Journal of Applied Geophysics最新文献_第8页

Ductile-brittle failure transition of rocks subjected to temperature heating and water cooling in process of drilling with high confining pressure 高围压钻井过程中温度加热和水冷却作用下岩石的韧脆破坏转变

IF 2.1 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Applied Geophysics

Pub Date : 2025-11-24 DOI: 10.1016/j.jappgeo.2025.106037

Jing Wang, Mingming He, Haoteng Wang, Faning Dang

Thermal stress and cooling shock play a critical role in the drilling geothermal exploitation. To enhance drilling efficiency, cooling fluids are typically employed to reduce the temperature of the bit. In this study, digital drilling, compression tests and acoustic emission tests were conducted on rocks subjected to high-temperature heating and water cooling with varying confining pressures. A theoretical model of ductile-brittle failure transition of rock was established considering the friction effect and confining pressure during drilling. The evolution mechanism of drilling parameters and failure modes of rocks was investigated under the influence of thermal shock during the drilling process with varying confining pressure. The results show that with the gradual increase in cutting depth, rock exhibits a transition from ductile to brittle failure subjected to thermal shock. Thrust force, cutting force, mechanical specific energy (MSE), cutting depth and acoustic emission ringing counts all show a positive correlation with the increase of confining pressure. However, thrust force, cutting force and the critical cutting depth for the transition of failure modes are significantly reduced for rocks subjected to thermal shock during the drilling process. This suggests that the thermal shock weakens rock's mechanical properties and alters its failure mode. The study proposes an efficient and precise method for identifying the critical point of failure mode transition in rocks treated with thermal shock during high confining pressure drilling. This method offers a new perspective for understanding the behavior of rock break in complex thermal-mechanical- hydraulic coupled environments.

热应力和冷却冲击在钻井地热开采中起着关键作用。为了提高钻井效率，通常使用冷却液来降低钻头的温度。本研究对不同围压下的岩石进行了高温加热和水冷却的数字钻井、压缩试验和声发射试验。建立了考虑钻井过程中摩擦作用和围压作用的岩石韧脆破坏转变理论模型。研究了在不同围压条件下，热冲击作用下钻孔参数和岩石破坏模式的演化机制。结果表明：随着切割深度的逐渐增加，岩石在热冲击作用下由韧性破坏向脆性破坏转变；推力、切削力、机械比能（MSE）、切削深度和声发射环数均与围压的增加呈正相关。而岩石在钻进过程中受到热冲击时，推力、切削力和破坏模式转变的临界切削深度都明显减小。这表明热冲击削弱了岩石的力学特性，改变了岩石的破坏模式。该研究为高围压钻井中热冲击岩石破坏模式转变临界点的识别提供了一种高效、精确的方法。该方法为认识复杂热-力-水耦合环境下岩石破碎行为提供了新的视角。

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引用次数: 0

An approach for determining the mechanical properties of joints with nonlinear deformation 一种确定非线性变形节理力学性能的方法

IF 2.1 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Applied Geophysics

Pub Date : 2025-11-21 DOI: 10.1016/j.jappgeo.2025.106030

Lifeng Fan, Mingzhu Ye, Qihao Yang

This paper proposes an approach for determining the mechanical properties of joints exhibiting nonlinear deformation, based on the propagation characteristics of stress waves in rock masses. Firstly, a series of theoretical analyses on wave propagation through nonlinear joints was conducted. The relationship between stress waves and the mechanical parameters of nonlinear joints was established using a characteristic method in conjunction with the BB model. Secondly, an approach was proposed that involves analyzing the initial joint stiffness and maximum allowable closure through the reflected wave. The approach was subsequently refined using the Newton iteration method to enable efficient iterative computation. Finally, the proposed approach was validated by comparing the predicted initial joint stiffness and maximum allowable closure with their theoretical values. The results indicate that the proposed approach can predict the mechanical parameters, such as initial joint stiffness and maximum allowable closure, of a nonlinear joint based on the reflected waves. Moreover, the relative errors for the predictions of initial joint stiffness and maximum allowable closure in the present study are less than 8.6 % and 3.2 %, respectively. The proposed approach has the potential to predict the mechanical properties of nonlinear joints with an acceptable margin of error.

本文提出了一种基于应力波在岩体中的传播特性来确定非线性变形节理力学特性的方法。首先，对波浪在非线性节理中的传播进行了一系列理论分析。结合BB模型，采用特征化方法建立了非线性节点应力波与力学参数之间的关系。其次，提出了一种通过反射波分析节点初始刚度和最大允许闭合的方法。随后使用牛顿迭代法对该方法进行了改进，以实现高效的迭代计算。最后，通过将预测的初始关节刚度和最大允许闭合度与理论值进行比较，验证了所提方法的有效性。结果表明，该方法可以根据反射波预测非线性节点的初始刚度和最大允许闭合度等力学参数。此外，在本研究中，预测初始关节刚度和最大允许闭合的相对误差分别小于8.6%和3.2%。提出的方法有可能在可接受的误差范围内预测非线性关节的力学性能。

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引用次数: 0

Methodology to feasibility and 4D interpretation support in a pre-salt carbonate reservoir 盐下碳酸盐岩储层可行性及四维解释支持方法

IF 2.1 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Applied Geophysics

Pub Date : 2025-11-21 DOI: 10.1016/j.jappgeo.2025.106035

Evângela P.A. da Silva , Alessandra Davólio , Marcos Sebastião dos Santos , Denis José Schiozer

Discovered in 2006 and with a current production of almost 70 % of hydrocarbons produced in Brazil, pre-salt carbonates are of great interest for 4D seismic analysis. 4D feasibility studies help to understand how production influences the 4D seismic response. We developed a workflow to obtain seismic amplitude data from a simulation model and then access estimated 4D attributes through a fast-track inversion procedure. Our aim was to understand the effect of dynamic changes (pressure and saturation) in 4D seismic attributes considering the challenges regarding carbonate reservoirs under a water alternation gas (WAG) production strategy, using a pre-salt like case. We also compared inverted 4D attributes with those obtained by petro-elastic modeling and with simulator data to evaluate the reliability of a fast-track inversion procedure.

The study showed that 4D positive amplitude anomalies are observed in the water alternation gas injectors regions, due to water replacing oil. These anomalies were also observed after 4D inversion, with the best results presented by ΔAI and ΔS_w. The application of the fast-track inversion method for 4D data is a viable alternative for those looking to perform a first qualitative analysis of 4D data quickly, but your limitations must be considered to avoid misinterpretations.

该油藏发现于2006年，目前产量占巴西油气产量的近70%，盐下碳酸盐岩对四维地震分析具有重要意义。四维可行性研究有助于了解生产如何影响四维地震反应。我们开发了一套工作流程，从模拟模型中获取地震振幅数据，然后通过快速反演程序获得估计的四维属性。我们的目标是了解动态变化（压力和饱和度）对四维地震属性的影响，考虑到在水交替气（WAG）生产策略下碳酸盐岩储层的挑战，使用盐下样例。我们还将反演的四维属性与石油弹性建模和模拟器数据进行了比较，以评估快速通道反演程序的可靠性。研究表明，在水交替注气区，由于水置换油，出现了四维正幅异常。这些异常在4D反演后也能观测到，以ΔAI和ΔSw的结果最好。对于那些希望快速对四维数据进行第一次定性分析的人来说，应用快速通道反演方法是一种可行的选择，但必须考虑到您的局限性，以避免误解。

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引用次数: 0

Void detection behind tunnel concrete lining by an SH-Ultrasonic-assisted GPR method sh超声辅助探地雷达法探测隧道混凝土衬砌后空洞

IF 2.1 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Applied Geophysics

Pub Date : 2025-11-20 DOI: 10.1016/j.jappgeo.2025.106034

Yao Wang , Hai Liu , Junhong Chen , Ruoyu Chen , Pei Wang , Qifang Liu , Yanliang Du

Voids behind tunnel linings can lead to leakage and stress concentration, posing significant risks to tunnel integrity. Non-destructive testing methods, particularly ground-penetrating radar (GPR), are commonly employed in screening of such anomalies. However, our experimental results indicate that GPR is less effective in identifying air-filled voids, primarily due to their long wavelength and low radar cross section. In addition, scattering and attenuation of electromagnetic signals caused by reinforcing bars (rebars) also make it difficult to accurately detect air-filled voids. To enhance accurate imaging of void defects behind concrete linings, this paper introduced shear horizontal (SH) wave ultrasonic testing as a complementary approach to GPR. SH-ultrasonic testing, utilizing multi-offset array acquisition, partially mitigates the scattering and attenuation effects of rebars. Moreover, since elastic shear waves cannot propagate through water or air, voids filled with both materials exhibit significant impedance contrasts with the surrounding medium, resulting in strong reflection signals in ultrasonic data. Additionally, ultrasonic methods can delineate grouting layer thickness with high resolution, providing complementary data to GPR imaging. These advantages are demonstrated by model experiments conducted on two test platforms constructed with local metro shield tunnel lining segments. The results substantiate the potential of the ultrasonic-assisted GPR imaging method in effectively detecting voids behind concrete linings/walls.

隧道衬砌背后的空洞可能导致渗漏和应力集中，对隧道的完整性构成重大威胁。非破坏性检测方法，特别是探地雷达（GPR），通常用于筛选此类异常。然而，我们的实验结果表明，探地雷达在识别充满空气的空洞方面效果较差，主要是由于它们的波长长，雷达横截面小。此外，钢筋（钢筋）引起的电磁信号的散射和衰减也给准确探测充气空洞带来了困难。为了提高混凝土衬砌后空洞缺陷的成像精度，本文引入了剪切水平波超声检测作为探地雷达的补充方法。利用多偏置阵列采集的sh超声检测，部分减轻了钢筋的散射和衰减效应。此外，由于弹性剪切波不能通过水或空气传播，这两种材料填充的空隙与周围介质表现出明显的阻抗对比，从而导致超声数据中的反射信号较强。此外，超声方法可以高分辨率圈定注浆层厚度，为探地雷达成像提供补充资料。在两个采用局部盾构隧道衬砌管片搭建的试验平台上进行了模型试验，验证了这些优点。结果证实了超声辅助探地雷达成像方法在有效探测混凝土衬砌/墙壁后空隙方面的潜力。

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引用次数: 0

Automatic velocity spectrum picking method based on a layer-wise fusion strategy 基于分层融合策略的速度谱自动提取方法

IF 2.1 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Applied Geophysics

Pub Date : 2025-11-19 DOI: 10.1016/j.jappgeo.2025.106031

Xiaodong Sun , Xichao Shi , Pengjie Xue , Ning Qin

The accuracy of seismic velocity analysis critically determines the quality of seismic data imaging. However, traditional manual picking methods suffer from low efficiency, while existing automated techniques often fail to effectively capture the multiscale characteristics of seismic data. To address these challenges, this paper proposes an automatic velocity spectrum picking method based on layer-wise multimodal fusion(MMNet). The approach constructs a multimodal neural network architecture based on U-Net, employing a layer-wise fusion strategy to hierarchically integrate features from both velocity spectra and Common Middle Point(CMP) gathers, thereby enhancing multiscale feature extraction. Furthermore, the method incorporates Transformer modules with multi-head attention mechanisms to achieve efficient parallel processing and semantic understanding of multimodal data. Experimental results on both 2D/3D synthetic models and field datasets demonstrate that the proposed method outperforms conventional approaches in terms of picking accuracy, noise resistance, and computational efficiency, providing a more reliable automated solution for seismic data processing.

地震速度分析的准确性直接决定了地震资料成像的质量。然而，传统的人工采集方法效率较低，而现有的自动化技术往往不能有效地捕捉地震资料的多尺度特征。为了解决这些问题，本文提出了一种基于分层多模态融合（MMNet）的速度谱自动提取方法。该方法构建了一种基于U-Net的多模态神经网络架构，采用分层融合策略对速度谱和共中点（CMP）聚类特征进行分层融合，从而增强了多尺度特征提取能力。此外，该方法还结合了具有多头关注机制的Transformer模块，实现了多模态数据的高效并行处理和语义理解。在2D/3D合成模型和现场数据集上的实验结果表明，该方法在拾取精度、抗噪性和计算效率方面优于传统方法，为地震数据处理提供了更可靠的自动化解决方案。

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引用次数: 0

Near-surface geothermal reservoir exploration by multichannel analysis of passive surface waves using urban traffic noise in Shanxi 基于城市交通噪声的多通道被动面波分析在山西近地表地热储层勘探中的应用

IF 2.1 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Applied Geophysics

Pub Date : 2025-11-19 DOI: 10.1016/j.jappgeo.2025.106032

Ling Ning , Tianyu Dai , Guoshu Huang , Liang Liu , Hanbing Ai , Chaoqiang Xi

Geothermal resource exploration is a key driver of urbanization and economic transformation in northern and northwestern China. Traditional geophysical methods (e.g., active-source seismic and electrical resistivity tomography), however, often struggle with high costs, limited spatial coverage, and low resolution in deeper layers under complex noise conditions, hindering accurate subsurface characterization. To address these problems, we applied the multichannel analysis of passive surface waves (MAPS) to investigate local-scale geothermal reservoirs in central Shanxi Province, northern China. Two pseudo-linear arrays were deployed to record ambient seismic noise. Using less than one day of noise data, we extracted a subset of the total station pairs to perform seismic interferometry and dispersion measurements. Beamforming outputs revealed that the azimuth of the ambient noise sources was mainly aligned with the linear array direction, resulting in cross-correlation functions with good temporal symmetry. Coherent surface waves in the frequency range of 0.5 to 3 Hz were successfully retrieved, and robust phase-velocity dispersion curves were obtained from virtual shot gathers using multichannel analysis of surface waves. The consistency of the dispersion curves with the results derived from both pseudo-linear-array analysis of passive surface waves (PLAS) and the spatial autocorrelation (SPAC) methods confirms that they are not affected by the off-line noise sources. These curves were inverted using a sine-cosine algorithm to obtain shear (S)-wave velocity profiles, which showed strong agreement with the resistivity profiles from electromagnetic inversion. This case study demonstrates the value of using integrated geophysical methods in geothermal exploration. Combining passive surface-wave with electromagnetic techniques, we can overcome the limitations of individual methods, improving both the resolution and reliability of subsurface imaging. Such integration enables more accurate assessments of geothermal systems and supports the sustainable use of geothermal energy in geologically complex settings.

地热资源勘探是中国北方和西北地区城市化和经济转型的关键驱动力。然而，传统的地球物理方法（如有源地震和电阻率层析成像）往往存在成本高、空间覆盖范围有限、在复杂噪声条件下较深地层分辨率低等问题，阻碍了准确的地下表征。为了解决这些问题，我们应用多通道被动表面波（MAPS）分析方法对山西中部地区局地尺度地热储层进行了研究。采用两个伪线性阵列记录环境地震噪声。利用不到一天的噪声数据，我们提取了全站仪对的一个子集来进行地震干涉测量和色散测量。波束形成结果表明，环境噪声源的方位角主要对准线阵方向，产生了具有较好时间对称性的互相关函数。在0.5 ~ 3hz频率范围内成功提取了相干表面波，并利用多通道表面波分析得到了虚拟射击集的鲁棒相速度色散曲线。频散曲线与被动表面波伪线性阵列分析和空间自相关分析结果的一致性证实了它们不受离线噪声源的影响。利用正弦余弦算法反演得到剪切(S)波速剖面，结果与电磁反演得到的电阻率剖面吻合较好。该实例说明了综合地球物理方法在地热勘探中的应用价值。将被动表面波技术与电磁技术相结合，可以克服单个方法的局限性，提高地下成像的分辨率和可靠性。这种综合能够更准确地评估地热系统，并支持在地质复杂的环境中可持续地利用地热能。

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引用次数: 0

Interpretation of corrected sea floor HVSR data on a gas emitting structure in the Sea of Marmara 马尔马拉海气体排放构造的修正海底HVSR数据解释

IF 2.1 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Applied Geophysics

Pub Date : 2025-11-17 DOI: 10.1016/j.jappgeo.2025.106025

A. Brindisi , S. D'Amico , L. Beranzoli , D. Embriaco , A. Giuntini , D. Albarello

Ocean bottom measurements of ambient vibrations at a gas emitting area in the Marmara region are analyzed. The overall stability of average Horizontal to Vertical Spectral Ratios (HVSR) of ambient vibrations values above 0.2 Hz obtained in different sea conditions suggests that the relevant pattern is weakly affected by oceanic disturbances and can be considered informative about the subsoil structure. A procedure based on the removal of the water column effect from sea floor HVSR data is illustrated which allows the application to off-shore data of inversion tools developed for inland measurements. On this basis, sea floor HVSR measurements are used to tentatively constrain the local seismostratigraphical configuration in terms of V_s and V_p profiles. On this basis three main seismic impedance contrasts have been identified (respectively around 10, 100 and 500 m below the sea floor) in good correspondence with geological unconformities revealed by seismic reflection data. Moreover, the interpretation of the body wave profiles and, in particular, of the V_s/V_p, ratios suggest the presence of unconsolidated material down to a depth of about 500 m below the sea level with an estimated porosity of the order of 30 %. Based on the Biot-Gassmann model, the body wave profile has been used for a preliminary estimate of the degree of gas saturation which reaches 70 % in the depth range 150–500 m of depths below the sea floor. Beyond these figures, results obtained suggest that a methodology base on the interpretation of HVSR data at sea bottom may represent a new important tool for the characterization of the sea bottom subsoil structure in correspondence of gas reservoirs.

对马尔马拉地区某气体排放区的海底环境振动测量结果进行了分析。在不同海况下获得的0.2 Hz以上环境振动值的平均水平与垂直谱比（HVSR）的总体稳定性表明，相关模式受海洋扰动的影响较小，可以被认为是关于底土结构的信息。说明了一种基于从海底HVSR数据中去除水柱效应的程序，该程序允许将为内陆测量开发的反演工具应用于近海数据。在此基础上，利用海底HVSR测量资料，对v和Vp剖面的局部地震地层配置进行了初步约束。在此基础上，已经确定了三个主要的地震阻抗对比（分别在海底以下10,100和500米左右），与地震反射数据显示的地质不整合相对应。此外，对体波剖面，特别是Vs/Vp比值的解释表明，在海平面以下约500米的深度存在松散物质，估计孔隙率为30%。在Biot-Gassmann模式的基础上，利用体波剖面初步估计了海底以下150 ~ 500 m深度范围内天然气饱和度达到70%。除此之外，所获得的结果表明，基于海底HVSR数据的解释方法可能成为表征气藏对应的海底底土结构的一种新的重要工具。

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引用次数: 0

Fracture detection using effective Azimuthal Young's modulus in terms of Fourier series 基于傅立叶级数的有效方位杨氏模量的裂缝检测

IF 2.1 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Applied Geophysics

Pub Date : 2025-11-17 DOI: 10.1016/j.jappgeo.2025.106033

Yuanyuan Tan , Guangzhi Zhang , Zhengqian Ma , Xingyao Yin

Natural fracture detection is a crucial task in exploratory geophysics. Nonetheless, it remains a challenging topic to predict fracture parameters with high precision from reflection seismic data due to the subtle seismic responses of fractures and the multi-parameter ill-posed inverse problem. Consequently, we propose a new method for predicting fracture parameters using the effective azimuthal Young's modulus in terms of Fourier series. Firstly, we derive an analytical expression of the effective azimuthal Young's modulus in terms of Fourier series for rocks with vertically aligned fractures, which isolates the fracture information from the rock matrix information. The second-order Fourier coefficient of the effective azimuthal Young's modulus (EFC) is proven to be a linear function of the fracture density. Additionally, numerical analysis reveals that the second-order EFC is always negative, which can be utilized to eliminate the 90-degree uncertainty in predicting fracture orientation. On this basis, we construct a method to estimate fracture orientation and density by introducing principal component analysis (PCA) and the discrete Fourier transformation (DFT). The effective azimuthal Young's modulus is inverted from the PCA processed azimuthal seismic data using Bayesian inversion theory. The effective azimuthal Young's modulus in the form of the truncated Fourier series can forecast the fracture orientation without the 90-degree uncertainty, where DFT is used to calculate EFC. Meanwhile, the fracture density can be directly anticipated using the second-order EFC. Ultimately, synthetic and field data examples proved the proposed method can effectively delineate the stratum with relatively developed fractures.

天然裂缝探测是勘探地球物理中的一项重要任务。然而，由于裂缝的地震反应非常微妙，且存在多参数不适定逆问题，因此利用反射地震数据进行裂缝参数的高精度预测仍然是一个具有挑战性的课题。因此，我们提出了一种利用有效方位角杨氏模量的傅立叶级数来预测裂缝参数的新方法。首先，我们推导了具有垂直排列裂缝的岩石有效方位杨氏模量的傅里叶级数解析表达式，将裂缝信息与岩石基质信息分离开来。证明了有效方位杨氏模量（EFC）的二阶傅里叶系数是裂缝密度的线性函数。此外，数值分析表明，二阶EFC总是负的，这可以用来消除预测裂缝方向的90度不确定性。在此基础上，引入主成分分析（PCA）和离散傅里叶变换（DFT），构建了裂缝方位和密度估计方法。利用贝叶斯反演理论，对主成分分析处理后的方位地震资料进行有效方位杨氏模量反演。截断傅立叶级数形式的有效方位角杨氏模量可以预测裂缝方向，而不需要90度的不确定性，其中DFT用于计算EFC。同时，利用二阶EFC可以直接预测裂缝密度。最终，综合和现场数据实例证明，该方法能有效圈定裂缝相对发育的地层。

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引用次数: 0

Three-dimensional shear-wave velocity structure of the longnan geothermal field in the Central Jiulianshan uplift derived from seismic ambient noise tomography 基于地震环境噪声层析成像的中九连山隆南地热田三维横波速度结构

IF 2.1 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Applied Geophysics

Pub Date : 2025-11-15 DOI: 10.1016/j.jappgeo.2025.106028

Ronghua Xu , Juzhi Deng , Cheng Li , Huajian Yao , Yang Gao , Zequn Wen

The Jiulianshan Uplift in Jiangxi Province, China, represents a typical mountainous convective-type geothermal metallogenic belt, where the origins of plentiful geothermal resources and the prospects for deep hot dry rock (HDR) reservoirs have attracted heightened scientific attention. This study examines the Longnan Geothermal Field in the central segment of the uplift, deploying a dense array of 195 three-component nodal seismometers to form a planar array. Utilizing seismic ambient noise tomography, a 3D shear-wave velocity structure for the upper 3 km of the crust within the study area was obtained. The imaging results were rigorously validated by integrating them with magnetotelluric and gravity inversion models, demonstrating the efficacy of ambient noise tomography in probing mountainous convective-type geothermal systems. The findings reveal widespread concealed magmatic intrusions in the top crust of the study area, spatially coupled with NE trending deep fault systems. The overlying caprocks along these faults exhibit sufficient thickness to form a characteristic HDR reservoir system defined by “basement heat source - fault conduction - caprock sealing - reservoir heat accumulation.” This discovery clarifies the deep-seated control mechanisms of the Jiulianshan geothermal system and provides novel technical methodologies and critical geological references for HDR exploration in South China.

江西九连山隆起是典型的山地对流型地热成矿带，其丰富地热资源的成因和深部热干岩储层的前景引起了科学界的高度关注。本研究对隆升中段陇南地热田进行了研究，采用195台三分量节点地震仪的密集阵列形成平面阵列。利用地震环境噪声层析成像技术，获得了研究区内地壳上部3 km的三维横波速度结构。将成像结果与大地电磁和重力反演模型相结合，对成像结果进行了严格验证，证明了环境噪声层析成像在探测山地对流型地热系统中的有效性。研究结果表明，研究区上地壳广泛隐伏岩浆侵入，在空间上与NE向深断裂系统相耦合。沿这些断层的上覆盖层具有足够的厚度，形成了“基底热源-断层传导-盖层封闭-储热聚集”的HDR储层体系。这一发现阐明了九连山地热系统的深层控制机制，为华南地区HDR勘探提供了新的技术方法和重要的地质参考。

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引用次数: 0

Mapping hydrothermal alteration zones of Gebel MU'TIQ area using ASTER and aeromagnetic data in central eastern desert, Egypt 埃及中东部沙漠Gebel MU’tiq地区热液蚀变带ASTER与航磁数据制图

IF 2.1 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Journal of Applied Geophysics

Pub Date : 2025-11-14 DOI: 10.1016/j.jappgeo.2025.106027

Osama Elghrabawy

This study integrates ASTER VNIR–SWIR imagery with aeromagnetic data for mineral exploration in the Gebel MU'TIQ area, Central Eastern Desert of Egypt, within the Arabian-Nubian Shield. Lithological discrimination was enhanced using ASTER image-processing techniques, Optimum Index Factor (OIF), Minimum Noise Fraction (MNF), and Principal Component Analysis (PCA), enabling clear mapping of rock units such as amphibolitic schist, felsitic mylonite, sericite/muscovite schist, schist groups, biotite-hornblende gneiss, and granitoid intrusions. Hydrothermal alteration zones, including argillic, phyllic, propylitic, and ferrugenous assemblages, were identified through Feature-Oriented Principal Component Analysis (FPCA) and Constrained Energy Minimization (CEM), showing strong spatial association with NW-SE shear systems and granitoid contacts. Circular Feature Transform (CET) analysis delineated porphyry-style mineralization, particularly in the northeastern, central, and southwestern sectors, coinciding with the Arieki granitoid, Abu Ziran granite, and Um Ba'anib gneiss. Structural analysis, combining surface lineaments (ASTER PC1) and subsurface magnetic lineaments, emphasized the structural control on mineralization. The integrated exploration map highlights first-priority targets along the MU'TIQ shear zone, validated by the spatial coincidence with known Cu, Fe, Cr, TaNb, talc, and asbestos occurrences. These results confirm that combining ASTER-based lithological and alteration mapping with aeromagnetic analysis provides a cost-effective reconnaissance tool for detecting structurally hosted mineralized zones.

该研究将ASTER VNIR-SWIR图像与航空磁数据相结合，用于在阿拉伯-努比亚盾内的埃及中东部沙漠Gebel MU'TIQ地区进行矿产勘探。利用ASTER图像处理技术、最优指数因子（OIF）、最小噪声分数（MNF）和主成分分析（PCA）增强了岩性识别能力，能够清晰地映射出岩石单元，如角闪片岩、长英质糜棱岩、绢云母/白云母片岩、片岩群、黑云母角闪片麻岩和花岗岩体。通过特征导向主成分分析（FPCA）和约束能量最小化（CEM），发现热液蚀变带与NW-SE剪切体系和花岗岩类接触具有很强的空间关联，包括泥质、叶基、丙质和铁质组合。圆形特征变换（CET）分析描绘了斑岩型矿化，特别是在东北部、中部和西南部，与Arieki花岗质、Abu Ziran花岗质和Um Ba'anib片麻岩相吻合。构造分析结合地表特征（ASTER PC1）和地下磁性特征，强调构造对成矿的控制作用。综合勘探图突出了MU’tiq剪切带的优先目标，与已知的Cu、Fe、Cr、TaNb、滑石粉和石棉的空间重合。这些结果证实，基于aster的岩性和蚀变填图与航磁分析相结合，为探测构造含矿带提供了一种经济有效的侦察工具。

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