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SummaryLower crustal high-velocity bodies (LCHBs) are key indicators of deep magmatic addition and lithospheric modification at rifted continental margins. Integrating 3D gravity modeling with regional geophysical and geological constraints, we identify a prominent LCHB beneath the Xihu Sag of the East China Sea (ECS) shelf basin. This body is NNE–SSW elongated, ~5–7 km thick, and spatially coincides with major depocenters and fault systems. We propose a two-stage mafic emplacement model linking its formation to the tectonic transition from fore-arc compression to back-arc extension. During the early–mid Cretaceous, compressional subduction of the Paleo-Pacific Plate facilitated arc-related underplating and accumulation of mafic material in the lower crust. In the early Cenozoic, slab rollback and asthenospheric upwelling during back-arc extension renewed melt supply, further thickening the lower crust. The absence of surface volcanism indicates that magmas were largely trapped and crystallized at depth, forming dense mafic cumulates. Present-day low shallow-mantle temperatures and high densities beneath the Xihu Sag suggest that preservation of these cumulates was sustained not solely by mantle thermal conditions, but also by prolonged subsidence, sedimentary insulation, and inherited compressional structures. These results underscore the need to integrate tectonic, thermal, and structural factors to fully understand deep magmatic processes in marginal basins.

SummaryWe develop a novel comprehensive theoretical framework, the Biot-patchy-spherical-squirt (BIPSSQ) model, for wave propagation in partially saturated dual-porosity media. This model simultaneously incorporates three key fluid flow mechanisms: macroscopic flow (Biot flow or global flow), mesoscopic flow, and microscopic flow (three-dimensional spherical squirt flow). The constitutive relations and fluid pressure expressions for the BIPSSQ model are first derived and then the governing wave equations are established using a Lagrangian approach based on the system’s kinetic energy, potential energy, and dissipation functions. Through plane wave analysis, we obtain the phase velocity and attenuation of the fast P-wave. Numerical examples demonstrate that the BIPSSQ model predicts multiple dispersion transition bands and corresponding attenuation peaks, attributed to two squirt flows and two Biot global flows from two immiscible fluids. Furthermore, the presence of squirt flow significantly suppresses the mesoscopic patchy saturation effect, leading to the disappear of mesoscopic dispersion transition band and attenuation peak. The influences of permeability, saturation, porosity, squirt-flow length and inclusion radius on velocity dispersion and attenuation are also analyzed. Finally, excellent agreement between theoretical predictions and experimental measurements from an Aksu outcrop rock sample (800 kHz), a gas-water-saturated Estaillades limestone (1 kHz), and an oil-brine-saturated Vosgian sandstone (350 kHz), validates the applicability and effectiveness of the BIPSSQ model. Moreover, the BIPSSQ model can degenerate to other theories (i.e. Biot, BISSQ, BR) under certain conditions. Our proposed model provides a unified and robust tool for interpreting wave propagation phenomena in complex, partially saturated reservoir rocks.

Publication date: Available online 12 March 2026

Source: Journal of Atmospheric and Solar-Terrestrial Physics

Author(s): Dr. Vishal Sorathiya, Sanjeev Kumar Mandal, Dr Sandhya Umrao, Dr. Keerti Rai, Pavan Chaudhary, Dr. Sumitra Padmanabhan

Publication date: Available online 12 March 2026

Source: Journal of Atmospheric and Solar-Terrestrial Physics

Author(s): B. Santhoshkumar, N.K. Sathyamoorthy, Ga Dheebakaran, V. Geethalakshmi, K. Boomiraj, N. Manikandan, M. Selva Kumar

Publication date: Available online 12 March 2026

Source: Journal of Atmospheric and Solar-Terrestrial Physics

Author(s): Garima Singh, Sudhir Kumar Singh

Publication date: Available online 11 March 2026

Source: Journal of Atmospheric and Solar-Terrestrial Physics

Author(s): Ananna Bardhan, D.K. Sharma, Gauri Verma

Publication date: April 2026

Source: Journal of Atmospheric and Solar-Terrestrial Physics, Volume 281

Author(s): Kavita, Saurabh Das, Nuncio Murukesh

Publication date: April 2026

Source: Journal of Atmospheric and Solar-Terrestrial Physics, Volume 281

Author(s): Ewen Jaffré, Christophe Bellisario, Philippe Keckhut, Pierre Simoneau, Pierre-Yves Froissart, Alain Hauchecorne

Publication date: April 2026

Source: Journal of Atmospheric and Solar-Terrestrial Physics, Volume 281

Author(s): James M. Weygand, Adnane Osmane

Publication date: April 2026

Source: Journal of Atmospheric and Solar-Terrestrial Physics, Volume 281

Author(s): Wenyuan Xing, Nuo Ma, Pengfei Wu, Honglin Pan, Yong Wang

Publication date: April 2026

Source: Journal of Atmospheric and Solar-Terrestrial Physics, Volume 281

Author(s): Mehmet Ali Çelik, Melahat Batu Ağırkaya, Dessalegn Obsi Gemeda

Publication date: March 2026

Source: Journal of Atmospheric and Solar-Terrestrial Physics, Volume 280

Author(s):

Publication date: April 2026

Source: Journal of Atmospheric and Solar-Terrestrial Physics, Volume 281

Author(s): A. Maghrabi, Abdulah Aldosari, Mohammed Al Mutairi, Mohammed Altlasi, Abdulah Alsherhri

Publication date: April 2026

Source: Journal of Atmospheric and Solar-Terrestrial Physics, Volume 281

Author(s): Nitin Dubey, Swati, Devbrat Pundhir, Dhananjali Singh, Raj Pal Singh

Publication date: March 2026

Source: Journal of Atmospheric and Solar-Terrestrial Physics, Volume 280

Author(s): C.L. Linsha, Hamza Varikoden, K. Nandhulal, R. Vishnu

Publication date: March 2026

Source: Journal of Atmospheric and Solar-Terrestrial Physics, Volume 280

Author(s): Alexander P. Nickolaenko

Publication date: March 2026

Source: Journal of Atmospheric and Solar-Terrestrial Physics, Volume 280

Author(s): Vishnu Rajendra Kumar, Richard L. Collins, Jintai Li, Rahsha Kerven, Jennifer Alspach, Denise Thorsen

Publication date: March 2026

Source: Journal of Atmospheric and Solar-Terrestrial Physics, Volume 280

Author(s): Pedro Da Costa Louro, Philippe Keckhut, Alain Hauchecorne, Robin Wing, Gerd Baumgarten, Michael Gerding, Thierry Leblanc, Bernd Kaifler, Natalie Kaifler, Wolfgang Steinbrecht, Ali Jalali, Robert J. Sica

Publication date: March 2026

Source: Journal of Atmospheric and Solar-Terrestrial Physics, Volume 280

Author(s): E.M. Takla, A. Yoshikawa, T. Uozumi

Publication date: March 2026

Source: Journal of Atmospheric and Solar-Terrestrial Physics, Volume 280

Author(s): Anand Shankar, Bikash Chandra Sahana