Events----INSTITUTE OF GEOLOGY AND GEOPHYSICS, CHINESE ACADEMY OF SCIENCES

Project Name: Chang'e-6 Samples Reveal the Evolutionary History of the Lunar Far Side

Introduction:
The Chang'e-6 mission successfully achieved the world's first-sampling of the lunar far side, with the landing site located within a basaltic unit of the South Pole-Aitken (SPA) Basin. The returned samples provide invaluable materials for investigating the timing and consequences of the SPA Basin-forming impact, the origin of lunar hemispheric dichotomy, and space weathering processes to the lunar far side.

To address these fundamental scientific questions, the research team conducted comprehensive investigations of the physical and chemical properties of the returned lunar regolith, complemented by detailed petrological, geochemical, and geochronological analyses of rock fragments. These efforts yielded a series of landmark findings that, for the first time, systematically elucidates the evolutionary history of the lunar far side: (1) A new type of lunar rock, termed SPA norite, was identified, and the age of the SPA basin-forming impact was constrained to approximately 4.25 billion years; (2) The mantle beneath the SPA Basin was revealed to be ultra-dry, ultra-depleted, and ultra-reduced; (3) Evidence for a rebound of the lunar magnetic field at approximately 2.8 billion years ago was discovered; (4) Basaltic glass in the lunar soil was identified as a potential major reservoir of water on the lunar surface, with latitude (temperature) and soil maturity exerting significant controls on water content; (5) The Chang'e-6 lunar soil exhibits weak magnetic field strength and high viscosity, likely reflecting the region’s distinctive impact history and space weathering processes.

Following publication, these findings attracted widespread international attention and acclaim. Professor Ben Weiss, a member of the U.S. National Academy of Sciences, commented that the results "significantly advance our understanding of the Moon's evolutionary history." Professor Mahesh Anand of The Open University noted that the work "challenges several long-held hypotheses and theories in lunar science," while Professor Stephen Elardo of the University of New Mexico, writing in Nature, emphasized that the study "provides key clues to lunar dichotomy and the effects of giant impacts."
Project Name: The Role of Heterogeneity in Controlling Plate Subduction Behavior

Introduction:
Plate subduction transports surface materials into the deep mantle, and its dynamic behavior governs material recycling, mass fluxes, and the formation of geochemical reservoirs. Despite its fundamental importance, seismic tomography reveals substantial variability in subduction geometries worldwide, and the key factors controlling slab behavior remain an unresolved frontier in Earth sciences.

The research team selected representative tectonic settings encompassing both oceanic and continental subduction to systematically investigate how lithospheric heterogeneity governs slab dynamics.

(1) In the Lesser Antilles region of Central America, the team identified the thickest mantle transition zone reported to date, with an increase in thickness of nearly 100 km. Thermodynamic calculations and seismic wave simulations suggest that this anomaly results from magma infiltration into slow-spreading ridge mantle lithosphere. The resulting compositional and density heterogeneity ultimately controls slab stagnation within the mantle transition zone.

(2) In the deep region of the Bangong–Nujiang Suture Zone, an arcuate Moho structure was imaged and interpreted as a remnant slab of the Bangong–Nujiang Ocean. Beneath the South China continental crust, inclined low-velocity anomalies and uplifted high-velocity domains were detected, indicating lithospheric modification associated with paleo-Pacific plate subduction. Together, these observations demonstrate how density heterogeneity related to oceanic plateaus influences subduction angles and slab fate.

(3) By reconstructing the geometry of the subducting Indian continental slab using shear-wave splitting analyses and integrating crustal structural data, the study reveals how intrinsic slab heterogeneity governs slab tearing and differential subduction behavior.

These findings received extensive coverage from major scientific media outlets in China and abroad, including ScienceDaily, SciTechDaily, and Voice of the Chinese Academy of Sciences. An anonymous reviewer for Nature remarked: “The invocation of slab enrichment in basaltic fraction, rather than the accumulation of delaminated oceanic crust, appears original and compelling.”
Project Name: Mechanisms of Sustained Supershear Rupture in Wide Fault Zones

Introduction:
During earthquake rupture, a portion of the released energy is dissipated within a damage surrounding the main fault plane, characterized by distributed inelastic deformation and a pronounced reduction in shear-wave velocity. Supershear rupture is typically associated with geometrically simple faults or so-called “high-speed channels,” where energy loss to the surrounding medium is minimized, allowing rupture to accelerate beyond shear-wave velocity and propagate over long-distances. However, the role of internal fault-zone structure—particularly low-velocity and damage zones—in initiating and sustaining long-distance supershear rupture remains poorly understood.

To investigate the physical mechanisms underlying supershear earthquake rupture and its relationship with fault damage zones, Professor Shengji Wei’s research team conducted an integrated study combining seismology and multi-source image geodesy. Using high-resolution seismic deformation measurements, kinematic rupture inversion, and receiver-function imaging, the team constructed a high-precision three-dimensional surface deformation field for the 2025 Myanmar earthquake. They quantified the width of the co-seismic damage zone, constrained rupture velocity and dynamic rupture processes, and characterized seismic velocity reductions and fault-zone geometry. The results reveal that the earthquake produced an approximately 480 km-long surface rupture along the Sagaing Fault zone—the longest intracontinental rupture ever documented. Average slip reached 3.7 meters and was distributed within a co-seismic damage zone averaging about 100 meters in width. The rupture accelerated to supershear velocity (~5.3 km/s) about 100 km south of the epicenter and maintained this speed for more than 200 km. The seismogenic fault zone itself exhibits a damage width of ~2 km and a seismic velocity reduction of ~45%, representing the widest damage zone observed to date. The fault’s straight geometry, unconsolidated materials, and low seismic velocities facilitated the concentration of seismic energy within a “high-speed channel,” enable sustained long-distance supershear rupture.

The observed transition distance from sub-shear to supershear rupture and the persistence of supershear propagation closely match predictions from dynamic rupture modeling, providing robust constraints on the physical mechanisms governing large earthquakes. This study highlights the coupled influence of fault geometry, damage zone thickness, and rupture dynamics, demonstrating that long-term fault evolution plays a critical role in controlling rupture behavior. These findings offer new constraints for earthquake cycle simulations and have important implications for seismic hazard assessment and disaster mitigation strategies.
Project Name: Source-Sink Mechanisms of Carbon Cycling in Plate Convergent Zones and Their Implications for Habitability

Introduction:
Deep degassing (carbon sources) and surface weathering (carbon sinks) constitute the first-order processes of the global carbon cycle, jointly regulating Earth’s long-term carbon budget, climate evolution, and the distribution of energy and mineral sources. Accurate characterization of the carbon cycle therefore requires a comprehensive understanding of the mechanisms, efficiencies, and controlling factors governing carbon release and sequestration. Focusing on plate convergent zones, this study integrates petrology, geochemistry, spectroscopy, and numerical modeling to achieve significant advances in the understanding of both deep and surface carbon cycling.

(1) This research quantitatively elucidates the mechanisms and efficiencies of carbon release during deep geological processes. It demonstrates that deep carbon occurs not only as CO₂ but also in reduced and organic forms, including CH₄, highly disordered carbon, and oxalic acid. For the first time, it was shown that Fe²⁺-bearing saline fluids in the deep crust and mantle can react with carbonates to reduce H₂O to H₂, followed by Fischer-Tropsch-type reactions that lead to the synthesis of organic matter.

(2) The study further reveals that acid generation resulting from sulfide oxidation in orogenic belts can strongly enhance carbonate weathering and promote CO₂ release, offsetting approximately 58% of the CO₂ consumption associated with silicate weathering. These findings suggest that the previously proposed amplification of the surface weathering carbon sink driven by tectonic uplift may have been substantially overestimated, providing new mechanistic constraints for refining tectonic-climate coupling models.

Collectively, these results systematically clarify the key source-sink mechanisms operating within Earth’s carbon cycle and provide critical constraints for global carbon flux estimates, climate modeling, and studies of planetary habitability. In parallel, this work offers new perspectives for frontier research areas, including deep hydrogen (“gold hydrogen”) resources and the origin of life in extreme environments. The findings have been published in leading journals such as PNAS, Nature Communications, Geology, and JGR, and have received extensive media coverage. Several prominent international scholars have authored a “Research Highlight” article on this work, and the research team was invited to contribute a review paper to the 40^th-anniversary special issue of Acta Petrologica Sinica.
Project Name: Cobalt Super-Enrichment: Controls of Magmatism, Weathering, Sedimentation, and Orogenesis

Introduction:
The mechanism of cobalt super-enrichment represents a major frontier in ore deposit research. This study systematically delineates the progressive enrichment pathways of cobalt through magmatic, weathering, sedimentary, and orogenic processes and elucidates the metallogenic mechanisms responsible for the formation of high-grade cobalt deposits.

The study proposes that lateral migration of the Tarim mantle plume induced high-degree partial melting, forming a key source region for the initial enrichment of magmatic cobalt. Injection of mafic magma into arc magmatic systems was identified as a critical process in porphyry-type cobalt mineralization. Continental exposure acted as a “switch” that intensified weathering, while continental weathering itself functioned as a “high-speed channel” transporting cobalt into the ocean. Intense oxidative weathering subsequently promoted oceanic sulfidation, leading to effective pre-enrichment of cobalt in sedimentary basins. During late orogenic events, hydrothermal fluids efficiently extracted cobalt from these sedimentary sequences, further upgrading it to form high-grade cobalt ores.

Aberration-corrected transmission electron microscopy provided atomic-scale evidence that the key mechanism underlying this extraction is fluid-induced solid-state diffusion. Vacancy defects in pyrites were shown to markedly accelerate cobalt migration, increasing diffusion efficiency by more than two orders of magnitude and enabling efficient cobalt liberation from source strata. This work reveals the complete metallogenic chain of cobalt mineralization, encompassing initial enrichment in magmatic source regions, pre‑enrichment in sedimentary strata, and super‑enrichment during orogenesis.

Research on large-scale continental exposure and weathering was selected as the cover article of the current issue of Geology. In a related commentary, the originator of the dissolution-reprecipitation theory noted that the team’s work published in Nature Communications resolved the long-standing challenge of explaining rapid solid-state diffusion in sulfide minerals.
Project Name: Theory and Key Technologies for Intelligent Site Selection of CO₂ Geological Storage in Saline Aquifers

Introduction:
CO₂ geological storage in saline aquifers is widely regarded as a critical “safeguard” technology for achieving carbon neutrality in the fossil energy sector, and scientifically robust site selection is a prerequisite for its successful implementation. Owing to the complex geological conditions of China, the selection of suitable storage sites presents significant scientific and technical challenges. Addressing these challenges, the research team focused on the key theoretical and technological issues associated with site selection for CO₂ geological storage in saline aquifers.

In 2025, the team published 13 SCI-indexed papers (including 2 in Nature Index top-tier journals and 6 in flagship journals of IGG), was granted 8 invention patents (5 in China and 3 in the United States), registered 4 software copyrights, and issued 1 industry standard. Major innovations include methods for evaluating the sealing capacity of geological formations, elucidating rock mass responses to dynamic disturbances under carbon storage conditions, and developing intelligent optimization technologies for site selection.

(1) A novel approach combining microbial and pneumatic response models was developed to identify inter-well and inter-layer hydraulic connectivity. When integrated with indicators such as groundwater age, this method enables comprehensive evaluation of the sealing performance of the sealing performance of saline aquifers.

(2) A suite of multiphase and multi-field coupled geomechanical testing techniques for carbon storage reservoirs was established. The results reveal that displacement rate and amplitude significantly enhance the degradation of structural surface morphology with cumulative displacement, leading to the development of a strength evolution model for rock masses under strong stress perturbations.

(3) A machine learning-based workflow for CO₂ storage site selection was proposed, and the associated indicator system was optimized. A rapid assessment technology for evaluating geological suitability was developed and successfully applied in China’s first deep saline aquifer CO₂ geological storage project. The Guidelines for Site Selection of Onshore CO₂ Geological Storage Projects, authored by the team and published by China Standard Press, have promoted the standardization and practical application of these research outcomes. As a key innovation, this work contributed to the project receiving the First Prize for Scientific and Technological Progress awarded by the Ministry of Natural Resources.
Project Name: Simulation of Earth’s Multi-Sphere Environmental Evolution and Resource Effects

Introduction:
Within the framework of the “multi-sphere driven theory of oil and gas formation and enrichment,” this research establishes an integrated data-modeling technology system to simulate Earth’s environmental evolution and associated resource effects. Carbon-based volatiles, such as methane and carbon dioxide, are used as key tracers to model their cycling across the sediment-ocean-atmosphere-hydrate multi-sphere system. This approach addresses two fundamental central to Earth system science and resource geology: “where did the carbon originate?” and “what role did the carbon play” during major geological events.

To address the question of carbon origin, the research team developed an innovative multi‑reservoir coupled box model of the carbon cycle, integrated with Bayesian inversion techniques. By constraining carbon cycle simulations with geochemical data, the model quantitatively reconstructs the magnitudes, fluxes, and temporal evolution of carbon sources. This approach substantially improves the ability to quantitatively characterize deep‑time warming events and episodic methane release.

To investigate the question of carbon function, the team adapted the Community Earth System Model (CESM) to study the formation and evolution of key hydrocarbon source rocks. Through scenario-based CO₂ simulations, the combined effects of volatile-driven climate change on terrestrial source rock development and ecosystem succession were disentangled. This work elucidates the coupled mechanisms linking volatile cycling, climate evolution, resource enrichment, and biotic responses, thereby providing technical support for climate risk assessment as well as for the evaluation and prediction of oil and gas resources.
Project Name: Fluxgate Magnetometer for Low-Earth-Orbit Geomagnetic Satellites

Introduction:
Macau Science Satellite-1 is the world’s first satellite dedicated to monitoring low-latitude geomagnetic fields and the space environment, and it currently achieves the highest geomagnetic field measurement precision among Chinese satellites. The mission provides high-accuracy geomagnetic vector data, particularly for the east-west gradient of Earth’s magnetic field, filling critical gaps in international geomagnetic satellite observations. Successfully launched on May 21, 2023, Macau Science Satellite-1 is designed to perform high-precision magnetic measurements over the near-equatorial South Atlantic Anomaly region, with the objective of investigating the origin and evolution of Earth’s geomagnetic field.

The fluxgate magnetometer (FGM) developed by the research team is one of the satellite’s core payloads. To address the challenges associated with geomagnetic vector measurement in low-Earth orbit, the team achieved key breakthroughs in triaxial concentric fluxgate probe technology and fully digital closed-loop feedback circuitry. These advances enabled the development of a spaceborne magnetometer with high-precision, high-linearity, and low-noise. In addition, major challenges related to high-precision in-orbit calibration and geomagnetic field inversion for low-inclination satellites were successfully resolved, significantly enhancing the accuracy of vector magnetic field measurements.

To date, the instrument has continuously acquired approximately 2.5 years of geomagnetic vector observation data. Operating under long-term powered conditions without ground intervention, the magnetometer has demonstrated stable performance, with all collected data verified as valid and reliable. Comparative evaluations against DanishVector Field Magnetometer (VFM) data and international geomagnetic field models indicate that the data products by this domestically developed instrument achieve accuracy comparable to that of advanced international geomagnetic satellite missions. These high-quality datasets provide critical support for studies of planetary and terrestrial dynamo processes, core-mantle coupling, and geomagnetic field reversal mechanisms. Furthermore, the technological advances established by this work lay a solid foundation for future field-aligned current measurements to be conducted by Macau Science Satellite-2.