic heavy metals in modern lacustrine sediments N Ahmad, SP Singh, S Sahu, R Bhattacharyya, AS Maurya, N Kumar, ... Environmental Pollution 349, 1-11 , 2024 2024 Citations: 15
No REE fractionation in an intensely humid tropical lake catchment developed over Deccan Traps, India S Sahu, SP Singh Goldschmidt, 21862 , 2024 2024
Grain size controls on Sr-Nd isotope composition of sandy Thar surface sediments from northwestern India R Bhattacharyyaa, SP Singh, S Yadav, A Sharma Goldschmidt, 21889 , 2024 2024
Ce anomaly in lithic clays from weathering profiles of Deccan Trap, India S Sahu, SP Singh CITE-2024 (Conference for Integrated Earth), IISER Pune , 2024 2024
Provenance and evolution of sandy Thar sediments, Rajasthan, India R Bhattacharyyaa, SP Singh, S Yadav CITE-2024 (Conference for Integrated Earth), IISER Pune , 2024 2024
Decadal growth of atmospheric heavy metal pollution in Central India: evidence from sediment geochemistry of Upper Lake Bhopal N Ahmad, SP Singh Environmental Earth Sciences 82, 1-13 , 2023 2023 Citations: 3
Radiogenic Sr-Nd isotope characterization of surface sediments and airborne dust from northwestern India R Bhattacharyyaa, SP Singh, S Yadav Goldschmidt, 14582 , 2023 2023
A sedimentary archive of atmospheric heavy metal pollution in Central India N Ahmad, SP Singh Goldschmidt, 14276 , 2023 2023
Geochemical clues to magmatic evolution of the Konkan Basalts, Deccan Trap, India S Sahu, SP Singh, P Nasipuri Frontiers in Geosciences Research Conference (FGRC), PRL , 2023 2023
Anthropogenic impacts on a Ramsar convention-protected freshwater lake in Central India N Ahmad, SP Singh Frontiers in Geosciences Research Conference (FGRC), PRL , 2023 2023
MOST CITED SCHOLAR PUBLICATIONS
Spatial distribution of dissolved neodymium and ε< sub> Nd</sub> in the Bay of Bengal: Role of particulate matter and mixing of water masses SP Singh, SK Singh, V Goswami, R Bhushan, VK Rai Geochimica et Cosmochimica Acta 94, 38-56 , 2012 2012 Citations: 132
Seasonal radiogenic isotopic variability of the African dust outflow to the tropical Atlantic Ocean and across to the Caribbean A Kumar, W Abouchami, SJG Galer, SP Singh, KW Fomba, JM Prospero, ... Earth and Planetary Science Letters 487, 94-105 , 2018 2018 Citations: 58
Characterization of Saharan and Sahelian dust sources based on geochemical and radiogenic isotope signatures D Guinoiseau, SP Singh, SJG Galer, W Abouchami, R Bhattacharyya, ... Quaternary Science Reviews 293, 1-16 , 2022 2022 Citations: 52
Internal cycling of dissolved barium in water column of the Bay of Bengal SP Singh, SK Singh, R Bhushan Marine Chemistry 154, 12-23 , 2013 2013 Citations: 39
Dissolved silicon and its isotopes in the water column of the Bay of Bengal: Internal cycling versus lateral transport SP Singh, SK Singh, R Bhushan, VK Rai Geochimica et Cosmochimica Acta 151, 172-191 , 2015 2015 Citations: 32
Behavior of dissolved redox sensitive elements (U, Mo and Re) in the water column of the Bay of Bengal SP Singh, SK Singh, R Bhushan Marine Chemistry 126, 76-88 , 2011 2011 Citations: 29
Evidence for enhanced chlorophyll-a levels in the Bay of Bengal during early north-east monsoon R Bhushan, S Bikkina, J Chatterjee, SP Singh, V Goswami, LC Thomas, ... Journal of Oceanography and Marine Science 9 (2), 15-23 , 2018 2018 Citations: 22
The late Holocene hydroclimate variability in the Northwest Himalaya: Sedimentary clues from the Wular Lake, Kashmir Valley AM Lone, SP Singh, RA Shah, H Achyuthan, N Ahmad, A Qasim, ... Journal of Asian Earth Sciences 229, 1-10 , 2022 2022 Citations: 21
Isotopic evidence of autochthonous organic matter acting as a major sink of anthropogenic heavy metals in modern lacustrine sediments N Ahmad, SP Singh, S Sahu, R Bhattacharyya, AS Maurya, N Kumar, ... Environmental Pollution 349, 1-11 , 2024 2024 Citations: 15
Dissolved Boron in the Tapi, Narmada and the Mandovi Estuaries, the Western Coast of India: Evidence for Conservative Behavior SP Singh, SK Singh, R Bhushan Estuaries and Coasts 37 (4), 1017-1027 , 2014 2014 Citations: 15
Inter-estuarine and seasonal to decadal variations of heavy metal pollution in the Gulf of Cambay, India A Qasim, SP Singh, N Ahmad, J Argal, AK Chandrashekhar Environmental Monitoring and Assessment 194, 1-22 , 2022 2022 Citations: 11
Geochemical and isotope tracing of groundwater salinity in the coastal Gujarat alluvial plain, India A Qasim, SP Singh, AK Chandrashekhar Journal of Contaminant Hydrology 248, 1-14 , 2022 2022 Citations: 10
Historical variations in autochthonous and allochthonous sediment supplies to the largest freshwater lake in Central India N Ahmad, SP Singh, AM Lone, A Qasim, R Bhushan, GR Tripathy, C Shah International Journal of Sediment Research 37 (5), 563-575 , 2022 2022 Citations: 7
Geochemical and Radiogenic Sr-Nd Isotope Characterization of Widespread Sandy Surface Sediments in the Great Indian Desert, Thar: Implications for Provenance Studies R Bhattacharyya, SP Singh, A Qasim, AK Chandrashekhar Journal of Geophysical Research: Earth Surface 129 (8), 1-22 , 2024 2024 Citations: 5
Decadal variations in oceanic properties of the Arabian Sea water column since GEOSECS R Bhushan, K Dutta, R Agnihotri, R Rengarajan, SP Singh Radiocarbon 56 (1), 313-325 , 2014 2014 Citations: 4
Decadal growth of atmospheric heavy metal pollution in Central India: evidence from sediment geochemistry of Upper Lake Bhopal N Ahmad, SP Singh Environmental Earth Sciences 82, 1-13 , 2023 2023 Citations: 3
Terrane-specific REE composition in the bulk materials of modern soils and aquatic sediments as a reliable provenance tracer in a progressive weathering scenario S Sahu, SP Singh, A Qasim, N Ahmad, R Bhattacharyya Catena 262, 1-16 , 2026 2026 Citations: 1
Geochemical and Sr–Nd isotope clues to the widespread subaerial dispersal of sandy desert sediments influenced by spatially variable sorting and weathering processes R Bhattacharyyaa, SP Singh, S Sahu, S Yadav, JK Tripathi, A Sharma Journal of Sedimentary Research 96 (3), 437-451 , 2026 2026
Seasonal and inter-estuarine Sr cycling controlled by water mixing and hydrogenous sediments: Low 87Sr/86Sr in groundwater loss via the Gulf of Cambay A Qasim, SP Singh Chemical Geology 703, 1-16 , 2026 2026
Plant Biomarkers in Arid Ecosystems: Molecular and Isotopic Insights from the Thar Desert DK Jha, N Miyash, P Gupta, R Rudd, SP Singh, P Roberts European Geophysical Union (EGU) General Assembly, 10135 , 2025 2025
