Baodi Wang

To improve the geological constraints on regional screening for alkali-metasomatic uranium deposits, we analysed high-resolution airborne gamma-ray spectrometric data from the Xinshuijing–Yushigou area of the Longshoushan metallogenic belt, integrating ground gamma-ray spectrometry, geological zoning, fault structures, and drill-hole geological sections from the Xinshuijing and Jiling deposits. We assessed the lithological dependence of K, equivalent uranium (eU), equivalent thorium (eTh), and total count (TC), and developed a multi-parameter interpretation framework comprising the expected uranium background (Gu), relative uranium deviation (Hu), U–K relative enhancement index (F), and normalized relative uranium deviation (B). The regional radioelement distribution is primarily controlled by granitic intrusions and parts of the pre-Sinian metamorphic basement. However, the spatial extent of several local anomalies does not fully coincide with lithological boundaries, indicating variations in radioelement proportions superimposed on the lithological background. Drill-hole sections from Xinshuijing and Jiling show that known ore bodies and mineralized zones occur within granitic–dioritic rock associations and structurally controlled alteration zones. Their surface-projection neighbourhoods are characterized by a combination of high radioactive backgrounds, locally negative Hu values, enhanced F values, and adjacent positive relative uranium deviations. This correspondence improves the geological interpretability of the multi-parameter anomalies, although it represents retrospective validation using known deposits. Yushigou exhibits a similar parameter assemblage near the contact between a granitic intrusion and a NW-trending fault and is therefore identified as a candidate exploration target requiring independent field verification. These results demonstrate that decomposing absolute radiometric responses into lithological background, relative uranium deviation, and K–U–Th ratio variations helps identify local radioelement decoupling within regionally elevated radioactive backgrounds, providing complementary near-surface evidence for regional screening of concealed uranium mineralization in complex bedrock terrains.

The Jiaduoling area is located in the northern segment of the Southwest Sanjiang Metallogenic Belt, a region characterized by complex geological structures and abundant mineral resources. This study systematically identifies the spatial correlation between subsurface magnetic bodies and tectonic structures by utilizing 1:50,000 high-precision aeromagnetic data. Advanced processing techniques—including upward continuation, vertical derivatives, total gradient modulus, and Euler deconvolution—were integrated to refine the structural framework and clarify the mechanisms of fault-controlled mineralization. The results indicate that the aeromagnetic anomaly pattern is predominantly governed by NW-trending faults. Specifically, the deep-seated major fault F₁ (with a calculated depth exceeding 3 km) served as the primary migration channel for ore-forming fluids, while secondary faults created localized ore-hosting spaces. Physical property analysis reveals a significant magnetic contrast, where Mesozoic intermediate-acid magmatic rocks act as the essential source for mineralization, providing both material and thermal energy for the formation of porphyrite-type iron deposits. Based on these findings, a three-dimensional “aeromagnetic anomaly-structural framework-mineralization” correlation model was established. Finally, two high-potential metallogenic prospective zones (P1 and P2) were delineated, providing precise geophysical evidence and strategic guidance for regional mineral exploration and the targeting of concealed ore bodies.

The Jiaduoling area is located in the northern segment of the Southwest Sanjiang Metallogenic Belt, a region characterized by complex geological structures and abundant mineral resources. This study systematically identifies the spatial correlation between subsurface magnetic bodies and tectonic structures by utilizing 1:50,000 high-precision aeromagnetic data. Advanced processing techniques—including upward continuation, vertical derivatives, total gradient modulus, and Euler deconvolution—were integrated to refine the structural framework and clarify the mechanisms of fault-controlled mineralization.The results indicate that the aeromagnetic anomaly pattern is predominantly governed by NW-trending faults. Specifically, the deep-seated major fault F1 (with a calculated depth exceeding 3 km) served as the primary migration channel for ore-forming fluids, while secondary faults created localized ore-hosting spaces. Physical property analysis reveals a significant magnetic contrast, where Mesozoic intermediate-acid magmatic rocks act as the essential source for mineralization, providing both material and thermal energy for the formation of porphyrite-type iron deposits.Based on these findings, a three-dimensional "aeromagnetic anomaly-structural framework-mineralization" correlation model was established. Finally, two high-potential metallogenic prospective zones (P1 and P2) were delineated, providing precise geophysical evidence and strategic guidance for regional mineral exploration and the targeting of concealed ore bodies.

冈底斯成矿带西段(谢通门县以西)近年来相继发现了尼雄、帮布勒、隆格尔等一批中-大型矿床(点), 显示出了良好的找矿前景。昌龙Fe-Sn多金属矿床是该带2025年新发现的矿床, 矿床地质特征研究薄弱, 制约了对该区成矿规律的认识。本文以昌龙矿床为研究对象, 综合运用矿床地质特征研究、岩矿鉴定及矿物微区(电子探针、LA-ICP-MS锆石U-Pb测年)分析等手段, 查明其成矿时代、矿物组合、成矿阶段与成因类型, 构建成矿模式。结果表明, 昌龙矿床石英斑岩形成于66.5±0.3Ma, 属于晚白垩世, 可能与成矿作用有关, 为羌塘-拉萨地体碰撞后伸展作用条件下岩浆侵入活动的结果。整体上, 矽卡岩属镁质矽卡岩建造, 石榴子石属钙铁-钙铝榴石系列, 辉石以透辉石为主, 闪石主要为透闪石、阳起石、镁角闪石。区域对比研究显示, 该矿床与帮布勒矿床地质特征相似, 昌龙矿床镁质矽卡岩带可能为矽卡岩成矿系统的根部, 而其顶部锰质矽卡岩部分可能已被剥蚀。昌龙矿床成矿环境经历了高氧逸度、低酸度→中氧逸度、中酸度→高氧逸度、高酸度→低氧逸度、低酸度的转变。Zk05钻孔深部发育强烈的绿泥石化与黄铜矿化, 指示晚期岩浆热液叠加于早期矽卡岩成矿系统之上。结合成矿岩体、成矿构造以及成矿作用特征, 建立了昌龙矿床的成矿模式。结合航磁异常特征及外围矿产地质调查成果, 本文进一步认为: 应在矿区东北部追索硅钙界面的发育与延伸情况, 以预测铅锌矿体的赋存部位; 钻孔资料显示, 矿区深部具备寻找岩浆热液型铜矿的潜力; 此外, 矿区西南部大面积发育的矽卡岩化与磁铁矿化, 亦显示出良好的外围找矿前景。

The evolution of continents is shaped by the growth and destruction of long-lived cratons, which serve as their stable cores. Processes for craton destruction are controversial because most invoked mechanisms occur frequently throughout Earth history, making the preservation of cratons for billions of years problematic. Here, we address this issue by presenting a crustal-scale analytical signal-amplitude model obtained from high-resolution airborne and shipborne magnetic data across cratons within East Asia. Magmatic, magnetic, and basin-history constraints show that the eastern North China craton experienced focused weakening, thickening, and catastrophic destruction of its mantle lithosphere due to a unique combination of circum-craton subduction and subsequent collision since the Paleozoic. By contrast, the adjacent South China craton was not impacted in this way, and thus, its mantle root was spared from destruction. The long-term survival of cratons may stem from the infrequent occurrence of sustained circum-cratonic subduction or collisional processes capable of destabilizing their lithospheric roots.

High-purity quartz is considered one of the world’s scarce mineral resources. During the evaluation process of high-purity quartz raw material deposits, metallurgical purification evaluation experiments are often required to assess the quality of quartz. However, these experiments are costly and time-consuming, and have other drawbacks. In addition, high-purity quartz is difficult to analyze by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) due to its extremely low impurity content, resulting in low accuracy. It is therefore essential to assess the validity of the results obtained from LA-ICP-MS analysis of quartz minerals and to establish an efficient and cost-effective method for the evaluation of high-purity quartz deposits. We selected samples from the high-purity quartz deposits at Yamansu and Taerlang in Xinjiang, which exhibit uniform cathodoluminescence (CL) characteristics. We conducted trace element analysis of quartz using four methods: nanosecond laser dot ablation, femtosecond laser dot ablation, femtosecond laser line ablation, and femtosecond laser area scanning. Combined with the results of metallurgical purification, the stability of quartz LA-ICP-MS analytical data and the proximity to the purification results are evaluated by using two methods, i.e., the comparison of casting diagrams and the construction of comprehensive stability and proximity evaluation models. The results show that the femtosecond laser line ablation has the best stability in the analysis of the elements of quartz Al, Ti, Li, and B and the highest proximity to the results of metallurgical purification, and the nanosecond laser dot ablation also has better stability and proximity, while femtosecond laser surface scanning data quality is relatively poor due to unavoidable inclusions and co-associated minerals. Geological mapping using in situ quartz trace element content can effectively delineate the potential areas of high-purity quartz, and the results of analysis and the metallurgical purification results have a high degree of proximity. Therefore, this paper recommends the use of femtosecond laser line ablation as a highly efficient exploration method for high-purity quartz deposits.

The factors that control strain partitioning along plate boundaries and within continental interiors remains poorly resolved. Plate convergence may be accommodated via distributed crustal shortening or discrete crustal‐scale strike‐slip faulting, but what controls these differing modes of deformation is debated. Here we address this question by examining the actively deforming regions that surround the Tarim Basin in central Asia, where deformation is uniquely partitioned into predominately strike‐slip faults in the east and distributed fold‐thrust belts in the west to accommodate Cenozoic India‐Asia plate convergence. We present integrated geological and geophysical observations to elucidate patterns in crustal deformation and compositional structure in and around the Tarim Basin. The thrust‐dominated western Tarim Basin correlates with a strongly‐magnetic lower crust, whereas strike‐slip faulting along the eastern margins of the Tarim Basin lack such magnetic signals. We suggest that the lower crust of the western Tarim is more mafic and stronger than in the east, which impacts intra‐plate strain partitioning. A stronger lower crust results in vertical decoupling to drive mid‐crust horizontal detachments and facilitate thrust faulting, whereas a more homogenized crust favored vertical transcrustal strike‐slip faulting. These rheological differences likely originated from the impingement of the Permian Tarim plume focused in the west. A comparison with the Longmen Shan of eastern Tibetan Plateau reveals remarkably similar strain partitioning that correlates with variations in foreland rheology. Our results highlight how variations in lower‐crust viscosity impact strain partitioning in an intra‐plate setting and how plume processes exert a strong control on later continental tectonic processes.

Accretionary complex study provides important knowledge on the subduction and the geodynamic processes of the oceanic plate, which represents the ancient ocean basin extinction location. Nevertheless, there exist many disputes on the age, material source, and tectonic attribute of the Lancang group, located in Southwest Yunnan, China. In this paper, the LA-ICP-MS detrital zircon U-Pb chronology of nine metamorphic rocks in the Lancang group was carried out. The U-Pb ages of the three detrital zircons mainly range from 590–550 Ma, 980–910 Ma, and 1150–1490 Ma, with the youngest detrital zircons having a peak age of about 560 Ma. The U-Pb ages of the six detrital zircons mainly range from 440–460 Ma and 980–910 Ma, and the youngest detrital zircon has a peak age of about 445 Ma. In the Lancang group, metamorphic acidic volcanic rock, basic volcanic rocks, intermediate-acid intrusive rocks, and high-pressure metamorphic rocks are exposed in the form of tectonic lens in schist, rendering typical melange structural characteristics of “block + matrix”. Considering regional deformation and chronology, material composition characteristics, and the previous data, this study thinks the Lancang group may be an early Paleozoic tectonic accretionary complex formed by the eastward subduction of the Changning-Menglian Proto-Tethys Ocean, which provides an important constraint for the Tethys evolution.