Provenance Difference Analysis of the Eastern and Western Taiyuan Formation in the Northern Margin of the Ordos Basin and Its Tectonic Significance

Abstract

The Taiyuan Formation, located on the northern margin of the Ordos Basin, has an important role in reconstructing tectonic paleogeography and evolutionary process due to its preservation of information about the tectonic evolution of the basin throughout the Late Paleozoic. The provenance, paleogeography, and tectonic activity traits of the Taiyuan Formation were examined using the sedimentary petrology and zircon chronology methods. The Alxa block is consistent with the dating results of the Taiyuan Formation in Shabatai, and the Daqing Shan is consistent with the results of the Taiyuan Formation in Xiachengwan and Adaohai. It is inferred that the provenance of the Taiyuan Formation in the western part of the northern margin of the basin is from the Alxa block, and the provenance in the eastern part is from the Daqing Shan when combined with the study of sandstone detrital components, and paleocurrent. In the late Paleozoic, the Siberian plate collided with the North China Craton, and the Taiyuan Formation was deposited in the northern margin of the Ordos Basin. However, on account of the different ages and types of basement rocks and the central paleo-uplift which has not completely disappeared, the Taiyuan Formation has obvious east-west zonation.

1. Introduction

The Ordos Basin is the largest multicycle craton basin in the North China Craton [1,2] (Figure 1), with sustained subsidence and has abundant oil and gas potential. The Sulige, Yulin, Wushen County, and Daniudi regions of the northern margin of the basin have recently seen significant breakthroughs in natural gas and oil development [2,3,4,5]. But as the depth of the exploration level increased, issues with the sedimentary system and ambiguous provenance started to make oil and gas extraction in this area more challenging. Sediments typically do a good job of preserving information on the transition between marine and continental facies [6], the process of structural evolution [7], and the evolution of the paleogeographical environment [8]. Provenance analysis can shed light on the Late Paleozoic sedimentary evolution process at the northern margin of the Ordos basin and give a scientific foundation for oil and gas exploration of this area. The Taiyuan Formation is the Ordos Basin’s primary oil and gas producing stratum [9], hence this formation was chosen as the subject of a thorough sedimentological study. The research on the formation has focused on organic matter characteristics, the shale pore system, the basinal sedimentary environment, and potential of continuous shale gas accumulations [10,11,12,13]. The provenance of this Formation is generally considered to be from the northern margin of the North China Craton, but the difference between the east and west of the provenance has not been clearly understood. Additional research is needed to determine the provenance area’s tectonic background and whether it can develop a corresponding relationship with the tectonic units of the surrounding orogenic belts. It is necessary to conduct a systematic and comprehensive study of Taiyuan Formation in the northern margin of Ordos Basin by using sedimentological methods, combined with zircon chronology.

2. Geological Setting and Lithostratigraphy

The Ordos Basin is an inland depression basin, located on the west of the North China Craton. It is bounded by Luliang Mountain in the east, Qinling orogenic belt in the south, Helan Mountain and Liupan Mountain in the west, and the Yinshan orogenic belt in the north (Figure 1). The basin is now gently topographic, with asymmetric monoclinic tectonics of gentle east and steep west. Based on the features of stratigraphic development and structure, the basin can be split into six structural units, including the Thrusts of the west margin of Ordos, North Shaanxi slope, Tianhuan depression, Western Shanxi flexural zone, Weibei uplift and Yimeng uplift (Figure 1).

2.1. Characteristics of Sedimentary Facies

In this study, three sections of Xiachengwan, Adaohai and Shabatai on the northern margin of the basin were selected for analysis (Figure 1 and Figure 2). The Adaohai section (110°27′20.27″ E, 40°24′36.37″ N; 110°29′6.54″ E, 40°38′55.32″ N) is situated 8 km to the northwest of Tumote Right Banner. The bottom of the section is the Ordovician carbonate, the middle is the Upper Carboniferous–Lower Permian Shuanmazhuang group, and the top is the Zahuaigou group (Figure 2a). By comparing the detailed sequence stratigraphic framework of the strata of the two formations and the iconic volcanic event layers, it is found that the upper portion of the Shuanmazhuang Formation in the Daqing Shan Coalfield and the Taiyuan Formation in the Ordos basin are the same sedimentary stratum [14]. This study will conduct a provenance analysis of the Shuanmazhuang Formation in order to provide new evidence for the sedimentary evolution of the northern margin of the basin during the Late Carboniferous–Early Permian. Thin strata of grayish-black siltstone are sandwiched between thick layers of coarse, yellowish-brown conglomerate at the base of the Shuanmazhuang Formation. As one moves upward, interbeds of gray-yellow and gray-brown coarse conglomerate and gray-yellow gravel-bearing coarse-grained sandstone can be seen, together with a thin layer of gray-black muddy siltstone. The top is composed of two giant thick and complex coal seams, and the coal seams are distributed with thin interbeds of gray-black muddy siltstone, carbonaceous mudstone, and interlayers of sedimentary tuff. The Xiachengwan section (111°22′3.31″ E, 39°44′11.35″ N; 111°22′1.82″ E, 39°44′9.61″ N) is located on the east bank of the Yellow River, 30 km southwest of Qingshuihe County, Hohhot. The Lower Permian Shanxi Formation, the Upper Carboniferous–Lower Permian Taiyuan Formation, and Upper Carboniferous Benxi Formation are sequentially exposed from top to bottom (Figure 2c). The Taiyuan Formation in this section is made up of two thin coal seams with a thickness of around 0.5–0.7 m in the upper part, a thick coal seam up to 4.8 m thick in the middle, and yellowish-brown, medium-thick layered coarse sandstone at the bottom. The Shabatai section (106°27′30.46″ E, 39°18′43.64″ N; 106°27′58.76″ E, 39°19′01.82″ N) is located 15 km northwest of Huinong in Shizuishan. From bottom to top, it includes the upper Carboniferous Yanghugou Formation mudstone, the Permian Taiyuan Formation coal-bearing strata, and the Permian Shanxi Formation coarse sandstone (Figure 2b). The section shows that the Taiyuan Formation is mostly interbedded with mudstone, and sandstone, interbedded muddy siltstone and siltstone interbeds, with occasionally containing conglomerate, pebbled sandstone, interbedded coal seam, marine limestone, tuff and so on. On the whole, the Taiyuan Formation is a set of sea–land transition deposit strata.

2.2. Microscopic Characteristics of Sandstone

The samples A002 and A003 were selected for lithological microscopic analysis in the Adaohai section (Figure 3a,b). The microscopic features of the two samples are comparable, with blocky and sandy structures and made of terrestrial clastic and gap-filling elements. Quartz (60%) makes up the majority of the clasts, followed by rocks debris (25%), and a tiny quantity of feldspar (5%). The support type is mainly granular support, with linear–convex contact. The cement is calcareous and siliceous. Among them, quartz is mainly sub-rounded, a few sub-angular, mostly single-crystal quartz, occasionally polycrystalline quartz, part of the quartz secondary increase in the edge of the visible, most of the grain size between 0.10–0.65 mm. With a tiny quantity of plagioclase, the feldspar is primarily potassium feldspar. The potassium feldspar typically has a lattice bicrystal and striated structure. The feldspar is also highly clayed, with a dirty surface and a dissolving effect, and its grain size is 0.2 mm–0.35 mm. The rocks debris is composed of phyllite debris and mudstone debris. Cement (6%) and matrix (2%) make up the majority of the interstitial fills, the cement includes iron cement, calcareous cement, and silica cement. The pore space is mainly secondary dissolution pore, with 2% porosity.

The sample L008 was selected for microscopic analysis of rock thin sections in the Xiachengwan section (Figure 3c,d). The sample microscopically shows a sandy and blocky structure. It is mainly composed of feldspar, quartz and rocks debris. The majority of the feldspar (1%–3%) is potassium feldspar, followed by plagioclase, which is sub-angular and scattered, with fresh and clean surface, about 0.1–0.25 mm in size, and some of them are smaller, about 0.05–0.1 mm in size. Plagioclase is slightly earthy, slightly dirty on the surface. Quartz (80%–85%) is primarily single crystal, seldom polycrystalline, primarily prismatic–sub-prismatic, oriented distribution, clean surface, with a grain size that ranges from 0.05–0.25 mm, a few can reach 0.25–0.5 mm. Rock debris (15%–20%) is mainly metamorphic claystone, metamorphic clay siltstone, metamorphic siltstone, metamorphic siliceous rock, metamorphic clay siliceous rock and a small amount of mud slate, part with metamorphic chlorite aggregate, sericite aggregate. Interstitial fillings (1%–5%) are clay matrix, in the form of fine scale, the diameter of the piece is generally 0.001–0.01 mm, part of 0.01–0.02 mm. Wave-like dentate sutures can be seen, with clayey, opaque mineral distribution within.

Samples S006-4 and S006-5 were selected from the Shabatai section for microscopic analysis (Figure 3e,f). The microscopic properties of the sandstone samples are typically comparable, they are all large in structure and sandy in composition. Mainly composed of feldspar, quartz and rocks debris. Debris is dominated by quartz (80%) and is mainly sub-rounded, with a few sub-angular distributions and occasional wave-like extinction, mostly single-crystal quartz. Part of the quartz has a secondary increased edge structure, the grain size is mostly between 0.15–0.55 mm. Feldspar (3%), mainly potassium feldspar, can be seen with a small amount of plagioclase. Potassium feldspar has a common lattice double crystal and striped structure. Plagioclase can be seen as poly-sheet double crystal or card sodium compound double crystal. Severe sericitization and argillization of feldspar with surface blurring, and grain size of 0.10–0.25 mm. Rock debris (7%) is mainly mudstone debris. Interstitial fillings include cement and matrix. Cement (5%) is calcareous cementation or siliceous cementation. The content of matrix is about 4%. The porosity is about 1%. Occasionally visible strawberry pyrite was observed with a microscope. The support type is granular support, and the contact is mainly linear contact–convex contact.

3. Analytical Procedures

3.1. Sandstone Detritus

The provenance region and the basin’s development process can be revealed to a great extent by the characteristics of the sandstone composition. Standard thin section counting was used to determine the particle number for the siltstone to coarse sandstone samples that were obtained in the sandstone layer for this study. Detailed clastic fraction counts were performed for the sandstones of the Taiyuan Formation in Shabatai, the Shuanmazhuang Formation in Adaohai and the Taiyuan Formation in Xiachengwan (

Table 1. The counting results of detrital sandstone composition in the north depression of the Ordos basin.

Sample Number	Qm	Qp	Qt	Pl	K	F	Lm	Ls	Lv	L	Lt
Xiachengwan
L-008	467	2	469	1	21	22	6	60	14	74	76
CT001	548	0	548	0	0	0	2	5	0	5	5
CT002	529	0	529	33	0	33	0	6	0	6	6
CT003	554	0	554	0	0	0	0	3	0	3	3
CT004	563	0	563	0	0	0	0	2	0	2	2
CT005	557	0	557	0	0	0	0	0	0	0	0
CT006	497	0	497	0	6	6	2	56	2	58	58
CT007	461	0	461	78	34	112	0	4	0	4	4
CT008	411	0	411	94	28	122	0	21	0	21	21
CT009	426	0	426	158	0	158	0	0	0	0	0
CT010	567	0	567	0	0	0	0	0	0	0	0
CT011	549	0	549	0	0	0	0	9	0	9	9
CT012	556	0	556	0	0	0	0	1	0	1	1
Adaohai
A002	295	63	358	21	13	34	26	39	33	72	161
A003	393	60	453	15	12	27	21	44	0	44	125
A008	364	63	427	9	16	25	29	45	0	45	137
Shabatai
S006-4	360	71	431	12	4	16	22	26	0	26	119
S006-5	400	80	480	4	2	6	15	31	0	31	126
S004-2	367	66	433	7	9	16	37	44	0	44	147
S004-3	370	65	435	8	10	18	39	44	0	44	148
S004-5	318	71	389	11	10	21	34	49	0	49	154

Qm, single crystal quartz; Qp, polycrystalline quartz, including flint and quartzite particles; Qt, total amount of quartz particles; Pl, plagioclase; K, potash feldspar; F, total feldspar; Lm, metamorphic rocks debris (except for chert and quartzite); Ls, sedimentary rock debris; Lv, magmatic rock debris; L, all non-siliceous debris; Lt, total debris.

) using the Gazzi–Dickinson [16] point counting method.

3.2. Zircon U–Pb Dating and Minor Element Analysis

Detrital zircon LA-ICP-MS U–Pb dating was tested in four samples. Sample L008 and L011 are from the Xiachengwan section, sample A003 is from the Adaohai section, sample S006-5 is from the Shabatai section.

At the Mineral Laser Microanalysis Laboratory of the China University of Geosciences, Beijing, zircon LA-ICP-MS U–Pb dating, and trace element analysis were carried out. The samples were laser ablated using a NewWave 193UC excimer laser ablation system, and the ablated samples were then carried by the carrier gas to an Agilent 7900 ICP-MS plasma mass spectrometer for examination. Each point analysis process includes 18 s of background analysis to monitor instrument stability, preheating the laser, 50 s of ablation-analysis time, and 10 s of purge–rinse time to remove residues from the previous sample and prepare for the next sample. A total of two 91,500 reference samples were introduced during the experiment at intervals of ten test samples, and the known age monitoring sample GJ-1 (599.2 ± 4.6 Ma, 2SD, n = 4) was inserted concurrently to check the instrument’s stability [17]. Agilent MassHunter software was used to acquire the analytical signals; ICP-MS-DataCal software was used to adjust the background value and integration interval; time drift correction and quantitative calibration were applied to the dating data and trace element data [18,19,20,21]; and ComPbCorr#3.17 was used to correct for common lead [22]. The processed data were plotted using Isoplot for correlation analysis [23]. ²⁰⁶Pb/²³⁸U age was applied as young zircon’s forming age (<1000 Ma) and ²⁰⁷Pb/²⁰⁶Pb age was applied as ancient zircon’s forming age (>1000 Ma). Both errors in single data and error in weighted mean of ²⁰⁶Pb/²³⁸U or ²⁰⁷Pb/²⁰⁶Pb age of zircon were 1σ.

3.3. Lu-Hf Isotopic Analysis

In situ Lu-Hf isotopic analysis of zircon was also performed at CUGB’s Milma Lab by the MC-ICP-MS method. A multi-receiver inductively coupled plasma mass spectrometer was used to evaluate the samples after they had been ablated by a NewWave 193UC ArF excimer laser (Model: Thermo Fisher Neptune Plus). Each point analysis goes through 50 s background blank, 50 s ablation sampling analysis process, 10 s purging and cleaning process. Software called Iolite was utilized for the final data debugging and processing. A 91500 external standard, and two monitoring standards, Plesovice and GJ-1 [17,24], were added during the experiment at intervals of 6–10 test samples based on the characteristics and amounts of the samples.

3.4. Heavy Mineral Analysis

Detrital heavy minerals have the characteristics of strong stability, reaction parent rock characteristics and little influence by the later period. It serves as an essential tool for provenance analysis. Their mineral assemblage types are very sensitive to provenance [25]. The direction, general location, and transportation process of the provenance region can be limited by examining the heavy mineral assemblage, the heavy mineral index, and the variation of the heavy mineral concentration on the plane. Heavy mineral identification was performed by the Langfang yuheng rock technology service company ltd.

4. Results

4.1. Sandstone Petrography

The samples of three sections all fall inside the quartz recycling range and the source area of the recycled orogenic belt, according to the Qm-F-Lt triangle figure (Figure 4). The clastic fractions of Shabatai and Adaohai are close to one another, and the drop points also are; while the drop points of the sandstone samples from Xiahengwan are closer to the inner region of the craton, and the drop points overlap, indicating that the material source is single and stable, and the percentage of single-crystal quartz in the clastic fractions is higher than that in the sandstones of the other two profiles. All three samples are located in the recycled orogenic belt provenance area, which is characterized by continental interior provenance, according to the Qt-F-L diagram. The Taiyuan Formation’s falling point in Xiachengwan is close to a stable craton and uplift basement area, but this is not proof that the provenance area has a stable craton and uplift basement background. It could be the result of the provenance area’s complicated lithology and transportation process. The analytical results of the triangle diagram suggest that the provenance input originates from the intracontinental orogenic belt. Quartz, predominantly single crystal quartz, makes up the majority of the detrital components in the three samples, according to statistics of the detrital results (Table 1). The absence of polycrystalline quartz of the Taiyuan Formation in Xiachengwan is compatible with the recycled orogenic belt’s character in the source region. It also shows how active the tectonic cycle and orogenic activity are in Xiachengwan.

Most samples contain very little feldspar, suggesting that terrestrial debris may have been transported over enormous distances and weathered over a long period of time. Only the three samples from the Xiachengwan section had more feldspar debris, which may indicate that the samples were deposited with material input from some of the more recent areas. The Shabatai and Adaohai samples’ features of rock debris are equivalent. There is essentially no volcanic rock debris, but there is an equal amount of sedimentary rock debris and metamorphic rock debris. It shows that both sedimentary rocks and metamorphic rocks may be the source of the provenance. The samples in Xiachengwan hardly contain any rocks debris. Sedimentary rock debris and metamorphic rock debris are only occasionally present in a few samples, whereas volcanic rock debris is almost entirely absent, which is consistent with the long transportation distance and long weathering time of the above debris.

4.2. Zircon Morphology

In morphology (Figure 5), L008 shows that zircons are mostly spherical, have short columns, have good roundness, and have complex internal structures. (Figure 5b). The particle size ranges from 60–100 μm, with a tiny portion reaching 150 μm. The majority of the particles are subangular–subcircular, and transmission reflection pictures reveal more developed inclusions, cracks, and evident ablation holes. The core is visible as a fuzzy rhythmic ring, indicating that it has undergone later metamorphism. The structure is complex, the edge is narrow, and the zoning is usually mottled. The majority of the zircons are spherical, have a short column, and have a particle size of about 80–100 μm in L011 (Figure 5c). A few zircons are long columnar, with a particle size of about 180 μm, have a length–width ratio of about 3:1, and are mostly subangular. The transmission reflection images reveal that the zircon contains several long strip inclusions and has surface ablation holes or fissures. A003 show that the particle size is about 50–150 μm, with some up to 200 μm. Zircons are mostly round–oval, with an equal distribution of long columnar and short columnar (Figure 5a). Good roundness indicates a long-distance transmission method that is more intricate. The core structure is complex, showing mottled, fan-shaped zonal, spongy, etc., and clear magmatic rhythmic zoning can be seen on the sides. S006-5 show that most zircon grain sizes are about 80–120 μm, with some up to 150 μm (Figure 5d). Zircons are mostly subangular or rounded, with a limited amount of angular shape, which reflects that the transport process is complex. Th/U ratios are greater than 0.1, and only one value in S006-5 is less than 0.1 (

Table 2. LA-ICP-MS U–Pb isotopic results of detrital zircons from the sandstone.

Measuring Point No	w (B)/10−6		Th/U	Isotope Ratio and Error					Age (Ma) and Error
	Th	U		207Pb/206Pb	1σ	207Pb/235U	1σ	206Pb/238U	1σ	207Pb/206Pb	1σ	207Pb/235U	1σ	206Pb/238U	1σ
A003
1	177.19	254.79	0.7	0.15364	0.00169	8.61581	0.15893	0.43523	0.00549	2387	16	2298	17	2329	25
2	76.4	186.28	0.41	0.1653	0.00392	8.93184	0.17796	0.39189	0.00505	2511	41	2331	18	2132	23
3	809.25	388.33	2.08	0.23274	0.00281	15.49429	0.32399	0.49973	0.0063	3071	75	3171	56	2996	33
4	430.67	878.26	0.49	0.11187	0.00329	4.57886	0.12056	0.29685	0.00389	1830	55	1745	22	1676	19
5	278.98	457.73	0.61	0.16282	0.00378	9.8008	0.19313	0.44993	0.00594	2485	40	2444	18	2395	26
6	106.85	137.51	0.78	0.14157	0.00155	6.92705	0.1486	0.32441	0.00409	2247	23	2570	21	2185	23
7	166.5	825.2	0.2	0.11381	0.00123	5.51602	0.08597	0.33686	0.00423	1861	21	2102	19	1811	20
9	123.37	245.24	0.5	0.14737	0.00157	8.89149	0.15976	0.42358	0.00533	2316	15	2337	16	2277	24
10	1255.01	1173.18	1.07	0.18268	0.00192	14.32972	0.87553	0.41926	0.00556	2677	19	2846	20	2613	27
11	229.14	90.61	2.53	0.117	0.00123	5.59104	0.14777	0.31994	0.00411	1911	13	1903	13	1872	20
12	129.46	265.88	0.49	0.15035	0.00157	8.87861	0.15241	0.43308	0.00544	2350	14	2326	16	2320	24
13	113.26	110.18	1.03	0.13572	0.00417	6.93053	0.19449	0.38105	0.00537	2173	55	2128	24	2081	25
15	517.26	1454.19	0.36	0.14617	0.00187	6.76891	0.21188	0.41231	0.00542	2302	36	2082	28	2225	25
16	193.44	578.65	0.33	0.10522	0.00149	4.08903	0.11588	0.3013	0.00392	1718	33	1652	23	1698	19
17	303.99	492.17	0.62	0.05775	0.00111	1.33487	0.032	0.14441	0.00184	520	31	861	14	870	10
18	823.34	1298.4	0.63	0.054	0.00188	1.61441	0.08755	0.15833	0.00219	371	97	976	34	947	12
19	154.47	184.58	0.84	0.19219	0.00879	11.23266	0.48813	0.42388	0.00606	2761	77	2543	41	2278	27
20	85.19	108.11	0.79	0.15082	0.00428	8.97021	0.22322	0.43137	0.00588	2355	50	2335	23	2312	27
21	199.15	574.98	0.35	0.13107	0.00134	6.76891	0.21188	0.41231	0.00542	2112	12	2157	13	2097	22
22	147.52	333.5	0.44	0.1096	0.00141	4.57886	0.12056	0.29685	0.00389	1793	30	1915	23	1789	20
23	377.27	3835.46	0.1	0.08502	0.00142	2.50705	0.06315	0.18462	0.00237	1316	47	1352	26	1368	16
24	339.17	338.85	1	0.14423	0.0015	8.57998	0.17084	0.4325	0.00545	2279	18	2294	18	2317	25
25	44.73	129.95	0.34	0.14679	0.0015	9.2664	0.1367	0.44079	0.00552	2309	11	2365	14	2354	25
28	358.45	242.95	1.48	0.12215	0.00126	5.60725	0.07407	0.34798	0.00435	1988	12	1899	13	1966	21
29	2380.22	843.36	2.82	0.17172	0.00229	10.44462	0.18701	0.44876	0.0059	2574	35	1820	27	2647	31
30	150.26	177.4	0.85	0.17881	0.00244	12.21207	0.74032	0.50556	0.00715	2642	82	2621	57	2638	31
31	202.34	170.6	1.19	0.05098	0.00062	0.36204	0.00563	0.04928	0.00062	240	16	314	4	310	4
33	178.19	502.73	0.35	0.13238	0.00153	6.86238	0.19214	0.40289	0.00519	2130	31	2094	25	2182	24
34	162.42	187.48	0.87	0.1264	0.00133	6.59292	0.12408	0.37368	0.00471	2048	16	2085	16	2047	22
35	395.93	1073.82	0.37	0.15683	0.0032	9.52703	0.15368	0.44522	0.00568	2422	35	2400	15	2374	25
36	225.46	768.26	0.29	0.1597	0.00218	8.86924	0.37334	0.46619	0.00638	2452	53	2325	38	2467	28
38	314.5	1495.97	0.21	0.14422	0.00292	8.44805	0.13458	0.42484	0.00533	2279	36	2280	14	2282	24
39	107.37	119.65	0.9	0.05216	0.0007	0.35375	0.00587	0.04911	0.00062	292	18	308	4	309	4
40	28.31	153.6	0.18	0.16169	0.00579	8.29493	0.2767	0.37208	0.00481	2473	62	2264	30	2039	23
41	1354.1	5099.6	0.27	0.08993	0.00096	2.46409	0.04793	0.248	0.00313	1424	19	1262	14	1428	16
42	524.46	508.36	1.03	0.11319	0.00112	5.49024	0.08175	0.35664	0.00447	1851	11	1917	11	1925	21
44	17.56	45.22	0.39	0.12922	0.00134	6.60346	0.10783	0.38445	0.00483	2087	14	2046	15	2097	22
45	33.48	151.89	0.22	0.12233	0.00125	6.49331	0.10604	0.36823	0.00462	1990	13	2072	14	2021	22
47	528.62	849.12	0.62	0.11912	0.00118	6.16147	0.08797	0.36304	0.00454	1943	11	1999	12	1997	21
48	226.93	396.23	0.57	0.13149	0.00178	5.2147	0.17165	0.39237	0.00524	2118	39	1855	28	2134	24
50	53.86	236.02	0.23	0.13019	0.00131	8.86305	0.17898	0.40063	0.00503	2101	19	2324	18	2172	23
52	144.45	268.88	0.54	0.23542	0.00566	17.1062	0.34322	0.52701	0.00698	3089	39	2941	19	2729	29
53	571.36	649.86	0.88	0.12321	0.00345	6.29673	0.15377	0.37066	0.0051	2003	51	2018	21	2033	24
54	277.99	522.54	0.53	0.17495	0.00244	11.56465	0.26584	0.40346	0.0051	2606	55	2161	40	2629	32
55	140.08	403.8	0.35	0.09983	0.00151	2.78808	0.09694	0.23648	0.00306	1621	51	1866	32	1679	19
56	315.23	186.8	1.69	0.13231	0.00129	8.52977	0.11455	0.42415	0.0053	2129	11	2289	12	2279	24
S006-5
1	344.38	617.58	0.56	0.09426	0.00082	3.5815	0.04554	0.26255	0.00335	1513	11	1545	10	1503	17
2	161.49	167.53	0.96	0.10829	0.0013	5.31644	0.14486	0.31512	0.00416	1771	31	1872	23	1766	20
3	90.92	155.41	0.59	0.13774	0.0012	8.02408	0.11025	0.40605	0.00519	2199	11	2245	12	2197	24
4	102.78	122.46	0.84	0.11172	0.00098	5.33889	0.07108	0.3308	0.00423	1828	11	1875	11	1842	20
5	368.39	283.67	1.3	0.12274	0.00106	2.74942	0.03363	0.15055	0.00192	1996	10	1342	9	904	11
6	101.63	214.32	0.47	0.06352	0.00057	1.4876	0.01905	0.15658	0.002	726	12	925	8	938	11
7	28.91	64.68	0.45	0.1483	0.00129	9.64772	0.13148	0.43845	0.0056	2326	10	2402	13	2344	25
8	335.37	334.72	1	0.05274	0.00049	0.57243	0.00728	0.07406	0.00095	318	13	460	5	461	6
9	781.07	1016.15	0.77	0.06757	0.00274	0.47158	0.02055	0.06172	0.00096	855	65	392	14	386	6
10	150.01	222.54	0.67	0.05221	0.00081	1.21088	0.02981	0.13223	0.00174	295	33	806	14	801	10
11	105.55	162.34	0.65	0.136	0.00117	8.44377	0.10467	0.40059	0.00511	2177	10	2280	11	2172	24
12	31.7	25.17	1.26	0.16231	0.00194	11.4022	0.41263	0.47091	0.00635	2480	43	2557	34	2488	28
13	16.41	54.61	0.3	0.11256	0.00107	6.34408	0.1156	0.33296	0.00429	1841	16	2025	16	1853	21
14	158.62	316.6	0.5	0.14011	0.00122	9.07317	0.12083	0.41322	0.00528	2229	10	2345	12	2230	24
15	539.16	484.76	1.11	0.14315	0.00123	10.85741	0.13139	0.50023	0.00638	2266	10	2511	11	2615	27
16	116.01	100.01	1.16	0.13779	0.00122	7.90876	0.11361	0.40628	0.0052	2200	11	2221	13	2198	24
17	60.44	396.09	0.15	0.06673	0.00058	1.57194	0.01935	0.16066	0.00205	829	12	959	8	960	11
18	729.44	598.73	1.22	0.05519	0.0012	0.28007	0.00719	0.03894	0.00053	420	34	251	6	246	3
19	261.85	300.8	0.87	0.05877	0.00052	0.96055	0.0119	0.11187	0.00143	559	13	684	6	684	8
20	132.26	213.55	0.62	0.13612	0.00124	7.46484	0.12626	0.40219	0.00517	2178	15	2120	16	2179	24
21	1489.18	1065.77	1.4	0.09393	0.001	4.52883	0.17072	0.26256	0.00344	1507	51	1736	31	1503	18
22	164.35	251.76	0.65	0.05067	0.00047	0.58991	0.00761	0.07671	0.00098	226	14	471	5	476	6
23	150.93	169.18	0.89	0.14756	0.0013	9.86253	0.14691	0.42973	0.0055	2318	11	2422	14	2305	25
25	116.52	227.57	0.51	0.06612	0.00058	1.88868	0.02359	0.18956	0.00242	810	12	1077	8	1119	13
26	766.31	717.17	1.07	0.10322	0.00104	3.83752	0.08017	0.29954	0.00389	1683	20	1601	17	1689	19
27	67.82	178.43	0.38	0.06374	0.0006	1.60877	0.02191	0.16101	0.00206	733	13	974	9	962	11
28	87.83	194.1	0.45	0.13978	0.0012	8.60186	0.10489	0.41086	0.00524	2224	10	2297	11	2219	24
29	15.23	20.22	0.75	0.1338	0.00127	6.7549	0.12039	0.39695	0.00512	2148	15	2080	16	2155	24
30	19.23	64.08	0.3	0.10692	0.00107	4.47094	0.08226	0.31224	0.00403	1748	17	1726	15	1752	20
31	29.96	35.53	0.84	0.13572	0.00181	9.54162	0.3994	0.40169	0.00548	2173	54	2392	38	2177	25
32	126.61	187.18	0.68	0.12757	0.0011	7.31868	0.09306	0.37556	0.00479	2065	10	2151	11	2056	22
33	200.9	237.35	0.85	0.12313	0.00111	6.61445	0.10725	0.36501	0.00468	2002	13	2061	14	2006	22
34	19.34	67.87	0.28	0.10748	0.00101	5.58197	0.09406	0.31272	0.00402	1757	14	1913	15	1754	20
35	22.45	32.09	0.7	0.17005	0.00149	17.22185	0.2664	0.63271	0.0081	2558	12	2947	15	3160	32
36	73.48	244.02	0.3	0.09699	0.00084	3.95202	0.04838	0.27469	0.0035	1567	11	1624	10	1565	18
37	40.22	34.17	1.18	0.14101	0.00127	7.74701	0.11516	0.40535	0.00531	2240	12	2183	14	2235	24
38	59.2	31.23	1.9	0.12979	0.002	7.44096	0.29423	0.38046	0.00527	2095	50	2166	35	2078	25
39	18.14	229.29	0.08	0.10304	0.00091	4.58041	0.06013	0.29942	0.00383	1680	11	1746	11	1688	19
40	960.14	1255.31	0.76	0.10333	0.00096	4.0442	0.0657	0.29571	0.0038	1685	14	1643	13	1670	19
41	78.67	90.59	0.87	0.1612	0.00159	8.8399	0.19221	0.4703	0.00612	2468	20	2322	20	2485	27
42	355.3	422.86	0.84	0.05056	0.00047	0.49559	0.0063	0.06526	0.00083	221	13	409	4	408	5
43	444.78	342.57	1.3	0.0509	0.00048	0.54831	0.00712	0.07074	0.0009	236	14	444	5	441	5
44	205.36	209.93	0.98	0.13345	0.00116	7.43616	0.11102	0.39456	0.00505	2144	13	2103	14	2144	23
45	180.39	705.58	0.26	0.06162	0.00053	1.47694	0.01786	0.16479	0.0021	661	12	921	7	983	12
47	115.78	89.83	1.29	0.07325	0.00075	1.86006	0.02992	0.16969	0.00218	1021	15	1067	11	1010	12
48	35.29	59.67	0.59	0.13429	0.00118	7.64128	0.1036	0.39828	0.00509	2155	11	2190	12	2161	23
49	192.21	395.68	0.49	0.06443	0.00057	1.65138	0.0208	0.16662	0.00213	756	12	990	8	993	12
50	40.54	150.89	0.27	0.06516	0.00072	1.40021	0.02351	0.14638	0.00189	780	16	889	10	881	11
51	33.31	63.54	0.52	0.13606	0.00132	8.73972	0.16964	0.40012	0.00517	2178	17	2311	18	2170	24
52	79.8	156.5	0.51	0.09864	0.00101	4.65806	0.10292	0.28028	0.00363	1599	23	1760	18	1593	18
53	52.25	80.95	0.65	0.05992	0.00056	1.67329	0.02319	0.17343	0.00222	601	13	998	9	1031	12
54	40.09	836.28	0.05	0.08692	0.0008	3.22312	0.04559	0.23452	0.003	1359	12	1463	11	1358	16
55	206.27	76.75	2.69	0.09257	0.00172	5.39205	0.31001	0.25806	0.00359	1479	88	1884	49	1480	18
56	222.31	203.15	1.09	0.13708	0.00118	8.45825	0.10501	0.40133	0.00512	2191	10	2281	11	2175	24
57	41.91	140.62	0.3	0.13526	0.00116	7.84366	0.09674	0.40054	0.00511	2167	10	2213	11	2172	24
L008
1	115.61	156.93	0.74	0.12437	0.00151	6.27524	0.07503	0.3649	0.00313	2020	10	2015	10	2005	15
3	177.85	239.18	0.74	0.13056	0.00148	6.36351	0.07182	0.35268	0.00312	2106	9	2027	10	1947	15
4	607.4	303.81	2	0.12828	0.00147	5.3934	0.06192	0.30417	0.00261	2075	10	1884	10	1712	13
6	251.86	285.81	0.88	0.13117	0.00143	5.65626	0.06371	0.31183	0.00246	2114	10	1925	10	1750	12
10	120.45	154.83	0.78	0.11883	0.00137	5.82219	0.07533	0.35473	0.00353	1939	11	1950	11	1957	17
11	70.51	77.76	0.91	0.12482	0.00152	6.397	0.08547	0.37078	0.0033	2026	12	2032	12	2033	16
13	334.87	231.3	1.45	0.12637	0.00161	5.22488	0.06598	0.30137	0.00428	2048	11	1857	11	1698	21
16	44.84	86.71	0.52	0.11833	0.00157	5.51371	0.07873	0.33743	0.00325	1931	13	1903	12	1874	16
18	293.19	258.76	1.13	0.13244	0.00155	5.8215	0.07151	0.3183	0.00274	2131	11	1950	11	1781	13
21	82.54	69.48	1.19	0.1155	0.00386	5.47323	0.172	0.3437	0.00394	1888	62	1896	27	1904	19
23	362.68	223.81	1.62	0.13039	0.00159	5.83029	0.0957	0.32465	0.00497	2103	13	1951	14	1812	24
25	178.11	185.53	0.96	0.11932	0.00148	5.6813	0.07091	0.34498	0.00305	1946	11	1929	11	1911	15
27	12.73	42.66	0.3	0.11906	0.00181	5.69499	0.09473	0.34666	0.00396	1942	15	1931	14	1919	19
28	124.77	338.82	0.37	0.12498	0.00361	5.57984	0.12751	0.3238	0.0057	2029	52	1913	20	1808	28
29	302.43	135.06	2.24	0.05744	0.00157	0.3767	0.00958	0.04784	0.00056	508	36	325	7	301	3
34	176.42	251.48	0.7	0.12548	0.00133	6.36394	0.07321	0.36675	0.00302	2036	10	2027	10	2014	14
35	120.92	120.69	1	0.05582	0.00168	0.37557	0.01113	0.04891	0.00054	445	46	324	8	308	3
40	165.16	293.48	0.56	0.133	0.00163	6.74387	0.08182	0.36678	0.00321	2138	10	2078	11	2014	15
41	198.79	271.29	0.73	0.13239	0.00166	6.44993	0.08612	0.35268	0.00387	2130	11	2039	12	1947	18
42	315.33	314.2	1	0.12887	0.00156	5.84014	0.07466	0.3286	0.00393	2083	10	1952	11	1832	19
47	130.07	245.37	0.53	0.12511	0.00134	6.36973	0.07331	0.36846	0.00347	2030	9	2028	10	2022	16
49	150.3	233.84	0.64	0.1319	0.00152	6.34214	0.07264	0.34779	0.00249	2123	11	2024	10	1924	12
50	251.18	309.45	0.81	0.12443	0.0014	5.66368	0.08088	0.32902	0.00364	2021	12	1926	12	1834	18
52	142.05	203.3	0.7	0.13636	0.00147	7.09846	0.08821	0.37666	0.00368	2182	10	2124	11	2061	17
53	177.81	254.04	0.7	0.12972	0.00149	5.57311	0.12638	0.30979	0.0059	2094	18	1912	20	1740	29
59	208.67	387.43	0.54	0.11901	0.00147	4.80729	0.06802	0.29211	0.00287	1941	12	1786	12	1652	14
60	504.12	270.81	1.86	0.12272	0.0016	4.91422	0.07257	0.28986	0.00315	1996	13	1805	12	1641	16
L011
1	95.85	149.06	0.64	0.05202	0.00123	0.33543	0.00789	0.0468	0.00046	286	49	294	6	295	3
2	63.36	104.63	0.61	0.0501	0.00127	0.32562	0.00805	0.04727	0.00049	200	57	286	6	298	3
3	76.99	108.39	0.71	0.0527	0.00128	0.33938	0.00823	0.04669	0.00043	316	52	297	6	294	3
5	58.99	101.17	0.58	0.05507	0.00132	0.36187	0.00849	0.04766	0.00048	415	47	314	6	300	3
6	92.82	132.89	0.7	0.05187	0.0012	0.33893	0.00784	0.04728	0.00043	279	50	296	6	298	3
7	119.02	173.14	0.69	0.05251	0.00118	0.34393	0.00739	0.04752	0.00043	308	54	300	6	299	3
8	114.95	149.59	0.77	0.05163	0.00126	0.33755	0.00765	0.04754	0.00047	269	58	295	6	299	3
9	208.15	218.5	0.95	0.05205	0.00118	0.34472	0.00778	0.04787	0.00039	287	56	301	6	301	2
11	97.62	135.91	0.72	0.0544	0.00127	0.36065	0.0084	0.04795	0.00045	388	58	313	6	302	3
12	95.75	137.95	0.69	0.05302	0.00122	0.35014	0.00749	0.04786	0.00044	330	54	305	6	301	3
13	141.06	172.11	0.82	0.0518	0.00139	0.34313	0.00819	0.04827	0.00049	277	61	300	6	304	3
14	93.53	118.98	0.79	0.05303	0.00126	0.34608	0.00807	0.04728	0.00051	330	60	302	6	298	3
15	138.05	195.48	0.71	0.0525	0.00119	0.35148	0.00764	0.04845	0.00048	307	56	306	6	305	3
16	162.46	206.86	0.79	0.05415	0.00122	0.34989	0.00751	0.04669	0.00044	377	54	305	6	294	3
17	119.09	170.2	0.7	0.05154	0.00129	0.34375	0.00822	0.04822	0.00045	265	60	300	6	304	3
18	98.65	133.83	0.74	0.05308	0.0015	0.35392	0.00922	0.04838	0.00053	332	66	308	7	305	3
19	91.45	121.04	0.76	0.05148	0.00141	0.33595	0.00817	0.04747	0.00053	262	63	294	6	299	3
20	89.01	131.41	0.68	0.05401	0.0014	0.35427	0.00825	0.0476	0.00053	372	60	308	6	300	3
21	86.45	123.51	0.7	0.05461	0.00173	0.3727	0.01253	0.04912	0.00052	396	81	322	9	309	3
22	67.68	101.88	0.66	0.05193	0.00158	0.34576	0.01032	0.04825	0.00049	282	74	302	8	304	3
25	204.96	199.74	1.03	0.05164	0.00113	0.33846	0.00717	0.04752	0.0005	270	56	296	5	299	3
26	122.23	149.05	0.82	0.05194	0.00127	0.34361	0.00783	0.04811	0.00047	283	58	300	6	303	3
27	109.41	165.26	0.66	0.05257	0.00116	0.34805	0.00741	0.04808	0.00046	310	54	303	6	303	3
29	188.17	197.67	0.95	0.05184	0.00113	0.34605	0.00726	0.04851	0.00044	278	54	302	5	305	3
30	85.2	129.35	0.66	0.05335	0.00133	0.35387	0.0085	0.04834	0.00052	344	61	308	6	304	3
31	69.2	104.62	0.66	0.05357	0.0016	0.35483	0.01044	0.04827	0.00055	353	73	308	8	304	3
32	64.06	101.89	0.63	0.0555	0.00169	0.36668	0.01085	0.04825	0.00056	433	72	317	8	304	3
34	140.05	194.97	0.72	0.05163	0.00103	0.34823	0.0064	0.04913	0.00044	269	48	303	5	309	3
36	128.15	185.52	0.69	0.05203	0.00122	0.35184	0.00819	0.04929	0.00054	287	60	306	6	310	3

). Combined with CL images, it is speculated that the zircons measured are magmatic zircons, which have undergone long-distance and long-term transport.

4.3. U–Pb Ages of Detrital Zircons

Sample L008 obtained 27 effective zircon U–Pb dating spots (concordance degree of the measured points is between 90%–110%) with age values varying between 301–2182 Ma (Table 2), mainly concentrated in the interval 1888–2182 Ma. Sample L011 obtained 29 effective zircon U–Pb dating spots (concordance degree of the measured points is between 90%–110%) with ages ranging from 294–310 Ma, which are extremely concentrated. The weighted average age is 301 ± 1.5 Ma. Sample A003 obtained 46 effective zircon U–Pb dating spots (concordance degree of the measured points is between 90%–110%) with ages ranging from 309–3089 Ma, mainly in the 1830–2387 Ma interval. Sample S006-5 obtained 55 effective zircon U–Pb dating spots (concordance degree of the measured points is between 90%–110%), with ages ranging from 246–2558 Ma. These ages were mainly distributed into four ranges of 408–476 Ma, 904–993 Ma, 1513–1841 Ma, and 2144–2558 Ma. The dating age values of the sample are close to the concord line (Figure 6) and their concord degree of the measured points is larger than 90%, which confirms the zircon U–Pb age is trustworthy.

4.4. Hf-Isotopes of Detrital Zircons

Zircons, having good U–Pb dating values and a high concordant degree should be used for zircon Hf isotope analysis. The measured zircons in this study have multiple surface fissures and a densely packed interior with inclusions. The CL image reveals that the surface spots are not clear, while the transmission map reveals that the interior is complex. It is difficult to locate a good Hf isotope analysis site near the zircon U–Pb dating point. Therefore, only 13 zircons from the Taiyuan Formation sandstone at Xiachengwan were chosen for analysis. The results of in situ Hf isotope analysis of 13 zircons from the sample L008 (

Table 3. Hf-Isotopes results of detrital zircons from the sandstone of the Taiyuan Formation in Xiachengwan.

Sheet Number	Age (Ma)	176Yb/177Hf	176Lu/177Hf	176Hf/177Hf	2σ	εHf(t)	TDM1(Ma)	TDM2(Ma)
4	1884	0.0585	0.001138	0.281551	0.000014	1.899	2377	2555
7	1733	0.05392	0.001098	0.281652	0.000015	9.348	2237	2231
16	1928	0.01514	0.000385	0.28147	0.000016	4.419	2442	2550
17	1928	0.01293	0.000324	0.281588	0.000012	1.061	2279	2496
21	1928	0.0274	0.000508	0.28148	0.000015	−4.052	2439	2777
25	1928	0.00482	0.000648	0.281553	0.000017	−0.269	2346	2589
27	1928	0.0852	0.00011	0.281534	0.000019	−0.328	2339	2590
28	1913	0.0628	0.002132	0.281734	0.000021	5.95	2185	2270
29	301	0.03976	0.001729	0.282233	0.000012	−8.217	1455	1985
31	1928	0.02329	0.000944	0.281489	0.000026	−9.948	2453	2941
35	308	0.01684	0.000698	0.282367	0.00002	−4.526	1232	1707
48	1876	0.03365	0.000387	0.281583	0.000013	4.89	2292	2402
57	1841	0.02048	0.000829	0.281438	0.000019	−0.94	2516	2759

) show that the ¹⁷⁶Lu/¹⁷⁷Hf ratio is between 0.0001097–0.002132. Except for points numbered 28, the ¹⁷⁶Lu/¹⁷⁷Hf of other points is less than 0.002, and the experimentally measured ¹⁷⁶Lu/¹⁷⁷Hf can represent the initial ¹⁷⁶Lu/¹⁷⁷Hf. The εHf(t) values of −9.9–−0.3 have two-stage model ages (T_DM2) of 2941–1707 Ma, mainly in the range of 2941–2589 Ma; the εHf(t) values of 1.1–−9.3 have two-stage model ages (T_DM2) of 2555–2231 Ma, mainly in the range of 2555–2496 Ma. Zircon with an age of 301 Ma, its εHf(t) value is −8.2, two-stage model age (T_DM2) is 1985 Ma. Zircon with an age of 308 Ma, its εHf(t) value is −4.5, two-stage model age (T_DM2) is 1707 Ma.

4.5. Rare Element Compositions of Detrital Zircons

Due to the differences in the rare earth element distribution curves of zircons with various genesis, it was widely used to determine the genesis of zircons [27,28,29]. The internal structure of detrital zircons in measured samples is complex, and the inclusions are well developed. Therefore, the distribution patterns of rare earth elements were exclusively examined in the sandstone of the Taiyuan formation in Xiachengwan. There were two rare earth element distribution curves that were discovered by analyzing the rare earth element concentration and distribution characteristics in detrital zircon with the designation L008. Type 1 is characterized by Ce positive anomalies and Eu negative anomalies (Figure 7a), it is a typical crustal magmatic zircon curve [27,28,29,30]. Type 2 is characterized by Ce positive anomalies (Figure 7b), which show an obvious Eu anomaly, and it may be caused by metamorphism during complex transportation. Both zircon groups show that LREE is more depleted than HREE, LREE/HREE is between 0.01–0.37, and the degree of light and heavy rare earth differentiation is high. The ∑REE content is between 59–7046 ppm, with an average value of 2265 ppm. Type 1 shows the δEu is between 0.08–0.72, with an average of 0.47, δCe is between 1.68–26.02, with an average of 5.64, showing obvious characteristics of Eu enrichment and Ce loss. The δEu of Type 2 is between 0.76–1.13, with an average value of 0.94, showing no obvious Eu anomalies, and the δCe is between 1.3–4.4, with an average value of 1.87, showing weak Ce positive anomalies.

4.6. Heavy Mineral Characteristics

The heavy mineral composition of the five samples of the Taiyuan formation in Shabatai can be divided into two types, namely hematite-limonite + zircon + rutile + monazite + leucoxene and tourmaline (brown) + zircon + rutile (

Table 4. Heavy mineral composition of the Taiyuan Formation in Shabatai and Adaohai (%).

Samples	Zircon	Apatite	Rutile	Anatase	Leucoxene	Tourmaline	Garnet	Hematite-Limonite	Magnetite	Monazite	Chrome Spinel	Ilmenite	Other
S006-4	6.08	0.4	5.27	12.57	14.59	6.58	-	52.92	-	-	-	-	1.59
S006-5	11.5	0.34	5.08	9.47	5.75	1.31	-	64.41	-	-	-	-	2.14
S004-2	54.5	-	6.23	9.35	7.31	9.81	-	-	-	3.32	-	-	9.48
S004-3	13.25	-	1.15	1.13	1.6	67.26	-	-	-	6.51	0.16	-	8.94
S004-5	45.66	-	4.78	5.15	14.8	13.12	-	-	-	0.93	0.07	-	15.49
A002	14.44	3.94	0.98	0.07	59.42	0.34	8.58	-	-	-	-	0.07	12.16
A003	48.36	-	16.35	0.71	3.56	0.18	-	-	-	15.64	-	-	15.2
A008	45.68	2.87	1.15	0.69	5.5	-	0.13	1.34	0.16	-	-	21.93	20.55

), indicating that the source rocks are mainly acidic magmatic rocks and metamorphic rocks. Among them, S006-4 and S006-5 heavy mineral identification found more hematite-limonite, which may indicate that a large amount of iron minerals were added when the sample was deposited. There are three types of heavy mineral composition in the sandstone of the Shuanmazhuang formation in Adaohai, namely leucoxene + zircon + garnet + apatite, zircon + rutile + monazite and zircon + ilmenite + leucoxene. The parent rock type corresponding to garnet and apatite is medium–basic extrusive rock, and the parent rock type corresponding to ilmenite is basic and ultra-basic intrusive rock, and the parent rock type corresponding to zircon, rutile and monazite is acidic magmatic rock. Based on this, it is considered that the parent rock of the source area of the Shuanmazhuang formation should be dominated by magmatic rock.

An efficient way to assess the compositional maturity of clastic rocks is to use the ZTR index (the ratio of the combined concentrations of zircon, tourmaline, and rutile to the total content of transparent minerals). With an increase in ZTR value, maturity rises. With the exception of A002 (56%), each of the eight samples has a ZTR index more than 80% (Figure 8). The data are highly concentrated, and the maturity is very high, which indicates that the process is more difficult and that the northern terrigenous debris of the basin is transported far away and the process is more complicated.

5. Discussion

5.1. Provenance Analysis of the Eastern Taiyuan Formation

Debris probably underwent a prolonged transport process since single crystal quartz predominates and feldspar concentration is extremely low in the sandstone detrital components of the Taiyuan Formation of the northern margin in the Ordos Basin. The paleocurrent direction indicates that the provenance is from the north, which provides conditions for long-distance transport of provenance. According to the Dickinson triangle diagram, the Taiyuan Formation sand sample belongs to the recycling orogenic belt, which is consistent with the background of the collision between the Xingmeng orogenic belt and the northern margin of the North China Craton. Additionally, the landing points are essentially coincident, demonstrating that the source is single and stable. It is inferred that the provenance is from the orogenic belt in the northern margin of North China Craton (Figure 9).

The discovery of tuff in the Taiyuan Formation in Xiachengwan may indicate that the northern margin of the North China Craton was affected by subduction and collision, which caused strong tectonic activity and volcanic activity around 301 Ma. At that time, the northern margin of the North China Craton was in the stage of subduction and collision, and the ancient metamorphic basement was eroded. The debris was likely to be transported to the eastern part of the northern margin of the basin by the paleocurrent relying on the high topography in the north and low topography in the south. Hf isotope analysis of detrital zircon shows that the second stage model age T_DM2 of εHf(t) negative age points is mostly between 2777 Ma–2590 Ma, it also includes 1985 Ma and 1707 Ma, indicating that the source area was in the stage of crustal proliferation in the early Archean [31]. A large-scale crustal accretion event occurred in the northern margin of the North China Craton at 2.7 Ga–2.5 Ga and 1.9 Ga–1.8 Ga. A small amount of mantle-derived magma entered the crust during 2.2 Ga–1.8 Ga, most of which was the recycling of existing crustal components [32] (Figure 10). This is the same as the zircon Hf isotope analysis results of the Taiyuan formation sandstone in Xiachengwan, indicating that the source area should be derived from the northern margin of the North China Craton. There are multi-stage tectonic-thermal events in the khondalite series in the northern margin of the North China Craton, with age spans of about 2.6 Ga–2.4 Ga, 2.3 Ga–2.0 Ga and 1.95 Ga–1.85 Ga [33,34,35] (Figure 10). A total of four magmatic events (2.5 Ga–2.45 Ga, 2.3 Ga–2.1 Ga, 1.97 Ga–1.93 Ga and 1.85 Ga) were found in the Daqing mountain complex in the khondalite belt [35,36]. This is consistent with the age of magmatic activity (1888–2182 Ma) of the Taiyuan Formation in Xiachengwan, and the age of magmatic activity (1830–2387 Ma) of the Shuanmazhuang Formation in Adaohai. It is more likely that the Daqing mountain–Wula mountain on the northern margin of the North China Craton is the source area of the Shuanmazhuang Formation and Taiyuan Formation.

5.2. Provenance Analysis of Western Taiyuan Formation

The rock debris components and paleocurrent characteristics of the Taiyuan Formation in the western part of the northern margin of the basin are the same as those in the eastern part of the northern margin, indicating that it mainly comes from the north and has undergone long-term and long-distance transport. The fact that the ZTR of heavy minerals is greater than 80% indicates that the provenance of the Taiyuan formation has undergone long-distance transport. The Dickinson triangle diagram is also very similar, showing that it comes from the recycled orogenic belt. Combined with the tectonic movement of the peripheral orogenic belt, it is speculated that it also comes from the orogenic belt on the northern margin of the North China Craton.

The Diebusi group rock age in the Alxa block is 1.98–1.97 Ga [37]. According to zircon SIMS U–Pb dating, the magmatic crystallization age of the Bayanwula mountain orthogneiss is 2.34–2.30 Ga [37,38]. The magmatic zircon ages of the orthogneiss in the Longshou mountain are 2.33 Ga, 2.17–2.15 Ga and 2.06–2.0 Ga, respectively [39,40]. The age of the magmatic zircon core in the Beidashan TTG gneiss is 2.51–2.55 Ga [41,42] (Figure 10). In addition, under the influence of the subduction of the Paleo-Asian Ocean, the Alxa region has developed a large Late Paleozoic arcuate tectonic-magmatic belt, in which a large number of Silurian magmatic rocks are developed [43,44,45]. The age of light granite in the Yingba area is 905.2 ± 6.1 Ma [46]. Obviously, the results of detrital zircon dating of sandstone in the Taiyuan Formation of Shabatai (408–476 Ma, 904–993 Ma, 1513–1841 Ma, 2144–2558 Ma) are in good agreement with the time of multiple magmatic activities found in Alxa. There is also a good correspondence between the widespread Silurian magmatic rocks in the Alxa and the 408–476 Ma magmatic activity obtained by detrital zircon dating. Therefore, it is believed that the Alxa block is likely to provide provenance for the Taiyuan formation in the western part of the northern margin of the basin.

In summary, the provenance of the Taiyuan Formation in the northern margin of the Ordos Basin comes from the uplift area of the northern margin of the North China Craton. However, the lithology of the Taiyuan Formation of the northern boundary in the basin also exhibits east–west differentiation as a result of the variations in the age and type of bedrock in the uplift area. Taking Hangjinqi as the margin, the western part of the northern margin of the basin is mainly from the Alxa block, and the eastern part is mainly from the Daqing Shan (Figure 9).

5.3. Tectonic Implications

The provenance analysis of the Taiyuan Formation in the northern margin of the Ordos Basin reveals that the provenance area of the Taiyuan Formation in the eastern part is the Daqing Shan in the middle of the northern margin of the North China Craton, and the provenance area of the western part is the Alxa block. It is inferred that during the deposition of the Taiyuan Formation, due to the ancient Asian Ocean gradually closing, the Alxa block and Yinshan orogenic belt in the northern margin uplift belt of North China were uplifted cyclically many times, forming the northern source supply (Figure 11b), and the area north of the Yimeng uplift became the main source area [47,48]. The east–west differentiation of the provenance area is likely because a north–south central paleo-uplift of the Ordos Basin in the late Carboniferous–Early Permian Taiyuan period still exists, making the Taiyuan Formation accept the provenance of different provenance areas.

In the Early Paleozoic, under the influence of the expansion of the Qinling–Qilian Trough and the Central Asia–Mongolia Trough, the mantle material of the North China Craton moved towards the expansion ridge of the two ocean basins, the North China Craton subsided, and transgression began, forming the North China Epicontinental Basin, which is the Ordos Basin [49]. In the Early Cambrian, the Ordos Basin was controlled by the Qinling–Qilian Trough and the Helan Aulacogen, and successively formed the north–south and east–west ancient uplift, and finally formed the prototype of the central paleolift with an “L” pattern [50,51]. In the Late Cambrian, the central paleo-uplift entered the formation period, and a large central paleo-uplift was formed. During the Majiagou Period of the Early Ordovician, the nature of the continental margin was transformed from a passive continental margin to an active continental margin. Due to the development of the central paleo-uplift, the sea areas on both sides of the basin are separated. West of the paleo-uplift is a carbonate ramp deposit, and to the east is a carbonate deposit in the epicontinental sea [49,52]. In the Late Paleozoic, the basin was gradually transformed from the depression in the cratonic margin to the depression inside the Craton [53]. Affected by continental-arc collisions on both sides of the basin, the Caledonian fold belt was formed, which isolated the connection between the basin and the ocean basin outside the plate [49], and sedimentary facies gradually changed from marine deposit to sea–land transitional deposit and continental deposit. Due to the compression of the bidirectional stress in the Qinling Trough and the Xingmeng Trough in the north and to south of the North China Craton [49], the original “L” type central paleo-uplift evolved into an “I” type from the Late Carboniferous to the early Permian. In the Early Permian, under the strong anti-extrusion action of the Siberian plate and the Yangtze plate and the filling of terrigenous debris [53,54], the seawater on both sides of the central paleo-uplift spread to the middle, according to the central paleo-uplift. The distribution of sedimentary sand bodies on both sides of the paleo-uplift suggests that the central paleo-uplift was submerged in the north–south direction (Figure 11a), and the sea areas on the east and west sides merged, but the depositional patterns on both sides were significantly different, indicating that the evolution of the central paleo-uplift into an underwater paleo-uplift affected the depositional process [55]. During the Shanxi period, the scope of the central paleo-uplift was further reduced, but there are still traces of the control of sedimentary processes on the east and west sides which are still visible. Until the Shihezi period, the central paleo-uplift completely disappeared. The Ordos Basin presents a paleogeographic pattern of low in the middle and high in the north and south [54].

6. Conclusions

(1)

The provenance of the Taiyuan Formation in the northern margin of the Ordos Basin is from the recycled orogenic belt, which is the uplift belt in the northern margin of the North China Craton, which underwent a prolonged transport process.

(2)

It is considered that the provenance of the Taiyuan Formation in the western part of the northern margin of the basin is the Alxa block, and the provenance in the eastern part is the Daqing Shan in the central and western parts of the Yinshan orogenic belt.

(3)

In the late Mesozoic, the central paleo-uplift that developed in the Ordos Basin was submerged, but it still controlled the deposition on the east and west sides of the north margin in the basin.

(4)

The Alxa block provided the source for the western part of the northern margin of the Ordos Basin in the Taiyuan period, indicating that there was no ocean barrier between the Alxa block and the North China Craton in this period, and the combination of the two should be before the late Paleozoic.