A high-resolution stalagmite delta 18O record from Mawsmai Cave (MAW), spanning from-11,807 to 5622 calibrated years before present (cal yr BP), sheds light on the dynamics of the Indian Summer Monsoon (ISM). In the early Holocene (- 11,807-7700 cal yr BP) the decreased delta 18O values suggest a period of intensified ISM, whereas in the middle Holocene (- 7700-5622 cal yr BP) the positive delta 18O values demonstrate a weak ISM. Petrographic and mineralogical analyses suggest a correspondence between changes in stalagmite fabric and delta 18O variability, implying a climatic control on stalagmite growth. The MAW record also depicts several multi-centennial scale ISM shifts that coincide with the Bond events 8, 7, 6, 5b, 5a, and 4, suggesting teleconnections between North Atlantic climate and ISM variability via changes in the Atlantic Meridional Overturning Circulation (AMOC). Spectral and continuous wavelet transform analyses of the MAW record reveal periodicities of-118 and-110 years, consistent with the centennial-scale Gleissberg solar cycles. These cyclicities indicate that solar variability in conjunction with coupled ocean-atmosphere dynamics, including the Pacific Decadal Oscillation (PDO) and the temperature gradient between the Tibetan Plateau and the Indian Ocean, played a dominant role in modulating ISM variability during the early to middle Holocene.

ABSTRACT Reliable absolute chronologies for the Early Iron Age in Vidarbha, eastern Maharashtra, have long remained constrained by dependence on ceramic typology, relative stratigraphy and unmodelled radiocarbon determinations derived from bulk charcoal. This study presents eight new AMS radiocarbon determinations from Pachkhed, a stratified multi‐period habitation site in Yavatmal District, obtained from stratigraphically secure Early Iron Age (Period IA) contexts, including a charred rice grain recovered in situ from a compact lime floor. All eight determinations were calibrated using the IntCal20 Northern Hemisphere calibration curve and analysed within a formal Bayesian phase model implemented in OxCal v4.4.4. The model employs a general outlier model specification with a Student's t ‐distribution, uniform scale prior and material‐type‐differentiated individual outlier priors to formally incorporate prior knowledge about inbuilt age susceptibility. The primary model constrains the onset of Early Iron Age occupation to 825–775 cal bce and its termination to 794–745 cal bce (95.4% probability), with overall model agreement indices of A model = 170.2 and A overall = 176.9. The formal duration of the phase, calculated using the OxCal Span command, is estimated at 0–51 years (95.4% probability). A sensitivity model excluding a probable outlier determination produces virtually identical boundary estimates (811–772 cal bce start; 791–746 cal bce end), confirming the robustness of these results. The Pachkhed sequence provides the first formally modelled, short‐lived‐material‐based AMS chronology for an Early Iron Age habitation site in Vidarbha and serves as a methodological and empirical reference for radiocarbon‐based chronology building in the region.

This study presents a continuous and well-dated environmental magnetic record of South Asian Monsoon variability since the Last Glacial Maximum (similar to 25 ka BP) from sediments of Bakhira Lake, the largest natural floodplain wetland in the Central Ganga Plain, India. The chronology is constrained by seven AMS radiocarbon dates, providing the temporal framework for interpreting millennial-scale hydroclimatic variability during the Late Quaternary. The magnetic mineral assemblage, dominated by detrital magnetite and hematite, shows negligible post-depositional alteration, confirming its primary catchment origin. The variations in magnetic concentration-dependent (chi lf, chi ARM, SIRM) and mineralogical (S-ratio, HIRM, L-ratio) parameters reveal alternating phases of weakened and strengthened ISM intensity that correspond closely with global climatic transitions. Low chi lf, chi ARM and S-ratio values during similar to 25.3-18.1 ka indicate a weakened monsoon and enhanced physical weathering under cold-dry Last Glacial Maximum conditions. A subsequent strengthening of ISM during similar to 18.1-16.8 ka and similar to 15.3-12.8 ka reflects the B & oslash;lling-Aller & oslash;d warm phase, while reductions during Heinrich 1 (similar to 16.8-15.3 ka) and the Younger Dryas (similar to 12.8-11.1 ka) signify cooler and drier episodes. Enhanced chi fd% and fine-grained magnetite during similar to 9.2-4 ka suggest intensified pedogenesis and stronger precipitation associated with the Holocene Climatic Optimum (HCO), followed by monsoon weakening between similar to 4-2 ka and renewed strengthening after 2 ka. Additionally, the comparison with regional terrestrial and marine records demonstrates coherent South Asian Monsoon variability driven by precession-scale insolation forcing and modulated by high-latitude climatic perturbations through AMOC-driven shifts in the ITCZ and associated monsoon circulation.

The Plio-Pleistocene lacustrine sequences of Kashmir Valley, NW Himalaya, represent one of the important terrestrial paleoenvironmental archives in the Indian subcontinent. However, their paleoenvironmental potential has not been studied in detail and thus represents an untapped reservoir of past climate changes. In this study, we integrated multi-proxy data, including phytolith assemblages, phytolith-based climatic indices (Iw, Ic, Ia), and major oxide geochemical data augmented with the previously existing magnetostratigraphy, to understand the depositional environment and the climatic conditions of the Pliocene Period, particularly the Piacenzian , from the basement sequences known as the Dubjan Member of Lower Karewa, Kashmir Valley, India. Phytolith assemblages indicate grass-dominated vegetation with mixed C3 and C4 grasses, reflecting shifts between warm and cool climatic conditions. This is augmented by Chemical Index of Alteration values (∼62-78), implying moderate chemical weathering, closely linked to climate and vegetation changes. Sedimentological evidence also suggests deposition in a fluvio-lacustrine system with alternating low- and high-energy conditions. Climatic indices reveal alternating warm–cool and humid–dry phases, with a clear signal of the MPWP (∼3.3–3.0 Ma) followed by increasing aridity associated with Northern Hemisphere glaciation, as reported elsewhere. The lacustrine sequences of the Lower Karewa thus provide a robust terrestrial record of climate–vegetation–weathering interactions during a critical phase of Plio-Pleistocene climatic transition.

The Antarctic Circumpolar Current (ACC) flows through the Drake Passage (DP), influencing global oceanic circulation and climate. However, there is a notable gap in understanding ecological responses to variability in ACC strength and to terrigenous flux driven by the melting of the Patagonian Ice Sheet (PIS). Hence, this research aims to assess the palaeoecological changes at the DP over the last 200 ka. The palaeoecological changes are reconstructed using planktic and benthic foraminifera abundance at International Ocean Discovery Programme Site U1544. Before that the age model was constrained using sortable silt plus fine sand size fraction (SSFS; 10–125 µm), along with a couple of 14C ages and a diatom biomarker ( Hemidiscus karstenii ) and compared with published-dated SSFS data from the DP and LR04 benthic stacks. Neogloboquadrina pachyderma was the dominant species during Marine Isotope Stage (MIS) 6 and 4, and bottom water was relatively oxic during MIS 6, as indicated by a higher abundance of Cibicides spp. The deglaciation is marked by a higher abundance of Turborotalita quinqueloba , suggesting reduced salinity due to the melting of PIS. The bottom water was suboxic during deglaciation, as indicated by peaks in Melonis spp. and Fursenkoina spp. The interglacial MIS 5 and 3 have enhanced primary productivity and marked the higher abundance of planktic foraminifera Globigerina spp. along with other warm water species and benthic foraminifera, Uvigerina spp. This study suggests that ACC and PIS melting control ecological variability at DP.

The collision between the Indian and Eurasian plates led to the development of foreland-propagating fold-and-thrust belts. The Main Frontal Thrust (MFT) is considered the youngest. However, geologists have also identified faults younger than the MFT in the foreland of the western Himalaya, which they named Piedmont faults. In this study, a similar fault is proposed in the foreland of the Darjeeling-Sikkim Himalaya, known as the Baradighi fault. Nakata (1972) first reported the scarp associated with the Baradighi fault, but little research has been conducted to understand its evolution. Sediment dating was performed using Optically Stimulated Luminescence (OSL) and 14C Accelerator Mass Spectrometry (AMS) methods. Results show that the activity on the Baradighi fault began around 30 ka and is still active. The region has traditionally been known as the ‘Siwalik Gap’ due to the absence of the Siwaliks, but this work reports the presence of the Siwaliks in the area. Geomorphic indices were used to assess the relative tectonic activity. The Asymmetry Factor indicated that most river basins are tilted westward. Basin elongation ratios suggest that not only E-W faults influence drainage, but also some active N-S aligned lineaments affect the fluvial system in the region. However, the hypsometric curve (HC) and index (HI) suggest that the area is not tectonically active, as most rivers originate in the unconsolidated Quaternary sediments, which are easily eroded. Consequently, deformation features caused by active tectonics have either been eroded or buried beneath river-deposited sediments.

The Bay of Bengal (BoB) is a low-saline tropical marine basin significantly influenced by the seasonal reversal of wind patterns, which bring the South-West monsoon (SWM) and North-East monsoon (NEM), as well as a huge discharge of freshwater and sediments to the BoB. Owing to these, the globally thickest of sediments accumulated in the BoB, particularly the northern and to some extent western parts of this basin, which are ideal for high-resolution paleoclimate and oceanographic proxies measured in the sediment cores. Despite several attempts at paleoclimate and paleocenography reconstruction, the region remains underexplored due to a limited high-resolution study. In this study, we present multidecadal to centennial resolution data on planktic foraminifera, magnetic proxies and spectral analysis measured on core SK 336/GC-2, retrieved from the western side of the oxygen minimum zone (OMZ) off Visakhapatnam. Along with the key climatic episodes, paleoenvironmental, and solar activity data over the past 5000 years BP, proxies indicate that the SWM generally weakens during the Atlantic cold events. However, the strengthening of the SWM was particularly highest during (similar to 4.4 ka, similar to 3.2-1.5 ka, similar to 900-650 years and after 200 years BP) associated with wet and humid phases by magnetic parameters. The LIA presents an intriguing contrast, despite low summer insolation, high sedimentation reflects increased winter precipitation and a southward shift of the Intertropical Convergence Zone (ITCZ), likely triggered by volcanic forcing. The spectral analysis of planktic foraminiferal species indicates that high-frequency cycles of groups are noticed around 273, 91, 68, and 4.0-2.2 years, which represent the climate forcing de Varies (Suess) cycle, the Gleissberg solar cycle, Atlantic Multidecadal Oscillation (AMO), and ENSO, respectively. The periodicities of both planktic species and mineral magnetic parameter data range between similar to 11-15 years and similar to 16-27 years correspond to the short solar cycles Schwabe cycle and the Hale Cycle. These findings underscore the significance of marginal BoB sediments as sensitive archives for unravelling monsoon variability and tropical climate evolution.

The Great Mica Belt of Jharkhand, India, is an intensively disturbed mining region due to long-term mica extraction, which increases anthropogenic pressures on environmental components. Despite the environmental fragility of this region, systematic baseline information on rainwater chemistry and trace metal deposition has been lacking, particularly in comparison to other mining-impacted regions where such studies are more extensively documented. Addressing this gap is crucial for understanding atmospheric deposition processes in mining-dominated landscapes of eastern India. Unlike previous studies that predominantly focus on coal-mining, urban, or industrial regions, this study specifically investigates a mica-mining dominated environment, which has distinct mineralogical composition and emission characteristics influencing rainwater chemistry. This study aims to evaluate the chemical composition and trace metal concentrations of monsoonal rainwater collected at Koderma and Tisri within the Great Mica Belt. A total of 60 rain water samples were analyzed for physicochemical parameters (pH, EC, TDS), major and minor ions (i.e., Ca2⁺, Mg2⁺, Na⁺, K⁺, Cl⁻, HCO₃⁻, SO₄2⁻, NO₃⁻, NH₄⁺ and F⁻), and metals. Source contributions were evaluated using enrichment factor (EF), non-sea-salt fraction (nssf), and neutralization factor analyses. Rainwater pH ranged from 5.38 to 7.26, indicating acidic to alkaline conditions, with 9

The Central Ganga Plain (CGP)—the middle sector of the Indo-Gangetic foreland basin—is a primary area of interest due to its thick and continuous Quaternary alluvial sediments. Its active tectonic setting, with rapid subsidence and structural segmentation, results in a continuous sedimentary record that provides clear evidence of past variability in monsoon and environmental changes. This article presents the reconstruction of the late Quaternary hydroclimatic variability during the last glacial maximum (LGM), post-LGM and the 4.2 ka events using multi-proxy analysis. During post-glacial climatic amelioration, a pronounced paleoenvironmental transition, with a sharp increase in total organic carbon (TOC) (3.97%), TC (6.29%) and C/S ratio (~300) around ~20 ka BP, reflecting enhanced organic productivity and freshwater deposition, is recorded. Mineral magnetism data reveal a significant increase in the concentration-dependent parameters (χlf (105.4 ×10 −8 m 3 kg −1 ); saturation isothermal remanent magnetisation (971 ×10 −5 Am 2 kg −1 ), ꭓARM (414 ×10 −5 Am 2 kg −1 )), recording a strong detrital input and monsoon weakening linked to regional aridification. The results align well with contemporaneous lake and fluvial records from the CGP.

Understanding the long-term variability of the Indian Summer Monsoon (ISM) and its impact on continental surface processes is critical for reconstructing Late Quaternary climate dynamics in South Asia. Here, we present a high-resolution multiproxy record from a lacustrine sediment recorded from Bakhira Lake, Central Ganga Plain (CGP), India. A chronology constrained by AMS radiocarbon (C-14) dates indicates continuous sedimentation spanning the last similar to 25.3 ka. Grain-size distributions, clay mineral assemblages, and bulk sediment geochemistry (major, trace, and rare earth elements) were integrated to reconstruct hydroclimatic variability and chemical weathering intensity. Provenance indicators, including REE patterns and immobile trace-element ratios (e.g., Th/Sc and La/Th), indicate that the sediments were predominantly derived from felsic lithologies of the Higher Himalayan Crystalline (HHC) sequence. The sediments are dominated by silt-sized particles and exhibit systematic shifts between fine- and coarse-grained end members, reflecting changes in energy conditions and fluvial input. Clay mineralogical variations in illite, smectite, chlorite, and kaolinite contents, together with smectite/(illite + chlorite) ratios and illite crystallinity, record alternations between dominant physical erosion and enhanced chemical weathering in the sediment source regions. These trends are supported by geochemical weathering indices (Chemical Index of Alteration (CIA) and alpha Na-Al) and trace-element ratios (Rb/Sr and Th/U). The integrated proxy record identifies four phases of strengthened ISM conditions (similar to 18-16.8 ka, similar to 14.5-12.8 ka, similar to 9.2-4 ka, and similar to 2 ka to present), alternating with four weakened phases (similar to 25.3-18 ka, similar to 16.8-14.5 ka, similar to 12.8-9.2 ka, and similar to 4-2 ka). These phases correspond closely with major regional and hemispheric climatic events, including the Last Glacial Maximum, deglacial oscillations, and Holocene variability. This study establishes a close coupling between ISM variability, chemical weathering intensity and sediment transport processes, driven primarily by orbital-scale insolation forcing and modulated by high-latitude climate perturbations.

The Ganga Basin is a Food Bowl of India, marked by a dynamic landscape which has been shaped by tectonic activity and Indian Summer Monsoon (ISM). To decipher past climatic variability and possible climate-cultural linkages across South Asia, we present a high-resolution Late Holocene record from a paleooxbow lake located near Sahaswan, Uttar Pradesh. The reconstruction is supported by a robust age-depth model using 23 AMS C-14 dates from a 3.30 m deep trench representing an age from similar to 4467 to 525 cal yr BP. This study is based on most comprehensive chronology from the Central Ganga Basin (CGB). Multi-proxy analyses reveal distinct episodes of reduced ISM strength during similar to 4467 to 4000 cal yr BP (4.2 ka event), 3200 to 3000 cal yr BP (3.2 ka event), 1400 to 1000 cal yr BP (Dark Ages Cold Period), and 650 to 525 cal yr BP (Little Ice Age or LIA). Phases of intensified ISM prevailed between 4000 and 3200 cal yr BP, 3000 and 1400 cal yr BP (including the Roman Warm Period, similar to 550 BCE to 350 CE), and from 1000 to 650 cal yr BP (Medieval Climate Anomaly). These hydroclimatic oscillations likely influenced fluvial dynamics and settlement patterns across the CGB, underscoring a strong linkage between climate variability, landscape evolution, and cultural transformations during the Late Holocene. The lake began to decrease in its size and extent since similar to 800 cal yr BP and was completely dried up at the beginning of the LIA (similar to 650 cal yr BP), when the ISM weakened.

This study presents integrated paleoseismic and geodetic studies from the Kaladungi Fault (KF) in the Kumaon-Garhwal Himalaya to constrain the rupture history of major historical earthquakes. A paleoseismic trench excavated at the base of a 15 m high fault scarp at Nandpur revealed geological evidence of four surface-rupturing paleoearthquakes. In total 24 Optically Stimulated Luminescence (OSL) and 24 radiocarbon (14C) ages allowed robust bracketing of these events. Based on offsets of sedimentary units and ages we infer that Event-I took place between BCE 2945-1990 and BCE 1480-862, and Event-II was between BCE 1264-643 and BCE 793-287. These events could not be correlated with any paleo-earthquakes due to broad age brackets and nonavailability of any pre-historic records. Event-III occurred between CE 1242-1408 and CE 1415-1529, while Event-IV (MRE) was between CE 1692-1761 and CE 1689-1822. To constrain and correlate the rupture lengths of Event III and Event IV, we considered historical records and regional paleoseismic data from Nepal, Kumaon-Garhwal to the western Himalaya. The Event-III corresponds to the CE 1505 earthquake and Event-IV (MRE) represents the CE 1803 earthquake. Moreover, the long-term slip-rate for the KF is estimated to be similar to 7.1 mm/yr, which suggests the similar to 40% of the total slip (similar to 17.7 mm/yr, estimated from geodetic) being partitioned on this fault. Paleoseismic evidence for the CE 1803 event indicates surface rupture, as demonstrated by fault displacements and tightly bracketed ages, countering previous claims of a blind rupture. Supporting this interpretation, geodetic modeling and seismicity patterns constrain the downdip locking extent of the Main Himalayan Thrust to similar to 100 km north of the Main Frontal Thrust. The reassessment of rupture dimensions for CE 1803 event aligns with a seismic moment magnitude Mw similar to 8.1-8.2 rupture. With updated strain budget of similar to 3.9 m of elastic strain accumulated since 1803, the region now represents a mature seismic gap with potential for another great earthquake. This study underscores the importance of integrating trench-based paleoseismic chronologies with GPS-constrained crustal deformation models to enhance seismic hazard assessments along the Himalayan front.

The Indian Summer Monsoon (ISM) plays a critical role in regulating hydroclimatic conditions in South Asia, yet its role in the evolution of fluviolacustrine systems remains debatable. To address this gap, we collected and analyzed a 5 m long sediment core from the Hansadanga oxbow lake in the Lower Ganga Plain (LGP) and have produced a high-resolution multiproxy record spanning ∼12,194 cal yr BP. Grain size, geochemical parameters, and environmental magnetic signatures are combined to reconstruct centennial scale hydroclimatic variability. A substantial abrupt drop in sand percent from >49% at 12194 cal yr BP to ∼4% at 11798 cal yr BP, suggests formation of Hansadanga oxbow lake at the transition from the Younger Dryas (YD) to the Holocene. Silt fraction markedly varied across the YD-Holocene transition from 49.69% at ∼12,194 cal yr BP to 87.52% at 11798 cal yr BP. The abrupt transition from fluvial to fluviolacustrine and lacustrine environments during ∼12,194–11,798 cal yr BP was driven by meander cutoff and avulsion of Jalangi river at the onset of ISM intensification in the early Holocene. Our data suggest strong ISM during ∼11,700–8700 cal yr BP, marked by high frequency, abrupt changes marking flood and drought events. The ISM intensity gradually declined in the late Holocene, although lake level remained reasonably high until ∼5000 cal yr BP. A correlation of our data with other land and marine proxy records indicates that majority of the fluviolacustrine landforms in the EGP are dynamically controlled by ISM variability.

Erosion and weathering in the Himalaya are primarily governed by the complex interplay among lithology, rainfall, glaciers, and active tectonics. Erosion rates derived from sediments collected at the outlet of major Himalayan river systems contain disproportionately high sediment contributions from the rapidly eroding geomorphic transition zone between the Lesser and Higher Himalaya, overestimating erosion rates for regions south of the topographic break and obscuring their spatial heterogeneity. In this study, we correlated catchment-averaged erosion rates of first- to third-order tributary catchments of the Alaknanda River, with hillslope erosion rates to evaluate the spatial variability of erosion in small, lithologically uniform catchments with negligible landslide activity in the Lesser Himalaya. The slopes characterized by thick weathering columns exhibit low surface erosion rates (18–60 mm/ka) than the published soil production rates (~60 mm/ka) over 103 to 105 years timescales, thereby sustaining the weathering columns. The catchment-averaged erosion rates are higher than those of regolith-mantled slopes, suggesting a significant sediment contribution from other rapidly eroding slopes to the main channels. Weathering intensity shows an inverse correlation with slope erosion rates, signifying that slopes with low erosion rates lead to longer residence times in the soil, thereby facilitating prolonged interaction with weathering agents and increased chemical alteration. Overall, the study demonstrate 17 to 69 mm/ka catchment averaged erosion rates in lithologically uniform small catchments in the Lesser Himalaya, which are substantially lower than those inferred from the large Himalayan river system (>1000 mm/ka), and exhibit considerable spatial heterogeneity, primarily controlled by hillslopes weathering dynamics and erosion processes. The heterogeneity tends be more pronounced in the lithologically non-uniform and landslide dominated catchments and highlights the need to refine the constraints on the coupled weathering-erosion processes to better resolve the feedback between weathering, erosion, and long-term landscape evolution in the Himalaya.

This study reconstructs the climatic variability of the Kashmir Valley over the past 42 thousand years (ka) using centennial scale multi-proxy analysis of the Karewa palaeolake sediments. Key proxies include mineral magnetic parameters, particle size End Member Analysis (EMA), stable carbon isotopes of organic matter associated with sediments (delta C-13 values), total organic carbon content (TOC), and delta C-13 and delta O-18 value from ostracod shells. Chronological control was established through luminescence and AMS C-14 dating. The results reveal a dynamic interplay between the Westerlies and the Indian Summer Monsoon (ISM), with alternating phases of dominance shaping the palaeoclimate of the region. Thirteen distinct climatic zones (CZ1-CZ13) were identified within the sedimentary profile. Periods dominated by intensified Westerlies occurred during similar to 40.6-38.2 ka, 34-29.4 ka, 28.5-27 ka, 24-16.5 ka, 11.9-10.3 ka, and 9.1-7.1 ka, while enhanced ISM influence was observed during 38.2-34 ka, 29.4-28.5 ka, 27-24 ka, 16.5-11.9 ka, 10.3-9.1 ka, and 7.1-1.4 ka. These climatic shifts correspond well with major global climatic events such as Heinrich Events (H1-H4), the Last Glacial Maximum (LGM), the Younger Dryas (YD), and the Holocene Climate Optimum, with cold phases (Westerlies-dominated) corresponding to Marine Isotope Stage 2 and Heinrich Stadials during MIS 3, and warm phases (ISM-dominated) aligning with Dansgaard-Oeschger interstadials and early Holocene insolation maxima. These patterns reflect the influence of both external solar insolation and internal ocean-atmosphere feedbacks, particularly fluctuations in the Atlantic Meridional Overturning Circulation (AMOC). Notably, enhanced Westerlies coincide with weakened AMOC phases. The palaeovegetation response is evident in delta C-13 values of organic carbon, indicating a consistent dominance of C-3 vegetation throughout colder intervals. Additionally, delta C-13 values from ostracod shells suggest a combination of atmospheric and aquatic CO2 inputs to the lake, while delta O-18 values reflect changes in lake water balance driven by regional temperature, precipitation and evaporation dynamics.

This study from Hulas Khera, in the Central Ganga Plain, reconstructs past climatic conditions and lake-level fluctuations since similar to 6350 calibrated years BP. It integrates sediment textural analysis, mineral magnetism, elemental composition, and AMS radiocarbon dating. Variations in detrital input reflect catchment erosion associated with shifts in rainfall patterns, indicating precipitation as the primary driver of magnetic property changes. The C-M diagram indicates floodplain deposition, driven by suspension settling. Grain-size end-members EM1 and EM2 (mean sizes: 8.9 and 53 mu m) in the fine to coarse silt domain are associated with surface runoff during periods of heightened seasonal precipitation, corresponding to intensified Indian Summer Monsoon activity around 5400 to 4600, 4000, 3300, 2000, and 800 cal yrs. BP. In contrast, EM3 and EM4 (mean sizes: 92 and 160 mu m), within fine sand domain, are prominent during intervals of extended drought and monsoon minima around similar to 6300-5400, similar to 4300, similar to 3600, similar to 2800-2200, similar to 1800-900, and similar to 600-300 cal yrs. BP, coinciding with regional dry phases recorded in the Kanwar Lake record from the Central Ganga Plain, and reduced upwelling record of the Arabian Sea. Abrupt shifts in Indian Summer Monsoon (ISM) strength recorded correspond to known monsoon minima during the Little Ice Age and the Dark Age Cold Period, highlighting the sensitivity of regional hydrodynamics to mid- to late-Holocene monsoonal variability.

This study attempts to reconstruct the glacial history of the Upper Changme Khangpu Basin (CKB), an eastern tributary of the River Tista in the Eastern Himalaya, using radiocarbon ( 14 C) method, supplemented by sedimentological and mineralogical analyzes. Despite being a monsoon-dominated glaciated region, the upper reaches of the basin still contain exceptionally well-preserved glacial landforms of the recent geological past. However, there remains a critical gap in understanding due to the lack of chronological studies to clarify and correlate the roles of climate and glacial interactions in an environment where intense monsoonal precipitation rapidly alters the landscape and glacier dynamics. In order to reconstruct the past glacier fluctuations and associated palaeoclimatic conditions, this study has employed a multi-proxy approach, integrating geomorphic feature mapping, sedimentological analysis, Accelerator Mass Spectrometry (AMS) 14 C dating, alongside the Schmidt Hammer rebound data for relative age determination. The results have yielded a well-defined glacial chronology for the Late Quaternary in the CKB, identifying four distinct glacial advances of varying magnitudes. The extensive glacial phase (Phase-II) resulted in the blockage of the ablation valley, forming a ∼700 m-long proglacial lake. Subsequent glacial recession seems to have intensified the paraglacial processes which progressively reshaped and modified the earlier landforms. A new dataset of 14 C ages (3.5 ka to 31.4 ka cal BP) indicates climatic oscillations during the intervening period. Post-glacial climatic shifts, particularly between 14.29 ka and 3.5 ka cal BP, show a regional correlation with climatic patterns observed in the Eastern Himalayas. Our finding underscores the need to further refine this enquiry to develop a robust glacial chronology of the basin using multiple modern geochronological techniques.

The Central Ganga Plain (CGP), a key sector of the Indo-Gangetic foreland basin, contains thick, continuous Quaternary alluvial sequences. Its rapidly subsiding basins preserve a high-resolution terrestrial archive, ideal for reconstructing Indian Summer Monsoon (ISM). This study examines sedimentary profiles from distinct river systems in the Central Ganga Plain (CGP) using a multi-proxy framework. A Late Quaternary trench from the Gomti river (26°52′ N, 80°56′ E, Lucknow) and a Holocene section from the Betwa river (25°28′ N, 79°5′ E, Hamirpur). Sediment sample from Lucknow profile were analysed for CHNS, AMS ¹⁴C dating, mineral magnetism, and bulk geochemistry (major, trace, and REE), while those from Hamirpur were analysed using OSL and AMS ¹⁴C dating, alongside CHNS. The established chronology or Lucknow trench, record from ~24 to 3 kyr BP. The CHNS data shows a significant shift at ~20 kyr, marked by high TOC (3.97%) and C/S ratio (~ 300) indicating enhanced organic productivity and freshwater conditions. Concurrent mineral magnetic signatures (χlf, SIRM and ꭓARM) suggest strong detrital input linked to weaker monsoon. This evolving climatic condition is further investigated through bulk geochemistry, (major, trace and REE), which provide critical insights into sediment provenance, weathering regimes, and paleo-hydrological conditions. The chronology for the Hamirpur trench covers from ~800-12000 years BP and the CHNS data provide distinct environmental phases, marked by a sharp peak in TC (3.31%), TOC (1.56%) and C/N ratio (~439), indicating a enhanced terrestrial organic matter preservation in a low-energy, waterlogged setting around ~3000 kyr BP. This integrated high-resolution multiproxy record from the two distinct river systems provides new insights into monsoon variability and sedimentary responses in the Central Ganga Plain during the late Quaternary.

The Arabian Sea sediments have the records of significant temporal and spatial variations in response to the neotectonic changes, paleoclimatic and paleo-sea level fluctuations particularly from the Quaternary period. In this study area, environmental mineral magnetic parameters, diffuse reflectance spectroscopy (DRS), XRF (Fe/K, Ti/Al and Ca %) have been studied in an AMS radiocarbon dated core- SK240/473 from the coast off Saurashtra, south-western part of Gujarat State, north-western continental margin of India, to unravel paleoclimatic and paleoceanographic sedimentation and sea level changes over the past 15 ka BP. Currently, the rainfall of this region mainly occurs during the summer monsoon season. Based on results of multi-proxies measured in this core indicate that three major changes in the climate: phase- I before the Holocene thermal maximum (HTM), phaseII during the HTM, and phase- III after the HTM. The phase-I is mainly characterized by abundance of hematite over goethite with high carbonate content, but lower in total organic carbon (TOC) and chemical weathering index (CWI) suggesting arid climate of oxidizing environment of sediment deposition during the rapid sea level rise from 14.5 ka BP to 12.0 ka BP with a standstill sea level from 12 ka BP - 10 ka BP. In contrast, the phase-II marked by a transition from arid to humid condition of sediment deposition characterized by higher CWI, abundant TOC and goethite, but lower in hematite and carbonate concentrations reflecting humid climate of reducing environment of sediment deposition during the Holocene thermal maximum (HTM) from 10.00 ka BP to 5.50 ka BP. Interpretations made here are generally in good agreement with the deglacial to Holocene Sea level fluctuations curve proposed for the west coast of India. In Phase III, the chi lf, chi fd, and Chemical Index of Alteration (CIA) data from sediments deposited after the HTM largely suggest deposition in a humid environment, occasionally interrupted by arid episodes in the study region's hinterland. Such arid events linked to paleo-El Nino episodes recorded in the tropical eastern Pacific Ocean. This interpretation is further supported by the reason explained to the current rainfall variability in the hinterland of the study area. Overall, the data of the core studied reveal significant environmental, sea-level and monsoonal changes in the NE Arabian Sea since the deglacial period. The goethite/hematite (G/H) ratio, chi lf and chi fd profiles which is an indicator of humidity/aridity and coastal upwelling are different from the sea-level curve, suggesting that formers are better indicator of monsoon intensity that often regulated by the ENSO.

The southern Bay of Bengal (BoB) is a pivotal region for paleoceanographic and paleoclimatic research, owing to its intricate interactions among monsoonal dynamics, ocean circulation, sedimentation patterns, and regional hydrology. Being the northern boundary of the tropical Indian Ocean, the area experiences significant freshwater input from major river systems and is modulated by the seasonal monsoonal wind regime. In this study, we present the first high-resolution, multi-proxy reconstruction of surface hydrographic and climatic variations over the past 44 kyr BP in the southern BoB. Our analysis integrates stable isotope records, planktonic foraminiferal assemblage distributions, textural studies and trace elemental data. The stable isotope records, along with the planktonic foraminiferal species abundances, indicate a strengthened Indian Summer Monsoon (ISM) during Marine Isotope Stages (MIS) 1 and 3, whereas a weakened ISM with predominant northeast monsoon influence during MIS 2. Species such as Globigerinoides ruber, Pulleniatina obliquiloculata, and Neogloboquadrina dutertrei exhibit sensitivity to variations in temperature, salinity, and thermocline depth, displaying distinct responses during major climatic events such as the Last Glacial Maximum (LGM), Heinrich Events, and the Younger Dryas. Proxy records reveal rapid deglacial warming coupled with monsoon intensification, while mid-Holocene trends suggest a gradual weakening of the ISM. Cluster and factor analyses effectively differentiate surface, thermocline, and subsurface dwelling foraminiferal species, facilitating comprehensive reconstructions of vertical water column structures. Fluctuations in planktonic/benthic foraminiferal (PF/BF) ratios, along with variations in trace elements such as molybdenum (Mo), vanadium (V), and uranium (U), underscore changes in productivity and bottom-water oxygenation over the last 44 kyr BP in the southern BoB. This comprehensive dataset highlights the intricate interplay between global climatic forces and regional monsoonal variability, which have collectively shaped the paleoceanographic evolution of the southern Bay of Bengal.