Carbon capture and its storage is widely recognized as one of the primary approaches for reducing anthropogenic carbon emissions. The role of geophysical investigation is then for the selection of a suitable site for the geological storage of CO₂ and the monitoring of the injection and storage process. The monitoring of the dynamic process can both detect leakage and minimize leakage potentials. To achieve this goal, this paper suggested the use of transient electromagnetic 3D finite-difference method to help realize the geospatial quantification of in-situ CO₂. First, the horizontal model and the deep saline aquifer inclined were developed to analyze the low resistivity response which is the characteristic of typical aquifers. Second, the geoelectrical modeling which demonstrates the changes at the time of the CO₂ injection, can be used to examine the temporal variations in subsurface resistivity. Thus, the impact to the volumetric changes due to the CO₂ injection can be quantified. The significance of the results of this study confirmed the potential of the development of efficient dynamic monitoring and boundary delineation strategies for CO₂ geological storage. Finally, a geoelectrical model for leakage has been established to investigate the likely changes in the resistivity of the subsurface strata because of CO₂ leakage, which is reflected in the transient electromagnetic response patterns along with the leakage paths. This contributes to the monitoring of CO₂ leakage in real time as well as detecting the location of leakage. This paper provided the theorical support of the transient electromagnetic method which has the potential to capture the dynamic diffusion process of CO₂ storage in a deep saline aquifer. Furthermore, it could be used to an efficient monitor of CO₂ leakage and identify the leakage paths.

Studies on post-collisional magmatic rocks can provide key clues to researching the crust–mantle interactions and the tectonic evolution of collisional orogenic belts. This study investigated a suite of newly discovered mafic intrusions in the middle of the East Kunlun orogenic belt through integrated analysis of petrology, petrography, and zircon U–Pb dating. The data could offer new insights into the generation of the Proto-Tethyan tectonic evolution. The result shows that these mafic intrusions are mainly gabbro and diabase, formed in the Early Devonian, with zircon U–Pb ages of 408.9 ± 2.0 Ma for gabbro and 411.1 ± 3.1 Ma for diabase. It consists of plagioclase, pyroxene, and dark minerals, and a small number of calcite and chlorite. Diabase has a small amount of amygdale. Their Na₂O + K₂O contents range from 3.47 wt.% to 5.45 wt.%, with Na₂O/K₂O ratios from 1.39 to 3.09, suggesting that they are calc–alkaline rocks. These rocks have an Fe₂O₃ᵀ content of 7.68 wt.%–11.59 wt.% and Mg^# of 50.58–59.48, belonging to the iron-rich and magnesium-poor type. The chondrite-normalized rare earth elements show similar patterns that are characterized by enrichment of light rare earth elements, with (La/Yb)_N of 3.27–6.75 and no significant europium anomaly, indicating the rocks are homogenous. The studied rocks are characterized by low contents of compatible elements Cr and Ni, enrichment of large-ion lithophile elements such as Rb, U, Sr, and Nd, and high-field-strength elements such as Nb, Ta, Zr, Hf, and Th. The mafic magma originated from the partial melting of the enriched mantle and was assimilated and mixed with crust materials during the process of migration. Based on the regional tectonic evolution, we interpret that the Proto-Tethys Ocean had closed in the Early Devonian, and that the East Kunlun region was in a post-collisional extensional tectonic setting.

The ophiolites in the Beishan Orogenic Belt provide important information about the evolution of the Beishan Ocean in the Paleozoic Era. We studied ophiolite petrology, geochemistry and isotopic chronology. The Shazouquan ophiolites consist of dunites, wehrlites, gabbros and anorthosites. Ophiolitic mélange belts are composed of matrixes and blocks, and different rocks are fault-bounded. Dunites and wehrlites are high in Mg^#, Cr^# and MgO, low in TiO₂, relatively depleted in large-ion lithophile elements (Ti and P) and enriched in high-strength elements (U, Zr and Hf). They have a total REE of 1.25 × 10^–6−5.39 × 10⁻⁶ and δEu of 1.12–3.54, which are similar to those of SSZ-type ophiolites, indicating that their parent magma source region may be a weakly depleted mantle source region. The anorthosite and gabbro are high in Al₂O₃, MgO and Mg^#, low in TiO₂, enriched in large-ion lithophile elements (Rb and Sr), and depleted in high-strength elements (Nb, Ta and Ti), but enriched in Zr and Hf. They have similar geochemical signatures to those of arc magmatic rocks. They are derived from the mantle peridotite formed against the tectonic background of subduction and modified by the fluid materials in the subduction zone. We collected anorthosite and gabbro, which were produced as ophiolite for U-Pb dating. The anorthosite yields a zircon U-Pb, aged 394 ± 11 Ma (MSWD = 0.84), and a gabbro zircon U-Pb, aged 466 ± 12 Ma (MSWD = 3.2), indicating that the Shazouquan ophiolite was formed in the Middle Ordovician–Early Devonian eras. Combining the above evidence, we conclude that the Beishan Ocean was in a subduction tectonic background from the Middle Ordovician to Early Devonian periods.

We conducted a study on the petrology, geochemistry, and zircon U–Pb dating of Late Devonian intrusive rocks in the Tulargen area of the Eastern Tianshan Orogenic Belt, Xinjiang, China. These intrusive rocks primarily consist of gabbro (382 ± 5 Ma), tonalite (370.9 ± 2.7 Ma), and biotite monzogranite (362.8 ± 4.4 Ma). Gabbro belongs to the low-K calc-alkaline series of quasi-aluminous rocks, with a high Al₂O₃ content (16.46–20.34 wt.%) and Mg^# value (64.55–67.73). Tonalite and biotite monzogranite, which belong to the high-K calc-alkaline series, are metaluminous or weakly peraluminous and also exhibit high Al₂O₃ contents (14.6–15.87 wt.%) and Mg^# values (40.12–62.47). These rocks are enriched in light rare-earth and large-ion lithophile elements (Rb, Ba, and K) and depleted in heavy rare-earth and high-field-strength elements (e.g., Ta, Nb, and Ti), characteristics typical of island-arc magmatic rocks. Gabbro melts are primarily derived from the mantle and result from the partial melting of a depleted mantle that has undergone fluid metasomatism due to subducted plates. Tonalite exhibits high ¹⁷⁶Hf/¹⁷⁷Hf and _εHf(t) values, with a younger two-stage model age (t_DM2) derived from partial juvenile crust melting. The source magma of the biotite monzogranite originated from partial metabasalt melting at a medium crustal depth combined with a new lower crustal material. We concluded that the Late Devonian intrusive rocks in this area formed within the island-arc tectonic setting are associated with the subduction of the North Tianshan Ocean.

The Xiangshan Uranium Deposit located in Jiangxi Province represents the largest volcanic-hosted uranium deposit in Asia and serves as a critical uranium production base in China. Clay alteration serves as a key prospecting indicator for this deposit, and its quantitative characterization through high-resolution spectroscopy is crucial for elucidating the relationship between hydrothermal activity and uranium mineralization. Addressing the current shortcoming in hyperspectral alteration mapping—which primarily focuses on qualitative mineral identification while lacking systematic quantitative characterization of diagnostic absorption trough parameters—this study utilized ZY1-02E (Chinese Resource Satellite-1-02E) satellite hyperspectral imagery as the data source. Following preprocessing, key parameters of the diagnostic absorption trough at 2205 nm for clay-altered minerals—including depth, area, and symmetry—were quantitatively extracted to construct a spectral index reflecting the intensity of clay alteration. Subsequently, the spatial distribution characteristics of these parameters were systematically analyzed. It was found that, with the line connecting Yankeng, Youjiashan, Xiangshan, and Yunji serving as a boundary, clay alteration generally exhibits a distribution trend of being stronger in the northwest and weaker in the southeast, with morphological features characterized by a combination of strip-like, ring-shaped, and nodular patterns. Based on these findings, nine prospective exploration areas were delineated, including five Class-I and four Class-II prospective exploration areas. High-value anomalies in the absorption trough parameters show good spatial correlation with known uranium deposits and fault structures, effectively indicating the centers of hydrothermal alteration and fluid migration pathways. This study advances the remote sensing identification of clay alteration from qualitative mapping to the quantitative analysis stage, providing a scientific basis for further exploration in the Xiangshan mineralized area. The established method is highly applicable to similar volcanic-type uranium mineralized areas.