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Article

The Early Cretaceous High-Nb Basalt and Arc Andesite Association in the Eastern Segment of the Altyn Tagh Fault: Petrological Records of Intracontinental Extension

by
Lu-Qing Qin
1,
Yong Bai
1,*,
Yu An
1,*,
Jin-Lin Wang
2,
Ying-Ying Ma
1,
Hai-Xin Lu
1 and
Yu-Hang Luo
3
1
School of Resource and Environmental Engineering, Inner Mongolia University of Technology, Hohhot 010051, China
2
Technology and Engineering Center for Space Utilization, Chinese Academy of Sciences, Beijing 100094, China
3
School of Earth Sciences, Lanzhou University, Lanzhou 730000, China
*
Authors to whom correspondence should be addressed.
Minerals 2025, 15(11), 1103; https://doi.org/10.3390/min15111103
Submission received: 24 September 2025 / Revised: 13 October 2025 / Accepted: 21 October 2025 / Published: 23 October 2025
(This article belongs to the Special Issue Geochronological, Petrological and Geochemical Studies of Basaltic Rocks from Oceanic Crust)
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Abstract

The Altyn Tagh Fault plays a critical role in understanding the tectonic evolution of the northern margin of the Tibetan Plateau. However, considerable debate persists regarding its activity and deformation history. This study investigates volcanic rocks from the Beidayao-Jianquanzi-Hanxia-Hongliuxia area in the eastern segment of the fault. By employing zircon U-Pb dating, whole-rock geochemistry, and Sr-Nd isotope analysis, we aim to elucidate their petrogenesis and tectonic setting, thereby providing new insights into the crustal evolution of the eastern Altyn Tagh Fault. Zircon U-Pb dating of the Hongliuxia rhyolite yields a weighted mean 206Pb/238U age of 106.6 ± 0.6 Ma, indicating an Early Cretaceous eruption. Geochemically, the western part of the study area (Beidayao and Jianquanzi) is dominated by basalts that exhibit significant enrichment in large ion lithophile elements and light rare earth elements, together with high Nb concentrations (>20 ppm), as well as high Nb/La (0.64–1.12) and Nb/U (29.8–35.42) ratios, consistent with the characteristics of high-Nb basalt. In contrast, the eastern area (Hanxia and Hongliuxia) is characterized by andesitic rocks that display typical continental arc affinities, marked by enrichment in Th, U, and Pb and depletion in Nb, Ta, and Ti. Isotopically, the basalts show initial 87Sr/86Sr ratios of 0.706–0.707 and εNd (t) values ranging from −3.2 to 0.8, whereas the andesites possess more radiogenic Sr isotopic compositions, with (87Sr/86Sr)i ratios of 0.710–0.717, and more negative εNd (t) values from −11.4 to −1.5, suggesting derivation from an enriched mantle source. Integrating geochemical data with regional geological records, we propose that the eastern part of the Altyn Fault experienced a significant intracontinental extensional setting during the Early Cretaceous, where asthenospheric mantle upwelling played a key role in the generation of the volcanic rocks. This study provides key petrological and geochemical constraints on Early Cretaceous deformation and activity along the Altyn Tagh Fault, and also offers a valuable reference for understanding the evolution of similar fault systems.

1. Introduction

Strike-slip fault zones (e.g., the Haiyuan Fault Zone; the San Andreas Fault Zone) are mainly developed at plate boundaries, intracontinental deformation zones, and transform tectonic systems, and often form large-scale strike-slip fault systems [1,2,3,4,5,6]. These fault zones not only serve as important tectonic boundaries delineating continental deformation zones and lithospheric blocks, but also undergo multiple phases of tectonic reactivation and extensional deformation events during subsequent tectonic evolution [7,8,9]. Accurately identifying the reactivation and deformation history of these fault zones is of great significance for seismic hazard assessment and prediction. However, this is often hampered by subsequent tectonic overprinting. In this regard, large-scale strike-slip faulting often triggers regional extension, thereby inducing upwelling of the deep asthenosphere and producing volcanism with distinctive geochemical signatures (e.g., high-Nb basalts, HNB) [10,11,12]. Therefore, the study of fault zone-related volcanic rocks can be used to invert the reactivation and deformation history of fault zones.
The Altyn Tagh Fault (ATF) (Figure 1a), a large-scale strike-slip fault zone along the northern margin of the Tibetan Plateau, separats major tectonic units including the Tarim Basin, Qaidam Basin, and Qilian Mountains, and is therefore of great tectonic significance [13,14,15]. Studies suggest that this fault may have originated as a paleo-plate suture zone before undergoing strike-slip deformation [16,17], and was subsequently subjected to multiple phases of tectonic transition. However, the slip history and dynamic evolution mechanisms of the ATF remain controversial. For instance, regarding the early activity of the ATF, a prevalent view suggests that it formed during the Cenozoic [18,19,20], while a significant body of research argues for an Early Paleozoic inception [21], with some views further suggesting significant strike-slip motion during the Triassic [22,23], Jurassic [24], or Cretaceous [25,26]. Currently, the limited understanding of deep crustal and mantle processes associated with strike-slip activity hinders a comprehensive interpretation of the long-term tectonic evolution of the ATF. A series of Mesozoic and Cenozoic volcanic rocks are developed along the ATF (Figure 1b) [27,28]. These rocks serve as important responses and records of the intense activity of this fault, and can provide crucial clues for revealing the deep dynamic processes and tectonic evolution history of the ATF.
This study selected volcanic rocks from the Beidayao-Jianquanzi-Hanxia-Hongliuxia area in the eastern ATF for zircon U-Pb dating, whole-rock geochemical, and Sr-Nd isotopic analysis to elucidate their magmatic sources, genetic mechanisms, and geodynamic background. Combining previous studies with our new results, we propose that the western Beidayao and Jianquanzi HNB rocks are attributed to partial melting of a subduction-fluid-metasomatized, enriched mantle wedge driven by asthenospheric upwelling; whereas the eastern Hanxia-Hongliuxia arc andesites originated from sedimentary melt-modified mantle wedge partial melting. Integration of regional tectonic evolution suggests that the eastern ATF experienced Cretaceous strike-slip deformation within an intracontinental extensional setting [25,26,27]. These findings provide key insights into the mechanisms of crust-mantle interaction during regional magmatism. Simultaneously, they contribute significant petrological and geochemical constraints for advancing our understanding of the ATF’s geological evolutionary history.

2. Geological Background and Samples

Multiple secondary faults and related structures have formed around the ATF [13,14], displaying a relatively distinct NE-SW orientation overall. Collectively, these structural assemblages record multi-stage tectonic responses, spanning from the closure of the Paleo-Tethys Ocean to the India-Eurasia collision, which range from subduction-collision orogeny to intracontinental strike-slip deformation [28,29,30]. The study area lies at the intersection of the North Qilian Thrust Fault and the ATF (Figure 2), and its tectonic evolution has been governed by the multiphase activity of these two major fault systems. During the reactivation of the fault zone, the fault system governed the tectonic evolution of the basin through spatiotemporal coupling and significantly influenced the sedimentary filling sequences and compositional characteristics across different tectonic stages [31,32]. The strata exposed in this area are predominantly composed of Precambrian metamorphic rocks, with subsidiary occurrences of Paleozoic, Mesozoic and Cenozoic units. The Precambrian metamorphic rocks are primarily composed of the Dunhuang Complex, which consists of biotite-plagioclase gneiss, quartz schist, and other lithologies. This complex is intruded by Early Paleozoic granodiorites and Late Paleozoic granites. The Paleozoic strata are dominantly sandstone and siltstone with limestone intercalations. The Mesozoic strata include the Lower Jurassic coal-bearing series, overlain unconformably by Cretaceous sandy mudstones. These Cretaceous deposits are primarily assigned to the Xinminpu Group. The Cenozoic strata are characterized as follows: the Oligocene comprises purplish-red sandy conglomerates and sandstones interbedded with mudstones; the Miocene consists of sandstones and mudstones interbedded with gypsum strata; the Pliocene is composed of sandstones and mudstones interbedded with conglomerates; and the Pleistocene is dominated by conglomerates with sandstone lenses [26].
The volcanic rocks of the ATF eastern section are hosted by the Xinminpu Formation and occur mainly as lava interbeds, formed in an Early Cretaceous extensional tectonic setting [33]. Spatially, the Beidayao and Hongliuxia lavas are exposed along the northern rim of the Jiuxi Basin, with the Hanxia lavas at its western edge, and the Jianquanzi lavas along the southwestern margin of the Changma Basin (Figure 2). Radiometric dating has constrained the eruption age of the Jiuxi Basin volcanics to 120.2–102.1 Ma [26], whereas samples from the Changma Basin yielded ages of 112.8 ± 3.4 Ma and 118.8 ± 3.6 Ma [27]. These results confirm an Early Cretaceous age for the volcanism, rather than the previously proposed Cenozoic age [34].
Through field sampling, a total of 11 volcanic rock specimens were systematically acquired from the Jiuxi and Changma basins, comprising basalt, andesite, and dacite (Table 1; Figure 3a–f). Among them, the Jianquanzi and Beidayao basalts are relatively similar in terms of their occurrence horizons and lithological characteristics, both occurring as lava interbeds in the Lower Cretaceous strata. From the perspective of macroscopic structures, the rocks generally develop amygdaloidal structures, and most of the vesicles are completely or partially filled with secondary carbonate minerals. Under the microscope, the rocks exhibit an intergranular texture. The phenocrysts are dominated by olivine, mostly presenting as subhedral-euhedral granular forms. Some larger phenocrysts have cracks developed inside, and partial olivine shows brown to reddish-brown iddingsitization at the edges or interiors. The groundmass consists of plagioclase microlites (elongated or needle-shaped) and opaque minerals (fine-grained and dispersed within the groundmass), which are interwoven to form an intersertal texture (Figure 3g). The Hanxia andesites occur conformably, interbedding with the grayish-green pebbly sandstones-sandstones of the Xiagou Formation. The rock exhibits a typical porphyritic texture, with plagioclase microlites mostly tabular or elongated and mutually interwoven. Additionally, the rock locally contains vesicles, some of which are filled with calcite (Figure 3h). The Hongliuxia andesites occur above the Early Cretaceous strata, existing as lava interbeds. Macroscopically, the rocks show a massive structure, being overall dense and homogeneous, with no obvious bedding or directional arrangement of vesicles observed. The microscopic texture is cryptocrystalline, and the mineral outlines can only be vaguely seen under a high-power microscope. Their mineral composition includes plagioclase, pyroxene, and so on. The Hongliuxia dacite sample was collected from the lower part of this andesite unit and exhibits a porphyritic texture, with phenocrysts dominated by biotite and plagioclase. The biotite occurs as flaky or scaly aggregates, dark brown in color, and under the microscope shows distinct cleavage plane reflections (Figure 3i).

3. Analytical Methods

3.1. LA-ICP-MS Zircon U–Pb Dating

The zircon grains, after undergoing gravity separation and magnetic separation, are handpicked under binocular microscopy based on criteria of crystalline integrity and translucency. The epoxy resin targets containing representative zircon grains undergo polishing to guarantee full cross-sectional exposure prior to analysis and testing. Before conducting zircon U-Pb isotope investigation, the internal composition of zircons was systematically observed using transmitted light, reflected light, and cathodoluminescence (CL) microscopy systems. Based on these observations, analytical spots were selected in areas free of fractures, mineral inclusions, and complex zoning interference.
The geochronological investigation was conducted on an Agilent 7900 ICP-MS (Agilent Technologies, Santa Clara, CA, USA) coupled with a NWR-193UC 193-nm ArF excimer (Electro Scientific Industries, Beaverton, OR, USA) laser ablation system. The laser beam diameter of 25 μm and an ablation frequency of 6 Hz were employed. The standard reference material NIST 610 was used for calibrating trace element contents, while isotopic fractionation corrections were applied using the zircon standards Plešovice (Ple), GJ-1, and 91500. The single-spot ablation protocol consisted of 100 s total acquisition time (30 s for background signal collection followed by 70 s for sample signal acquisition). Standard reference materials were analyzed following each group of 10 unknown sample spots to monitor instrumental stability. Iolite software was used to process the raw data for filtering and background correction [35]. The concluding age reckoning and the creation of concordia diagrams were carried out with the Isoplot 4.15 program [36]. The magmatic crystallization age was determined by the weighted mean method based on the 207Pb/235U-206Pb/238U ratios, with age data selected within a concordance range of 90–110%.

3.2. Whole-Rock Major and Trace Element Analysis

Geochemical analysis of whole-rock samples was carried out on relatively fresh rock specimens. The samples underwent crushing and grinding to achieve 200 mesh (particle size < 75 μm), followed by major and trace element testing conducted at Wuhan SampleSolution Analytical Technology Co., Ltd. (Wuhan, China). We conducted a comprehensive elemental investigation using a Rigaku Primus II X-ray fluorescence (XRF) spectrometer (Rigaku Corporation, Tokyo, Japan), following the procedures and analytical techniques outlined by Ma et al. (2012) [37]. The trace element analytical procedure consisted of the following steps: 200-mesh whole-rock powder was placed in Teflon high-pressure digestion vessels, subjected to closed-acid digestion using an HF-HNO3 mixed acid system, and the digested products were diluted to fixed volumes before quantitative analysis with an Agilent 7700e ICP-MS (Agilent Technologies, Santa Clara, CA, USA). For quality control, blank samples (BLANK) were processed to eliminate background interference, while international reference materials including GSR-3 (basalt), JA-2 (andesite), and JB-3 (basalt) were used for data calibration and method validation.

3.3. Whole-Rock Sr-Nd Isotope Analysis

Sr-Nd isotopic ratios were measured using a Thermo Fisher Scientific Neptune Plus MC-ICP-MS (Thermo Fisher Scientific, Waltham, WA, USA). All sample preparation procedures performed in a Class 1000 clean laboratory environment with Class 100 laminar flow workstations. The sample powder was sequentially digested using electronic-grade ultrapure nitric acid (HNO3), hydrofluoric acid (HF), and hydrochloric acid (HCl) through a stepwise dissolution protocol. After obtaining clear solutions, the digested products were purified through cation-exchange resin columns to isolate Sr and Nd fractions for isotopic analysis. Data reduction incorporated mass fractionation corrections using the exponential law with the following normalization ratios: 86Sr/88Sr = 0.1194 and 146Nd/144Nd = 0.7219. Instrumental stability was monitored using certified reference materials NBS-987 (for Sr isotopes) and GSB (for Nd isotopes). During the analytical sessions, the measured values of NBS-987 standard yielded 87Sr/86Sr = 0.710243 ± 0.000004 (2σm, n = 6), while the GSB standard gave 143Nd/144Nd = 0.512440 ± 0.000005 (2σ, n = 7). The reliability of the experimental data has been confirmed by these results being consistent with their certified values within analytical uncertainties.

4. Results

4.1. Geochronology

A dacite sample (24HLX-03) from the Hongliuxia volcanic rocks was analyzed using zircon U-Pb geochronology in this study, and the analytical results are presented in Table 2. The analyzed zircon grains predominantly exhibit euhedral to subhedral short prismatic morphologies, with a minor population displaying rounded or subrounded shapes. Their long-axis diameters range from 50–130 μm, and the range of their aspect ratios is from 1:1 to 3:1 (Figure 4a). Rhythmic zoning characteristics were identified in most grains via CL images, while Th/U ratios (0.4–1.2) at individual spots suggest a magmatic origin. From 20 zircon grains analyzed, two spots were excluded for being discordant, and three spots that yielded anomalously older ages were excluded from the age calculation and concordia diagram construction. The anomalously older zircon grains are considered to be xenocrysts, which probably came from the country rocks during the magma rising up. The remaining 15 analytical spots form a tight cluster along the concordia curve (Figure 4b), demonstrating robust age consistency. The calculated 206Pb/238U weighted mean age is 106.6 ± 0.6 Ma (MSWD = 1.14, n = 15), representing the formation age of the Hongliuxia dacite.

4.2. Whole-Rock Geochemistry

The volcanic rock samples were analyzed for major and trace elements, with loss on ignition (LOI) values ranging from 1.80 to 8.83 wt.% (Table 3). Sample 24HX-04 exhibits an exceptionally high LOI (8.83 wt.%), likely resulting from post-magmatic quartz veinlets intrusion and intense alteration, which has significantly modified its primary geochemical composition. Consequently, this sample was excluded from subsequent calculations and graphical representations. During alteration processes, alkali metals (e.g., K, Na) and large-ion lithophile elements (LILE; e.g., Rb, Sr, Pb, Ba) demonstrate significant mobility, whereas high-field-strength elements (HFSE; e.g., Ti, Zr, Y, Nb) remain relatively immobile. Therefore, these alteration-resistant elements were selected as the primary geochemical proxies for petrological classification and petrogenetic interpretation in this study [38]. We proceeded to normalize all the major elemental data and recalculate them to 100% post-removal of the LOI. The study area’s volcanic rocks are identified as primarily alkali-basalt and andesite in the Zr/TiO2-Nb/Y diagram (Figure 5a), whilethe Th-Co diagram assigns them to calc-alkaline to high-K calc-alkaline series (Figure 5b).
The basalt samples from the Jianquanzi and Beidayao areas exhibit compositions with 48.88–51.01 wt.% SiO2, 7.06–9.00 wt.% MgO, and Mg# of 57–63. They are characterized by high HFSE contents (e.g., Nb = 27.25–31.30 ppm, Zr = 147–197 ppm) and high Nb/La (0.64–1.12) and Nb/U (29.80–35.42) ratios. These geochemical signatures are comparable to those of typical HNB (Nb/La > 0.5, Nb/U > 10) [40,41]. The chondrite-normalized rare earth element (REE) pattern of basalts from both areas exhibit smooth and right-sloping profiles, relatively enriched in light rare earth elements (LREE) [(La/Yb)N = 8.93–17.10], and show weak positive or negative Eu anomalies (δEu = 0.99–1.10) (Figure 6a). Primitive mantle-normalized patterns indicate that LILEs (e.g., K, Ba, Sr) are moderately enriched relative to OIB, whereas HFSEs (e.g., Nb, Ta, Zr, Ti) are marginally depleted. Overall, the trace element pattern resembles that of OIB (Figure 6b).
The andesite samples from the Hongliuxia and Hanxia areas exhibit compositions of SiO2 = 59.09–64.05 wt.%, Al2O3 = 15.89–19.26 wt.%, MgO = 2.49–7.01 wt.%, Fe2O3T = 6.06–6.96 wt.%, and Mg# = 44–67. In contrast, the Hongliuxia volcanic rocks exhibit a lower Mg# (44) and a higher K2O/Na2O ratio (2.84–3.35) than those at Hanxia. Chondrite-normalized REE distributions indicate LREE enrichment and HREE depletion [(La/Yb)N = 6.96–11.41] in both suites, coupled with weakly to moderately negative Eu anomalies (0.70–0.96), reflecting crystal-melt fractionation processes (Figure 6c). Both sample groups show LILE enrichment (e.g., Pb, Th, U,) and HFSE depletion (e.g., Nb, Ta, Ti) on primitive mantle-normalized diagrams, aligning with the geochemical fingerprint of Continental Arc Andesite (CAA) (Figure 6d).

4.3. Whole-Rock Sr-Nd Isotope Geochemistry

Five whole-rock samples were subjected to Sr-Nd isotopic analysis, and the resultant data are compiled in Table 4. Using K-Ar ages from Tang et al. (2012) and this study’s geochronological data for initial ratio correction [26], the calculated initial Sr-Nd isotopic compositions for the Beidayao and Jianquanzi basalts are as follows: (87Sr/86Sr)i = 0.70605–0.70708, (143Nd/144Nd)i = 0.51232–0.51253, and εNd (t) = −3.3–0.8; The Hanxia and Hongliuxia andesites exhibit initial isotopic ratios of (87Sr/86Sr)i = 0.70982–0.71676 and (143Nd/144Nd)i = 0.51232–0.51253, with all εNd (t) values being negative (−1.5–−11.4) (Figure 7).

5. Discussion

5.1. Spatiotemporal Distribution of Volcanic Rocks in the Altyn Tagh Fault

Volcanic rocks are extensively developed along both the eastern and western segments of the ATF, yet they exhibit a remarkable chronological disparity, which is crucial for understanding the tectonic-magmatic evolution of the fault zone. The volcanic rocks in the western segment are chronologically younger, having formed predominantly during the Cenozoic era as a direct tectonic response to the continental collision between the Indian and Eurasian plates (Figure 1b) [51,52,53]. Among them, the Ashikule volcanic rocks represent the youngest activity, with eruptions persisting until 2.3–0.17 Ma [53,54], reflecting tectonic-magmatic processes since the Late Cenozoic. In contrast, the formation ages of volcanic rocks in the eastern segment of the fault are predominantly confined to the Cretaceous period. For instance, K-Ar whole-rock dating of the Jianquanzi volcanic rocks in the Changma Basin yielded ages of 112.8 ± 3.4 Ma and 118.8 ± 3.6 Ma [27]. In the Hongliuxia area of the Jiuxi Basin, two distinct magmatic episodes have been identified at 112–116 Ma and ~83 Ma [26,55,56]. The Beidayao volcanic rocks, located at the junction of the ATF and the North Qilian Thrust Fault, also exhibit K-Ar whole-rock ages distributed between 99 Ma to 118 Ma [26,27]. This Cretaceous magmatic pulse is further recorded by volcanic rocks in the Hanxia area, with ages ranging from 102 Ma to 120 Ma [26].
A weighted mean age of 106.6 ± 0.6 Ma was obtained by LA-ICP-MS zircon U-Pb dating for a dacite sample from Hongliuxia (Figure 4b). This finding is broadly in agreement with previous research, suggesting that the eastern segment of the ATF experienced large-scale magmatic eruptions during the Early Cretaceous, thereby providing critical chronostratigraphic constraints for investigating its tectonic evolution.

5.2. Origin and Formation Mechanisms of Basalt

5.2.1. Crustal Contamination and Fractional Crystallization of Basalt

The common occurrence of crustal assimilation during magma ascent and storage in the continental crust necessitates an evaluation of its potential effects. The continental crust is marked by depleted HFSE (e.g., Nb, Ta, Ti) relative to adjacent elements [47], coupled with elevated LREE/HFSE ratios [57]. These geochemical signatures serve as key discriminants for identifying crustal contamination processes. The basalts in the western study area exhibit subtle negative anomalies in Nb, Ta, and Ti (Figure 6b), suggesting a potential contribution from crustal materials to the magmatic system. In continental crust, Th is significantly more enriched than Nb [47]. When mantle-derived magmas experience crustal contamination, they typically exhibit negative correlations in MgO versus Th/Nb variation diagrams. However, the absence of a negative correlation between MgO and Th/Nb ratios in the basalt samples (Figure 8a), indicating negligible crustal contamination. The characteristics of low Nb/La and high La/Sm ratios from the continental crust are inherited by crustal contamination, thereby intensifying the variation trends of these two ratios. Nevertheless, the Nb/La and La/Sm ratios remain essentially constant with decreasing MgO content (Figure 8b,c), which implies that the basalt samples have not experienced obvious crustal assimilation. These geochemical characteristics collectively indicate that the western basalts experienced negligible to weak crustal contamination during their formation.
Primitive mantle-derived melts are characterized by elevated Cr (>1000 ppm), Ni (>400 ppm) contents and high Mg# values (73–81) [49]. Compared with the primitive melt, the basalt samples in this study exhibit lower Mg# (57–63), Cr (223–269 ppm), and Ni (104–152 ppm) contents, which indicates that fractional crystallization of ferromagnesian minerals to varying degrees may have been undergo during the magma’s formation and evolution. The observed geochemical trends of decreasing MgO with slightly increasing SiO2 and decreasing Fe2O3T suggests fractional crystallization of olivine or clinopyroxene (Figure 8d,e). Furthermore, the decreasing Cr and Ni contents with MgO in the Beidayao basalts indicate fractionation of both olivine and clinopyroxene (Figure 8f,g). In contrast, the increase in Al2O3 with decreasing MgO (Figure 8h) demonstrates that no significant plagioclase fractionation occurred during the magma’s evolution. Furthermore, the lack of pronounced variation in La/Sm and Dy/Yb ratios with MgO depletion implies negligible amphibole fractionation (Figure 8i).

5.2.2. Magma Source Regions of Basalt

The western basalts in the study area exhibit elevated concentrations of Nb (27.2–31.3 ppm), Zr (147–197 ppm), and TiO2 (1.79–1.90 wt.%), coupled with high Nb/La (0.64–1.12) and Nb/U (29.80–35.42) ratios (Figure 9a,b). These geochemical signatures closely resemble those of HNB [40,58]. NEBs form when you mix enriched OIB-type components with depleted MORB-type mantle sources [59,60,61,62,63], or when you partially melt slab-derived adakitic melt-metasomatized mantle wedge peridotite [40,64]. The similar REE partitioning patterns and trace element characteristics between Beidayao and Jianquanzi basalts suggest a shared parental magma source or co-evolved magmatic processes. Compared to the positive Nb and Ta anomalies characteristic of typical MORB and OIB, the basalts in this study, despite their high Nb and Ta contents, still exhibit negative anomalies on the spidergram. (Figure 6b). Moreover, their Ce/Pb (9.61–10.18) and Nb/U (29.8–35.42) ratios are significantly lower than those of OIB endmembers (Ce/Pb = 25 ± 5; Nb/U = 47 ± 10) [65], these lines of evidence indicate that the basalts were not directly derived from OIB or MORB type mantle sources. Furthermore, in the Ba/Nb-La/Nb discrimination diagram (Figure 9c), the studied basalts fall within the arc volcanic rock domain, distinct from MORB and OIB, implicating the addition of subduction-related components to the mantle source [66,67]. Thus, a magmatic source formed by the mixing of an enriched mantle (OIB) and a depleted mantle (MORB) cannot adequately explain the genesis of the HNB in this study. The second hypothesis proposes that metasomatic interactions between adakitic melts and overlying mantle wedges can generate HFSE-enriched basaltic melts [68]. Metasomatism of the mantle wedge by adakitic melts would result in high (La/Yb)N and Sr/Y ratios coupled with low Y content [69]. However, the western basalts in the study area display relatively low (La/Yb)N (8.93–17.10) and Sr/Y (23.97–67.48) ratios, along with elevated Y concentrations (21.5–24.6 ppm). These geochemical features collectively indicate that the Beidayao and Jianquanzi basalts were not significantly affected by adakitic melt metasomatism during their formation.
Within subduction zone dynamic systems, the mantle wedge can be altered by not just slab-derived melts, but also sediment melts and fluids derived from the slab [70,71]. Ba is considered to be a fluid-mobile element, while Th and La are classified as melt-mobile elements. Therefore, elevated Ba/La and Ba/Th ratios can serve as indicators of fluid metasomatism [72]. The basalts in the study area exhibit high and variable Ba/La and Ba/Th ratios (Figure 9d,e), which suggests that fluids from a subducted slab are involved in their mantle source. In the εNd (t) vs. Th/Nd isotope binary mixing diagram (Figure 9f), the basaltic samples exhibit trends consistent with metasomatism by subduction-related fluids. Given the low mobility of HFSE in subduction zone fluids [73,74], slab-derived fluids contribute minimally to the HFSE budget of the mantle wedge. In the Th/Yb-Nb/Yb and V-Ti/1000 diagrams (Figure 10a,b), the study area basalts plot near the OIB field. These geochemical signatures collectively suggest that the basalts may also incorporate contributions from an OIB enriched mantle source. Consequently, involvement of such enriched mantle domains likely accounts for the observed enhancement of Nb abundances in the sampled basalts. The basalts in the research area are part of the calc-alkaline series and display comparatively low Th concentrations (3.16–3.90 ppm) (Figure 5b), which clearly separate them from high-K calc-alkaline mafic rocks that come from enriched lithospheric mantle sources [75]. Concurrently, these basalts exhibit elevated Ti and Zr contents (TiO2 = 1.79–1.90 wt.%, Zr = 147–197 ppm), which are significantly higher than those typically found in arc basalts derived from partial melting of a metasomatized mantle wedge (typically TiO2 < 1 wt.%) [76]. These geochemical characteristics suggest that asthenospheric mantle components were involved in their formation. Furthermore, the basaltic samples exhibit a transition from weakly depleted to mildly enriched Nd isotopic compositions (Figure 7), providing additional evidence for asthenospheric mantle contributions. In summary, the study area’s western basalts most likely originated from partial melting of an enriched mantle wedge that had been fluxed by subduction-related fluids, with a significant input from asthenospheric mantle components.
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Figure 9. (a) Nb/La vs. MgO diagram and (b) Nb/U vs. Nb diagram [68]; (c) Ba/Nb vs. La/Nb diagram; (d) Th/Yb vs. Ba/La diagram; (e) (La/Sm)N vs. Ba/Th diagram; (f) εNd (t) vs. Th/Nd diagram (Mantle wedge, slab melt, slab fluid, and sediment melt compositions from Plank and Langmuir, 1998; Johnson and Plank, 2000; Zhang et al. 2016) [77,78,79].
Figure 9. (a) Nb/La vs. MgO diagram and (b) Nb/U vs. Nb diagram [68]; (c) Ba/Nb vs. La/Nb diagram; (d) Th/Yb vs. Ba/La diagram; (e) (La/Sm)N vs. Ba/Th diagram; (f) εNd (t) vs. Th/Nd diagram (Mantle wedge, slab melt, slab fluid, and sediment melt compositions from Plank and Langmuir, 1998; Johnson and Plank, 2000; Zhang et al. 2016) [77,78,79].
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Figure 10. (a) Th/Yb vs. Nb/Yb illustration [80]; (b) V vs. Ti/1000 illustration [81]; (c) La/Sm vs. La illustration; (d) La/Yb vs. La illustration.
Figure 10. (a) Th/Yb vs. Nb/Yb illustration [80]; (b) V vs. Ti/1000 illustration [81]; (c) La/Sm vs. La illustration; (d) La/Yb vs. La illustration.
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5.3. Origin and Formation Mechanisms of Andesite

5.3.1. Crustal Contamination and Fractional Crystallization of Andesite

Research has shown that crustal contaminants often result in significant variations in La/Nb ratios and are characterized by elevated Th/Nb ratios (>5) [82]. The andesites in the study area exhibit limited variation in La/Nb ratios (2.05–3.07) and low Th/Nb ratios (0.63–1.07), indicating minimal crustal contamination. In Harker diagrams, the andesite samples exhibit decreasing Cr and Ni contents with declining MgO (Figure 8f,g), indicative of early-stage fractional crystallization of olivine and/or clinopyroxene. Moreover, chondrite-normalized REE patterns exhibit distinct negative Eu anomalies (Figure 6c), suggesting probable fractional crystallization of plagioclase. Based on the above analysis, the andesites in the study area formed without significant crustal contamination and likely underwent fractional crystallization of olivine, clinopyroxene, and plagioclase during their petrogenesis.

5.3.2. Magma Source Regions of Andesite

The primitive mantle-normalized spider diagram displays pronounced negative anomalies in HFSE (e.g., Nb, Ta, Ti, and P), coupled with positive anomalies in LILE (e.g., Th, U, and K). This pattern closely resembles the characteristic trace element distribution of typical CAA (Figure 6d). Moreover, on the Th/Yb vs. Nb/Yb discrimination diagram (Figure 10a), all andesite samples fall squarely within the continental arc field, confirming their classification as CAA. Two primary genetic models have been proposed for arc andesites: (1) According to the basaltic magma input model, the magma evolves into andesitic magma through a series of processes that encompass fractional crystallization, crustal assimilation, and magma mixing [83,84,85,86]; (2) The andesitic magma input model, which proposes that andesitic melts can be directly generated from mantle sources [87,88].
The studied andesite samples exhibit low SiO2 contents (59.09–64.05 wt.%) and Mg# (44–67), which distinctly differ from magmas derived by partial melting of lower crustal sources (Mg# < 40) [89]. Additionally, crust-derived magma has relatively low Ti/Zr (<20) and Ti/Y (<100) ratios [90,91]. The andesites from the investigated region exhibit Ti/Zr (28.85–41.87) and Ti/Y (153.64–197.09) ratios that differ from those typical of crustal melts. In contrast, the observed values of Nb/Ta (13.46–14.36) and Lu/Yb (a constant 0.15) are consistent with those exhibited by mantle-derived magmas (Nb/Ta = 17.8, Lu/Yb = 0.14–0.15) [42], implying a genesis primarily within the mantle. In diagrams of La/Yb vs. La and La/Sm vs. La, partial melting typically exhibits a linear trend with a slope of 1, whereas fractional crystallization displays a horizontal trend. The andesite samples in this study show a partial melting trend in these diagrams (Figure 10c,d), indicating that the magma composition was primarily controlled by partial melting of a mantle source.
The andesites in the study area are enriched in LILE and LREE but depleted in HFSE, indicating that the mantle source was metasomatized by subduction-related fluids/melts [92]. The andesite samples are characterized by radiogenic Sr isotopic compositions ((87Sr/86Sr)ᵢ = 0.70982–0.71676) and depleted Nd isotopes (εNd (t) = −1.5–−11.4) (Figure 7), which suggests that their mantle source underwent metasomatism by slab-derived melts or sediment melts. Notably, compared to the Hanxia andesites, the Hongliuxia andesites show higher initial 87Sr/86Sr ratios and lower εNd (t) values, which likely reflect varying degrees of melt metasomatism. Meanwhile, in the binary mixing diagram of εNd (t) ratios versus Th/Nd (Figure 9f), the andesite samples plot closer to the sediment melt metasomatic trend, further supporting the significant contribution of sediment-derived melts to their mantle source. Collectively, the findings support the interpretation that the eastern andesites within the investigated region originated from a mantle source that had been metasomatized by melts derived from subducted sediments.

5.4. Tectonic Implications

The pre-existing tectonic framework of the Mesozoic era exerted crucial control over the formation and evolutionary processes of the Tibetan Plateau, as evidenced by previous multidisciplinary studies and investigations focusing on the ATF. Thermochronological evidence reveals that the granites within the Lapeiquan Fault recorded two rapid cooling events during the Early Jurassic and Early Cretaceous, corresponding to two episodes of extensional tectonic activity along the ATF [93]. Paleomagnetic data indicate that the eastern segment of the fault zone underwent significant clockwise rotation from the Early Cretaceous to Cenozoic, whereas the western segment remained relatively stable with no apparent rotation relative to the Eurasian continent [94]. This differential rotation pattern implies that strike-slip deformation had become the dominant tectonic regime. The tectonic characteristics of peripheral basins further demonstrate that the development of Mesozoic basins was governed by approximately EW trending extension, with the initiation of ATF strike-slip activity occurring during the Cretaceous [14,25,95]. The convergence of evidence points to the Cretaceous as a key interval of transpressional deformation along the ATF, including a major episode of strike-slip displacement.
The Cretaceous reactivation of the ATF is attributed to far-field stresses from Asian margin convergence, including the Lhasa-Qiangtang collision post Paleo-Tethys closure [96,97] and westward subduction of the Izanagi Plate [33,98] (Figure 11). Elevated concentrations of Zr (131–252 ppm) accompanied by high Zr/Y ratios (5.33–9.55) are revealed as distinctive geochemical signatures of the volcanic rocks in the research locale. Geochemical discrimination using the Zr/Y vs. Zr ratio diagram indicates an intraplate affinity for these volcanic rocks (Figure 12a), as their values cluster well outside the field defined by typical island arc basalts. As revealed by Ta/Hf-Th/Hf tectonic environment discrimination diagrams (Figure 12b), the spatial distribution of volcanic rocks in the study area is mainly constrained to intracontinental rift tholeiitic basalts and intracontinental extensional tectonic basalts, suggesting a regional extensional setting. The extensional mechanism is likely controlled by the combined far-field effects of the closure of the Paleo-Tethys Ocean and the subduction of the Paleo-Pacific Plate. The coupling of these processes triggered local stress adjustments along the pre-existing weak zones of the ATF on the northern margin of the Tibetan Plateau, ultimately leading to strike-slip motion. In this context of regional lithospheric extension and thinning, upwelling of the asthenospheric mantle induced partial melting of the mantle wedge, thereby generating the volcanic rocks in the study area. Therefore, the Early Cretaceous tectonic deformation in the eastern segment of the ATF is interpreted as the result of combined influences from both the Paleo-Pacific and Paleo-Tethys tectonic domains.

6. Conclusions

  • LA-ICP-MS zircon U-Pb dating results indicate that the volcanic rocks in the Hongliuxia area of the Jiuxi Basin erupted during the Early Cretaceous (106.6 ± 0.6 Ma).
  • The OIB-type geochemical signature observed in the Nb-enriched basalts (Nb > 20 ppm) from Jianquanzi and Beidayao in the western study area is interpreted as originating from partial melting of an enriched mantle wedge, which was metasomatized by slab-derived fluids with a contribution from the asthenospheric mantle. Magmas from this source region probably underwent fractional crystallization of olivine and clinopyroxene without significant crustal contamination.
  • The andesites from Hanxia and Hongliuxia in the eastern study area show trace element patterns characteristic of Continental Arc Andesites. This indicates their derivation from the partial melting of a mantle wedge that had been metasomatized by sediment-derived melts, followed by probable fractional crystallization involving olivine, clinopyroxene, and plagioclase.
  • Based on a comprehensive review of regional geological evidence, we propose that the eastern Altyn Tagh Fault volcanic rocks formed in response to asthenospheric mantle upwelling. This reveals an intracontinental extensional tectonic setting, implying intense strike-slip activity along the eastern Altyn Tagh Fault segment during the Cretaceous.

Author Contributions

Conceptualization, L.-Q.Q. and Y.A.; data curation, L.-Q.Q.; formal analysis, Y.B. and J.-L.W.; funding acquisition, Y.-Y.M.; investigation, L.-Q.Q.; methodology, L.-Q.Q., Y.A., Y.B., J.-L.W., Y.-Y.M., H.-X.L. and Y.-H.L.; project administration, Y.-Y.M.; supervision, Y.A. and Y.B.; validation, Y.A., Y.B., J.-L.W. and Y.-Y.M.; visualization, L.-Q.Q. and H.-X.L.; writing—original draft, L.-Q.Q.; writing—review and editing, Y.A. and Y.B. All authors have read and agreed to the published version of the manuscript.

Funding

This research was supported by the National Natural Science Foundation of China (Grant No. 42362019) and the Basic Research Business Fees for Directly Affiliated Colleges and Universities in Inner Mongolia Autonomous Region (Grant Nos. JY20250013, JY20250014).

Data Availability Statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.

Acknowledgments

We gratefully acknowledge the technical support provided by the State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences (Beijing), and Wuhan SampleSolution Analytical Technology Co., Ltd., for conducting U-Pb zircon dating, whole-rock major and trace element analysis, and Sr-Nd isotope measurements. We also extend our sincere gratitude to the anonymous reviewers and editors for their valuable comments and suggestions.

Conflicts of Interest

The authors declare no conflicts of interest.

References

  1. Woodcock, N.H. The role of strike-slip fault systems at plate boundaries. Philosophical Transactions of the Royal Society of London. Ser. A Math. Phys. Sci. 1986, 317, 13–29. [Google Scholar]
  2. Cunningham, W.D.; Mann, P. Tectonics of Strike-Slip Restraining and Releasing Bends; Geological Society: London, UK, 2007; Volume 290, pp. 1–12. [Google Scholar]
  3. Pirajno, F. Intracontinental strike-slip faults, associated magmatism, mineral systems and mantle dynamics: Examples from NW China and Altay-Sayan (Siberia). J. Geodyn. 2010, 50, 325–346. [Google Scholar] [CrossRef]
  4. Yin, A. Cenozoic tectonic evolution of Asia: A preliminary synthesis. Tectonophysics 2010, 488, 293–325. [Google Scholar] [CrossRef]
  5. Zuza, A.V.; Yin, A.; Lin, J.; Sun, M. Spacing and strength of active continental strike-slip faults. Earth Planet. Sci. Lett. 2017, 457, 49–62. [Google Scholar] [CrossRef]
  6. Wu, G.H.; Ma, B.S.; Han, J.F.; Guan, B.Z.; Chen, X.; Yang, P.; Xie, Z. Origin and growth mechanisms of strike-slip faults in the central Tarim cratonic basin, NW China. Pet. Explor. Dev. 2021, 48, 595–607. [Google Scholar] [CrossRef]
  7. Crider, J.G.; Peacock, D.C. Initiation of brittle faults in the upper crust: A review of field observations. J. Struct. Geol. 2004, 26, 691–707. [Google Scholar] [CrossRef]
  8. Curren, I.S.; Bird, P. Formation and suppression of strike–slip fault systems. Pure Appl. Geophys. 2014, 171, 2899–2918. [Google Scholar] [CrossRef]
  9. Cheng, F.; Zuza, A.V.; Haproff, P.J.; Wu, C.; Neudorf, C.; Chang, H.; Li, X.Z.; Li, B. Accommodation of India–Asia convergence via strike-slip faulting and block rotation in the Qilian Shan fold–thrust belt, northern margin of the Tibetan Plateau. J. Geol. Soc. 2021, 178, jgs2020-207. [Google Scholar] [CrossRef]
  10. Yogodzinski, G.M.; Volynets, O.N.; Koloskov, A.V.; Seliverstov, N.I.; Matvenkov, V.V. Magnesian andesites and the subduction component in a strongly calc-alkaline series at Piip Volcano, far western Aleutians. J. Petrol. 1994, 35, 163–204. [Google Scholar] [CrossRef]
  11. Ruppel, C. Extensional processes in continental lithosphere. J. Geophys. Res. Solid Earth 1995, 100, 24187–24215. [Google Scholar] [CrossRef]
  12. Timm, C.; Hoernle, K.; Werner, R.; Hauff, F.; Bogaard, P.; White, J.; Mortimer, N.; Garbe-Schönberg, D. Temporal and geochemical evolution of the Cenozoic intraplate volcanism of Zealandia. Earth-Sci. Rev. 2010, 98, 38–64. [Google Scholar] [CrossRef]
  13. Dai, S.; Dai, W.; Zhao, Z.B.; Luo, J.H.; Qiang, L.; Ma, X.; Zhang, X.W.; Xu, J.J. Timing, displacement and growth pattern of the Altyn Tagh fault: A review. Acta Geol. Sin.-Engl. Ed. 2017, 91, 669–687. [Google Scholar] [CrossRef]
  14. Dai, S.; Ma, X.J.; Zhao, Z.B.; Fan, X.; Wang, Y.L.; Wang, Z.X.; Zhang, X.; Cai, L.P.; Deng, W.; Hou, X.B.; et al. Jurassic evolution of the Dunhuang Basin and its implications for the history of the Altyn Tagh fault, Northeast Tibet Plateau. Tectonics 2023, 42, e2022TC007620. [Google Scholar] [CrossRef]
  15. Yan, B.; Chen, P.; Gao, Y. Stepwise decrease in strike-slip rate along the eastern Altyn Tagh Fault and its relation to the Qilian Shan thrust system, northeastern Tibetan Plateau. J. Struct. Geol. 2024, 179, 105037. [Google Scholar] [CrossRef]
  16. Zhuang, G.; Hourigan, J.K.; Ritts, B.D.; Kent-Corson, M.L. Cenozoic multiple-phase tectonic evolution of the northern Tibetan Plateau: Constraints from sedimentary records from Qaidam Basin, Hexi Corridor, and Subei Basin, northwest China. Am. J. Sci. 2011, 311, 116–152. [Google Scholar] [CrossRef]
  17. Wu, C.L.; Lei, M.; Wu, D.; Zhang, X.; Chen, H.J.; Li, T.X. Zircon U-Pb Dating of Paleozoic Granites from South Altun and Response of the Magmatic Activity to the Tectonic Evolution of the Altun Orogenic Belt. Acta Geol. Sin. 2016, 90, 2276–2315. (In Chinese) [Google Scholar]
  18. Tapponnier, P.; Xu, Z.Q.; Roger, F.; Meyer, B.; Arnaud, N.; Wittlinger, G.; Yang, J.S. Oblique stepwise rise and growth of the Tibet Plateau. Science 2001, 294, 1671–1677. [Google Scholar] [CrossRef] [PubMed]
  19. Wu, L.; Xiao, A.C.; Yang, S.F.; Wang, L.Q.; Mao, L.G.; Wang, L.; Dong, Y.P.; Xu, B. Two-stage evolution of the Altyn Tagh Fault during the Cenozoic: New insight from provenance analysis of a geological section in NW Qaidam Basin, NW China. Terra Nova 2012, 24, 387–395. [Google Scholar] [CrossRef]
  20. Cheng, F.; Jolivet, M.; Fu, S.T.; Zhang, C.H.; Zhang, Q.Q.; Guo, Z.J. Large-scale displacement along the Altyn Tagh Fault (North Tibet) since its Eocene initiation: Insight from detrital zircon U-Pb geochronology and subsurface data. Tectonophysics 2016, 677, 261–279. [Google Scholar] [CrossRef]
  21. Liu, Y.J.; Genser, J.; Ge, X.H.; Neubaue, F.; Friedl, G.; Chang, L.H.; Ren, S.M.; Handler, R. 40Ar/39Ar age evidence for Altyn fault tectonic activities in western China. Chin. Sci. Bull. 2003, 48, 2024–2030. (In Chinese) [Google Scholar] [CrossRef]
  22. Li, H.B.; Yang, J.S.; Xu, Z.Q.; Wu, C.L.; Wan, Y.S.; Shi, R.D.; Liou, J.G.; Tapponnier, P.; Ireland, T.R. Geological and chronological evidence of Indo-Chinese strike-slip movement in the Altyn Tagh fault zone. Chin. Sci. Bull. 2002, 47, 28–33. [Google Scholar] [CrossRef]
  23. Wang, Y.; Zhang, X.M.; Wang, E.; Zhang, J.F.; Li, Q.; Sun, G.H. 40Ar/39Ar thermochronological evidence for formation and Mesozoic evolution of the northern-central segment of the Altyn Tagh fault system in the northern Tibetan Plateau. Geol. Soc. Am. Bull. 2005, 117, 1336–1346. [Google Scholar] [CrossRef]
  24. Liu, Y.J.; Franz, N.; Ge, X.H.; Johann, G.; Yuan, S.H.; Li, W.M.; Gong, Q.L.; Chen, Y.Z. Geochronology of the Altun Fault zone and rising of the Altun Mountains. Chin. J. Geol. 2007, 42, 134–146. (In Chinese) [Google Scholar]
  25. Zhu, L.D.; Wang, C.S.; Zheng, R.C.; Li, X.H.; Ran, B.; Wang, M.F.; Liu, Y.C.; Li, F.Q.; Liu, H.J. Evolutionary characteristics of the Jiuquan basin and character of the Kuantaishan-Heishan fault on the northeastern margin of the Qinghai-Tibet Plateau. Geol. Bull. China 2005, 24, 837–840. (In Chinese) [Google Scholar]
  26. Tang, W.H.; Zhang, Z.C.; Li, J.F.; Chen, C.; Li, K. Geochemical characteristics and tectonic significance of the Cretaceous volcanic rocks in the Eastern Terminal of the Altyn Tagh fault zones. Earth Sci. Front. 2012, 19, 051–062. (In Chinese) [Google Scholar]
  27. Li, H.B.; Yang, J.S.; Xu, Z.Q.; Sun, Z.M.; Tapponnier, P. The constraint of the Altyn Tagh fault system to the growth and rise of the northern Tibetan plateau. Earth Sci. Front. 2006, 13, 059–079. (In Chinese) [Google Scholar]
  28. Liu, L.; Wang, C.; Chen, D.L.; Zhang, A.D.; Liou, J.G. Petrology and geochronology of HP-UHP rocks from the South Altyn Tagh, northwestern China. J. Asian Earth Sci. 2009, 35, 232–244. [Google Scholar] [CrossRef]
  29. Wang, C.; Liu, L.; Yang, W.Q.; Zhu, X.H.; Cao, Y.T.; Kang, L.; Chen, S.F.; Li, R.S.; He, S.P. Provenance and ages of the Altyn Complex in Altyn Tagh: Implications for the early Neoproterozoic evolution of northwestern China. Precambrian Res. 2013, 230, 193–208. [Google Scholar] [CrossRef]
  30. Liu, Q.; Zhao, G.C.; Li, J.H.; Yao, J.L.; Han, Y.G.; Wang, P.; Tsunogae, T. Provenance of early Paleozoic sedimentary rocks in the Altyn Tagh orogen: Insights into the paleoposition of the Tarim craton in northern Gondwana associated with final closure of the Proto-Tethys Ocean. GSA Bull. 2020, 133, 505–522. [Google Scholar] [CrossRef]
  31. Zhang, M.Z.; Ji, L.M.; Du, B.X.; Dai, S.; Hou, X.W. Palynology of the Early Cretaceous Hanxia Section in the Jiuquan Basin, Northwest China: The discovery of diverse early angiosperm pollen and paleoclimatic significance. Palaeogeogr. Palaeoclimatol. Palaeoecol. 2015, 440, 297–306. [Google Scholar] [CrossRef]
  32. Ma, B.; Ji, L.M.; Jin, P.H.; Zhang, M.Z.; Yuan, B.C.; Long, L.W. Geochemical characteristics and depositional paleoenvironment of source rocks from the Lower Cretaceous Chijinbao Formation in Jiuxi Basin, China. J. Pet. Sci. Eng. 2022, 210, 109968. [Google Scholar] [CrossRef]
  33. Kuang, H.W.; Liu, Y.Q.; Liu, Y.X.; Peng, N.; Xu, H.; Dong, C.; Chen, J.; Liu, H.; Xu, J.L.; Xue, P.L. Stratigraphy and depositional palaeogeography of the Early Cretaceous basins in Da Hinggan Mountains-Mongolia orogenic belt and its neighboring areas. Geol. Bull. China 2013, 32, 1063–1084. (In Chinese) [Google Scholar]
  34. Lai, S.C. Petrogenesis of the Cenozoic volcanic rocks from the northern part of the Qinghai-Tibet Plateau. Acta Petrol. Sin. 1999, 15, 98–104. (In Chinese) [Google Scholar]
  35. Hellstrom, J.; Paton, C.; Woodhead, J.; Hergt, J. Iolite: Software for spatially resolved LA-(quad and MC) ICPMS analysis. Mineral. Assoc. Can. Short Course Ser. 2008, 40, 343–348. [Google Scholar]
  36. Ludwig, K.R. User’s Manual for Isoplot 3.00: A Geochronological Toolkit for Microsoft Excel; Berkeley Geochronology Center Special Publication, No. 4; Berkeley Geochronology Center: Berkeley, CA, USA, 2003; pp. 1–70. [Google Scholar]
  37. Ma, Q.; Zheng, J.P.; Griffin, W.L.; Zhang, M.; Tang, H.Y.; Su, Y.P.; Ping, X.Q. Triassic “adakitic” rocks in an extensional setting (North China): Melts from the cratonic lower crust. Lithos 2012, 149, 159–173. [Google Scholar] [CrossRef]
  38. Winchester, J.A.; Floyd, P.A. Geochemical discrimination of different magma series and their differentiation products using immobile elements. Chem. Geol. 1977, 20, 325–343. [Google Scholar] [CrossRef]
  39. Hastie, A.R.; Kerr, A.C.; Pearce, J.A.; Mitchell, S.F. Classification of altered volcanic island arc rocks using immobile trace elements: Development of the Th–Co discrimination diagram. J. Petrol. 2007, 48, 2341–2357. [Google Scholar] [CrossRef]
  40. Defant, M.J.; Jackson, T.E.; Drummond, M.S.; DeBoer, J.Z.; Bellon, H.; Feigenson, M.D.; Maury, R.C.; Stewart, R.H. The geochemistry of young volcanism throughout western Panama and southeastern Costa Rica: An overview. J. Geol. Soc. 1992, 149, 569–579. [Google Scholar] [CrossRef]
  41. Azizi, H.; Asahara, Y.; Tsuboi, M. Quaternary high-Nb basalts: Existence of young oceanic crust under the Sanandaj-Sirjan Zone, NW Iran. Int. Geol. Rev. 2013, 56, 167–186. [Google Scholar] [CrossRef]
  42. Sun, S.S.; McDonough, W.F. Chemical and isotopic systematics of oceanic basalts: Implications for mantle composition and processes. Geol. Soc. Lond. Spec. Publ. 1989, 42, 313–345. [Google Scholar] [CrossRef]
  43. McDonough, W.F.; Sun, S.S. The composition of the Earth. Chem. Geol. 1995, 120, 223–253. [Google Scholar] [CrossRef]
  44. Kelemen, P.B.; Hanghøj, K.; Greene, A.R. One View of the Geochemistry of Subduction-Related Magmatic Arcs, with an Emphasis on Primitive Andesite and Lower Crust; Elsevier: Amsterdam, The Netherlands, 2014; pp. 749–806. [Google Scholar]
  45. Sun, T.; Qian, Z.Z.; Li, C.; Xia, M.Z.; Yang, S.H. Petrogenesis and economic potential of the Erhongwa mafic-ultramafic intrusion in the Central Asian Orogenic Belt, NW China: Constraints from olivine chemistry, U-Pb age and Hf isotopes of zircons, and whole-rock Sr-Nd-Pb isotopes. Lithos 2013, 182, 185–199. [Google Scholar] [CrossRef]
  46. Zindler, A.; Hart, S.R. Chemical geodynamics. Annu. Rev. Earth Planet. Sci. 1986, 14, 493–571. [Google Scholar] [CrossRef]
  47. Rudnick, R.L.; Gao, S. Composition of the Continental Crust. Treatise Geochem. 2014, 4, 1–51. [Google Scholar] [CrossRef]
  48. Hart, S.R. Heterogeneous mantle domains: Signature, genesis and mixing chronologies. Earth Planet. Sci. Lett. 1988, 90, 273–296. [Google Scholar] [CrossRef]
  49. Wilson, M. Igneous Petrogenesis; InHarper Collins Academic: London, UK, 1989; Volume 466. [Google Scholar]
  50. Staudigel, H.; Zindler, A.; Hart, S.R.; Leslie, T.; Chen, C.Y.; Clague, D. The isotope systematic of a juvenile intraplate volcano: Pb, Nd and Sr isotope ratios of basalts from Loihi Seamount, Hawaii. Earth Planet. Sci. Lett. 1984, 69, 13–29. [Google Scholar] [CrossRef]
  51. Lin, Q.C.; Xia, B.; Zhang, Y.Q. 40Ar-39Ar datings for volcanic rocks from Karakorum-Kunlun mountains, west China, and its geological. Chin. J. Geol. 2007, 42, 388–394. (In Chinese) [Google Scholar]
  52. Ding, R.; Luan, P.; Yu, H.M.; Wei, F.X.; Zhao, B.; Yang, W.J.; Xu, J.D. Study on the magmatic processes of post-collisional potassic volcanic rocks from west Kunlun: Taking the Pulu and Kangxiwa volcanic rocks as examples. Seismol. Geol. 2024, 46, 312–335. (In Chinese) [Google Scholar]
  53. Xu, J.D.; Zhao, B.; Sindney, H.; Chen, Z.Q.; Zhang, L.Y. Geological features and eruption history of Ashikule volcano clusters in western Kunlun Mountain. Acta Petroiogica Sin. 2014, 30, 3521–3530. (In Chinese) [Google Scholar]
  54. Xu, J.D.; Zhao, B.; Yu, H.M.; Wei, F.X.; Chen, Z.Q. Volcanic geology and petrochemistry of Ashikule volcanic field in western Kunlun Mountains of the Tibetan plateau. Geol. Soc. Lond. Spec. Publ. 2021, 510, 133–146. [Google Scholar] [CrossRef]
  55. Yang, J.S.; Meng, F.C.; Zhang, J.X.; Li, H.B. The shoshonitic volcanic rocks at Hongliuxia: Pulses of the Altyn Tagh fault in Cretaceous? Sci. China Ser. D Earth Sci. 2001, 44, 94–102. [Google Scholar] [CrossRef]
  56. Wang, X.L.; Zhou, H.R.; Wang, Z.T.; Gao, Z.S.; Yang, L.C.; Zhang, H.J.; Yu, Z.D.; Jv, P.C. Late Early Cretaceous Magmatic Event in Hongliuxia in Eastern Sector of the Altyn Tagh Fault, and Its Regional Tectonic Implications. Geoscience 2018, 32, 1–15. (In Chinese) [Google Scholar]
  57. Niu, Y.; O’Hara, M.J. MORB mantle hosts the missing Eu (Sr, Nb, Ta and Ti) in the continental crust: New perspectives on crustal growth, crust-mantle differentiation and chemical structure of oceanic upper mantle. Lithos 2009, 112, 1–17. [Google Scholar] [CrossRef]
  58. Hastie, A.R.; Mitchell, S.F.; Kerr, A.C.; Minifie, M.J.; Millar, I.L. Geochemistry of rare high-Nb basalt lavas: Are they derived from a mantle wedge metasomatised by slab melts? Geochim. Cosmochim. Acta 2011, 75, 5049–5072. [Google Scholar] [CrossRef]
  59. Castillo, P.R.; Solidum, R.U.; Punongbayan, R.S. Origin of high field strength element enrichment in the Sulu Arc, southern Philippines, revisited. Geology 2002, 30, 707–710. [Google Scholar] [CrossRef]
  60. Castillo, P.R.; Rigby, S.J.; Solidum, R.U. Origin of high field strength element enrichment in volcanic arcs: Geochemical evidence from the Sulu Arc, southern Philippines. Lithos 2007, 97, 271–288. [Google Scholar] [CrossRef]
  61. Castillo, P.R. Origin of the adakite high-Nb basalt association and its implications for postsubduction magmatism in Baja California, Mexico. Geol. Soc. Am. Bull. 2008, 120, 451–462. [Google Scholar] [CrossRef]
  62. Hao, L.L.; Wang, Q.; Zhang, C.; Ou, Q.; Yang, J.H.; Dan, W.; Jiang, Z.Q. Oceanic plateau subduction during closure of the Bangong—Nujiang Tethyan Ocean: Insights from central Tibetan volcanic rocks. GSA Bull. 2019, 131, 864–880. [Google Scholar] [CrossRef]
  63. Zhang, Y.Y.; Yuan, C.; Sun, M.; Long, X.P.; Huang, Z.Y.; Jiang, Y.D.; Li, P.F.; Du, L. Two late Carboniferous belts of Nb-enriched mafic magmatism in the Eastern Tianshan: Heterogeneous mantle sources and geodynamic implications. Bulletin 2020, 132, 1863–1880. [Google Scholar] [CrossRef]
  64. Smithies, R.H.; Champion, D.C.; VanKranendonk, M.J.; Howard, H.M.; Hickman, A.H. Modern-style subduction processes in the Mesoarchaean: Geochemical evidence from the 3.12 Ga Whundo intra-oceanic arc. Earth Planet. Sci. Lett. 2005, 231, 221–237. [Google Scholar] [CrossRef]
  65. Hofmann, A.W.; Jochum, K.P.; Seufert, M.; White, W.M. Nb and Pb in oceanic basalts: New constraints on mantle evolution. Earth Planet. Sci. Lett. 1986, 79, 33–45. [Google Scholar] [CrossRef]
  66. Ji, Z.; Zhang, Y.L.; Wan, C.B.; Ge, W.C.; Yang, H.; Dong, Y.; Jing, Y. Recycling of crustal materials and implications for lithospheric thinning: Evidence from Mesozoic volcanic rocks in the Hailar–Tamtsag Basin, NE China. Geosci. Front. 2021, 12, 101184. [Google Scholar] [CrossRef]
  67. Jing, Y.; Ge, W.C.; Santosh, M.; Dong, Y.; Yang, H.; Ji, Z.; Bi, J.H.; Zhou, H.Y.; Xing, D.H. Generation of Nb-enriched mafic rocks and associated adakitic rocks from the southeastern Central Asian Orogenic Belt: Evidence of crust-mantle interaction. Geosci. Front. 2022, 13, 101341. [Google Scholar] [CrossRef]
  68. Kepezhinskas, P.; Defant, M.J.; Drummond, M.S. Progressive enrichment of island arc mantle by melt-peridotite interaction inferred from Kamchatka xenoliths. Geochim. Cosmochim. Acta 1996, 60, 1217–1229. [Google Scholar] [CrossRef]
  69. Defant, M.J.; Drummond, M.S. Derivation of some modern arc magmas by melting of young subducted lithosphere. Nature 1990, 347, 662–665. [Google Scholar] [CrossRef]
  70. Class, C.; Miller, D.M.; Goldstein, S.L.; Langmuir, C.H. Distinguishing melt and fluid subduction components in Umnak Volcanics, Aleutian Arc. Geochem. Geophys. Geosyst. 2000, 1, 1004. [Google Scholar] [CrossRef]
  71. Zheng, Y.F. Subduction zone geochemistry. Geosci. Front. 2019, 10, 1223–1254. [Google Scholar] [CrossRef]
  72. Woodhead, J.D.; Hergt, J.M.; Davidson, J.P.; Eggins, S.M. Hafnium isotope evidence for ‘conservative’ element mobility during subduction zone processes. Earth Planet. Sci. Lett. 2001, 192, 331–346. [Google Scholar] [CrossRef]
  73. Elliott, T.; Plank, T.; Zindler, A.; White, W.; Bourdon, B. Element transport from slab to volcanic front at the Mariana arc. J. Geophys. Res. Solid Earth 1997, 102, 14991–15019. [Google Scholar] [CrossRef]
  74. Pearce, J.A.; Stern, R.J.; Bloomer, S.H.; Fryer, P. Geochemical mapping of the Mariana arc-basin system: Implications for the nature and distribution of subduction components. Geochem. Geophys. Geosyst. 2005, 6, Q07006. [Google Scholar] [CrossRef]
  75. Zhu, D.C.; Zhao, Z.D.; Niu, Y.L.; Dilek, Y.; Wang, Q.; Ji, W.H.; Dong, G.C.; Sui, Q.L.; Liu, Y.S.; Yuan, H.L.; et al. Cambrian bimodal volcanism in the Lhasa Terrane, southern Tibet: Record of an early Paleozoic Andean-type magmatic arc in the Australian proto-Tethyan margin. Chem. Geol. 2012, 328, 290–308. [Google Scholar] [CrossRef]
  76. Perfit, M.R.; Gust, D.A.; Bence, A.E.; Arculus, R.J.; Taylor, S.R. Chemical characteristics of island-arc basalts: Implications for mantle sources. Chem. Geol. 1980, 30, 227–256. [Google Scholar] [CrossRef]
  77. Plank, T.; Langmuir, C.H. The chemical composition of subducting sediment and its consequences for the crust and mantle. Chem. Geol. 1998, 145, 325–394. [Google Scholar] [CrossRef]
  78. Johnson, M.C.; Plank, T. Dehydration and melting experiments constrain the fate of subducted sediments. Geochem. Geophys. Geosyst. 2000, 1, 1007. [Google Scholar] [CrossRef]
  79. Zhang, X.Z.; Dong, Y.S.; Wang, Q.; Dan, W.; Zhang, C.F.; Deng, M.R.; Xu, W.; Xia, X.P.; Zeng, J.P.; Liang, H. Carboniferous and Permian evolutionary records for the Paleo-Tethys Ocean constrained by newly discovered Xiangtaohu ophiolites from central Qiangtang, central Tibet. Tectonics 2016, 35, 1670–1686. [Google Scholar] [CrossRef]
  80. Pearce, J.A. Trace element characteristics of lavas from destructive plate boundaries. Orogenic Andesites and Related Rocks; John Wiley and Sons: Chichester, UK, 1982; pp. 528–548. [Google Scholar]
  81. Shervais, J.W. Ti-V plots and the petrogenesis of modern and ophiolitic lavas. Earth Planet. Sci. Lett. 1982, 59, 101–118. [Google Scholar] [CrossRef]
  82. Neal, C.R.; Mahoney, J.J.; CHAZEY III, W.J. Mantle sources and the highly variable role of continental lithosphere in basalt petrogenesis of the Kerguelen Plateau and Broken Ridge LIP: Results from ODP Leg 183. J. Petrol. 2002, 43, 1177–1205. [Google Scholar] [CrossRef]
  83. Reubi, O.; Blundy, J. A dearth of intermediate melts at subduction zone volcanoes and the petrogenesis of arc andesites. Nature 2009, 461, 1269–1273. [Google Scholar] [CrossRef] [PubMed]
  84. Kent, A.J.R.; Darr, C.; Koleszar, A.M.; Salisbury, M.J.; Cooper, K.M. Preferential eruption of andesitic magmas through recharge filtering. Nat. Geosci. 2010, 3, 631–636. [Google Scholar] [CrossRef]
  85. Lee, C.T.A.; Bachmann, O. How important is the role of crystal fractionation in making intermediate magmas? Insights from Zr and P systematics. Earth Planet. Sci. Lett. 2014, 393, 266–274. [Google Scholar] [CrossRef]
  86. Lee, C.T.A.; Lee, T.C.; Wu, C.T. Modeling the compositional evolution of recharging, evacuating, and fractionating (REFC) magma chambers: Implications for differentiation of arc magmas. Geochim. Cosmochim. Acta 2014, 143, 8–22. [Google Scholar] [CrossRef]
  87. Gómez-Tuena, A.; Straub, S.M.; Zellmer, G.F. An introduction to orogenic andesites and crustal growth. Geol. Soc. Lond. Spec. Publ. 2013, 385, 1–13. [Google Scholar] [CrossRef]
  88. Chen, L.; Zhao, Z.F. Origin of continental arc andesites: The composition of source rocks is the key. J. Asian Earth Sci. 2017, 145, 217–232. [Google Scholar] [CrossRef]
  89. Rapp, R.P.; Shimizu, N.; Norman, M.D.; Applegate, G.S. Reaction between slab-derived melts and peridotite in the mantle wedge: Experimental constraints at 3.8 GPa. Chem. Geol. 1999, 160, 335–356. [Google Scholar] [CrossRef]
  90. Pearce, J.A. The role of sub-continental lithosphere in magma genesis at active continental margins. In Continental Basalts and Mantle Xenoliths; Shiva: Cheshire, UK, 1983; pp. 230–249. [Google Scholar]
  91. Tischendorf, G.; Paelchen, W. Zur Klassifikation von Granitoiden. Z. Fuer Geol. Wiss. 1985, 13, 615–627. [Google Scholar]
  92. Zheng, Y.F.; Zhao, Z.F.; Chen, R.X. Ultrahigh-pressure metamorphic rocks in the Dabie-Sulu orogenic belt: Compositional inheritance and metamorphic modification. Geol. Soc. Lond. Spec. Publ. 2019, 474, 89–132. [Google Scholar] [CrossRef]
  93. Chen, X.H.; Yin, A.; Gehrels, G.E.; Cowgill, E.S.; Grove, M.; Harrison, T.M.; Wang, X.F. Two phases of Mesozoic north-south extension in the eastern Altyn Tagh range, northern Tibetan Plateau. Tectonics 2003, 22, 8. [Google Scholar] [CrossRef]
  94. Sun, Z.M.; Li, H.B.; Pei, J.L.; Xu, W.; Pan, J.W.; Si, J.L.; Zhao, L.S.; Zhao, Y. Strike-slip movement of the Altyn Tagh fault and implications for mountain formation inferred from paleomagnetic data in northeastern Tibetan Plateau. Acta Petrol. Sin. 2012, 28, 1928–1936. (In Chinese) [Google Scholar]
  95. Peng, N.; Kuang, H.W.; Liu, Y.Q. Sedimentary evolution and palaeogeography of the Early Cretaceous basins from the northern Qilian Mountains to Jiuxi areas. Earth Sci. Front. 2011, 18, 077–087. (In Chinese) [Google Scholar]
  96. Zhu, D.C.; Li, S.M.; Cawood, P.A.; Wang, Q.; Zhao, Z.D.; Liu, S.A.; Wang, L.Q. Assembly of the Lhasa and Qiangtang terranes in central Tibet by divergent double subduction. Lithos 2016, 245, 7–17. [Google Scholar] [CrossRef]
  97. Yang, Y.T.; Guo, Z.X.; Luo, Y.J. Middle-Late Jurassic tectonostratigraphic evolution of Central Asia, implications for the collision of the Karakoram-Lhasa Block with Asia. Earth-Sci. Rev. 2017, 166, 83–110. [Google Scholar] [CrossRef]
  98. Yang, Y.T. An unrecognized major collision of the Okhotomorsk Block with East Asia during the Late Cretaceous, constraints on the plate reorganization of the Northwest Pacific. Earth-Sci. Rev. 2013, 126, 96–115. [Google Scholar] [CrossRef]
  99. Yang, Y.T.; Guo, Z.X.; Song, C.C.; Li, X.B.; He, S. A short-lived but significant Mongol Okhotsk collisional orogeny in latest Jurassic–earliest Cretaceous. Gondwana Res. 2015, 28, 1096–1116. [Google Scholar] [CrossRef]
  100. Pearce, J.A.; Norry, M.J. Petrogenetic implications of Ti, Zr, Y, and Nb variations in volcanic rocks. Contrib. Mineral. Petrol. 1979, 69, 33–47. [Google Scholar] [CrossRef]
  101. Wang, Y.L.; Zhang, C.J.; Xiu, S.Z. Th/Hf-Ta/Hf identification of tectonic setting of basalts. Acta Petrol. Sin. 2001, 17, 413–421. (In Chinese) [Google Scholar]
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Figure 1. (a) Geotectonic map of the Tibetan Plateau showing the geotectonic location of the ATF [14]; (b) geologic map of the ATF showing the spatial and temporal distribution of the volcanic rocks of the ATF and the location of sampling of the chronological samples in this paper [14,28].
Figure 1. (a) Geotectonic map of the Tibetan Plateau showing the geotectonic location of the ATF [14]; (b) geologic map of the ATF showing the spatial and temporal distribution of the volcanic rocks of the ATF and the location of sampling of the chronological samples in this paper [14,28].
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Figure 2. Geological map of the study area and sampling locations (modified from the 1:20,000 regional geological map of the Changma, Yumen City, Jien’en Temple and Yumen Town formations, surveyed by the Second Regional Survey Team of the Gansu Provincial Bureau of Geology from 1965 to 1972).
Figure 2. Geological map of the study area and sampling locations (modified from the 1:20,000 regional geological map of the Changma, Yumen City, Jien’en Temple and Yumen Town formations, surveyed by the Second Regional Survey Team of the Gansu Provincial Bureau of Geology from 1965 to 1972).
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Figure 3. (a) Field photograph of the Beidayao basalt; (b,c) Field photographs of the Hanxia andesite; (d) Field photograph of the Jianquanzi basalt; (e) Field photograph of the Hongliuxia andesite; (f) Field photograph of the Hongliuxia dacite; (g) Microscopic orthogonal polarized photograph of the Beidayao basalt; (h) Microscopic orthogonal polarized photograph of the Hanxia andesite; (i) Microscopic orthogonal polarized photograph of the Hongliuxia dacite. Mineral abbreviations: Ol—olivine; Cpx—Clinopyroxene; Pl—Plagioclase; Cal—calcite; Bi—Biotite.
Figure 3. (a) Field photograph of the Beidayao basalt; (b,c) Field photographs of the Hanxia andesite; (d) Field photograph of the Jianquanzi basalt; (e) Field photograph of the Hongliuxia andesite; (f) Field photograph of the Hongliuxia dacite; (g) Microscopic orthogonal polarized photograph of the Beidayao basalt; (h) Microscopic orthogonal polarized photograph of the Hanxia andesite; (i) Microscopic orthogonal polarized photograph of the Hongliuxia dacite. Mineral abbreviations: Ol—olivine; Cpx—Clinopyroxene; Pl—Plagioclase; Cal—calcite; Bi—Biotite.
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Figure 4. (a) Cathodoluminescence image of representative zircon from the Hongliuxia Dacite sample; (b) Concordia diagram and weighted mean plot of zircon U-Pb ages for the Hongliuxia dacite.
Figure 4. (a) Cathodoluminescence image of representative zircon from the Hongliuxia Dacite sample; (b) Concordia diagram and weighted mean plot of zircon U-Pb ages for the Hongliuxia dacite.
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Figure 5. (a) Zr/TiO2 vs. Nb/Y diagram [39]; (b) Th vs. Co diagram [40].
Figure 5. (a) Zr/TiO2 vs. Nb/Y diagram [39]; (b) Th vs. Co diagram [40].
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Figure 6. Maps of standardized partitioning patterns for rare earth element globular meteorites (a,c) and trace element raw mantle standardized spider diagrams (b,d) for volcanic rocks in the study area. Chondrite and primitive mantle values from Sun and McDonough (1989) and McDonough and Sun (1995) [42,43]; OIB data from Sun and McDonough (1989) [42], MORB and CAA data from Kelemen et al. (2014) [44].
Figure 6. Maps of standardized partitioning patterns for rare earth element globular meteorites (a,c) and trace element raw mantle standardized spider diagrams (b,d) for volcanic rocks in the study area. Chondrite and primitive mantle values from Sun and McDonough (1989) and McDonough and Sun (1995) [42,43]; OIB data from Sun and McDonough (1989) [42], MORB and CAA data from Kelemen et al. (2014) [44].
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Figure 7. εNd (t) vs. (87Sr/86Sr)i diagram [45]; DMM data from Zindler and Hart (1986) [46], LC and UC data from Rudnick and Gao (2014) [47], EMI and EMII data from Hart (1988) [48], MORB from Wilson (1989) [49], OIB from Staudigel et al. (1984) [50].
Figure 7. εNd (t) vs. (87Sr/86Sr)i diagram [45]; DMM data from Zindler and Hart (1986) [46], LC and UC data from Rudnick and Gao (2014) [47], EMI and EMII data from Hart (1988) [48], MORB from Wilson (1989) [49], OIB from Staudigel et al. (1984) [50].
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Figure 8. (a) Nb/La vs. MgO diagram; (b) La/Sm vs. MgO diagram; (c) Th/Nb vs. MgO diagram; (d) SiO2 vs. MgO diagram; (e) Fe2O3T vs. MgO diagram; (f) Cr vs. MgO diagram; (g) Ni vs. MgO diagram; (h) Al2O3 vs. MgO diagram; (i) Dy/Yb vs. MgO diagram.
Figure 8. (a) Nb/La vs. MgO diagram; (b) La/Sm vs. MgO diagram; (c) Th/Nb vs. MgO diagram; (d) SiO2 vs. MgO diagram; (e) Fe2O3T vs. MgO diagram; (f) Cr vs. MgO diagram; (g) Ni vs. MgO diagram; (h) Al2O3 vs. MgO diagram; (i) Dy/Yb vs. MgO diagram.
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Figure 11. A schematic tectonic reconstruction of Central Asia during the Early Cretaceous [99].
Figure 11. A schematic tectonic reconstruction of Central Asia during the Early Cretaceous [99].
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Figure 12. (a) Zr/Y vs. Zr diagram [100]; (b) Th/Hf vs. Ta/Hf diagram [101]; I. N-MORB area at the divergent edge of the plate; II. Plate convergence edge (II1. Oceanic island arc basalt area; II2. Basalt areas of continental margin island arcs and volcanic arcs); III. Basalt areas of oceanic islands and seamounts within the oceanic plate, as well as T-MORB and E-MORB areas; IV. Within the continental plate (IV1. Within the continental rift and continental margin rift areas of tholeiite; IV2. Intracontinental rift alkaline basalt area; IV3. Basalt areas in continental tension zones); V. Mantle plume basalt region.
Figure 12. (a) Zr/Y vs. Zr diagram [100]; (b) Th/Hf vs. Ta/Hf diagram [101]; I. N-MORB area at the divergent edge of the plate; II. Plate convergence edge (II1. Oceanic island arc basalt area; II2. Basalt areas of continental margin island arcs and volcanic arcs); III. Basalt areas of oceanic islands and seamounts within the oceanic plate, as well as T-MORB and E-MORB areas; IV. Within the continental plate (IV1. Within the continental rift and continental margin rift areas of tholeiite; IV2. Intracontinental rift alkaline basalt area; IV3. Basalt areas in continental tension zones); V. Mantle plume basalt region.
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Table 1. Sampling location and lithology of the study area.
Table 1. Sampling location and lithology of the study area.
SampleLocationLat. (°N)Long. (°E)Rock Type
24HX-04~20 km southeast of Hongliuxia39°48′41″97°13′36″Andesite
24HX-05~20 km southeast of Hongliuxia39°48′40″97°13′5″Andesite
24HX-06~20 km southeast of Hongliuxia39°48′40″97°13′5″Andesite
24HLX-01~50 km south of Yumen City39°58′39″97°09′30″Andesite
24HLX-02~50 km south of Yumen City39°58′39″97°09′30″Andesite
24HLX-03~50 km south of Yumen City39°58′39″97°09′30″Dacite
24BDY-01~20 km west of Hongliuxia40°0′53″96°52′15″Basalt
24BDY-02~20 km west of Hongliuxia40°0′52″96°52′12″Basalt
24BDY-04~20 km west of Hongliuxia40°0′47″96°52′13″Basalt
24JQZ-05~10 km southwest of Changma Township39°45′8″96°44′1″Basalt
24JQZ-07~10 km southwest of Changma Township39°45′8″96°44′1″Basalt
Table 2. Zircon U-Pb age data for the Hongliuxia dacite in the eastern section of the ATF.
Table 2. Zircon U-Pb age data for the Hongliuxia dacite in the eastern section of the ATF.
Point No.Element Contents (ppm) and RatioIsotope Ratio and ErrorAge (Ma) and ErrorConcordance (%)
UThTh/U207Pb/
206Pb		1σ207Pb/
235U		1σ206Pb/
238U		1σ207Pb/
206Pb		1σ207Pb/
235U		1σ206Pb/
238U		1σ
24HLX-03 011901140.6010.041700.003250.101170.008180.017340.00037−19313198811120.88
24HLX-03 025094730.9290.054780.000790.534450.008220.070690.0004040324435544020.99
24HLX-03 035553090.5560.049610.001930.114320.004330.016950.0001817769110410811.02
24HLX-03 042581140.4410.048000.002540.107860.005380.016610.000239986104510610.98
24HLX-03 058153490.4280.046690.001000.106320.002070.016820.000163328103210810.95
24HLX-03 061001171.1720.051550.003730.111470.007440.016570.00032266117107710621.01
24HLX-03 072411030.4280.054400.003780.121620.007580.016860.00032388106117710821.08
24HLX-03 081071201.1210.052330.003850.119000.008870.016680.00028300140114810721.07
24HLX-03 092011600.7960.045800.002550.102700.005600.016450.00018−129599510510.94
24HLX-03 10105690.6600.056810.004320.125990.008970.016620.00035484120120810621.13
24HLX-03 113481010.2900.050090.002180.115760.004950.016850.0001819980111510811.03
24HLX-03 123661660.4520.048360.002770.109260.005650.016930.0002911786105510820.97
24HLX-03 134524541.0060.047750.001800.109570.004050.016710.0001587671064106.910.99
24HLX-03 14218430.1950.048190.002150.108580.004650.016310.00016109801054104.311.01
24HLX-03 15500610.1220.070880.000701.506500.015240.153380.0008495412933692051.01
24HLX-03 16115790.6850.052320.003120.117240.006580.016650.0003029995113610621.07
24HLX-03 172201870.8510.053760.002350.121190.004930.016790.0002336167116410711.08
24HLX-03 18132750.5680.047860.002780.111160.006410.016680.0002493101107610721.00
24HLX-03 193081920.6220.050920.002260.118110.005320.016530.0001823784113510611.07
24HLX-03 204532010.4430.048610.001910.120820.004290.018300.0002012963116411710.99
Table 3. Results of whole-rock major and trace element data for volcanic rocks in the study area.
Table 3. Results of whole-rock major and trace element data for volcanic rocks in the study area.
Sample24HX-0424HX-0524HX-0624HLX-0124HLX-0224BDY-0124BDY-0224BDY-0424JQZ-0524JQZ-07
Rock TypeAndesiteAndesiteAndesiteAndesiteAndesiteBasaltBasaltBasaltBasaltBasalt
Major elements (wt.%)
SiO262.7955.7957.7361.8361.1448.4049.6448.3547.6747.95
TiO20.540.920.940.860.851.761.841.751.741.78
Al2O39.2015.0015.2618.1418.4714.7715.8914.4315.1815.59
Fe2O3T3.605.726.646.626.2210.199.1910.3410.7310.45
MnO0.100.130.150.180.140.140.120.140.150.11
MgO2.634.896.682.632.398.037.118.788.366.81
CaO8.974.952.471.310.917.787.417.908.528.83
Na2O1.986.674.861.251.303.343.133.073.573.54
K2O1.280.110.443.574.362.162.322.151.160.99
P2O50.160.220.220.150.140.630.670.620.430.44
LOI8.835.895.053.013.802.302.111.802.352.83
Total100.10100.29100.4399.5599.7399.5099.4399.3199.8699.32
Trace elements (ppm)
Li29.240.671.218893.111.818.611.416.323.5
Be1.290.951.132.823.201.762.181.681.771.76
Sc8.9819.118.220.620.323.024.723.624.625.7
V60.5115136135135174180166165173
Cr89.0220220120116256223269243255
Co12.023.927.324.823.541.837.641.842.143.1
Ni37.012413258.156.3128104136146152
Cu23.726560.360.056.446.246.844.456.865.0
Zn47.491.993.793.597.391.188.789.678.581.3
Ga10.917.317.123.624.318.520.918.017.618.4
Rb57.12.2211.216220127.231.328.98.293.82
Sr16499.235823311914548961035604590
Y26.322.518.933.432.421.523.621.924.024.6
Zr252131135178173163197147185188
Nb10.87.557.8917.216.429.031.327.230.531.3
Sn1.761.231.263.863.171.551.621.451.701.76
Cs4.080.972.127.755.340.860.290.625.626.04
Ba44732.383.31134100487080526514331588
La29.215.524.248.850.143.645.842.427.327.9
Ce56.337.644.893.293.387.189.784.351.853.6
Pr6.914.765.2610.810.910.811.410.36.276.43
Nd25.217.619.837.637.940.142.538.324.024.4
Sm5.284.164.137.757.537.117.546.715.065.16
Eu1.151.151.291.701.672.152.272.221.651.82
Gd5.034.324.036.796.795.946.385.675.145.44
Tb0.800.660.591.091.040.840.890.840.810.86
Dy4.673.933.346.136.044.484.774.334.714.85
Ho0.910.700.651.201.180.790.880.810.880.92
Er2.551.951.803.453.392.182.342.152.452.52
Tm0.380.260.260.510.500.300.320.290.340.35
Yb2.331.601.523.243.171.831.951.802.162.24
Lu0.350.240.230.490.480.270.300.270.320.33
Hf6.763.343.444.994.953.884.503.464.054.12
Ta0.820.530.561.241.221.661.751.561.781.81
Tl0.300.0250.0960.830.880.100.0810.0860.0190.015
Pb12.013.222.233.831.68.569.338.325.265.38
Th10.64.894.9417.717.53.463.903.683.163.20
U2.681.761.714.053.210.820.920.841.021.05
Nb/Y0.410.330.420.510.511.351.331.251.271.27
Nb/U4.034.284.614.245.1135.4233.9832.4829.8029.80
Sr/Y6.214.4018.986.993.6867.4837.9947.3025.1023.97
(La/Yb)N9.006.9611.4110.8311.3417.1016.8216.959.078.93
Table 4. Results of whole-rock Sr-Nd isotope data for volcanic rocks in the study area.
Table 4. Results of whole-rock Sr-Nd isotope data for volcanic rocks in the study area.
SampleAge
(Ga)		Sm
(ppm)		Nd (ppm)147Sm
/144Nd		143Nd
/144Nd		Error
(2s)		(143Nd/
144Nd)i		εNd (t)tDM2
(Ga)		Rb
(ppm)		Sr
(ppm)		87Rb
/86Sr		87Sr
/86Sr		Error
(2s)		(87Sr/86Sr)i
24HX-060.1204.1319.80.1260.5125040.0000060.512405−1.51.011.23580.0910.7099760.0000060.70982
24HLX-010.1127.7537.60.1240.5120050.0000050.511914−11.31.81622332.0060.7197770.0000060.71658
24BDY-020.1177.5442.50.1070.5124000.0000050.512318−3.31.231.38960.1010.7062230.0000070.70605
24BDY-040.1176.7138.30.1060.5124030.0000040.512322−3.21.228.910350.0810.7072190.0000080.70708
24JQZ-050.1185.0624.00.1270.5126250.0000070.5125270.80.98.296040.0400.7063110.0000100.70624
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Qin, L.-Q.; Bai, Y.; An, Y.; Wang, J.-L.; Ma, Y.-Y.; Lu, H.-X.; Luo, Y.-H. The Early Cretaceous High-Nb Basalt and Arc Andesite Association in the Eastern Segment of the Altyn Tagh Fault: Petrological Records of Intracontinental Extension. Minerals 2025, 15, 1103. https://doi.org/10.3390/min15111103

AMA Style

Qin L-Q, Bai Y, An Y, Wang J-L, Ma Y-Y, Lu H-X, Luo Y-H. The Early Cretaceous High-Nb Basalt and Arc Andesite Association in the Eastern Segment of the Altyn Tagh Fault: Petrological Records of Intracontinental Extension. Minerals. 2025; 15(11):1103. https://doi.org/10.3390/min15111103

Chicago/Turabian Style

Qin, Lu-Qing, Yong Bai, Yu An, Jin-Lin Wang, Ying-Ying Ma, Hai-Xin Lu, and Yu-Hang Luo. 2025. "The Early Cretaceous High-Nb Basalt and Arc Andesite Association in the Eastern Segment of the Altyn Tagh Fault: Petrological Records of Intracontinental Extension" Minerals 15, no. 11: 1103. https://doi.org/10.3390/min15111103

APA Style

Qin, L.-Q., Bai, Y., An, Y., Wang, J.-L., Ma, Y.-Y., Lu, H.-X., & Luo, Y.-H. (2025). The Early Cretaceous High-Nb Basalt and Arc Andesite Association in the Eastern Segment of the Altyn Tagh Fault: Petrological Records of Intracontinental Extension. Minerals, 15(11), 1103. https://doi.org/10.3390/min15111103

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