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Article

Geochemistry and U–Pb Chronology of the Triassic Yanchang Formation in the Southern Ordos Basin, China: Implications for Provenance and Geological Setting

by
Fenhong Luo
1,
Hujun Gong
1,*,
Hang Liu
1,
Bin Lv
2 and
Dali Xue
2
1
State Key Laboratory of Continental Dynamics, Department of Geology, Northwest University, Xi’an 710069, China
2
Liaohe Oilfield Company Qingyang Exploration and Development Branch, Yan’an 716200, China
*
Author to whom correspondence should be addressed.
Minerals 2025, 15(3), 233; https://doi.org/10.3390/min15030233
Submission received: 29 December 2024 / Revised: 24 February 2025 / Accepted: 25 February 2025 / Published: 26 February 2025
(This article belongs to the Section Mineral Geochemistry and Geochronology)
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Abstract

:
During the deposition of the Middle–Upper Triassic Yanchang Formation, the southern margin of the Ordos Basin (OB) serves as a critical area for investigating the tectonic interactions between the North China Block (NCB) and Qinling Orogenic Belt (QOB). The provenance record of this sedimentary succession can be utilized to trace basin–mountain interactions using petrological, geochemical, and zircon age geochronological studies. We analyzed lithic fragments, geochemistry, and detrital zircon U–Pb ages of samples from the Xunyi Sanshuihe field profile, Weibei Uplift. Discrimination diagrams of major and trace elements revealed provenances and tectonic-sedimentary settings. Middle–Upper Triassic sandstones comprise quartz, feldspar, and lithic fragments. Their compositions are plotted within recycled orogenic and magmatic arc provenance fields. Multiple element diagrams reveal a felsic igneous rock provenance. Detrital zircon age spectra display four prominent age groups, which are ca. 240–270, 410–450, 1800–2200, and 2400–2600 Ma, and one minor age group, that is, 870–1197 Ma in the Late Triassic sample. We conclude that the provenance of the Yanchang Formation changed significantly during the Middle–Late Triassic. The Late Triassic sediments were mainly QOB-derived, and the basement was from the NCB. The pre-Triassic strata and Longmen pluton in the southwest of OB were the provenance of Middle Triassic sediments. The QOB suffered rapid uplift and denudation, resulting in rapid deposition and deep-water deposition in the southern OB, which provides excellent conditions for the high-quality oil shale of Ch 7.

1. Introduction

The composition of clastic sediments is mainly controlled by the original composition of source rocks [1,2]. The characteristics of the source rocks can be determined by studying sediments. Many analytical tools are available for quantifying sediment properties (e.g., isotopic, mineral, chemical, and petrographic compositions; grain size and shape distributions; age spectra) [3]. Because a single method may have limitations, combining multiple methods should be used to constrain the source area and interpret ancient sediment routing systems.
The southern Ordos Basin (OB) lies within the transitional zone connecting the OB and Qinling Orogenic Belt (QOB). Triassic strata are extensively exposed in the southern OB and its adjacent areas, preserving critical records of tectonic events and sedimentary transport systems in the South China Block (SCB) and the North China Block (NCB). The Triassic was the main period during which the NCB and SCB collided [4,5,6,7,8,9,10]. The closure of the Mianlue Ocean between the NCB and SCB greatly influenced its sedimentary characteristics. Chemical composition and sedimentary provenance are keys to understanding sedimentary basin and basin–orogeny systems. The Yanchang Formation of the Middle–Upper Triassic represents the first oil-producing strata after forming the inland lake basin in the OB [11,12]. A suite of lacustrine sedimentary rocks within the Yanchang Formation offers crucial data for recovering the evolutionary history of basin–mountain coupling processes.
Many researchers have focused on the eastern, southwestern, and southeastern OB [10,13,14,15]. Researchers have recently begun to use detrital zircons to study Triassic strata in the southern OB [6,16,17]. Xie and Heller [6] used detrital zircon data from the Yanchang Formation of the southern OB. They suggested that Middle Triassic sandstone mostly originated from pre-Triassic rocks in the NCB. Other researchers believe that the northern margins of the NCB, QOB, and previous clastic rocks of the eastern NCB provided clastics for the southern OB during the Middle Triassic [16,17]. Most of the previous studies on the provenance of the southern OB concentrated on the Middle Triassic [6,16,17]. They did not involve the Late Triassic or even throughout the Middle–Late Triassic, which limits the comprehensive discussion of the provenance region and the provenance change. Their provenances and tectonic settings remain debatable during the Triassic.
In this study, the comprehensive composition of sandstone clasts, detrital zircon U–Pb geochronology, and mudstone geochemistry were utilized to study the provenance, provenance change, and geological setting throughout the Middle–Late Triassic Yanchang Formation in the Sanshuihe profile of Xunyi City, southern OB. The results provide insights into the provenance, depositional system, and evolution of QOB and its effect on sedimentation and oil–gas accumulation in the southern OB during the Middle–Late Triassic.

2. Geological Setting

The OB is the second-largest sedimentary basin in the southwestern region of the NCB (Figure 1). It is enriched with multiple energy resources such as oil, gas, coal, coalbed methane, and uranium ore [11,12]. The OB is a large, intracontinental basin surrounded by several orogenic belts. Geographically, the OB is surrounded by the Yinshan, Lüliang, QOB, Liupan, and Helan Mountains (Figure 1). The OB can be divided into six first-order tectonic units: Yimeng Uplift, Yishan Slope, southern Weibei Uplift, Western Thrust Zone, western Tianhuan Depression, and Jinxi Flexural Fold Belt (Figure 1). The Sanshuihe profile is located in Xunyi City, within the Weibei Uplift subunit in the southern OB. The Weibei Uplift has a crystalline basement similar to the OB [12]. The stratigraphic sequence, arranged from the oldest to the youngest formations, spans from the Proterozoic to the Cretaceous periods. Notably, Silurian to Early Carboniferous and Upper Cretaceous strata are absent. The Middle–Late Triassic Yanchang Formation consists of fluviolacustrine terrigenous clastic deposits predominantly composed of medium–thick gray and gray–green sandstones interbedded with dark gray and gray–black shale layers (Figure 2). Based on the petroleum geological characteristics and sedimentary cycles, the Yanchang Formation is subdivided into ten members, known as Chang (Ch) 10 at the base to Ch1 at the top [18]. The top of the Yanchang Formation (Ch 1–Ch 3) was eroded by tectonic uplift (Figure 2) in the study area.

3. Sampling and Analytical Methods

Fresh samples were collected from the southern OB from Sanshuihe outcrop, Xunyi City (Figure 1). We defined each member of the Yanchang Formation by marker layer, such as the bottom of Ch 7, which was identified by the “Zhangjiatan” oil shale (Figure 3b,d), and the lithological combination and thickness from the nearby area’s well.
All samples were analyzed at the State Key Laboratory of Continental Dynamics, Northwest University, Xi’an, China. We made six thin sections per sample for statistical analysis of detrital composition, carried out under a Nikon (E200, Beijing, China) microscope. The zircons’ cathodoluminescence (CL) imaging was conducted for internal structure using an electron microscope (FEI Quanta 400 FEG, Brno, Czech Republic). Subsequently, U–Th–Pb isotope and trace elements analyses were conducted on randomly selected zircon grains using laser ablation inductively coupled plasma mass spectrometry (LA–ICP–MS). Elemental analyses were conducted using an X-ray fluorescence spectrometer (Rigaku RIX 2100, Tokyo, Japan). Trace elements were analyzed using an ICP–MS (Agilent 7500a, Santa Clara, CA, USA). Please refer to the literature for detailed analysis procedures and instrument parameters [21].

4. Results

4.1. Petrography and Detrital Composition of Sandstones

The sandstone from Ch 6 was dominated by quartz (37–60%), rock fragments (14–47%), and feldspar fragments (12–44%; Figure 4a). It mainly falls within the feldspatho–litho–quartzose and recycled orogenic provenance fields (Figure 5). The sandstone from Ch 7 was dominated by quartz (39–44%), rock fragments (14–25%), and feldspar fragments (17–40%; Figure 4b). It mainly falls within the feldspatho–litho–quartzose, litho–feldspatho–quartzose, and recycled orogenic provenance fields (Figure 5). The sandstone from Ch 8 was dominated by quartz (32–58%), rock fragments (9–45%), and feldspar fragments (14–30%; Figure 4c). It mainly falls within the feldspatho–quartzo–lithic, feldspatho–litho–quartzose, and recycled orogenic and magmatic arc provenance fields (Figure 5). The sandstone from Ch 9 was dominated by quartz (20–30%), rock fragments (11–49%), and feldspar fragments (12–61%; Figure 4d). It mainly falls within the quartzo–litho–feldspathic, quartzo–feldspatho–lithic, and magmatic arc provenance fields (Figure 5).
The sandstone from the Middle–Late Triassic Yanchang Formation unit (Ch 9–Ch 6) in the southern OB is compositionally immature. The sandstone from the Yanchang Formation is primarily fine and medium grain. Volcanic, metamorphic, and sedimentary lithics generally characterize rock fragments.

4.2. Detrital Zircon U–Pb Ages of Sandstones

Detrital zircon ages and trace elements are presented in Supplementary Table S1. We randomly analyzed 120 zircon grains from each sample. Zircons from all samples exhibit long to short columnar shapes with clear magmatic oscillatory zones (Figure 6). Most of the Th/U ratios of the zircons exceed the value of 0.2, indicating that they are derived from a magmatic provenance [24] (Figure 7). The zircon U-Pb ages were analyzed, with data selected within a concordance range of 0.9 to 1.1. For 206Pb/238U ages older than 1000 Ma, 207Pb/206Pb ratios were used for the calculation (concordance = (207Pb/206Pb age)/(206Pb/238U age), whereas 206Pb/238U ratios were utilized for those younger than 1000 Ma (concordance = (207Pb/235U age)/(206Pb/238U age).
Sample SSH-28 from the Ch 6 member yielded 104 concordant data. Detrital zircon U–Pb ages range from 249 to 2694 Ma (Figure 7a). Three predominant age populations were defined: 249–298, 391–488, and 1702–2101 Ma, with peaks at ~269, 434, and 1877 Ma. Two subordinate age groups, 870–1197 and 2270–2694 Ma, with peaks at ~936 and 2450 Ma, were also defined (Figure 7b).
Sample SSH-18 from the Ch 7 member yielded 102 concordant data. Detrital zircon U–Pb ages range from 230 to 2748 Ma (Figure 7c). Three major age groups were identified, which are 230–284, 1651–1996, and 2413–2748 Ma, with peaks at ~254, 1870, and 2537 Ma, in addition to one minor age group at 1870–2537 Ma and one subordinate peak at ~2020 Ma (Figure 7d).
Sample CSH-01 from the Ch 8 member yielded 80 concordant data. Detrital zircon U–Pb ages range from 209 to 2517 Ma (Figure 7e), showing two predominant groups of ages at 2209–326 and 2374–2626 Ma and one minor age group at 1647–2049 Ma. Two prominent peaks are evident in the age spectra, centered at ~240 and 2487 Ma, in addition to one subordinate peak at ~1858 Ma (Figure 7f).
Sample SSH-12 from the Ch 9 member yielded 86 concordant data. Detrital zircon U–Pb ages range from 234 to 2799 Ma (Figure 7g). Two prominent age groups were identified: 234–261 and 2385–2799 Ma, with peaks at ~240 and 2480 Ma. One subordinate age group, 1643–2173 Ma, which peaked at ~1820 Ma, was also identified (Figure 7h).

4.3. Mudstone Geochemistry

The major and trace element contents of mudstone are listed in Supplementary Table S2. Mudstones were enriched in SiO2 and Al2O3, ranging from 51.62 to 62.14 wt.% and 15.59 to 17.25 wt.%, respectively. The TiO2 content varied between 0.68 and 0.84 wt.%, and the Al2O3/TiO2 ratio ranged from 20.04 to 24.82. The K2O/Na2O ratio varied from 1.58 to 21.40, and the CaO content varied between 0.55 and 3.24 wt.%.
The UCC (upper continental crust)-normalized trace element diagram showed an overall depletion of Hf, Sr, Ni, and the enrichment of Cu, Ga, Cs, and Nb compared with the UCC (Figure 8a). The analyzed samples exhibited relatively high total rare earth element (REE) contents (ΣREE = 138–384 ppm, avg. 197 ppm). Clear fractionation between light and heavy REEs was observed, with (La/Yb) N ratios varying between 8.64 and 14.12. The chondrite-normalized REE diagram was a rightward-inclined curve with a notable negative Eu anomaly (δEu = 2 ∗ EuN/ (SmN + GdN) = 0.61–0.77; Figure 8b).

5. Discussion

5.1. Source Rock Type

The petrological and geochemical characteristics of clastic materials offer significant data regarding the tectonic environment of a basin and the sedimentary sources [1,2,27]. The clastic composition of the sampled sandstones suggests that they were derived from recycled orogenies and magmatic arc provenances (Figure 5) [23]. We can conclude that almost all Middle Triassic (Ch 9 and Ch 8) detritus was derived from magmatic arc provenances. In contrast, most of the detritus during the Late Triassic (Ch 7 and Ch 6) originated from recycled orogenic regions, processing a notably greater quartz proportion in comparison to those from magmatic arc sources (Figure 5); this can be explained by the contribution from the QOB [6].
Several geochemical indicators can be used to distinguish the source rock type. For instance, Hayashi et al. [28] showed that Al2O3/TiO2 ratios indicate differing characteristics of rock source types. The Al2O3/TiO2 ratios of 3–8, 8–21, and 21–70 signify mafic, intermediate, and felsic igneous rock provenance, respectively. The mudstones from the Yanchang Formation have Al2O3/TiO2 ratios ranging from 20 to 25 (avg. 22), suggesting mainly felsic igneous rock provenances (Figure 9a). Furthermore, some trace elements, including Th, Hf, Zr, Sc, Ni, and REEs, are applicable for reflecting the provenance of sediments. We use multiple-element discriminant diagrams to differentiate the types of source rocks. The Zr/Sc and Th/Sc ratios are efficacious approaches for discerning the parent rock’s composition. In the Th/Sc versus Zr/Sc diagram (Figure 9b), all data exhibited a pattern conforming to the compositional variations, implying that the composition of all samples was predominantly governed by igneous differentiation related to their source rocks and was scarcely influenced by zircon enrichment caused by the sedimentary sorting and recycling process [29,30,31]. The sampled sedimentary rocks also show a low La/Th ratio (3.00~5.99) and Hf (3.13~5.39) value and suggest the component is primarily derived from an acidic arc source [32] (Figure 9c). In the TiO2 versus Ni diagram, all sampled clastic rocks are plotted in magmatic trend (Figure 9d) [33], and the Ni (24.59~50.61 ppm) content consists of acid and intermediate magmatic rocks [33]. Right-inclined chondrite-normalized REE patterns and Eu-negative anomalies (Figure 8b) also indicate that these mudstones originated from felsic or intermediate igneous rocks. Therefore, the main source rocks of the Yanchang Formation clastics are felsic magmatic rocks.

5.2. Potential Provenances

The dispersion of detrital zircons correlates to the history of possible tectonic event provenances, and provenance area analysis can be carried out through their comparison. The detrital zircon CL images and Th/U values suggest a primary magmatic origin for the provenances [24], and whole-rock geochemistry implies that these mudstones originated from acidic igneous rocks (Figure 9). Therefore, to identify the provenances of detrital zircons from the Yanchang Formation in the Xunyi area of the southern OB, we conducted a statistical analysis of regional magmatic events (crystallization ages of magmatic rocks) from potential source areas of the southern OB.
The outcomes indicate that the Precambrian NCB basement is distinguished by magmatic occurrences approximately at 2500 and 1800 Ma, along with a small number of magmatic activities at 2000–2300 and around 2700 Ma [34,35,36,37,38,39,40,41]. The QOB is on the southern margin of the OB and is divided into two parts by the Shangdan suture zone: South Qinling Belt (SQB) and North Qinling Belt (NQB). The NQB is marked by the occurrence of a great number of early Neoproterozoic (900–1000 Ma) and early Paleozoic (400–520 Ma) intrusive bodies, whereas the SQB is characterized by Neoproterozoic (670–840 Ma) and Mesozoic (100–250 Ma) zircon ages [8,42,43,44,45,46]. Many Mesozoic magmatic rocks (114~248 Ma) also developed in the western part of the NQB, such as the Taibai pluton [47]. To the northwest, the Qilian Orogenic Belt (QiOB) has experienced polycyclic tectonic events and preserved many periods of granitic magmatism activities, that is, mainly concentrated on 1192–736, 516–350, and 271–211 Ma, with minor ~2400 and ~1800 Ma granitic magmatism [48]. Simultaneously, the paleoflow indicates a S–N direction [7,15]; thus, a provenance supply from the north can be excluded. Hence, the Central Asian Orogenic Belt (CAOB) in the basin’s northern section is excluded from the current analysis.

5.3. Sedimentary Provenance Analysis

Based on the age proportion of studied detrital zircons, age distributions were mainly concentrated in three different periods, which are the Permian, Silurian, and Paleoproterozoic, with major populations of ~2400–2600, 1800–2200, 410–450, and 240–270 Ma. Only one Late Triassic sample (Ch 6: SSH-28) showed a minor age concentration during the Neoproterozoic, with an age probability peak at ~936 Ma (Figure 7b). To systematically analyze the provenance contribution, we summarized the results of previous research on different parts of the Yanchang Formation in the southern OB. Because the strata above Ch 6 were less preserved in the southern OB, they were denuded by late uplift [20]. The late Triassic includes the Ch 6 and Ch 7 members from the southern OB [15,16], which shows the same characteristics as the Ch 6 in this study, with the age group of 400~500 and 800~1000 Ma (Figure 10a). The Ch 7~9 members have consistent age composition features with middle Triassic data as previous studies [6,7,17] (Figure 10b). It shows that there are obvious provenance changes from the Middle–Late Triassic.
The Late Triassic Ch 6 member in this study and Ch 7 member from Sun et al. [15] shows a minor age concentration during the Neoproterozoic, with an age probability peak at ~936 and 950 Ma, consistent with the granite age (929–955 Ma) within the NQB [43] and QiOB [48] (Figure 11), which proves a QOB and QiOB provenance of this age group. However, this age group is missing from this study’s Middle Triassic of Yanchang Formation; this precludes the QOB and QiOB as provenance areas in the Middle Triassic, as any records from the provenance region before the depositional age may be preserved. Paleocurrent analysis revealed that the provenance direction of this area was near-north (335°, 340°) during the Middle–Late Triassic [7,15]. QiOB is located west of the study area, implying that this group probably mainly originated from the southern QOB.
The two oldest populations (1800–2200 and 2400–2600 Ma) are most likely inherited from the NCB (Figure 11); zircons of these age groups are widespread throughout the NCB and recorded crustal accretion [41,49]. The youngest group (240–270 Ma) is considered to have originated from the QOB (Figure 11) during the Late Triassic, which developed a large amount of granite body of the SQB and West Qinling [43,47]. Researchers have argued that these zircons were derived from the CAOB to the north [16,17]. However, at this time, the depositional center was located in the Huachi–Zhengning area, and the study area was south of the depositional center. Therefore, it was difficult for the provenance of the CAOB to cross the depositional center to reach the study area, which rules out the possibility of a CAOB provenance.
For the age group of 410–450 Ma, it is generally believed that they all come from QOB and QiOB [14,17], since the development of intense magmatism corresponds to this age. Meanwhile, a lot of Neoproterozoic magmatism was reported in QOB and QiOB [43], which cannot be ignored. The 410–450 Ma age group in the Middle Triassic should not come from QOB and QiOB, the Late Triassic, and vice versa. We can also find that the detrital age group of 410–450 Ma derived from QOB in the Ch 6 member has increased significantly (Figure 7b); this indicates the possibility of a larger contribution of the QOB during Late Triassic, which is similar to the detrital composition study, indicating that the NQB terrane was rapidly uplifted during this time, providing massive provenance for the southern OB in the Late Triassic.
The sediments in the Middle Triassic could have been eroded from older continental arcs that were active long before the Triassic of sedimentation in the OB, which has a similar age spectrum (Figure 11g), except for the youngest group (240–270 Ma). In the Middle Triassic, the youngest group could not derive from QOB because it was ruled out as a source area. The pre-Triassic strata’s youngest peak (~280 Ma) is greater than 240 Ma; this means that the youngest group could not have come from the pre-Triassic strata. Researchers have found a Mesozoic Longmen pluton in southwest OB, aged ~242 Ma [50], which should be the provenance of the youngest age group in the Triassic.
In summary, the detrital zircon chronology and geochemistry data obtained in this study indicate that the provenances of the Yanchang Formation in southern OB significantly changed during the Middle–Late Triassic. The Middle Triassic strata were derived from the pre-Triassic sedimentary rocks and Longmen pluton. The Late Triassic strata were mainly derived from the QOB and NCB basement. The provenance contribution of the QOB significantly added during the Late Triassic.
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Figure 11. Igneous rock U–Pb age distribution of the potential provenance of the southern OB (data sources: see text). Igneous zircon age distributions for Qilian orogeny (a), Qiling Orogen (b), and North China Block (h), detrital zircon age distributions of this study (c–f), and pre-Triassic strata (g) (obtained from Li et al. [51]).
Figure 11. Igneous rock U–Pb age distribution of the potential provenance of the southern OB (data sources: see text). Igneous zircon age distributions for Qilian orogeny (a), Qiling Orogen (b), and North China Block (h), detrital zircon age distributions of this study (c–f), and pre-Triassic strata (g) (obtained from Li et al. [51]).
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5.4. Tectonic Implications

The tectonic activities, which govern the subsidence speed, landform, configuration, and sediment influx of sedimentary basins, along with the regional climate conditions, might prompt the accumulation of materials within the lacustrine system. The detrital deposits in the peripheral basins, originating from the neighboring orogeny, precisely document the constituents of their source areas and offer indications regarding the evolutionary processes of the orogenic belts [52,53,54]. The southern OB is adjacent to the QOB, and collisional orogenic and uplift denudation in the Qinling area directly controls and influences the sedimentary tectonic environment and provenance material composition of the southern OB. All mudstones within the four studied members’ plots in continental island arc areas in the trace element ternary diagrams (Figure 12a,b) and the active continental margin fields in the major element cross-plot diagrams (Figure 12c,d). Based on these graphical analyses, the tectonic setting of the provenance system was dominated by a continental island arc and an active continental margin during the Middle–Late Triassic.
The cumulative distribution curves of detrital zircons clarify the differences in tectonic conditions within the source regions recognized in this research [54]. It can be concluded that the Middle Triassic (Ch 8 and Ch 9) samples reflect a convergent setting (crystallization age (CA)–depositional age (DA) < 100 Ma at 30% of the youngest zircon). The Late Triassic samples (Ch 6 and Ch 7) reflect a collisional basin setting (150 > CA–DA > 100 Ma at 30% of youngest zircon; Figure 13), which reflects the ongoing northward subduction and collision of the Mianlue Ocean between the NCB and SCB during the Middle–Late Triassic; this is consistent with a sedimentary shift causing the change in the types of sandstone and mineral components during the Middle–Late Triassic [55].
The evolution of QOB mainly influenced the sedimentary system in the southern OB. The results of this study show that the detrital composition shows obvious changes in the provenance of the Middle and Late Triassic, and the Late Triassic deposition of the Ch 6 member in the southern OB involved detrital zircon predominantly derived from the NQB, suggesting that the NQB terrane experienced remarkable uplift and denudation in the Late Triassic; this indicates that the Mianlue Ocean had been closed by this moment. It follows that the northward thrusting within the QOB, along with the related crustal thickening in this area during the Late Triassic and the consequent large-scale uplift of the QOB, produced copious detrital materials, which were deposited to form the upper Triassic Yanchang Formation in the southern OB. This conclusion is consistent with the results of previous studies.
The QOB has experienced multiple stages of metamorphic, magmatic, and orogenic processes. In the Triassic, collision orogeny occurred mainly along the Mianlue suture zone [5,56]. Researchers previously suggested that the Mianlue Ocean initiated its subduction along the southern margin of the QOB during the Early Triassic (~250 Ma). During the middle stage of the Late Triassic (~220–210 Ma), the progressive subduction of the Mianlue oceanic crust resulted in a collision between the NCB and SCB [8,56], resulting in the uplift and erosion of QOB. Wang et al. [57] also obtained the QOB uplift and erosion during Late Triassic by the granite 40Ar/39Ar geochronology. Many magmatic rocks occurred along with the subduction and collision of orogenic belts, which we can find the tuff in the Ch 7 member, providing more productivity for the source rock in Ch 7 [58]. At the same time, the uplift of QOB led to rapid deposition and deep-water deposition in the southern OB, which provided conditions for developing high-quality hydrocarbon source rocks of Ch 7, which is the well-known “Zhangjiatan” oil shale.
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Figure 12. Discrimination diagrams of the tectonic setting for the Yanchang Formation provenance area in the southern OB. (a) La–Th–Sc ternary plot, (b) Th–Sc–Zr/10 ternary plot, (c) K2O/Na2O–SiO2 cross-plot, and (d) SiO2/Al2O3–K2O/Na2O cross-plot (after [29,59,60]).
Figure 12. Discrimination diagrams of the tectonic setting for the Yanchang Formation provenance area in the southern OB. (a) La–Th–Sc ternary plot, (b) Th–Sc–Zr/10 ternary plot, (c) K2O/Na2O–SiO2 cross-plot, and (d) SiO2/Al2O3–K2O/Na2O cross-plot (after [29,59,60]).
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Figure 13. Cumulative probability curves of detrital zircons for different basin settings (after Cawood et al. [54]).
Figure 13. Cumulative probability curves of detrital zircons for different basin settings (after Cawood et al. [54]).
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6. Conclusions

(1) Detrital zircon age distributions were mainly concentrated in four periods: ~240–270, ~410–450, ~1800–2200, and 2400–2600 Ma. Only one Late Triassic sample (Ch 6: SSH-28) showed a minor age concentration during the Neoproterozoic, with an age probability peak at ~936 Ma.
(2) Combining our results with the detrital composition, zircon chronology, and geochemical analysis, we conclude that the Yanchang Formation’s provenance significantly changed during the Middle–Late Triassic. The Late Triassic sediments were mainly derived from the QOB and Precambrian basement within the NCB. In contrast, the Middle Triassic sedimentary rocks were mainly derived from pre-Triassic strata and the Longmen pluton southwest of OB.
(3) The Middle and Late Triassic were characterized by convergent and collisional basin settings, respectively. These settings were closely related to the collision of NCB and SCB, which resulted in the rapid uplift of the QOB and deep-water deposition in the southern OB; this provides excellent conditions for the high-quality oil shale of Ch 7.

Supplementary Materials

The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/min15030233/s1, Table S1: Zircon U–Pb data of Yanchang Formation in southern Ordos Basin; Table S2: Geochemical data of Yanchang Formation in southern Ordos Basin.

Author Contributions

Writing—original draft preparation, F.L. and H.G.; writing—review and editing, H.L.; resources, B.L.; data curation, D.X. All authors have read and agreed to the published version of the manuscript.

Funding

This research was funded by the National Natural Science Foundation of China, grant number 42172010.

Data Availability Statement

The data presented in this study are openly available in article.

Conflicts of Interest

Authors Hang Liu, Bin Lv and Dali Xue was employed by the company Liaohe Oilfield Company Qingyang Exploration and Development Branch. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

References

  1. Madhavaraju, J. Geochemistry of Late Cretaceous sedimentary rocks of the Cauvery Basin, south India: Constraints on paleo-weathering, provenance, and end Cretaceous environments. Chemostratigraphy 2015, 124, 185–214. [Google Scholar]
  2. Verma, S.P.; Armstrong-Altrin, J.S. Geochemical discrimination of siliciclastic sediments from active and passive margin settings. Sediment. Geol. 2016, 332, 1–12. [Google Scholar] [CrossRef]
  3. Caracciolo, L.; Garzanti, E.; von Eynatten, H.; Weltje, G.J. Sediment generation and provenance: Processes and pathways. Sediment. Geol. 2016, 336, 1–2. [Google Scholar] [CrossRef]
  4. Hacker, B.R.; Ratschbacher, L.; Webb, L.; McWilliams, M.O.; Ireland, T.; Calvert, A.; Dong, S.; Wenk, H.-R.; Chateigner, D. Exhumation of ultrahigh-pressure continental crust in east Central China: Late Triassic-Early Jurassic tectonic unroofing. J. Geophys. Res. 2000, 105, 13339–13364. [Google Scholar] [CrossRef]
  5. Zhang, G.W.; Zhang, B.R.; Yuan, X.C.; Xiao, Q.H. Qinling Orogenic Belt and Continental Dynamics; Sci. Press: Beijing, China, 2001; pp. 1–874. [Google Scholar]
  6. Xie, X.Y.; Heller, P.L. U-Pb Detrital zircon geochronology and its implications: The early Late Triassic Yanchang Formation, south Ordos Basin, China. J. Asian Earth Sci. 2013, 64, 86–98. [Google Scholar] [CrossRef]
  7. Xie, X.Y. Provenance and sediment dispersal of the Triassic Yanchang Formation, southwest Ordos Basin, China, and its implications. Sediment. Geol. 2016, 335, 1–16. [Google Scholar] [CrossRef]
  8. Dong, Y.P.; Santosh, M. Tectonic architecture and multiple orogeny of the Qinling Orogenic Belt, central China. Gondwana Res. 2016, 29, 1–40. [Google Scholar] [CrossRef]
  9. Meng, Q.R.; Wu, G.L.; Fan, L.G.; Wei, H.H. Tectonic evolution of Early Mesozoic sedimentary basins in the North China block. Earth Sci. Rev. 2019, 190, 416–438. [Google Scholar] [CrossRef]
  10. Xu, Y.; He, D. Triassic provenance shifts and tectonic evolution of southeast Ordos Basin, Central China. Palaeogeogr. Palaeoclimatol. Palaeoecol. 2022, 598, 111022. [Google Scholar] [CrossRef]
  11. Ren, Z.L.; Yu, Q.; Cui, J.P.; Qi, K.; Chen, Z.J.; Cao, Z.P.; Yang, P. Thermal history and its controls on oil and gas of the Ordos Basin. Earth Sci. Front. 2017, 24, 137–148. [Google Scholar]
  12. Liu, C.Y.; Wang, J.Q.; Zhang, D.D.; Zhao, H.G.; Zhao, J.F.; Huang, L.; Wang, W.Q.; Qin, Y. Genesis of rich hydrocarbon resources and their occurrence and accumulation characteristics in the Ordos Basin. Oil Gas Geol. 2021, 42, 1011–1019. [Google Scholar]
  13. Luo, J.L.; Li, J.; Yang, B.; Dai, Y.; Li, B.; Han, Y.; Wang, H.; Du, J. Provenance for the Chang 6 and Chang 8 Member of the Yanchang Formation in the Xifeng area and in the periphery Ordos Basin: Evidence from petrologic geochemistry. Sci. China Earth Sci. 2007, 50, 75–90. [Google Scholar]
  14. Qiao, X.Y.; Lin, J.; Zhu, Q.; Gong, H.J.; Wang, J.; Li, Z.F. The sedimentary source of Chang 6 Formation in the Huanglong district-southern part of Ordos Basin: The evidence from U-Pb age in zircons. J. Northwest. Univ. (Nat. Sci. Ed.) 2017, 47, 593–607. [Google Scholar]
  15. Sun, D.; Feng, Q.; Liu, Z.; Lu, C.J.; Xia, L. Detrital zircon U-Pb dating of the Upper Triassic Yanchang Formation in southwestern Ordos basin and its provenance significance. Acta Geol. Sin. 2017, 11, 2521–2544. [Google Scholar]
  16. Sun, N.L.; Zhong, J.H.; Ni, L.T.; Hao, B.; Luo, K.; Qu, J.L.; Liu, C.; Yang, G.Q.; Cao, M.C. Provenance analysis and thermal evolution of Upper Triassic Yanchang Formation in southern Ordos Basin. Geol. China 2019, 46, 537–556. [Google Scholar]
  17. Zhang, X.; Meng, X.H.; Wang, D.Y. Provenance analysis of the Middle Triassic Ordos Basin: Constraints from zircon U-Pb geochronology. Geochemistry 2020, 80, 125521. [Google Scholar]
  18. Fu, J.H.; Li, S.X.; Liu, X.Y.; Deng, X.Q. Sedimentary facies and its evolution of the Chang 9 interval of Upper Triassic Yanchang Formation in Ordos Basin. J. Palaeogr. 2012, 14, 0269–0284. [Google Scholar]
  19. Yang, P.; Ren, Z.L.; Fu, J.H.; Bao, H.P.; Xiao, H.; Shi, Z.; Wang, K.; Zhang, Y.Y.; Liu, W.H.; Li, W.H. A tectono-thermal perspective on the petroleum generation, accumulation and preservation in the southern Ordos Basin, North China. Petrol. Sci. 2024, 21, 1459–1473. [Google Scholar] [CrossRef]
  20. Li, W.H.; Chen, Q.; Li, K.Y.; Zhang, Q.; Li, Y.H.; Ma, Y.; Feng, J.P.; Guo, Y.Q.; Yuan, Z.; Ouyang, Z.J.; et al. Atlas of Sedimentary Facies and Field Profile of Ordos Basin; Geol. Publishing House: Beijing, China, 2023; pp. 287–288. [Google Scholar]
  21. Luo, F.H.; Gong, H.J.; Liu, H. Early-Paleozoic rapakivi-textured granite from the North Qinling (Central China): Implications for crust–mantle interactions in a post-collisional setting. Mineral. Petrol. 2024, 118, 281–303. [Google Scholar]
  22. Garzanti, E. From static to dynamic provenance analysis—Sedimentary petrology upgraded. Sediment. Geol. 2016, 336, 3–13. [Google Scholar] [CrossRef]
  23. Dickinson, W.R.; Beard, L.S.; Brakenridge, G.R.; Erjavec, J.L.; Ferguson, R.C.; Inman, K.F.; Knepp, R.A.; Lindberg, F.A.; Ryberg, P.T. Provenance of North American Phanerozoic sandstones in relation to tectonic setting. GSA Bull. 1983, 94, 222–235. [Google Scholar] [CrossRef]
  24. Hoskin, P.W.O.; Schaltegger, U. The composition of zircon and igneous and metamorphic petrogenesis. Rev. Mineral. Geochem. 2003, 53, 27–62. [Google Scholar] [CrossRef]
  25. Taylor, S.; Mclennan, S.M. The Continental Crust: Its Composition and Evolution; Blackwell Publishing: Oxford, UK, 1985; pp. 1–312. [Google Scholar]
  26. Sun, S.S.; McDonough, W.F. Chemical and isotopic systematics of oceanic basalts: Implications for mantle composition and processes. Geol. Soc. 1989, 42, 313–345. [Google Scholar] [CrossRef]
  27. Armstrong-Altrin, J.S.; Nagarajan, R.; Balaram, V.; Natalhy-Pineda, O. Petrography and geochemistry of sands from the chachalacasChachalacas and Veracruz beach areas, western Gulf of Mexico, Mexico: Constraints on provenance and tectonic setting. J. S. Am. Earth Sci. 2015, 64, 199–216. [Google Scholar] [CrossRef]
  28. Hayashi, K.I.; Fujisawa, H.; Holland, H.D.; Ohmoto, H. Geochemistry of ca. 1.9 ga sedimentary rocks from northeastern Labrador, Canada. Geochim. Cosmochim. Acta 1997, 61, 4115–4137. [Google Scholar] [CrossRef]
  29. McLennan, S.M.; Hemming, S.; McDaniel, D.K.; Hanson, G.N. Geochemical approaches to sedimentation, provenance, and tectonics. GSA 1993, 284, 21–40. [Google Scholar] [CrossRef]
  30. Armstrong-Altrin, J.S.; Nagarajan, R.; Madhavaraju, J.; Rosalez-Hoz, L.; Lee, Y.I.; Balaram, V.; Cruz-Martínez, A.; Avila-Ramírez, G. Geochemistry of the Jurassic and Upper Cretaceous shales from the Molango Region, Hidalgo, Eastern Mexico: Implications for source-area weathering, provenance, and tectonic setting. C. R. Geosci. 2013, 345, 185–202. [Google Scholar] [CrossRef]
  31. Mongelli, G.; Critelli, S.; Perri, F.; Perrone, V. Sedimentary recycling, provenance and paleoweathering from chemistry and mineralogy of Mesozoic continental redbeds mudrocks, Peloritani Mountains, Southern Italy. Geochem. J. 2006, 40, 12–25. [Google Scholar] [CrossRef]
  32. Floyd, P.A.; Leveridge, B.E. Tectonic environment of the Devonian Gramscatho basin, south Cornwall: Framework mode and geochemical evidence from turbiditic sandstones. J. Geol. Soc. 1987, 144, 531–542. [Google Scholar] [CrossRef]
  33. Floyd, P.A.; Winchester, J.A.; Park, R.G. Geochemistry and tectonic setting of Lewisian clastic metasediments from the Early Proterozoic Loch Maree Group of Gairloch, NW Scotland. Precamb. Res. 1989, 45, 203–214. [Google Scholar] [CrossRef]
  34. Lin, C.L. Geochemistry, Geochronology and Tectonic Settings of Archean Gneisses in Lushan, Henan Province. Master’s Thesis, Northwest University, Xi’an, China, 2006. [Google Scholar]
  35. He, Y.H.; Zhao, G.C.; Sun, M.; Xia, X.P. SHRIMP and LA-ICP-MS zircon geochronology of the Xiong’er volcanic rocks: Implications for the Paleo-Mesoproterozoic evolution of the southern margin of the North China Craton. Precamb. Res. 2009, 168, 213–222. [Google Scholar] [CrossRef]
  36. Huang, X.L.; Niu, Y.L.; Xu, Y.G.; Yang, Q.J.; Zhong, J.W. Geochemistry of TTG and TTG-like gneisses from Lushan-Taihua complex in the southern North China Craton: Implications for late Archean crustal accretion. Precamb. Res. 2010, 182, 43–56. [Google Scholar] [CrossRef]
  37. Diwu, C.R.; Sun, Y.; Lin, C.L.; Wang, H.L. LA-(MC)-ICPMS U–Pb zircon geochronology and Lu–Hf isotope compositions of the Taihua Complex on the southern margin of the North China Craton. Chin. Sci. Bull. 2010, 55, 2557–2571. [Google Scholar] [CrossRef]
  38. Diwu, C.R.; Sun, Y.; Zhang, H.; Wang, Q.; Guo, A.; Fan, L. Episodic tectonothermal events of the western North China Craton and North Qinling Orogenic Belt in central China: Constraints from detrital zircon U–Pb ages. J. Asian Earth Sci. 2012, 47, 107–122. [Google Scholar] [CrossRef]
  39. Zhang, J.; Zhang, H.F.; Lu, X.X. Zircon U–Pb age and Lu–Hf isotope constraints on Precambrian evolution of continental crust in the Songshan area, the south-central North China Craton. Precamb. Res. 2013, 226, 1–20. [Google Scholar] [CrossRef]
  40. Yu, X.Q.; Liu, J.L.; Li, C.L.; Chen, S.Q.; Dai, Y.P. Zircon U–Pb dating and Hf isotope analysis on the Taihua complex: Constraints on the formation and evolution of the Trans-north China Orogen. Precamb. Res. 2013, 230, 31–44. [Google Scholar] [CrossRef]
  41. Zhao, G.C.; Zhai, M.G. Lithotectonic elements of Precambrian basement in the North China Craton: Review and tectonic implications. Gondwana Res. 2013, 23, 1207–1240. [Google Scholar] [CrossRef]
  42. Wang, T.; Wang, X.X.; Tian, W.; Zhang, C.L.; Li, W.P.; Li, S. North Qinling Paleozoic granite associations and their variation in space and time: Implications for orogenic processes in the orogens of central China. Sci. China Earth Sci. 2009, 52, 1359–1384. [Google Scholar] [CrossRef]
  43. Wang, X.X.; Wang, T.; Zhang, C.L. Granitoid magmatism in the Qinling orogen, central China and its bearing on orogenic evolution. Sci. China Earth Sci. 2015, 58, 1497–1512. [Google Scholar] [CrossRef]
  44. Zhang, C.L.; Liu, L.; Wang, T.; Wang, X.X.; Li, L.; Gong, Q.F.; Li, X.F. Granitic magmatism related to Early Paleozoic continental collision in North Qinling. Chin. Sci. Bull. 2013, 58, 4405–4410. [Google Scholar] [CrossRef]
  45. Qin, J.F.; Lai, S.C.; Long, X.P.; Zhang, Z.Z.; Ju, Y.J.; Zhu, R.Z.; Wang, X.Y.; Li, Y.F.; Wang, J.B.; Li, T. Thermotectonic evolution of the Paleozoic granites along the Shangdan suture zone (Central China): Crustal growth and differentiation by magma underplating in an orogenic belt. GSA Bull. 2021, 133, 523–538. [Google Scholar] [CrossRef]
  46. Qin, J.F.; Lai, S.C.; Zhang, Z.H.; Zhang, Z.Z.; Long, X.P.; Zhu, R.Z. Crustal growth and evolution in convergent margin: Evidence from three Paleozoic granitic pulses in the junction zone between Qinling and Qilian orogenic belt. Lithos 2022, 434, 106938. [Google Scholar] [CrossRef]
  47. Li, X.F.; Li, Y.S.; Dong, G.C.; Lv, X.; Xia, Q. Granitoid magmatism and tectonic evolution in eastern part of West Qinling: Constraints from geochemistry, zircon U-Pb chronology and Hf istopic. Acta Ptrologica Sinca 2021, 37, 1691–1712. [Google Scholar] [CrossRef]
  48. Zhu, X.H.; Chen, D.L.; Feng, Y.M.; Ren, Y.F.; Zhang, X. Granitic magmatism and tectonic evolution in the Qilian Mountain Range in NW China: A review. Earth Sci. Front. 2022, 29, 241–260. [Google Scholar]
  49. Zhai, M. Cratonization and the formation of the North China block. Sci. China Earth Sci. 2011, 41, 1037–1046. [Google Scholar]
  50. Hou, Y.D.; Jiang, Z.W.; Liu, X.S.; Luo, J.L.; Fan, L.Y.; Hu, X.Y.; Du, Y.F. Age and petrogenetic implication of the Early Mesozoic dykes in the southwestern Ordos Basin. Chin. Sci. Bull. 2023, 42, 1098–1117. [Google Scholar] [CrossRef]
  51. Li, D.; Liu, L.; Wang, Z.W.; Hu, C.; Chen, H.D.; Zhu, S.Y.; Zhang, R.; Zhao, F. Tectonosedimentary patterns of multiple interacting source-to-sink systems of the Permian Shanxi Formation, ordos basin, China: Insights from sedimentology and detrital zircon U-Pb geochronology. Mar. Petrol. Geol. 2024, 168, 107034. [Google Scholar] [CrossRef]
  52. Cuthbert, S.J. Evolution of the Devonian Hornelen Basin, west Norway: New constraints from petrological studies of metamorphic clasts. Geol. Soc. Lond. Spec. Publ. 1991, 57, 343–360. [Google Scholar] [CrossRef]
  53. Colombol, F. Normal and reverse unroofing sequences in syntectonic conglomerates as evidence of progressive basin ward deformation. Geol. Soc. Am. 1994, 22, 235–238. [Google Scholar]
  54. Cawood, P.A.; Hawkesworth, C.J.; Dhuime, B. Detrital zircon record and tectonic setting. Geology 2012, 40, 875–878. [Google Scholar] [CrossRef]
  55. Wang, J.Q.; Liu, C.Y.; Guo, Z.; Zhang, D.D. Sedimentary response of regional tectonic transformation in Late Triassic Yanchang period at the central and southern Ordos Basin. Earth Sci. Front. 2015, 22, 194–204. [Google Scholar]
  56. Dong, Y.P.; Sun, S.S.; Santosh, M.; Zhao, J.; Sun, J.; He, D.; Shi, X.; Hui, B.; Cheng, C.; Zhang, G.W. Central China Orogenic Belt and amalgamation of east Asian continents. Gondwana Res. 2021, 100, 131–194. [Google Scholar] [CrossRef]
  57. Wang, F.; Zhu, R.; Hou, Q.; Zheng, D.; Yang, L.; Wu, L.; Shi, W.; Feng, H.; Sang, H.; Zhang, H. 40Ar/39Ar thermochronology on Central China Orogen: Cooling, uplift and implications for orogeny dynamics. Geol. Soc. Lond. Spec. Publ. 2014, 378, 189–206. [Google Scholar] [CrossRef]
  58. Zhang, K.; Liu, R.; Liu, Z. Sedimentary sequence evolution and organic matter accumulation characteristics of the Chang 8–Chang 7 members in the Upper Triassic Yanchang Formation, southwest Ordos Basin, central China. J. Petrol. Sci. Eng. 2021, 196, 107751. [Google Scholar] [CrossRef]
  59. Roser, B.P.; Korsch, R.J. Determination of tectonic setting of sandstone-mudstone suites using SiO2 content and K2O/Na2O ratio. J. Geol. 1986, 94, 635–650. [Google Scholar] [CrossRef]
  60. Bhatia, M.R.; Crook, K.A.W. Trace element characteristics of graywackes and tectonic setting discrimination of sedimentary basins. Contrib. Mineral. Petrol. 1986, 92, 181–193. [Google Scholar] [CrossRef]
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Figure 1. The location and main tectonic units of the Ordos Bain are aligned with the sample location (modified after Yang et al. [19]).
Figure 1. The location and main tectonic units of the Ordos Bain are aligned with the sample location (modified after Yang et al. [19]).
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Figure 2. Simplified stratigraphic histogram of the Yanchang Formation in Sanshuihe outcrop, Xunyi City (modified after Li et al. [20], the color of the lithology column refers to the color of the sedimentary rocks).
Figure 2. Simplified stratigraphic histogram of the Yanchang Formation in Sanshuihe outcrop, Xunyi City (modified after Li et al. [20], the color of the lithology column refers to the color of the sedimentary rocks).
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Figure 3. Field outcrop photos of the Sanshuihe profile, Xunyi city, with sample locations (yellow stars). The red line is the dividing line between the different members. (a) gray-green sandstone, Ch 6 member; (b) grey-white sandstone with oil shale in Ch 7 member and grey sandstone in Ch 8 member; (c) grey sandstone mudstone interlayer in top of Ch 9 member and sandstone in bottom of Ch 8 member; (d) “Zhangjiatan” oli shale in Ch 7 member.
Figure 3. Field outcrop photos of the Sanshuihe profile, Xunyi city, with sample locations (yellow stars). The red line is the dividing line between the different members. (a) gray-green sandstone, Ch 6 member; (b) grey-white sandstone with oil shale in Ch 7 member and grey sandstone in Ch 8 member; (c) grey sandstone mudstone interlayer in top of Ch 9 member and sandstone in bottom of Ch 8 member; (d) “Zhangjiatan” oli shale in Ch 7 member.
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Figure 4. Thin section photomicrographs (cross-polarized) of the sampling horizons of Yanchang Formation sandstones (Kfs: K-feldspar, Ms: muscovite, Qz: quartz, Bt: biotite, Pl: plagioclase, Cal: calcite, Lv: volcanic lithic grains, Lm: metamorphic lithic grains, Ls: sedimentary lithic grains).
Figure 4. Thin section photomicrographs (cross-polarized) of the sampling horizons of Yanchang Formation sandstones (Kfs: K-feldspar, Ms: muscovite, Qz: quartz, Bt: biotite, Pl: plagioclase, Cal: calcite, Lv: volcanic lithic grains, Lm: metamorphic lithic grains, Ls: sedimentary lithic grains).
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Figure 5. (a) Classification of sandstones from Garzanti [22] and (b) classification of provenance types from Dickinson et al. [23].
Figure 5. (a) Classification of sandstones from Garzanti [22] and (b) classification of provenance types from Dickinson et al. [23].
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Figure 6. Typical CL and U–Pb ages of detrital zircon grains with the analysis location (white circle) from the Yanchang Formation.
Figure 6. Typical CL and U–Pb ages of detrital zircon grains with the analysis location (white circle) from the Yanchang Formation.
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Figure 7. U–Pb concordia diagrams with Th/U ratios (a,c,e,g) and the histograms, showing the probability distribution of the age of detrital zircons (b,d,f,h).
Figure 7. U–Pb concordia diagrams with Th/U ratios (a,c,e,g) and the histograms, showing the probability distribution of the age of detrital zircons (b,d,f,h).
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Figure 8. (a) UCC-normalized trace elements diagram and (b) chondrite-normalized REE diagram for mudstone from the southern OB. UCC values were obtained from Taylor et al. [25], and chondrite values were adopted from Sun and McDonough [26].
Figure 8. (a) UCC-normalized trace elements diagram and (b) chondrite-normalized REE diagram for mudstone from the southern OB. UCC values were obtained from Taylor et al. [25], and chondrite values were adopted from Sun and McDonough [26].
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Figure 9. Source rock classification diagrams for Triassic mudstones. (a) Al2O3 versus TiO2 (after Hayashi et al. [28]), (b) Th/Sc versus Zr/Sc (after Mongelli et al. [31]), (c) La/Th versus Hf (after Floyd and Leveridge, [32]) and (d) TiO2 versus Ni (after Floyd et al. [33]).
Figure 9. Source rock classification diagrams for Triassic mudstones. (a) Al2O3 versus TiO2 (after Hayashi et al. [28]), (b) Th/Sc versus Zr/Sc (after Mongelli et al. [31]), (c) La/Th versus Hf (after Floyd and Leveridge, [32]) and (d) TiO2 versus Ni (after Floyd et al. [33]).
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Figure 10. Age spectrum and the histograms, showing the probability distribution of zircon from previous studies. (a) The late Triassic data are from Sun et al. [15,16], and (b) the middle Triassic are from Xie [6,7] and Zhang et al. [17].
Figure 10. Age spectrum and the histograms, showing the probability distribution of zircon from previous studies. (a) The late Triassic data are from Sun et al. [15,16], and (b) the middle Triassic are from Xie [6,7] and Zhang et al. [17].
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Luo, F.; Gong, H.; Liu, H.; Lv, B.; Xue, D. Geochemistry and U–Pb Chronology of the Triassic Yanchang Formation in the Southern Ordos Basin, China: Implications for Provenance and Geological Setting. Minerals 2025, 15, 233. https://doi.org/10.3390/min15030233

AMA Style

Luo F, Gong H, Liu H, Lv B, Xue D. Geochemistry and U–Pb Chronology of the Triassic Yanchang Formation in the Southern Ordos Basin, China: Implications for Provenance and Geological Setting. Minerals. 2025; 15(3):233. https://doi.org/10.3390/min15030233

Chicago/Turabian Style

Luo, Fenhong, Hujun Gong, Hang Liu, Bin Lv, and Dali Xue. 2025. "Geochemistry and U–Pb Chronology of the Triassic Yanchang Formation in the Southern Ordos Basin, China: Implications for Provenance and Geological Setting" Minerals 15, no. 3: 233. https://doi.org/10.3390/min15030233

APA Style

Luo, F., Gong, H., Liu, H., Lv, B., & Xue, D. (2025). Geochemistry and U–Pb Chronology of the Triassic Yanchang Formation in the Southern Ordos Basin, China: Implications for Provenance and Geological Setting. Minerals, 15(3), 233. https://doi.org/10.3390/min15030233

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