Continental Geodynamics and Earth's Environment: Introduction

The evolution of continents and supercontinents has been one of the fundamental processes in Earth's 4.6 billion year history, which has significant effects in moulding the present-day Earth and its global geodynamics. These processes are driven by tectonic, magmatic, metamorphic, and surface interactions, which have profoundly influenced and shaped the Earth's surface environment over time. To understand these dynamic processes shaping continents is crucial for reconstructing Earth's past and predicting future environmental changes. This special issue focuses on these relationships, highlighting research that provides a comprehensive understanding of Earth's dynamic geological history and its impact on environmental changes. The special issue is composed of 16 papers that are classified into four different groups such as (i) Geophysical studies on continental lithosphere, (ii) Petrological and geochemical studies on continental and oceanic crust, (iii) Geochronological studies and (iv) Present and past environmental studies. The special issue starts with the contribution from Ba et al. (2025) on the mantle dynamics beneath the Shandong Peninsula. They analysed 9073 P-to-S receiver functions from 129 broadband seismic stations. The study reveals a depression in the 410 km discontinuity and a significant 50 km westward depression of the 660 km discontinuity, suggesting the presence of a low velocity anomaly and the stagnation of the cold Pacific slab at the base of the Mantle Transition Zone (MTZ). These findings provide new insights into the complex tectonic processes including slab dehydration and the sinking of the flat lying subducting Pacific slab. Zhu et al. (2025) investigated the high-velocity layer in the lower crust of the Pearl River Mouth Basin (PRMB) in the South China Sea, using seismic reflection profiles and global gravity anomaly data. The gravity modelling results show variations in crustal thickness ranging from 12 to 23 km and highlights crustal thinning due to extensional processes. The findings suggest that the high-velocity layer (HVL) is formed by high-temperature mantle upwelling and intense magmatic activity during the early Mesozoic. Zhang et al. (2025) studied the cyclostratigraphy of the coal-bearing Eocene Pinghu Formation in the Xihu Sag using natural gamma-ray logging data from four boreholes. The analysis revealed that sedimentation lasted between 4.31 and 5.94 Myr, with an average rate of 13.47–18.57 cm/kyr, and identified four regional sea-level cycles in the formation. The study also highlighted the influence of astronomical and non-astronomical factors such as regional tectonism and facies changes on the distribution and thickness of coal seams. Baidya et al. (2025) focused on utilising rare earth element fractionation in volcanic rocks using Ce-Yb and Th-Nb-Yb proxies with a geochemical modelling approach to understand petrogenetic processes and the potential tectonic settings. This study utilised a large database of available geochemical data sets for Phanerozoic volcanic rocks and an existing magma chamber simulator tool, as well as binary mixing models, to infer the extents of assimilation and fractional crystallisation in Phanerozoic volcanic rocks from diverse tectonic settings. This approach is applied to volcanic rocks from greenstone belts of the Dharwar and Yilgarn cratons to infer their tectonic settings and finally suggest that subduction–accretion played a significant role in the crustal evolution during the Meso- and Neoarchean. Ahmad et al. (2025) applied Raman Spectroscopy of Carbonaceous Materials (RSCM) to study the thermal evolution of low- to medium-grade metasedimentary rocks from the Western Himalaya, Pakistan. The results show a clear correlation between Raman spectra and peak metamorphic temperatures, ranging from 300°C to 600°C across the region with increasing metamorphism from south to north following a progressive path of metamorphism. Satish-Kumar et al. (2025) examined metacarbonate layers from the Sør Rondane Mountains in East Antarctica to constrain thermal events using carbon isotope exchange between dolomite/calcite and graphite. The results show peak metamorphic temperatures reached up to 802°C at Balchenfjella locality, with some samples suggesting ultrahigh-temperature conditions, while isotopic variations in graphite revealed retrograde metamorphism and fluid infiltration. The findings provide robust constraints on peak and post-peak metamorphic temperatures, highlighting the robustness of carbon isotope thermometry in deciphering thermal histories in polymetamorphic terrains. Sreehari et al. (2025) investigated the metamorphic evolution of Chitradurga Schist Belt (CSB) in Western Dharwar Craton, southern India, to understand tectono-metamorphic history, by integrating Raman Spectra of Carbonaceous Material (RSCM) thermometry with mineral chemistry and deformation analyses. This study identified a distinct metamorphic gradient, with the Bababudan Group reaching amphibolite facies (> 500°C) and other units recording greenschist facies (< 450°C). Also, this study linked higher-grade metamorphism to early collisional events and lower-grade hydration to later hinterland-thrust belt processes and highlighted the influence of plate tectonics on regional-scale metamorphism and deformation in the Meso-Neoarchean Dharwar Craton. Dharmapriya et al. (2025) carried out a detailed investigation on the geochemical, petrological, and U–Pb zircon geochronology of granulite facies rocks in the boundary between the Highland Complex and Wanni Complex in Sri Lanka, which is an important region in constraining the geodynamic history of Gondwana supercontinent. Tectonic discrimination diagrams revealed a distinctive geodynamic history indicating a subduction-related collisional tectonic setting. Suzuki et al. (2025) conducted U–Pb detrital zircon dating on lower Palaeozoic metamorphic complexes and Silurian-Devonian strata of the South Kitakami belt, northeast Japan to reconstruct the early Palaeozoic palaeogeography of proto-Japan along the northeastern Gondwanan margin. The age distributions correspond to a Pacific Gondwana signature and suggest tectonic associations of Proto-Japan magmatic arcs with regions in eastern Australia, Antarctica, and northeast Asia during the Ordovician-early Silurian. Hui et al. (2025) investigated the Huodiya Group in the Hannan-Micangshan Massif on the northwestern margin of the Yangtze Block in South China based on zircon U–Pb dating. The detrital zircon ages suggested that the Huodiya Group was deposited prior to 950–900 Ma in a passive continental margin setting, with the major age populations consistent with tectonothermal events within the Yangtze Block. Qi et al. (2025) conducted petrologic and detrital zircon U–Pb geochronologic analyses on the Erlangping Group in the Tianshui Area, North China to determine depositional age and provenance. This study indicates that the Erlangping Group was deposited during the Early Palaeozoic, providing insights into the evolution of the Erlangping back-arc basin. He et al. (2025) investigated the tectonic events of the North Qilian Accretionary Belt focusing on granitoids from the Changma region in the western segment. Zircon U–Pb dating reveals emplacement ages of 436 Ma for the Qingshixia pluton and 425 Ma for the Heixialao pluton with contrasting Hf isotopic compositions suggesting different sources. These findings suggest that the western segment of the North Qilian Ocean closed during the Late Silurian contributing to the diachronic closure of the Proto-Tethys Ocean. Xiong et al. (2025) carried out a detailed study on the sedimentary petrological, paleocurrent analyses and detrital zircon studies to reveal the Late Triassic to Jurassic tectonic evolution of the northern Sichuan foreland basin, South China Craton. Based on the paleocurrent orientations and age distribution, the authors elegantly conclude that the sediments in the Qinling Orogenic Belt were sourced from northern South China Craton and the depositional basin was affected by two tectonic events of extreme shortening with a tectonic quiescence in between. Sharma et al. (2025) studied the Central Indian Tectonic Zone (CITZ) focusing on its evolution and the pre-suture plate margin history. The CITZ records significant events from two supercontinents, Columbia and Rodinia, spanning the Paleoproterozoic to Neoproterozoic, giving insights into the tectonic processes that shaped the Indian subcontinent. Saha (2025) examined the sedimentological characteristics of the Meso- to Neoproterozoic Rautgara Formation in NW India, focusing on fluvial–marine transitions before the appearance of vascular vegetation. The study identified six facies associations using sedimentological analysis. The study concludes that the Proterozoic Rautgara Formation in the NW Himalaya was deposited in a transgressive nearshore environment under mixed wave and tidal energy conditions. The findings suggest that sandy barrier systems were common in the Proterozoic and that vegetation and thick mud flats were not essential for the stability of a barrier-beach system. Chen et al. (2025) studied the Taixinan canyon-channel system (TCCS) in the northeastern South China Sea, focusing on its geomorphological features and formation mechanisms. Using multi-beam bathymetry data, this study identified that the TCCS consists of several submarine canyons and channels located between active and passive continental margins. This work proposes a three-stage evolutionary model, where the canyons initially formed due to tectonic activity developed through sediment transportation and weak erosion and evolved further under intense turbidity current erosion. The present stage TCCS is formed by continuous canyon migration and sediment wave formation, reflecting its dynamic evolution. All authors contributed to the editing of the special issue. This special issue resulted from the International Association for Gondwana Research (IAGR) 2023 Convention and the 20th International Conference on ‘Gondwana to Asia’ organised at Niigata University, Japan, and we indebted to Prof. M. Santosh for his insightful suggestions at various stages. We are grateful to the Geological Journal (John Wiley & Sons Inc.) for providing the opportunity to assemble this special issue. We thank Prof. Ian Somerville and Prof. Yunpeng Dong, Editors-in-Chief of Geological Journal, for overseeing the Editorial process. The guest editors are thankful to the authors for their contributions and patience during the review process. We thank the dedicated reviewers for their comments that helped in improving the contributions. The data that support the findings of this study are available from the corresponding author upon reasonable request.