Revealing the shallow characteristics of dome structures by deep reflection surface wave imaging — A study on the Cuonadong dome

doi:10.21203/rs.3.rs-1433464/v1

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Revealing the shallow characteristics of dome structures by deep reflection surface wave imaging — A study on the Cuonadong dome

https://doi.org/10.21203/rs.3.rs-1433464/v1

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As interference waves in deep reflection data processing, surface waves are often suppressed as noise, but surface waves carry considerable underground media information, including structural information and the physical properties of rocks. Reasonable extraction and use of surface wave signals are of great significance for studying the underground structure, regional velocity characteristics, and physical properties of rocks. The deep reflection data are collected using large offsets, trail spacing, and explosive sources. The surface wave energy tends to be stronger, and the high-frequency surface wave signal is abundant. After extraction and inversion, the shallow high-precision shear wave velocity structure can be obtained. Near the Cuonadong dome in the southern Tibet detachment system (STDS), a large number of leucogranites are developed in the core, containing important rare metal minerals and high metallogenic potential. However, the research degree is relatively low, especially for the shallow part. In this paper, we use deep reflection data from a profile through the Cuonadong dome to obtain the S-wave velocity structure of the shallow 0-1.5 km layer by extracting the surface wave fundamental-order dispersion curve and inversion. Combined with the regional geological and geomagnetic data, we explained the variation in the sedimentary layer thickness of the Cuonadong dome; speculate that there may be several hidden faults in the Cuonadong dome that extend shallowly; revealed the high-velocity anomaly and its characteristics under the Cuonadong dome. These understandings of the structure and velocity field of the Cuonadong dome can provide a powerful geophysical basis for establishing the dome structure model and searching for hidden ore bodies.

Surface wave

Deep reflection

Cuonadong dome

Leucogranite

S-wave velocity

Surface waves, as strong amplitude, low-frequency linear interference waves, are often suppressed by various combinations of filtering in deep reflection data processing. However, surface waves carry considerable underground media information, including the structure, rock physical properties, and fluid. Therefore, the reasonable use of surface wave signals can obtain high-precision velocity structures in the shallow subsurface, which is important for studying shallow tectonic features and mineralization (Feng et al. 2019; Zhang et al. 2020). With the emergence of high-precision seismic instruments and the improvement in surface wave technology, surface wave imaging has become a research focus for many scholars in recent years. Deep reflection seismic data often have strong surface wave signals in single-shot records due to acquisition methods with large offsets, strong energy, and trail spacing, especially in high-frequency signals of 1–10 Hz, which can be used to study fine structures in the shallow subsurface (Xie et al. 2021). The dome is located in the Tethys Himalayan orogenic belt close to the southern Tibet detachment system (STDS). The interior of the dome contains a large number of leucogranites surrounding a large number of sandstones, slates, marls, and other important mineralized rocks, and the metallogenic potential is enormous (Zhou et al. 2014; Lin et al. 2016; Guo et al. 2019). At present, many tungsten, tin, and beryllium deposits have been found around the Cuonadong dome (Fu et al. 2017; 2018; 2020; Huang et al. 2018; Shi et al. 2020). The former Ministry of Land and Resources designated the Zhaxikang mining area and the surrounding Cuonadong dome as a national integrated exploration area (Blisniuk et al. 2001; He et al. 2020; Li et al. 2016; 2017; 2020). However, studies on the Cuonadong dome are mostly based on geochemistry and tectonic geology, and there is relatively little geophysical information, especially shallow geophysical information, which is crucial to constrain the tectonic features of the dome and study the characteristics of faults and sedimentary layers. This shallow information can provide corresponding geophysical evidence for mineralization and mineral searches (Li et al. 2017; Fan et al. 2019; Jiao et al. 2016; 2019).

In this paper, we use an east-west deep reflection profile across the Cuonadong dome to extract the surface wave signal. After preprocessing, dispersion extraction, inversion, and other steps, we obtain the high-precision S-wave velocity structural characteristics of the dome surface (1.5 km). Combined with the geological surface data and magnetotelluric data, we obtain the relationship between the thickness changes in the sedimentary layer of the Cuonadong dome, the fluctuation characteristics of the bedrock interface, the location and extension of the hidden fault, and the changes in the velocity of the dome structure and metal deposit (Beaumont et al. 2001; Zhang et al. 2020; Liu et al. 2021).

The northern Himalayan tectonic belt is located in the southern Yajiang suture zone (ITSZ) and northern STDS. It is located in the middle and eastern parts of the Himalayan Tethys orogenesis and has experienced a long-term sedimentary-structural evolution since the Pan-African movement on the northern margin of Gondwanan land. In particular, it has been subjected to the expansion, reduction, and closure of the Yarlung Zangbo ocean basin since the Triassic, as well as the strong collisional orogen and large-scale compression and extension between the Himalayan block and the Gangdise block (Chen et al. 1990; Lee et al. 2004; Wang et al. 2012; Dong et al. 2018; Li et al. 2020). Multiple dome structures have been formed (Fig. 1a). Among them, the Cuonadong dome is located in the eastern part of the Himalayan dome belt in the Tethyan, approximately 40 km southeast of the Yalashangbo dome, and approximately 23 km north of the southern Tibetan detachment system. The dome is close to the Cuona Rift, its geographical location is relatively special (Cao et al. 2020), and it mainly contains Paleozoic, Triassic, Jurassic, Cretaceous, Quaternary, and other stratigraphic units. Magmatic rocks are widely distributed, mainly in the Mesozoic and Cenozoic. The representative acidic intrusive rocks are Cuonadong leucogranites, and the basic intrusive rocks are mainly Early Cretaceous dyke intrusions. In addition to loose Quaternary sediments, the rest of the strata have undergone different degrees and different periods of metamorphism, forming different metamorphic rock types and different metamorphic facies belts, mostly slate, schist, metamorphic sandstone, etc.

Due to the collision and extrusion of the Indian plate and the Asian-European plate, a large number of detachment faults appear around the Cuonadong dome. The underground thermal material gushes up through the detachment fault and interacts with the surrounding rock mass, providing conditions for the formation of polymetallic deposits (Wang et al. 2010; Yang et al. 2011; Fu et al. 2018; 2020). In recent years, tungsten, tin, and beryllium mineralization clues have been found in the Cuonadong dome located in the contact zone between granite and Jurassic surrounding rock (Fig. 1b) (Zhang et al. 2017; Xie et al. 2017; 2018; 2019; Jiao et al. 2020).

3.1 Data acquisition

The geological structure around the Cuonadong dome is complex and includes multiple structural areas (STDS, Dongga syncline, Naji anticline, Cuonadong dome, etc.) and mining areas (Zhaxikang mining area, Mingsai mining area, Suoyue mining area, etc.). To study the deep geophysical characteristics and metallogenic background of the Cuonadong dome, the Institute of Geology, Chinese Academy of Geosciences set a deep reflection profile across the Cuonadong dome in 2019 (Fig. 1). The profile, which is approximately 40 km, crosses the core and the sides of the dome and passes through an area of mainly Quaternary sediments, Jurassic sandstones, slates, leucogranite, and Cambrian gneisses.

A total of 183 single-shot points were collected from deep reflection profiles, with specific acquisition parameters, as shown in Table 1. In the raw data (Fig. 2), surface waves are relatively developed, especially the near-offset surface wave signal (red circle), showing regular linear characteristics indicating strong energy. The far offset (green circle) can also track the surface wave signal. By extracting regular linear surface wave signals, the mapping quality of surface wave dispersion energy can be improved, the reliability of picking up dispersion curves can be enhanced, and the inversion results can be more accurate.

Table 1

Field data acquisition parameters
Acquisition parameters
Shot interval	Small shot 250 m; Medium shot 3000 m; Large shot 50000 m
Trace interval	50 m
Sampling rate	2 ms
Record duration	Medium, small 30 s; Large shot 60 s
Offset	Small shot: 14975 m; Medium shot: 22475 m; Big shot: full array
Receiving mode	Medium, small: 720 channel reception; Big shot; full array
Instrument types	428 Digital seismograph
Source mode	Explosive source

3.2 Spectrum analysis

Traditional multichannel surface wave data processing tends to suppress other forms of interference waves to achieve the desired filtering effect while also losing some of the effective signals. Spectrum analysis reveals that the surface wave energy is mainly concentrated between 6 and 20 Hz (Fig. 3a). We conducted different forms of bandpass filtering according to the frequency band range and obtained different dispersion energy maps. As shown in Fig. 3b, in the original single-shot data without filtering, the continuity of the fundamental-order dispersion energy is relatively excellent, rich in high- and low-frequency information, and it is easier to pick up the fundamental-order dispersion curve (Fig. 3b); the bandpass is 1-2-9-10-filtered, the continuity of the fundamental-order dispersion curve is still excellent, but some of the low frequency data is missed (Fig. 3c); the bandpass is 7-8-18-19, the low-frequency information in the dispersion energy is missed, and there is no continuity in the low-frequency signal before 7 Hz. The above tests show that preserving the surface wave signals in the main frequency range while losing more effective signals is not conducive to extracting low-frequency signals and studying deeper geological structures (Fig. 3d). Therefore, we use the original data to preserve the effective signals in different frequency ranges of the surface waves by intercepting the data and extracting the dispersion curves.

3.3 Channel number test

To obtain the reflection signal of the crust-mantle structure in deep reflection seismic exploration, the reflection data are collected by a large offset and explosive source. In multichannel surface wave imaging, a single-shot can reflect only a certain point of shear wave velocity information. Therefore, it is difficult to accurately assess the underground medium information by directly using the 720-channel reception data with the deep reflection single-shot data. However, when the number of receiving channels is small, it affects the mapping quality of dispersion energy, which is not conducive to improving the accuracy of dispersion curve extraction. Therefore, we conducted tests to select the most suitable multichannel collection method for data interception in our region. As shown in Fig. 4, (1) the tests of bilateral 60-channel reception and bilateral 40-channel reception are as follows: in the dispersion diagram with bilateral 60-channel reception, the continuity of the fundamental-order dispersion curve is better, especially for the low-frequency information, which can be continuously traced, even to 1.5 Hz, and the high-frequency signal is also more developed, which can be traced to 9.5 Hz; for bilateral 40-channel reception, the continuity of the fundamental-order dispersion is significantly reduced, and the low-frequency signal can be picked only to 2 Hz, but the continuity of the high-frequency signal is still better, and higher-order dispersion appears. (2) The single-sided 60-channel reception and single-sided 40-channel reception tests are as follows: for the single-sided 60-channel reception, the high- and low-frequency parts of the fundamental-order dispersion curve do not have continuity, the imaging quality is poor, and the continuity of the high-order dispersion is also poor; for the single-sided 40-channel reception, the fundamental-order dispersion curve between the 2.5-4 Hz part of the high-order dispersion dominates, although the continuity has improved, the imaging quality is still poor, and the high-frequency part of the dispersion curve is difficult to track. Through the comparison of different reception methods and different channels, the 60-channel bilateral reception method was finally adopted to extract the dispersion curves based on the consideration of improving the accuracy of the dispersion curve pickup and increasing the reliability of the inversion.

3.4 Forward simulation

The surface wave inversion is inseparable in a good initial model. Establishing a suitable initial model can provide better constraints on the inversion of the fundamental surface wave. Because the deep reflection profile across the Cuonadong dome is relatively long and passes through multiple tectonic units and ore-concentration areas, the regional velocity changes drastically, and the initial model is difficult to set. For data processing, we performed forward simulations by calculating the curvature of the original data dispersion curve and the sparsity of the dispersion points, given an initial model by the Parkseis surface wave software. The one-dimensional velocity structure is inverted according to the initial model, and the velocity structure obtained from the inversion is used as the forward model. The single-shot forward simulation is performed by setting the same acquisition parameters (Fig. 5), and the dispersion curve of the simulated single gun is inverted to obtain the one-dimensional transverse velocity structure (Fig. 5f). By comparison, for a detection point, the initial model is set by the dispersion curve curvature and sparsity, the obtained results are similar to the forward results, and the velocity structure has the same morphology; however, the actual data are influenced by topography, horizontal anisotropy, and multiple other convenient factors, which make it impossible to fit the forward results with certain inaccuracies. Therefore, in the process of data processing, we set the initial model of each point according to the curvature and sparsity of different dispersion curves to inversion one-dimensional velocity structure.

3.5 Dispersion curve extraction and reliability analysis

The extraction of the dispersion curve is the most important step in surface wave data processing. Reasonable acquisition of the dispersion curve is conducive to improving the inversion accuracy. In the process of picking the dispersion, the high-quality fundamental dispersion curve is picked by combining automatic picking with manual picking to remove the dispersion curve with poor quality. The total length of the deep reflection data line is approximately 40 km, and the line is mainly through the core and edge of the Cuonadong dome. The frequency band range of the dispersion curve varies greatly, but in the range of 1.5-8 Hz, the continuity of the dispersion curve is better, and the phase velocity is basically within 500–3500 m/s.

According to different structural positions, we selected three representative single shots for reliability analysis (Point 21433, Point 21695, and Point 21837). (1) Point 21433 (Fig. 6a) is located in the Quaternary sedimentary layer close to the Cuona Rift; the sedimentary layer is thicker, and the S-wave velocity is lower. The one-dimensional S-wave velocity indicates that at a position above 200 m underground, the velocity changes greatly, showing a trapezoidal increase, which may be related to the surface sediment and groundwater, and the velocity changes are small below 230 m. (2) Point 21695 (Fig. 6b) is located in the core of the Cuonadong dome, and it is mainly composed of leucogranite and metamorphic rocks. The dispersion curve shows that the phase velocity corresponding to a low frequency is significantly higher than that of other points. The S-wave velocity is generally high, and the minimum velocity is close to 1000 m/s. (3) Point 21837 (Fig. 6c) is located on a rare metal mineralization belt on the edge of the Cuonadong dome; around this point is mainly sandstone, slate, and schist. The dispersion curve indicates that the phase velocity increases significantly in the high-frequency and low-frequency parts, and the maximum S-wave velocity is close to 4000 m/s. This trend is mainly due to the existence of a metal metallogenic belt, which makes the consolidation and compactness of the rock increase, and the S-wave velocity increases significantly.

Through the above analysis, the different dispersion curves can reflect the characteristics of different tectonic and metallogenic zones, which are consistent with the actual stratigraphic and geological conditions and have higher accuracy. Finally, we used the selected fundamental dispersion curves and set different initial models for different measuring points according to the sparsity and curvature of each curve so that the final two-dimensional initial model is more representative and can reflect the real situation of the subsurface. To make the inversion results more accurate, the inversion fitting error was controlled to within 5% as much as possible. By inversion, the S-velocity structural characteristics of the east-west survey line were finally obtained (Fig. 7). The profile indicates that the Cuonadong dome shows obvious high-speed features underneath, and there are features of high- and low-velocity undulations in the core that may be related to the existence of hidden faults. The metamorphic rocks in the eastern part of the dome show more high-speed features, mainly because the rocks at this location are denser and have higher velocities.

The S-wave velocity profile reflects the characteristics of the velocity field and tectonic variations in the Cuonadong dome and its adjacent area. We combined geological and geomagnetic data to interpret the faults, sedimentary layers, and the degree of lithological weathering of the Cuonadong dome and its adjacent area. Based on the velocity profile (Fig. 8), obtained the following points:

4.1 Sedimentary characteristics

The Cuonadong dome margin is covered with Quaternary sediments, and the exact thickness of these Quaternary sediments has not been studied and detected thus far, while the morphology of the rocks beneath the sediments has important reference significance for studies on the tectonic movement and mineralization formation. S-wave velocity profiles were combined with the results of previous experimental studies on rock transverse wave velocities (Ma et al. 2012; Xu et al. 2012; Chen et al. 2021). For sedimentary and strongly weathered rocks with large natural water contents and a wide range of variations in pore ratios, S-wave velocities generally range from 480 m/s to 1400 m/s. We take 1400 m/s as the interface between the sedimentary layer and the strongly weathered bedrock (Fig. 8, white line). The structure of the S-wave velocity shows (Fig. 8a, white line) that the thickness of the sedimentary layer (strongly weathered interface) varies laterally, reaching the deepest thickness of more than 1 km in the Cuona Rift, and the sedimentary layer gradually thins to the east, where it becomes thicker again at the Jisong fracture and is distributed in bands. In the eastern Triassic strata, the average sedimentary layer (strongly weathered rocks) thickness is smaller than that in the western part of Juela Mountain. In general, with Juela Mountain as the boundary, the average sedimentary layer (strongly weathered interface) thickness in the west is greater than the average sedimentary layer thickness (strongly weathered interface) in the east, and the sedimentary layer thickness in the Cuona Rift reaches the maximum, which is more than 1 km, followed by a low-velocity band near the Jisong fault, with a depth of approximately 800 m.

4.2 Bedrock interface and weathering characteristics

The shear wave velocity of different rocks varies greatly after weathering. The core of the Cuonadong dome is mainly leucogranite, and the S-wave velocity of the slightly weathered granite ranges from 1200–2200 m/s based on laboratory data (Ma Haiyi et al., 2012; Chen Jiwei et al., 2021). In this paper, an S-wave velocity greater than 2200 m/s is designated as slightly weathered rock (Fig. 8, black line). Figure 8 shows that mainly moderately weathered leucogranite may be present beneath the Cuonadong dome (1400–2200 m/s) (between the white and black lines), and the degree of weathering (black circles) on the western side of the dome may be higher than that on the eastern side. The micro-weathering interface starts from the middle of the Cuonadong dome, approximately 1 km from the surface, and in the location of the Jisong fracture, the micro-weathering interface extends down to 1.2 km near Juela Mountain. The micro-weathering interface is only approximately 500 m from the surface. There is an anomalous bump in the micro-weathering interface in the Triassic stratigraphy in the eastern part of Juehla Mountain. Several outcrops of gabbro are present on the eastern part of the survey line, and gabbro is a basal shallow-forming intrusive rock with a relatively high density and high S-wave velocity. Therefore, we infer that the anomalous convexity of the eastern micro-weathered interface may be an intrusive gabbro with a lower degree of weathering and a larger S-wave velocity. By defining the degree of weathering of the rock body in the Cuonadong dome, we infer that the degree of undulation of the micro-weathered interface is greater than that of the sedimentary interface (strongly weathered interface), and the degree of weathering of the rock in the middle and western parts of the dome is higher than that in the east, and in the eastern position, there is an abnormal undulation of the micro-weathered interface, which may be an intrusive vein of gabbro.

4.3 Hidden fault

The formation of the Cuonadong dome was influenced not only by east-west and north-south detachment but also by the intrusion of multiple phases of magma, and the surface cover was severely damaged. At present, several faults have been found around the dome, and they control the structural form of the dome; for example, the surface of the Cuona fault in the western part of the profile is covered with Quaternary sediments, and the S-wave velocity profile shows (Fig. 8a) that the velocity is less than 1400 m/s, and the dip angle is relatively large; the Jisong fault shows a banded low-velocity body, which can extend down to 800 m. These two main faults are well reflected in the S-wave velocity profile. We infer that there may be several hidden secondary faults inside the Cuonadong dome via S-wave velocity imaging combined with geomagnetic data (Jiao et al. 2019) (black dashed line in Fig. 8a). The S-wave velocity profile shows that these secondary faults are mostly located between high and low speeds, and the extension depth is shallow, basically within 1 km. The magnetotelluric results (Fig. 8b) also show that there are multiple secondary faults in the core of the Cuonadong dome, mainly in the position between high and low resistances (Jiao et al. 2019), which can be well correlated with the S-wave velocity profile. Therefore, through the S-wave velocity profile and electromagnetic profile, we infer that there are several hidden secondary faults in the core of the Caunadong dome, which have larger dip angles, shallow extension depths, and low velocities. The study of secondary faults can provide an important geophysical basis for exploration prospecting.

4.4 S-wave velocity anomaly and mineralization

The S-wave velocity profiles show that there are three important velocity anomaly regions, reflecting the velocity-field characteristics of different geological structures. Region A includes the Quaternary Pleistocene glacial river and lake sedimentation; significant lower S-wave velocities, especially in the direction of the Cuona fault, can extend to 1 km, and the low-velocity layer to the east gradually becomes shallow, which is reflected the spatial morphology of the east-west characteristics of the Cuona fault. Region B is the core of the Cuonadong dome (Fig. 8 black square), has a large variety of horizontal S-wave velocities, and the overall high-speed characteristics are mainly due to the intrusion of Miocene leucogranite, which destroyed the surface cover and caused the horizontal S-wave velocity to vary widely. From the morphology of the high-speed body, we find that the intrusive body of leucogranite in the Cuonadong dome shows the characteristics of low in the west and high in the east. Region C, which is the edge area of the Cuonadong dome, is mainly composed of Cambrian granitic gneiss, Permian schist, Triassic sandstone and slate, and Jurassic cordierite slate. These metamorphic rocks are important metallogenic rocks. The survey line passes through a tungsten-tin ore at 20 km(Red star). The S-wave velocity profile shows that there is a high-speed abnormal uplift below it (Fig. 8 red circle), the velocity is significantly higher than that of leucogranite in the core of the Cuonadong dome, and the weathering degree is relatively low. These characteristics may occur because the deep thermal matter rises to the shallow surface along the channel of the Jisong fault, interacts with the surrounding rock, and forms important metallic minerals.

According to the transverse wave velocity profile and combined with geological and geophysical data, the shallow surface transverse wave velocity variation and tectonic characteristics of the dome and adjacent areas are revealed; in addition, the thickness variation in the sedimentary layer of the dome, bedrock interface undulation characteristics, location and extension depth of the hidden secondary fault, relationship between shear wave velocity variation and metal deposits.

(1) The thickness of the Cuonadong dome sediment layer varies greatly from east to west, the thickness of the sediment layer is the deepest near the Cuona fault, i.e., more than 1 km, the sediment layer in the core of the dome is the thinnest, and the sediment layer becomes thicker again at the Jisong fault and has a band distribution.

(2) The degree of rock weathering is higher in the western part of the Cuonadong dome than in the eastern part, and the micro-weathered bedrock interface starts from the middle of the Cuonadong dome, which is approximately 1 km away from the surface; at the location of the Jisong fault, the micro-weathered interface extends down to 1.2 km; below Jue La Mountain, the micro-weathered interface is only approximately 500 m away from the surface. There is an anomalous micro-weathered interface in the eastern part of the survey line, which may be an intrusive gabbro vein.

(3) There are many secondary faults in the study area, the depth of the Cuona fault exceeds 1 km, and the Jisong fault is distributed in a band. There are several hidden secondary faults in the core of the Cuonadong dome, which are shallow and may be related to later tectonic movement.

(4) Surface wave imaging reveals S-wave velocity characteristics in the Cuonadong dome and its adjacent areas, with obvious high-velocity anomalies below the Cuonadong dome and large horizontal S-wave velocity fluctuations, which are mainly related to the destruction of magmatic activities since the Miocene; the basement is mainly leucogranite, showing low western and high eastern intrusion characteristics; a tungsten-tin ore exists at the location of the Jisong fault, showing a high-velocity anomalous projection below, which may be a channel for deep hydrothermal fluids to intrude upward along the Jisong fault and interact with the surrounding rocks to form metal deposits.

STDS: Southern Tibet detachment system; S-wave velocity: Shear wave velocity; W-Sn: Tungsten and tin ore; ITSZ: Yajiang suture zone

Availability of data and materials

The datasets used and/or analyzed during the current study are available from the corresponding author upon reasonable request.

Funding

This work is supported by the National Natural Science Foundation of China (Grant Nos. 91962109, 42174124 and 42174094)

Authors’ Contributions

All authors were involved with the work. GW helped collect the data, data processing, analysis, interpreted the data, and prepared the manuscript. ZL helped collect the data and assisted with interpretation. HW reviewed and completed the manuscript. SX and WL provided project funding support to this work. YC participated in the preparation of the first draft. SC and WC helped collect the data. All authors read and approved the fnal manuscript.

Acknowledgements

We thank all those who helped collect the data and provided project support, especially Sinopec Geophysical Company. We thank associate researcher Li Hongqiang of the Chinese Academy of Geological Sciences(CAGS) for providing the processing software. Finally, we would like to thank all reviewers for their valuable comments on the article.

Competing interests

No competing interests.

Author details

¹Lithosphere Center, Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China. ²Deep Earth Dynamics Key Laboratory of the Ministry of Natural Resources, Beijing 100037, China

Beaumont C, Jamieson RA, Nguyen MH, Lee B(2001)Himalayan tectonics is explained by the extrusion of a low-viscosity crustal channel coupled to focused surface denudation. Nature 414(6865):738-742. https://doi.org/10.1038/414738a
Blisniuk PM, Hacker BR, Glodny J, Ratschbacher L, Bi S, Wu Z, Calvert A(2001)Normal faulting in central Tibet since at least 13.5 Myr ago. Nature 412(6847):628-632.https://doi.org/ 10.1038/35088045
Cao HW, Li GM, Zhang Z, Zhang LK, Dong SL, Xia XB, Zhang YH(2020)Miocene Sn polymetallic mineralization in the Tethyan Himalaya, southeastern Tibet: A case study of the Cuonadong deposit. Ore Geology Reviews 119:103403.https://doi.org/10.1016/j. oregeorev. 2020.103403
Chen Z, Liu Y, Hodges KV, Burchfiel BC, Royden LH, Deng C(1990)The Kangmar Dome: A Metamorphic Core Complex in Southern Xizang (Tibet).Science 250(4987):1552-1556. https://doi:10.1126/science.250.4987.1552
Chen JW, Zhao DD, Zong QB, Zhang BS, Di BY, Zhu HB, Wang JL(2021)High precision microtremor technology based on linear array and its application to the fine division of lithostratigraphy. Geophysical and Geochemical Exploration 45 (02): 536-545. http:// doi. org. 10.11720/wtyht.2021.1418
Dong L, Li GM, Huang Y, Li YX, Cao HW, Zhang Z(2018)Geochemical characteristics, chronology and tectonic significance of the granitic gneiss in the Yardoi dome, southern Tibet. Mineralogy and Petrology 38 (04): 76-87.http://doi:10.19719/j.cnki.1001-6872.2018.04.10
Fu JM, Li GM, Wang GH, Huang Y, Zhang LK, Dong SL, Liang W(2017)First field identification of the Cuonadong dome in southern Tibet: implications for EW extension of the North Himalayan gneiss dome. International Journal of Earth Sciences 106(5): 1581-1596.https:// doi. org/10.1007/s00531-016-1368-2
Fu JG, Li GM, Wang GH, Huang Y, Zhang LK, Dong SL, Liang W(2018)Establishment of the North Himalaya double gneiss domes: evidence from field identification of the Cuonadong dome, south Tibet. Geology in China 45 (04): 783-802. https:// doi:10.12029/gc20180410
Fu JG, Li GM, Wang GH, Zhang LK, Liang W, Zhang Z, Zhang XQ, Huang Y(2018)Synchronous granite intrusion and E–W extension in the Cuonadong dome, southern Tibet, China: evidence from field observations and thermochronology results. International Journal of Earth Sciences 107(6):2023-2041.https://doi.org/10.1007/s00531-018-1585-y
Fu JG, Li GM, Wang GH, Zhang LK, Liang W, Zhang XQ, Jiao YJ, Dong SL, Huang Y(2020)Structural analysis of sheath folds and geochronology in the Cuonadong Dome, southern Tibet, China: New constraints on the timing of the South Tibetan detachment system and its relationship to North Himalayan Gneiss Domes. Terra Nova, 32(4): 300-323. https:// doi.org/10.1111/ter.12462
Fu JG, Li GM, Wang GH, Zhang LK, Liang W, Zhang XQ, Jiao YJ, Dong SL(2020)Syntectonic skarn characteristics and mineralization age of associated Be-W-Sn rare metal deposit in Cuonadong Dome, Southern Tibet, China. Journal of Jilin University(Earth Science Edition) 50 (05): 1304-1322.https://doi:10.13278/j.cnki.jjuese.20190285
Fan WX, Li GM, Jiao YJ, Liang SX(2019)Enlightenment of the characteristics of gravity and magnetic field on the tectonic framework and metallogenesis of the Zhaxikang Ore-Concentrating area, Tibet. Journal of Jilin University(Earth Science Edition) 49(06): 1741-1754.http://dx.doi.org/10.13278/j.cnki.jjuese.20190018
Feng HW, Yan WH, Yan S, Guo YX, Hui SX, Chang C(2019)Joint inversion of ambient noise and surface wave for S-wave velocity of the crust and uppermost mantle beneath weihe basin and its adjacent area.Seismology and Geology 41(05):1185-1205.http://doi:10.3969/j.issn. 0253-4967.2019.05.008
Guo J, Jiao YJ, Liang SX(2019)Electrical variation of Carbonaceous rocks in ore-bearing fault zone and its prospecting significance, in Zhaxikang Pb-Zn-Sb polymetallic ore deposit, Tibet, China. Journal of Chengdu University of Technology(Science & Technology Edition) 46 (04): 471-481.http://doi:10.3969/j.issn.1671-9727.2019.04.07
Guo J, Li WC, Li GM, Jiao YJ, Liang SX(2019)Application of multi-scale integrated geophysical method in prospecting prediction of Zhaxikang Pb-Zn-Sb-Au polymetallic deposit. Earth Science 44 (06): 2129-2142. https://doi.org/10.3799/dqkx.2018.362
He CT, Qin KZ, Li JX, Zhou QF, Zhao JX, Li GM(2020)Preliminary study on occurrence status of beryllium and genetic mechanism in Cuonadong tungsten-tin-beryllium deposit, eastern Himalaya. Acta petrologica Sinica 36 (12): 3593-3621. https://doi:10.18654/1000-0569/ 2020.12.03
Huang CM, Li GM, Zhang Z, Liang W, Huang Y, Zhang LK, Fu JG(2018)Petrogenesis of the Cuonadong leucogranite in South Tibet: constraints from bulk-rock geochemistry and zircon U-Pb dating. Earth Science Frontiers 25 (06): 182-195.https://doi: 10.13745/j.esf.sf.2018.11.2
Jiao YJ, Huang XR, Li GM, Liang SX, Guo J(2019)Deep structure and mineralization of Zhaxikang ore-concentration area, Southern Tibet: evidence from geophysics. Earth Science 44 (06): 2117-2128.https://doi.org/10.3799/dqkx.2018.352
Jiao YJ, Liang SX, Guo J, Zhang W, Liao GZ(2016)The geophysical characteristics of ore-hosted strike slip fault and the prospecting direction in Zhaxikang Pb-Zn-Ag deposit, Tibet. Contributions to Geology and Mineral Resources Research 31 (03): 434-439.https://doi: 10.6053/j.issn.1001-1412.2016.03.016
Jiao YJ, Huang XR, Liang SX, Zhang Z, Li GM(2020)Deep structure and prospecting significance of the Cuonadong dome, Tethys Himalaya, China: Geophysical constraints. Geological Journal 56(1): 253-264.https://doi.org/10.1002/gj.3962
Lee J, Hacker B, Wang Y(2004)Evolution of North Himalayan Gneiss Domes: Structural and Metamorphic Studies in Mabja Dome, Southern Tibet. Journal of Structural Geology, 26(12): 2297-2316.https://doi.org/10.1016/j.jsg.2004.02.013
Liu GF, Liu Y, Meng XH, Liu LB, Su WJ, Wang YZ, Zhang ZF(2021)Surface wave and body wave imaging of passive seismic exploration in shallow coverage area application of Inner Mongolia. Chinese Journal of Geophysics 64 (03): 937-948.https://doi: 10.6038/cjg2021O 0064.
Li HL, Li GM, Ding J, Zhang Z, Qing CS, Fu JG, Ling C, Liu YQ(2020)Genesis of Zhaxikang Pb-Zn Polymetallic Deposit in Southern Tibet: Evidence from in Situ S Isotopes of Sulfides. Journal of Jilin University(Earth Science Edition) 50 (05): 1289-1303.https://doi:10.13278/ j.cnki.jjuese.20190287
Li QS, Gao Y, Wang XB, Zhao JM(2020)New research progress in geophysics and continental dynamics of the Tibetan Plateau. Chinese Journal of Geophysics 63 (03): 789-801.https://doi: 10.6038/cjg2020O0063.
Li HL, Li GM, Li YX, Dong SL, Qing CS, Fu JG, Liu H, Huang HX(2017)A study on ore geological characteristics and fluid inclusions of Jienagepu gold deposit in Zhaxikang ore concentration district, Southern Tibet, China. Acta Mineralogica Sinica 37 (06): 684-696.https://doi:10.16461/j.cnki.1000-4734.2017.06.002
Li GM, Zhang LK, Jiao YJ, Xia XB, Dong SL, Fu JG, Liang W, Zhang Z, Wu JY, Dong L, Huang Y(2017)First discovery and implications of Cuonadong superlarge Be-W-Sn polymetallic deposit in Himalayan metallogenic belt,southern Tibet. Mineral Deposits 36 (04): 1003-1008.https://doi:10.16111 /j.0258 - 7106.2017.04.014
Li HL, Li GM, Zhang Z, Fu JG, Liang SX(2016)Ore-controlling Factors and Prospecting Prediction of Zhaxikang Pb-Zn Polymetallic Deposit, Southern Tibet. Metal Mine (10): 103-108.https://doi:10.3969/j.issn.1001-1250.2016.10.021
Lin B, Tang JX, Zheng WB, Leng QF, Lin X, Wang YY, Meng Z, Tang P, Ding S, Xu YF, Yuan M(2016)Geochemical characteristics, age and genesis of Cuonadong leucogranite, Tibet. Acta Petrologica et Mineralogica 35 (03): 391-406.https://doi:10.3969/j.issn.1000-6524.2016. 03.002
Liang W, Li GM, Basang YD, Zhang LK, Fu JG, Huang Y, Zhang Z, Wang YY, Cao HW(2021)Metallogenesis of Himalaya gneiss dome: An example from Cuonadong gneiss dome in Zhaxikang ore concentration area. Mineral Deposits 40 (05): 932-948.https://doi:10. 16111/j.0258-7106.2021.05.003
Ma HY, Lu ZD(2012)Investigation of physico-mechanical properties for highly weathered granite
of nuclear power station in coastal site of western Guangdong province. Rock and Soil Mechanics 33 (02): 361-366.https://doi:10.16285/j.rsm.2012.02.006
Shi DN, Klemperer SL, Shi JY, Zhao WJ(2020)Localized foundering of Indian lower crust in the India-Tibet collision zone. Proceedings of the National Academy of Sciences,117(40): 24742-24747.https://doi.org/10.1073/pnas.2000015117
Wang XX, Zhang JJ, Liu J, Yan SY, Wang JM(2012)Transformation of the tectonic system of the Himalayan orogenic belt in the middle Miocene. Chinese Science Bulletin 57 (33): 3162-3172.https://doi.org/10.1360/csb2012-57-33-3162
Wang G, Yi HS, Liu S, Shen JH(2010)The deformation transfer from orogen stage to plateau stage in the central part of Tibetan Plateau during Miocene time and its tectonic mechanism. Chinese Journal of Geophysics 53 (06): 1384-1398.https://doi: 10.3969/j.issn.0001-5733.20 10.06.017.
Xie F, Wang HY, Hou HS, Gao R(2021)Near-Surface Fine Velocity Structure in Eastern Segment of Central Asian Orogenic Belt: Revealed by First-Arrival Wave Tomography from Deep Seismic Reflection Profile. Journal of Jilin University(Earth Science Edition) 51 (02): 584-596.https://doi:10.13278/j.cnki.jjuese.20200016
Xie YL, Yu L, Ying X, Li GM, Liu HF, Li YX, Dong SL, JunjieZhou JJ(2017)Genesis of the Zhaxikang epithermal Pb-Zn-Sb deposit in southern Tibet, China: Evidence for a magmatic link. Ore Geology Reviews 80: 891-909. https://doi.org/10.1016/j.oregeorev.2016.08.007
Xie JJ, Qiu HN, Bai XJ, Zhang WF, Wang Q, Xia XP(2018)Geochronological and geochemical constraints on the Cuonadong leucogranite, eastern Himalaya. Acta Geochimica 37(3): 347-359.https://doi.org/10.1007/s11631-018-0273-8
Xie L, Tao XY, Wang RC, Wu FY, Liu C, Liu XC, Li XK, Zhang RQ(2019)Highly fractionated leucogranites in the eastern Himalayan Cuonadong dome and related magmatic Be-Nb-Ta and hydrothermal Be-W-Sn mineralization. Lithos 354-355:10528.https://doi.org/10.1016/j. lithos.2019.105286
Xu PF, Shi W, Ling SQ, Guo HL, Li ZH(2012)Mapping sphericaly weathered “Boulders” using 2D microtremor profiling method: A case study along subway line 7 in Shenzhen. Chinese Journal of Geophysics 55 (06): 2120-2128.https://doi:10.6038/j.issn.0001-5733.2012.06.034
Yang PX, Chen ZW, Ren JW, Zhang J(2011)Activity and segmentation of Gyaring Co fault-zone in central Qingzang plateau. Acta Seismologica Sinica 33 (03): 362-372.https://doi:10.3969／j.issn.0253-3782.2011.03.009
Zhang H, Liu ZW, He RZ, Li QL(2020)Near surface shear wave velocity structure inversion using multi-order surface wave dispersion curves constructed from deep seismic reflection data: a real case of deep seismic reflection profile across Bangong-Nujiang suture zone. Chinese Journal of Geophysics 63 (12): 4410-4430.https://doi: 10.6038/cjg2020O0116.
Zhang ZQ, Yao HJ, Yang Y (2020)Three dimensional S-wave velocity structure and dynamic significance of the crust and upper mantle on the southeast edge of the Qinghai Tibet Plateau. Scientia Sinica(Terrae) 50 (09): 1242-1258. https://doi: 10.1360/SSTe-2020-0016
Zhang Z, Zhang LK, Li GM, Liang W, Xia XB, Fu JG, Dong SL, Ma GT(2017)The Cuonadong Gneiss Dome of North Himalaya: A New Member of Gneiss Dome and a New Proposition for the Ore-controlling Role of North Himalaya Gneiss Domes. Acta Geoscientica Sinica 38 (05): 754-766.https://doi: 10.3975/cagsb.2017.05.15
Zhou Q, Li GM, Xia XB, Wu JY, Lai Y, Li YX, Li YC(2014)Metallogenic model of Zhaxikang lead-zinc polymetallic ore concentration area in southern Tibet. Mineral Deposits 33 (S1): 353-354.https://doi:10.16111/j.0258-7106.2014.s1.179

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Editorial decision: Major Revision
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11 Mar, 2022
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Revealing the shallow characteristics of dome structures by deep reflection surface wave imaging — A study on the Cuonadong dome

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Abstract

Figures

1. Introduction

2. Geological Background

3. Data Processing

3.1 Data acquisition

3.2 Spectrum analysis

3.3 Channel number test

3.4 Forward simulation

3.5 Dispersion curve extraction and reliability analysis

4. Analysis And Discussion

4.1 Sedimentary characteristics

4.2 Bedrock interface and weathering characteristics

4.3 Hidden fault

4.4 S-wave velocity anomaly and mineralization

Conclusion

Abbreviations

Declarations

References

Supplementary Files

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Version 1