Organic matter types in the Taodonggou Group mudstone exhibit
significant differences with depth. In order to understand the formation
mechanism of this special phenomenon, we analyzed the mineralogy and
geochemistry of the mudstone, as well as the source rocks, depositional
environment, and depositional processes of the Taodonggou Group. Based on
this, we have gained the following insights. (1) The Taodonggou Group
mudstone was deposited in an intermediate-depth or deep, dysoxic,
freshwater–brackish lake environment under warm and humid paleoclimatic
conditions. The input of terrestrial debris was stable, but the
sedimentation rate was slow. In addition, the sedimentation in the middle
stage was influenced by hydrothermal activities, and the changes in the
depositional environment corresponded to variations in organic matter types.
(2) The source rocks of the Taodonggou Group mudstone are mainly andesitic
and feldspathic volcanic rocks. Sediment sorting and recycling were weak,
and hydrocarbon source information was well preserved. The tectonic
background of the source area was a continental island arc and an oceanic
island arc. Furthermore, changes in the provenance of the Taodonggou Group
also had a significant impact on the variations in organic matter types. (3) The sedimentation of the Taodonggou Group involved both traction and gravity
flows. The variations in source area, depositional environment, and
depositional processes during different depositional periods led to changes
in the organic matter types of the Taodonggou mudstone. (4) Based on the
depositional environment, provenance, and depositional processes, the
sedimentation of the Taodonggou Group can be divided into three stages. In
the early stages, the sedimentation center was in the Bogda area. At this
time, the Bogda Mountain region was not exposed, and the depositional
processes inherited the characteristics of early Permian gravity flow
sedimentation, resulting in the widespread deposition of a series of
high-quality Type III source rocks in the basin. In the middle stage of the
Taodonggou Group sedimentation, the sedimentation center gradually migrated
to the Taibei Sag. During this period, the Bogda Mountain region experienced
uplift and hydrothermal activity, and the depositional processes gradually
transitioned to traction flows, resulting in the widespread deposition of a
series of Type II source rocks in the basin. In the late stage of the
Taodonggou Group, the uplift of the Bogda Mountain region ceased, and the
sedimentation center completely shifted to the Taibei Sag. Meanwhile, under
the influence of gravity flows, the organic matter types of the Taodonggou
mudstone changed to Type III.
National Major Science and Technology Projects of China2016ZX05066001-0022016ZX05034-001-052017ZX05064-003-0012017ZX05035-02Innovative Research Group Project of the National Natural Science Foundation of China4187213542072151PetroChina2021DJ0602Introduction
Turpan–Hami Basin, Junggar Basin, and the Bogda area all belong to the southern
part of the ancient Asian Ocean in the Paleozoic era (Korobkin and Buslov,
2011; Jiang et al., 2015). During the early Carboniferous to early Permian,
they began momentously to separate due to the continuous expansion of the
Bogda Rift and began to enter the basin-forming period in the middle Permian
(Miao et al., 2004; Novikov, 2013; Jiang et al., 2015; J. Wang et al., 2019;
S. Zhang et al., 2019). The middle Permian is a momentous stage in the tectonic
evolution of the Turpan–Hami Basin. During this period, the expansion of the
Bogda Rift stopped. With the gradual withdrawal of seawater from Xinjiang,
the sedimentary environment of the Turpan–Hami Basin gradually shifted to
continental facies, and the sedimentary center gradually shifted from the
Bogda area to the Taibei Sag (Miao et al., 2004; Shi et al., 2020; Li et al.,
2022). Taodonggou Group mudstones are widely deposited in the Turpan–Hami
Basin. Previous studies have confirmed that Taodonggou Group mudstone is a
very good to excellent source rock with huge hydrocarbon generation
potential (Song et al., 2018; Miao et al., 2021, 2022a, b). It has been found that the organic matter types of the
Taodonggou mudstone can be classified into two categories, with the upper
and lower sections being Type III and the middle section being Type II (Miao
et al., 2021, 2023).
The hydrocarbon generation potential of mudstone is closely related to its
sedimentary environment (Wu et al., 2021; Li et al., 2022; K. Zhang et al.,
2019; Zhao et al., 2021; Miao et al., 2004). Regarding the sedimentary
environment of the Taodonggou Group mudstone, previous researchers have
conducted extensive research. Miao et al. (2004) believed that the mudstone
in the Taodonggou Group was deposited in a warm and humid paleoclimate,
high-salinity waterbodies, and an anoxic environment. Yang et al. (2010),
based on the sedimentary characteristics of the Taerlang Formation and the
Daheyan Formation, believed that the Taodonggou Group was deposited in a
subhumid climate and that climate change is periodic. Wei (2015) also
confirmed that the paleoclimate change in the Taodonggou Group stratum has a
cyclical feature through tree rings and is mainly a warm and humid
paleoclimate. At the same time, Song et al. (2018) also confirmed this by
using the elemental geochemical characteristics of the Taodonggou Group
shale outcrops in the field. Tian et al. (2017) analyzed the biomarkers of
the Taodonggou Group in seven outcrops around the Turpan–Hami Basin and
concluded that the mudstone of the Taodonggou Group was deposited in a
balanced, filled lake with little or no terrestrial organic matter; a large
amount of algal organic matter input; and weakly alkaline, hypoxic to
hypoxic brackish water. Miao et al. (2021) found biomarkers in the
Taodonggou Formation mudstone from wells YT1 and L30 from different
perspectives of Tian et al. (2017), which may be related to the weathering effect of
outcrop samples. Through the research of the above scholars, we have found
that there is some controversy over the sedimentary environment of the
Taodonggou Group, and the relationship between the cyclic changes in the
sedimentary environment and the changes in the organic matter types of the
Taodonggou Group mudstone is still unclear.
In addition, the provenance and sedimentation mode of sediments also have a
significant influence on the organic matter types in mudstones (Mei et al.,
2020). Mudstone belongs to a category of fine-grained sediment that is
challenging to analyze using traditional heavy-mineral analysis methods
(Rollinson, 1993; Roser and Korsch, 1988; Gehrels et al., 2008). Therefore,
elemental geochemical methods can be employed for provenance analysis
(McLennan et al., 1983; Taylor and McLennan, 1985; Li et al., 2020). Elemental
geochemical analysis compares the major, trace, and rare-earth element
characteristics of mudstones in the sedimentary area with those of
lithologies in the provenance area to determine the lithology of source
rocks, weathering degree, and tectonic background of the sediment source
area (Li et al., 2020; Floyd and Leveridge, 1987; Basu et al., 2016).
Previous studies have found that the sediment source not only affects
variations in the salinity of lake water but also influences the input of
nutrients and terrestrial organic matter, thus impacting the quality of
mudstones (Li et al., 2020; Deditius, 2015; Essefi, 2021). The tectonic
activity in the source area not only affects changes in the sedimentary
center but also influences the source area (Miao et al., 2022c; Pinto et
al., 2010). Therefore, reconstructing the location and sedimentation mode of
the sediment source area is of great significance for understanding the
variations in organic matter types in the Taodonggou Group mudstones.
Based on the mineralogical and elemental geochemical characteristics of 16
mudstone samples collected from well YT1, this study aims to reconstruct
the paleoclimatic features, provenance, and tectonic background of the
sedimentary period in the source area of the Taodonggou Group mudstones. It
also aims to explore the influence of sedimentary environment, provenance
changes, and sedimentation mode on the deposition of the Taodonggou Group
mudstones in order to reveal the formation process of the mudstones.
Geological setting
The Turpan–Hami Basin, located in the eastern part of the Xinjiang Uygur
Autonomous Region, is one of the three major petroliferous basins in
Xinjiang. It is 660 km long from east to west and 130 km wide from north to
south, with a total covered area of 5.35×104 km2. The
Turpan–Hami Basin has undergone four stages: the extensional rift basin
development stage; the compressional foreland basin development stage; the
extensional faulted basin development stage; and the compressional
regenerated foreland basin development stage, which finally formed the
current pattern of the Mesozoic–Cenozoic superimposed composite inland basin
(Zhu et al., 2009; Jiang et al., 2015; Wartes et al., 2002; Greene et al.,
2005). According to the tectonic evolution characteristics of the
Turpan–Hami Basin, the Turpan–Hami Basin can be divided into three primary
tectonic units from east to west: the Hami Depression, the Liaodun Uplift,
and the Turpan Depression (Miao et al., 2021; Fig. 1a).
Geological overview of the study area (modified after Miao et al.,
2021, 2023): (a) geological background of the Turpan–Hami Basin,
(b) thickness contour map of Taodonggou Group mudstone in the Taibei Sag, (c)
YT1 stratum of the Taodonggou Group.
Taibei Sag, the secondary sag of the Turpan Depression in the Turpan–Hami Basin, is
the largest sedimentary unit in the Turpan–Hami Basin (Fig. 1b). The Taibei Sag
is a Paleozoic–Cenozoic-inherited subsidence area (Li et al., 2021), which
is a key area for oil and gas exploration in the Turpan–Hami Basin due to
its high degree of thermal evolution of hydrocarbon source rocks; good
physical reservoir properties; good cap sealing; and rich oil and gas
resources, which are the focus of oil and gas exploration in the Turpan–Hami
Basin (Wu et al., 2021; Li et al., 2021). The Taodonggou Group is the general
name of the Daheyan Formation and the Taerlang Formation. The Daheyan
Formation is composed of a sequence of sandstone and conglomerate deposits,
with locally interbedded gray to dark-gray mudstone. It is unconformably
overlain by the Yierxitu Formation. The Taerlang Formation is predominantly
composed of gray–black mudstone, with localized occurrences of gray–green
siltstone and medium-grained sandstone. Due to the fact that the
stratigraphic boundary between the Taerlang Formation and the Daheyan
Formation is not obvious, they are collectively called the Taodonggou Group.
The middle Permian Taodonggou Group is mainly located in the western part of
the study area. At present, only wells YT1 and L30 are drilled (well YT1
is drilled through; well L30 is not drilled through). The burial
depth of the stratum is 4000–6500 m, and the thickness of the mudstone is
50–200 m (Miao et al., 2022c).
Samples and experimentsSamples
In this study, 16 mudstone samples were collected from well YT1, numbered
YT1-1 to YT1-16 in order of depth. After cleaning the samples, X-ray diffraction (XRD), X-ray fluorescence spectrometer (XRF), and
inductively coupled plasma mass spectrometer (ICP-MS) experiments were conducted.
Experiments
The XRD experiment was carried out at Hangzhou Yanqu Information Co., Ltd.
The experimental instrument was the Ultima VI XRD testing instrument of
Rigaku Corporation. In accordance with the Chinese industry standard
SY/T 5163-2018, the mudstone was broken to a particle size of fewer than 200
meshes, and 2 g of samples was weighed to obtain XRD images through Cu / Ka
radiation at a scanning speed of 2∘ min-1. The measurement angle
range was 3∘≤ 2θ≤ 70∘, and finally,
quantitative interpretation is made with the software X'Pert HighScore Plus
of Malvern Panalytical.
The XRF experiment was conducted at Hangzhou Yanqu Information Co., Ltd.,
and the experimental instrument was a Malvern Panalytical Axios tester. The mudstone was first crushed to a particle size of fewer than
200 meshes. Then 10 g of the sample was weighed and calcined in a muffle
furnace for 4 h to get rid of organic matter and carbonates, and
the weight loss was recorded. Finally Li2B4O7 was added,
mixed evenly, and made into glass bead, and the main element concentration
was tested.
The ICP-MS test was performed at Beijing Orient Smart, and the test
instrument was an Element XR inductively coupled plasma emission
spectrometer manufactured by Thermo Fisher, Inc. Before analysis, the
samples were ground to a particle size of less than 40 µm. An
appropriate amount of the sample was weighed and dissolved in HF (30 %)
and HNO3 (68 %) at 190 ∘C for 24 h. After evaporating the
excess solvent with deionized water, the solution was redissolved in 2 mL of
6.5 % HNO3 and then stored at
150 ∘C for 48 h. Subsequently, after evaporating the
solution, 1 mL of the 6 mol L-1 HNO3 evaporated solution was added to the
sample.
ResultsMineralogy
The XRD test results of 16 samples from well YT1 are shown in Table A1 and
Fig. 2. As can be seen from Table A1 and Fig. 2, Taodonggou Group
mudstones are composed of clay, quartz, calcite, plagioclase, baryte, and
K-feldspar, and some samples contain siderite and pyrite. The content of
clay is the highest (23.9 %–70.9 %, mean = 40.78 %), followed by quartz
(17.2 %–59.2 %, mean = 34.69 %), calcite (1 %–35.4 %, mean = 16.97 %), baryte (0 %–13.3 %, mean = 4.21 %), plagioclase
(0 %–5.4 %, mean = 2.93 %), and K-feldspar (0 %–2.3 %, mean = 0.9 %).
Mineral composition of Taodonggou Group mudstone in well YT1.
The mineral composition can be used to analyze the lithofacies type of
mudstone, and different lithofacies types often have different
characteristics (Glaser et al., 2014). Previous scholars believed that
mudstone types could be divided by the ternary diagram of mineral
composition. The three end elements of the ternary diagram are quartz + feldspar + mica (QFM), calcite + dolomite + ankerite + siderite + magnesite (carbonate), and clay. The XRD results of 16 mudstone samples from
well YT1 in the study area are put into the ternary map (Fig. 3). The
results show that the data points of Taodonggou Group mudstone in the study
area are located in four areas, namely mixed mudstone, silica-rich
argillaceous mudstone, argillaceous siliceous mudstone, and mixed siliceous
mudstone, and most of the points are mixed mudstone and argillaceous
siliceous mudstone areas, which indicates that Taodonggou Group mudstone can
be divided into four types – mixed mudstone, silica-rich argillaceous
mudstone, argillaceous siliceous mudstone, and mixed siliceous mudstone – and
the main lithofacies are mixed mudstone and argillaceous siliceous mudstone.
Lithofacies classification of Taodonggou Group mudstone in well
YT1 (modified from Glaser et al., 2014).
Major element
Table A2 shows the results of the major elements in 16 mudstone samples from
well YT1. From Table A2, we can see that the major elements of the
Taodonggou Group mudstone are mainly SiO2, Al2O3,
Fe2O3, CaO, and TiO2. The highest content of SiO2 is
from 43.11 %–70.11 %, with an average value of 56.18 %.
Al2O3 content takes second place, accounting for 11.65 % to
25.75 %, with an average value of 18.69 %; the average content of
another main element is less than 10 %.
Trace element
The trace element content of the Taodonggou Group mudstone is shown in Table A3. The enrichment factor (EF) is an important indicator of element enrichment
(Taylor and McLennan, 1985; Ross and Bustin, 2009). By comparing the trace
element content of the mudstone of the Taodonggou Group with the global
average shale (AS), the trace element enrichment factors in the study area
are calculated as follows:
XEF=(X/Al)samples(X/Al)AS,
where X and Al represent the concentrations of elements X and Al (Taylor and
McLennan, 1985; Ross and Bustin, 2009). XEF< 1 represents the
dilution concentration of element X relative to the standard composition,
XEF> 1 represents the relative enrichment of element X
compared to the AS concentration, XEF> 3 represents the
detectable autogenetic enrichment, and XEF> 10 is considered
an indicator of moderate to strong autogenetic enrichment (Taylor and
McLennan, 1985; Ross and Bustin, 2009).
Figure 4 and Table A4 present the enrichment factors of Taodonggou Group
mudstone in the study area. It can be seen from Fig. 4 and Table A4 that
only Hf (0.5–2.11, mean = 1.29) is enriched in the Taodonggou Group
mudstone compared with AS, and other elements are not enriched.
AS standardized multi-element diagrams of Taodonggou Group
mudstone in the study area.
Rare-earth element
The rare-earth element (REE) content of Taodonggou Group mudstone in the study area is shown in
Table A5. According to Table A5, the ∑ REE content of Taodonggou Group
mudstone ranged from 43.247 to 257.997 ppm, with an average value of
159.206 ppm. The light rare-earth element (LREE) content was the highest
(mean value = 133.45 ppm), followed by medium rare-earth element (MREE) (mean
value = 17.438 ppm) and heavy rare-earth element (HREE) (mean value 6.684 ppm)
in that order. After chondrite standardization (Taylor and Mclennan, 1985),
Taodonggou Group mudstone shows a right-dipping REE distribution pattern
(Fig. 5); (La / Yb)N is 6.228–10.081, with an average value of 7.358.
Standardized map of rare-earth element chondrite in mudstone of
the Taodonggou Group.
In addition, in Fig. 5, although the YT1-13 sample exhibits a weak right-dipping REE distribution pattern similar to other samples, its rare-earth
elements are significantly depleted. Based on Fig. 4 and Table A4, the
trace elements in the YT1-13 sample are depleted compared to AS, indicating
that the YT1-13 sample has been influenced by groundwater leaching.
Reconstruction of paleosedimentary environment based on elemental
geochemical characteristicsPaleoclimate and weathering
The paleoclimate affects not only the weathering degree of the parent rock
but also the transport distance of sedimentary debris and the
transport of nutrients (Zhang et al., 2005). There are many evaluation
indices for paleoclimate, such as the chemical-alteration index (CIA) and
the climate index (C). It is generally believed that CIA = 50–65 and
C< 0.2 reflect that the sedimentary system is in a dry and cold
climate against the background of a lower degree of chemical weathering, CIA = 65–85 and 0.2 <C< 0.8 indicate that the
sedimentary system is in a warm and humid climate against the background of
a medium degree of chemical weathering, and CIA = 85–100 and C> 0.8 reflect the humid and hot climate against the background
of a high degree of chemical weathering (Zhang et al., 2019; Nesbitt and
Young, 1984). The calculation formula for CIA and C is as follows:
2CIA=Al2O3×100Al2O3+Na2O+CaO*+K2O3C=Fe+Mn+Cr+Ni+V+CoCa+Mg+Sr+Ba+K+Na.
In Eq. (2), CaO* only refers to CaO in silicate minerals. Due to the
lack of direct measurement means, it is often calculated indirectly by the
content of P2O5, namely
CaO*=mol(CaO)-103molP2O5,
where mol(CaO) and mol(P2O5) are the mole numbers of CaO and
P2O5, where when mol (Na2O) ≤ mol (CaO*), mol (CaO*) = mol (Na2O); in contrast, when mol(Na2O) > mol(CaO*), mol(CaO*) = mol(CaO) (Nesbitt and Young, 1984). The CIA
values of the Taodonggou Group mudstone in the study area were calculated
based on Eqs. (2) and (3), ranging from 68.71 to 96.97, with a
mean value of 80.17. The climate index (C) is 0.22–2.42 (average = 1.01;
Table 3). The overall paleoclimate was warm, humid, and hot (Fig. 6a).
Paleoclimate of the Taodonggou Group: (a) CIA characteristics of
Taodonggou Group mudstone (modified from Nesbitt and Young, 1984), (b) cross-plot of K2O / Al2O3 and Ga / Rb (modified from Roy and Roser,
2013), (c) cross-plot of CIA and C, (d) cross-plot of CIA and Ga / Rb,
(e) cross-plot of C and
Ga / Rb.
In addition, the cross-plot of Ga / Rb and K2O / Al2O3 can also
be used to analyze the paleoclimate characteristics during the formation of
sedimentary rocks (Lerman and Baccini, 1987; Liu and Zhou, 2007). As shown
in the cross-plot of Ga / Rb and K2O / Al2O3 (Fig. 6b), almost
all points are in the warm/wet area, which indicates that Taodonggou Group
mudstone was deposited in a warm and humid paleoclimate.
By analyzing the correlations between CIA, C, and Ga / Rb (Fig. 6c–e), it
can be observed that there is the strongest correlation between CIA and C
(Fig. 6c; R2=0.7566). Additionally, the correlation coefficients
between CIA and Ga / Rb and between C and Ga / Rb are both greater than 0.4
(Fig. 6d and e). This indicates that CIA, C, and Ga / Rb are reliable
indicators of the paleoclimate during the sedimentation of the Taodonggou
Group mudstone. Based on the above analysis, the Taodonggou Group mudstone
in the study area was deposited in a warm, humid, and hot paleoclimate. This
result is consistent with Miao's indicator result using the biomarker
parameter CPI (carbon advantage index) (Miao et al., 2021), indicating that the biomarker parameter
CPI can be used to explain the paleoclimate change characteristics of
hydrocarbon source rocks with Ro ≤ 1.49.
Paleoredox conditions
Redox environments are critical to the preservation of organic matter in
sedimentary rocks, and sensitive elements such as Co, Mo, U, Th, V, Ni, and
Cr are commonly used to identify redox conditions in ancient waterbodies.
Previous evidence suggests that U / Th < 0.75, V / Cr < 2, and
V / (V + Ni) < 0.45 represent oxic conditions; 0.75 < U / Th < 1.25, 2 < V / Cr < 4.25, and 0.45 < V / (V + Ni) < 0.84 represent dysoxic conditions; and U / Th < 1.25, V / Cr < 4.25, and V / (V + Ni) < 0.84 represent anoxic
conditions (Hatch and Leventhal, 1992; Rosenthal et al., 1995; Tribovillard
et al., 2006, 2012). There is no significant correlation
between V, U, and Th and Al2O3 contents in the Taodonggou Group
mudstone samples, indicating that V, U, and Th contents in Taodonggou Group
mudstone are mainly controlled by authigenic deposition under redox
conditions (Tribovillard et al., 1994). The U / Th, V / Cr, and V / (V + Ni) of
the Taodonggou Group mudstone range from 0.21 to 0.52 (mean = 0.29), 1.62
to 4.95 (mean = 2.7), and 0.65 to 0.92 (mean = 0.75). In light of
U / Th, Taodonggou Group mudstones were deposited in an oxic environment, and
according to V / Cr and V / (V + Ni), Taodonggou Group mudstones were deposited in
a dysoxic environment. This is because U / Th cannot accurately identify the
redox environment of the sediments under highly weathered conditions (Cao et
al., 2021), so V / Cr and V / (V + Ni) were used in this study to identify the
redox environment of Taodonggou Group mudstone. The cross-plot of V / Cr and
V / (V + Ni) shows (Fig. 7) that Taodonggou Group mudstones were deposited in
a dysoxic environment.
Cross-plot of V / Cr and V / (V + Ni).
Paleosalinity
Paleosalinity is an important indicator of the paleoenvironment of a water
body. The level of paleosalinity affects the stratification of the
sedimentary waterbody and the development of plankton, thereby affecting
the paleoproductivity and enrichment of organic matter in the sedimentary
environment (Thorpe et al., 2012; Wang et al., 2021; Shi et al., 2021).
Previous research has found that Sr / Ba and B / Ga can represent changes in
paleosalinity. It is generally believed that Sr / Ba < 0.5 or
B / Ga < 3 represents fresh water, 0.5 < Sr / Ba < 1 or
3 < B / Ga < 6 means brackish water, and Sr / Ba > 1 or
B / Ga > 6 represents saline water. The correlation between Sr and
CaO of Taodonggou Group mudstone in the study area is not obvious
(R2=0.17); Sr / Ba of Taodonggou Group mudstone in the study area
ranges from 0.32 to 1.83, with an average value of 0.71, and the B / Ga is
2.53–5.81 (average = 3.36), indicating that Taodonggou Group mudstone was
deposited in freshwater and brackish-water environments (Fig. 8a).
In addition, Ca / (Ca + Fe) is a reliable indicator for evaluating the
salinity of lake waters (Z. Wang et al., 2021). The Ca / (Ca + Fe) distribution
of Taodonggou Group mudstone in the study area ranges from 0.14 to 0.78,
with a mean value of 0.42. The Sr / Ba and Ca / (Ca + Fe) intersection diagram
(Fig. 8b) shows that Taodonggou Group mudstones were deposited in
freshwater and brackish-water environments, which is in accordance with the
Sr / Ba and B / Ga intersection diagram.
Cross-plot of B / Ga and Sr / Ba (a) and cross-plot of Ca / (Ca + Fe)
and Sr / Ba (b).
Paleobathymetry
Previous research has shown that some elements of the sedimentation process
change dramatically with offshore distance. These elements can be used to
judge the water depth variation during the sedimentation period. The
commonly used indicators are Zr / Al, Rb / K, and MnO content (Xiong and Xiao,
2011; Herkat et al., 2013). It is now believed that the lower the Zr / Al
ratio or the higher the Rb / K ratio, the further offshore and the deeper the
water (Xiong and Xiao, 2011; Herkat et al., 2013). Zr / Al of Taodonggou Group
mudstone is 5.19 × 10-4–22.51 × 10-4 (average = 13.44 × 10-4), showing first a decreasing and
then an increasing trend with the depth; Rb / K ranges from 7.32 × 10-4
to 29.79 × 10-4 (mean = 19.02 × 10-4), with large
fluctuations with depth of burial. The high-value area of Rb / K is basically
consistent with the low-value area of Zr / Al, which indicates that the
ancient water depth during the Taodonggou Group mudstone deposition process
has first a decreasing and then an increasing trend.
For the content of MnO, it is generally believed that < 0.00094 %
is a shore lake, 0.00094 %–0.0075 % is a shallow lake,
0.0075 %–0.051 % is an intermediate-depth lake, and > 0.051 % is a deep lake (Herkat et al., 2013). MnO of Taodonggou Group
mudstone is 0.05 %–0.30 %, with an average of 0.16 %, which
indicates that the Taodonggou Group mudstone is mainly deposited in
an intermediate-depth–deep sedimentary lake environment.
Terrigenous detritus input
Ti, Si, and Al are relatively stable during diagenesis and are usually used
as indicators of debris flux input (Algeo and Maynard, 2004; Maravelis et
al., 2021). Generally, Ti in sediments comes from ilmenite (FeTiO3) or
rutile (TiO2), while Al can exist in feldspar, clay minerals, and other
aluminum silicate minerals (Algeo and Maynard, 2004). Compared with Ti and
Al, Si comes from many sources, including sources of biological origin and
hydrothermal and terrigenous clastic input (Kidder and Erwin, 2001).
Therefore, when using SiO2 as the evaluation index for terrigenous
clastic input, its source needs to be analyzed. The correlation of
Al2O3 and TiO2 with SiO2 in well YT1 of the study area
is not obvious, which indicates that their sources are more complex and not
dominated by terrestrial debris sources (Fig. 9). Therefore, Al2O3
and TiO2 are used in this study to indicate the terrestrial debris
input during the deposition of the Taodonggou Group mudstone.
The Al2O3 content of well YT1 is higher, ranging from 11.65 %
to 25.75 %, with an average value of 18.69 %; the TiO2 is 1.15 %–4.22 % (average = 1.77 %). As can be seen from Table A2, the
Al2O3 content of well YT1 fluctuates more with depth, and there
is first an increasing and then a decreasing trend with depth overall, while the
TiO2 fluctuates less with depth, and on the whole, there is an increasing trend with depth. Combined with the results of paleoclimate analysis in
the study area, it is found that the terrestrial debris input during the
deposition of the Taodonggou Group strata has the characteristics of
first an increasing and then a decreasing trend.
Intersection diagram of TiO2 and SiO2(a) and
intersection diagram of Al2O3 and SiO2(b).
Paleoproductivity
Paleoproductivity determines the quantity of original organic matter in
sedimentary rocks (Wei et al., 2012; Algeo and Ingall, 2007; Ross and
Bustin, 2009; Schoepfer et al., 2015). The elements P, Si, Ba, Zn, and Cu
are indicators of the magnitude of paleoproductivity, but they all have a
certain range of application; for example, only the biogenic parts of Si and
Ba can represent productivity, and Zn can only represent productivity change
in the sulfide reduction environment (Wei et al., 2012; Algeo and Ingall,
2007).
P is not only a key nutrient element in biological metabolism but also an
important component of many organisms, so it can also be used to
characterize biological productivity (Kidder and Erwin, 2001). P /Ti and P / Al
are commonly used to reflect biological productivity in order to eliminate
the influence of terrigenous detritus. The P /Ti of Taodonggou Group mudstone
in the study area ranges from 0.04 %–0.74 %, with an average value of
0.17 % and an overall low productivity. As shown in Table A2, the
relationship between P /Ti and depth was analyzed, and the results showed
that the paleontological productivity tended to increase and then decrease
with depth.
In addition, Cu is also an important nutrient and, unlike P, is generally
indicative of productivity, including the sum of primary productivity and
productivity from terrestrial inputs (Schoepfer et al., 2015). For the
purpose of eliminating the dilution interference of terrigenous detritus,
Cu / Ti is used as an indicator to evaluate the paleoproductivity in this
study. The distribution range of Cu / Ti of Taodonggou Group mudstone in the
study area is from 0.55 to 1.96, with an average value of 1.02, and gradually
decreases with depth, indicating a gradual increase in paleoproductivity
during the deposition of Taodonggou Group mudstone.
Deposition rate
The deposition rate is one of the parameters characterizing the magnitude of
the dilution effect during deposition and is commonly characterized by
(La / Yb)N. It is generally believed that the difference between LREE and
HREE migration is not significant when the sedimentation rate of the lake
basin is faster, and the (La / Yb)N value is close to 1. Conversely, when
the (La / Yb)N value is greater or less than 1, it indicates that the
sedimentation rate of the lake basin is slower (A. Wang et al., 2021; Cao et
al., 2018). The (La / Yb)N values of the Taodonggou Group mudstones are
6.228–10.081, with an average value of 7.358 in the study area, which is
much greater than 1. This indicates that the mudstone of the Taodonggou
Group has a slower deposition rate.
Hydrothermal activity
The study area has been extremely volcanically active from the Carboniferous
to the Permian, with extensive volcanic deposits in the middle Permian
Taodonggou Group, the lower Permian Yierxitu Formation, and the
Carboniferous. In order to explore whether hydrothermal activity is involved
in the middle Permian sedimentation, the Zn–Ni–Co ternary diagram and the
(Cu + Co + Ni) × 10–Fe–Mn ternary diagram are applied in this study
(Xu et al., 2022; You et al., 2019). Based on the Zn–Ni–Co ternary diagram
(Fig. 10a), some data points of the Taodonggou Group mudstone are
distributed in the hydrothermal sedimentary zone, and based on the
(Cu + Co + Ni) × 10–Fe–Mn ternary diagram (Fig. 10b), all data
points of the samples fall in the hydrothermal sediment zone and Red Sea
hydrothermal sediment zone, which indicates that the Taodonggou Group
mudstone deposition was influenced by hydrothermal fluids.
Zn–Ni–Co ternary diagram (a) and (Cu + Co + Ni) × 10–Fe–Mn ternary diagram (b) (modified after You et al., 2019).
Tectonic setting
Sedimentary rocks of different tectonic settings have prominent differences
in element composition and content, so the geochemical characteristics of
sedimentary rocks can be used to reflect the tectonic setting of sedimentary
basins (Kroonenberg, 1992).
The elements Co, Th, Sc, Zr, and La are relatively stable and less affected
by geological activities such as weathering, transportation, and deposition.
Therefore, the La–Th–Sc ternary diagram and the Th–Co–Zr/10 ternary diagram
can be utilized to distinguish the tectonic setting during the formation of
sediments (Bhatia and Crook, 1986; Cai et al., 2022). Based on the La–Th–Sc
ternary diagram (Fig. 11a), most of the data points fall in the continental
island arc region, and based on the Th–Co–Zr/10 ternary diagram (Fig. 11b), almost
all the data points fall in the continental island arc and oceanic island
arc regions. This indicates that the tectonic setting of the Taodonggou
Group's source area is a continental island arc and an oceanic island arc.
Tectonic setting of source area in Taodonggou Group mudstone: (a)
La–Th–Sc ternary diagram (modified after Zhu et al., 2021), (b) Th–Co–Zr/10
ternary diagram (modified after Zhu et al., 2021), (c) cross-plot of
Al2O3/ SiO2 and Fe2O3+ MgO (modified after Bhatia,
1983), (d) cross-plot of TiO2 and Fe2O3+ MgO (modified after
Bhatia, 1983), (e) cross-plot of SiO2 and Al2O3/ SiO2 (modified after Roser and Korsch, 1988).
Additionally, previous studies have shown that SiO2, TiO2,
Al2O3/ SiO2, and Fe2O3+ MgO are also important
parameters for identifying the source tectonic setting. Cross-plots of
Al2O3/ SiO2 and Fe2O3+ MgO, TiO2 and
Fe2O3+ MgO, and SiO2 and Al2O3/ SiO2 are often
employed to recognize the tectonic setting (Bhatia, 1983; Li et al., 2020;
Roser and Korsch, 1988). Based on the cross-plot of
Al2O3/ SiO2 and Fe2O3+ MgO (Fig. 11c), all data
points are distributed around the continental island arc and oceanic island
arc, which is consistent with the cross-plot of TiO2 and
Fe2O3+ MgO (Fig. 11d) and the cross-plot of SiO2 and
Al2O3/ SiO2 (Fig. 11e). As a result, the tectonic setting of
the Taodonggou Group mudstone source area is continental island arc and oceanic
island arc.
Discussion
The sedimentary environment, provenance location, and sedimentation mode are
factors that influence the quality of mudstones. In this study, based on the
mineralogical and elemental geochemical characteristics of the Taodonggou
Group mudstones, we discuss the influence of sedimentary environment,
provenance location, and sedimentation mode on the quality of the Taodonggou
Group mudstones.
The influence of paleosedimentary environment on the quality of
mudstone
Based on the mineralogical and elemental geochemical characteristics and
previous studies on the organic geochemical characteristics of the
Taodonggou Group mudstones (Miao et al., 2021), a comprehensive geochemical
profile of well YT1 was established. The results are shown in Fig. 12.
It can be observed from Fig. 12 that the sedimentary environment of the
Taodonggou Group mudstones is closely related to their organic matter types
and can be divided into three periods. In the early stage of the Taodonggou
Group, the overall climate was warm and humid under moderate chemical-weathering conditions. The sedimentary waterbody was dysoxic–anoxic brackish
water. At this time, productivity was weak, and organic matter was mainly
derived from terrestrial sources. In the middle stage of the Taodonggou
Group, the paleoclimate gradually shifted to a dry and humid climate under
strong chemical-weathering conditions, accompanied by hydrothermal activity.
This provided abundant nutrients for the growth of algae and other
microorganisms. At the same time, the sedimentation rate increased,
resulting in a predominance of algae in the organic matter composition
during this period. During the late stage of the Taodonggou Group, the
climate again shifted to a warm and humid climate under moderate chemical-weathering conditions. The sedimentation rate slowed down, and the input of
organic matter shifted back to predominantly terrestrial sources.
The geochemical profile of the Taodonggou Group in well YT1.
ProvenanceLithology of parent rock
Previous studies have found that the chemical composition of the rocks in
the sedimentary area and the parent rock in the provenance area have a
strong affinity, and the type of parent rock will directly affect the
elemental geochemical characteristics of the sediment (Tribovillard et al.,
2006; Shi et al., 2021; McLennan et al., 1993; Basu et al., 2016; Hu et al.,
2021; Floyd and Leveridge, 1987; Wronkiewicz and Condie, 1987). Generally
speaking, the transport of sediment from the source area to the sedimentary
area goes through multiple complex processes such as mechanical transport
and chemical action, and hence it is necessary to analyze the impact of
sediment sorting and recycling on each chemical component when identifying
the source. Previous studies have shown that trace elements Zr, Th, and Sc
are relatively stable in geological processes such as weathering,
transportation, and sorting and are not easily lost, which can be used as
one of the indicators for parent rock identification (Floyd and Leveridge,
1987; Wronkiewicz and Condie, 1987). According to the Th / Sc and Zr / Sc
intersection diagram of Taodonggou Group mudstone (Fig. 13a), Taodonggou
Group mudstone is close to andesite and felsic volcanic rock of the upper
crust, and its composition is controlled by the composition of its felsic
parent rock and has not undergone sediment sorting and recycling.
Parent rock type of the Taodonggou Group in well YT1 (data of
Lucaogou Formation in the Junggar Basin are from Li et al., 2020): (a) Th / Sc and
Zr / Sc intersection diagram (modified after Floyd and Leveridge, 1987), (b)
La / Th and Hf intersection diagram (modified after Floyd and Leveridge, 1987),
(c) Co / Th and La / Sc intersection diagram (modified after Wronkiewicz and
Condie, 1987), (d) TiO2 and Zr intersection diagram, (e) La / Yb and
∑ REE intersection diagram (modified after Allègre and Minster,
1978).
In addition, REE and trace elements in mudstone from different parent rocks
are obviously different, so the ratio of REE to trace elements can be used
to analyze the type of parent rock, and the most common ones are La / Sc,
La / Co, Th / Sc, Th / Co, and Cr / Th (Basu et al., 2016; Hu et al., 2021; Floyd
and Leveridge, 1987; Wronkiewicz and Condie, 1987; Allègre and Minster,
1978). Based on the Hf and La / Th intersection diagrams (Fig. 13b) and the
La / Sc and Co / Th intersection diagrams (Fig. 13c), we can see that the
mudstones of the Taodonggou Group have both andesitic island arc sources and
felsic volcanic sources. It can be seen from the cross-plot of TiO2 and
Zr (Fig. 13d) that the mudstone of the Taodonggou Group is a source of
intermediate igneous rocks and felsic igneous rocks. As can be seen from the
cross-plot of La / Yb and Σ REE (Fig. 13e), almost all data points are
located in the sedimentary rock, alkali basalt, and granite areas.
In summary, the parent rocks of the Taodonggou Group mudstone are andesitic
and feldspathic volcanic rocks with weak sedimentary sorting and
recirculation, and the material source information is well preserved.
Location of parent rock
There is a great deal of controversy about the provenance location of the
middle Permian in the Turpan–Hami Basin (Shao et al., 2001; Jiang et al., 2015; J. L. Wang
et al., 2019; Zhao et al., 2020; Song et al., 2018; Wang et al., 2018a, b; Tang
et al., 2014). Shao et al. (1999) believed that the provenance of the
Permian was mainly from the Jueluotage Mountains in the south of the
Turpan–Hami Basin, Song et al. (2018) considered that it came from the Bogda
area, and Zhao et al. (2020) believed that the provenance of the Permian in the
Turpan–Hami Basin was consistent with that in the Junggar Basin and originated from
the Kelameili mountains and the northern Tianshan. Summarizing the previous
research results, it is found that the main controversial point is the time
of the first uplift of the Bogda Mountains.
At present, there are many opinions about the time of the Bogda Mountain
uplift, suggesting that it initially occurred in
the early Permian (Carroll et al., 1990, 1995; Shu et al., 2011; Wang et al., 2018a; Li
et al., 2022), middle Permian (Zhang et al., 2006; Liu et al., 2018; Wang et
al., 2018b), late Permian–Early Triassic (Zhao et al., 2020; Guo et al.,
2006; Wang, 1996; Sun and Liu, 2009; Tang et al., 2014; Wang et al., 2018b),
Middle Triassic (Guo et al., 2006), Early Jurassic (Green et al., 2005; Liu
et al., 2017; Ji et al., 2018), and Late Jurassic (Yang et al., 2015). If the
initial uplift of the Bogda Mountains was after the middle Permian, the
parent rock types of the Taodonggou Group mudstone in the Turpan–Hami Basin
and the Lucaogou Formation mudstone in the Junggar Basin should be the
same.
We have counted the elemental geochemical characteristics of the Lucaogou
Formation in the Junggar Basin (Li et al., 2020) and found that the parent
rock type of Lucaogou Formation mudstone in the Junggar Basin is greatly
different from that of P2td, which is felsic volcanic rock (Fig. 14).
As a result, the Bogda Mountains' initial uplift should be late Permian–Early
Triassic in the early Permian or middle Permian. This is consistent with Li
et al. (2022) and Wang et al. (2018a), who inferred the uplift of the Bogda
Mountains at 289.8–265.7 Ma. Shao et al. (2001) believed that the
sandstone of the Daheyan Formation in the Turpan–Hami Basin has a good affinity
with the early Permian and Carboniferous, so the provenance direction of the
sandstone of the Daheyan Formation is consistent with that of the early
Permian, and they all come from the Jueluotage Mountains. However, the
paleocurrent direction of the early Permian in Xinjiang is southeast (Zhang
et al., 2005; Li et al., 2007; J. L. Wang et al., 2019), and the provenance area
is located in the north of the Bogda area. Zhao et al. (2020) calculated the
U–Pb dating results of 5250 zircons in the Tianshan and believed that the
provenances of the Turpan–Hami Basin and the Junggar Basin both came from the
northern Tianshan and the Kelameili mountains, which is also consistent with
the ancient ocean current direction in the early Permian (Zhang et al.,
2005; Li et al., 2007; J. L. Wang et al., 2019; Fig. 14a). Consequently, the first
uplift of the Bogda Mountains should have occurred in the early Permian, but it
was not exposed in the early–middle Permian, and it still received
sedimentation. In the middle Permian, the exposed water began to be denuded,
becoming the source area of the Turpan–Hami Basin (Wang et al., 2018a).
Provenance location from early Permian to middle Permian in
the Tianshan area (modified after Zhao et al., 2020): (a) early Permian, (b)
early Taodonggou Group, (c) middle to later Taodonggou Group.
Based on the above analysis, in the early–middle Permian, although the Bogda
Mountains in the north of the Turpan–Hami Basin were uplifted due to orogeny, it
did not emerge from the water surface, and it still accepted the provenance
of the northern Tianshan and Kelameili mountains. At this time, there was a
NE-trending ancient ocean current (Carrollet et al., 1995; Obrist-Farnert et
al., 2015; Zhao et al., 2020), so the Jueluotage Mountains, which had been
uplifted in the south of the Turpan–Hami Basin, became a secondary provenance
area (Shao et al., 1999; Fig. 14b). With the continuous uplift of the Bogda
Mountains, the sedimentary center of the Turpan–Hami Basin gradually shifted to
Taibei Sag, and the provenance area of the Turpan–Hami Basin changed to the Bogda and Jueluotage mountains (Fig. 14c).
Sedimentation mode
In previous studies, scholars have believed that the sedimentation of the
Permian in the Turpan–Hami Basin is mainly controlled by traction currents
(Chen et al., 2003). However, recent research has revealed the presence of
gravity flow deposits in the Permian of the Turpan–Hami Basin (2018a; Xu, 2022). Yang et al. (2010) found poorly sorted
debris flow deposits in the Daheyan Formation, and Xu (2022) discovered
alluvial and fluvial facies in the Daheyan Formation, consisting of
volcaniclastic rocks and conglomerates that are similar in composition to
the lower Permian volcaniclastic rocks and conglomerates. This suggests the
existence of gravity flow deposits during the early Permian in the
Turpan–Hami Basin. Wang et al. (2018a) also suggested the development of
gravity flow deposits and pillow lavas in the early Permian. Meanwhile, in
the early–middle Permian, the sedimentation inherited the provenance and
sedimentation style from the early Permian, but the gravity flow deposits
transitioned gradually into traction current deposits. Due to the influence
of gravity flow deposits, terrestrial organic matter can be transported to
the deep lake area (Yu et al., 2022; Li et al., 2011), thereby altering the
type of organic matter.
During the middle of the Taodonggou Group, the Turpan–Hami Basin entered the
foreland basin sedimentation stage due to the uplift of the Bogda Mountains.
The sedimentary environment of the Taodonggou Group in the Tainan Sag is
similar to that in the Taibei Sag (Li, 2019). During this time, the
sedimentary waterbody of the Taodonggou Group in the Turpan–Hami Basin
became shallower, and the dominant sedimentation style transitioned to
traction currents. Xu (2022) conducted lithological observations on the
Taerlanggou section, the Zhaobishan section, and the well YT1 in the
Taodonggou Group and found the presence of traction structures of gravity
flow origin in the middle and upper parts of the Taerlang Formation.
Additionally, a large number of calcareous and iron nodules appeared in the
formation, indicating the occurrence of gravity flow deposits during the
late-stage sedimentation of the Taodonggou Group. The organic matter type in
the mudstones during this period was influenced by gravity flows.
Formation mechanism of the Taodonggou Group mudstone
Based on the sedimentary environment, provenance, and sedimentation mode
during the deposition of the Taodonggou Group mudstones, this study has
constructed the formation mechanism of the Taodonggou mudstones. The results
indicate that the formation of the Taodonggou Group mudstones can be divided
into three stages.
In the early part of the Taodonggou Group, the Bogda Mountains began to rise but did
not emerge from the water surface. The sediment source is mainly from the northern
Tianshan and Kelameili mountains, and the secondary source area is the Jueluotage
Mountains in the south of the Turpan–Hami Basin. The stratum of the
Taodonggou Group was deposited in a warm and humid paleoclimate with high
weathering intensity and a stable input of terrigenous detritus. In
addition, the sedimentary waterbody is deep at this time, creating a deep
lake environment of brackish and dysoxic water. However, this period
inherited the gravity flow sedimentation characteristics from the early
Permian. Due to the influence of gravity flows, terrestrial organic matter
was transported to the deep lake, resulting in the input of organic matter
in the mudstones primarily derived from higher terrestrial plants (Miao et
al., 2021). Consequently, a high-quality Type III organic matter source rock
was formed (Fig. 15a).
Middle Permian source–sink system and lake basin evolution
history of the Turpan–Hami Basin: (a) early Taodonggou Group, (b) middle
Taodonggou Group, (c) late Taodonggou Group.
In the middle of the Taodonggou Group, with the continuous uplift of the Bogda
Mountains and hydrothermal activity, the climate changed into a hot and humid
paleoclimate, the weathering degree further increased, and the input of
terrigenous detritus increased. The provenance areas are the Bogda and
Jueluotage mountains. In addition, during this period, the sedimentary center
gradually transferred to the Taibei Sag, and the sedimentary waterbody
became shallow, which was a dysoxic, intermediate-depth lake environment. Due
to the nutrients brought by hydrothermal activity, the lower algae
multiplied during this period, and the salinity of the sedimentary water
body became lower, becoming a freshwater environment and thus depositing a
set of high-quality Type II2 organic source rocks.
In the late Taodonggou Group, the uplift of the Bogda Mountains basically
stopped, and the climate changed to a warm and humid paleoclimate again. The
weathering degree was high, and the input of terrigenous debris was reduced.
The Bogda and Jueluotage mountains remained the provenance areas. The
sedimentary center was essentially transferred to the Taibei Sag at this
time. During this period, the salinity of the sedimentary waterbody was
high, and the sedimentary waterbody became deeper. It was a deep lake
environment with dysoxic and brackish water. During this period, the
sedimentation was also influenced by gravity flows, leading to changes in
lithology and organic matter type. As a result, the organic matter type in
the mudstones deposited during this period transitioned to Type III.
Conclusions
Through the mineral composition and element geochemistry analysis of the
Taodonggou Group mudstone, the following insights have been obtained:
The mudstone minerals of the Taodonggou Group are mainly clay and quartz
and can be classified into four petrographic types according to their mineral
fractions.
The Taodonggou Group mudstone was deposited in an intermediate-depth or
deep, dysoxic, freshwater–brackish lake environment under warm and humid
paleoclimatic conditions. The input of terrestrial debris was stable, but
the sedimentation rate was slow. In addition, the sedimentation in the
middle stage was influenced by hydrothermal activities. Moreover, the
source rocks of the Taodonggou Group mudstone are mainly andesitic and
feldspathic volcanic rocks. Sediment sorting and recycling were weak, and
hydrocarbon source information was well preserved. The tectonic background
of the source area was a continental island arc and an oceanic island arc.
The sedimentary environment, sources, and sedimentary methods have
significant impacts on the organic matter types of the Taodonggou Group. In
the early Taodonggou Group, the sedimentation center was in the Bogda area.
At this time, the Bogda Mountain region was not exposed, and the
depositional processes inherited the characteristics of early Permian
gravity flow sedimentation, resulting in the widespread deposition of a
series of high-quality Type III source rocks in the basin. In
the middle Taodonggou Group, the sedimentation center gradually migrated to
the Taibei Sag. During this period, the Bogda Mountain region experienced
uplift and hydrothermal activity, and the depositional processes gradually
transitioned to traction flows, resulting in the widespread deposition of a
series of Type II source rocks in the basin. In the late
Taodonggou Group, the uplift of the Bogda Mountain region ceased, and the
sedimentation center completely shifted to the Taibei Sag. Meanwhile, under
the influence of gravity flows, the organic matter types of the Taodonggou
mudstone changed to Type III.
Mineral composition of Taodonggou Group mudstone in well YT1.
Characteristics of REE in Taodonggou Group mudstone.
SamplesDepth (m-1)Content (ppm) (La / Yb)NLaCePrNdSmEuGdTbDyHoErTmYbLu∑ REELREEMREEHREEYT1-1608431.7057.706.7328.805.141.465.190.723.890.682.170.302.120.352146.953124.93017.0774.94610.081YT1-2609227.3047.805.5122.904.790.844.130.734.250.712.400.372.560.408124.695103.51015.4475.7387.190YT1-3610227.3048.305.6223.104.711.324.170.804.630.882.680.412.890.464127.271104.32016.5116.4406.369YT1-4611326.4045.605.2022.204.370.964.090.683.880.722.350.362.560.408119.78399.40014.7055.6786.953YT1-56122.32.6062.807.6131.706.561.965.770.985.350.972.890.432.920.429162.971134.71021.5906.6717.527YT1-6612933.1080.107.4831.706.190.625.980.995.580.993.010.503.310.564180.108152.38020.3457.3836.742YT1-7613633.5066.407.7031.206.191.185.460.915.240.963.050.493.180.454165.914138.80019.9367.1787.102YT1-8614035.9065.807.2329.205.471.654.960.965.350.962.970.473.010.426164.346138.13019.3446.8728.041YT1-9614339.0073.409.6040.007.181.445.641.025.911.083.450.523.410.519192.169162.00022.2707.8997.711YT1-106144.732.6066.437.3426.406.310.984.820.844.970.863.120.333.210.436158.646132.77018.1307.0966.847YT1-116145.327.9062.235.2323.205.421.044.460.925.410.882.880.443.020.423143.453118.56017.8806.7636.228YT1-126145.830.2065.605.6425.405.931.025.010.474.540.912.940.463.010.501151.631126.8405.5316.9116.764YT1-1361478.8416.801.756.901.390.301.320.271.870.391.270.221.670.26543.24734.2905.5313.4263.569YT1-14615139.4073.608.6433.604.221.844.321.215.831.033.420.432.980.392180.912155.2405.5317.2228.914YT1-15615452.60105.0012.3050.809.092.457.651.257.141.163.860.573.620.510257.997220.70028.7408.5579.796YT1-16616139.7085.7011.1052.109.762.298.331.347.471.253.750.523.390.502227.206188.60030.4408.1667.895
LREE = La + Ce + Pr + Nd. MREE = Sm + Eu + Gd + Tb + Dy + Ho. HREE = Er + Tm + Yb + Lu. (La / Yb)N= (La / Yb) / (La / Yb)chondrite.
Data availability
Data will be made available on request.
Author contributions
HM and JG designed the experiments; YW and ZJ revised
the first draft of the manuscript; JG, YW, and ZJ procured funding; HM and CZ provided language
services and figure production; and CL investigated and revised the ideas
of the article.
All authors contributed to the review of the manuscript.
Competing interests
The contact author has declared that none of the authors has any competing interests.
Disclaimer
Publisher’s note: Copernicus Publications remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Acknowledgements
This study was supported by the National Major Science and Technology Project of
China (grant nos. 2016ZX05066001-002, 2017ZX05064-003-001, 2017ZX05035-02,
and 2016ZX05034-001-05), the Innovative Research Group Project of the National
Natural Science Foundation of China (grant nos. 41872135, 42072151, and 42372144),
a PetroChina science and technology project (grant no. 2021DJ0602), and
the National Energy Shale Gas R&D (Experiment) Center (grant no.
2022-KFKT-15). We thank Hangzhou Yanqu Information Co., Ltd, as well as the Key Laboratory
of Natural Gas Accumulation, the Research Institute of Petroleum Exploration and Development, and Beijing Orient Smart for providing testing samples and test
equipment. We also thank our colleagues for their useful suggestions.
Financial support
This research has been supported by the National Major Science and Technology Projects of China (grant nos. 2016ZX05066001-002, 2016ZX05034-001-05, 2017ZX05064-003-001, and 2017ZX05035-02), the Innovative Research Group Project of the National Natural Science Foundation of China (grant nos. 41872135 and 42072151), the PetroChina Company Limited (grant no. 2021DJ0602), and the National Energy Shale Gas R&D (Experiment) Center (grant no. 2022-KFKT-15).
Review statement
This paper was edited by Andrea Di Muro and reviewed by three anonymous referees.
ReferencesAlgeo, T. J. and Ingall, E.: Sedimentary Corg:P ratios, paleocean
ventilation, and Phanerozoic atmospheric pO2, Palaeogeogr. Palaeocl., 256, 130–155, 2007.
Algeo, T. J. and Maynard, J. B.: Trace-element behavior and redox facies in
core shales of Upper Pennsylvanian Kansas-type cyclothems, Chem. Geol., 206,
289–318, 2004.
Allègre, C. J. and Minster, J. F.: Quantitative models of trace element
behavior in magmatic processes, Earth Planet. Sc. Lett., 38, 1–25, 1978.
Basu, A., Bickford, M. E., and Deasy, R.: Inferring tectonic provenance of
siliciclastic rocks from their chemical compositions: A dissent, Sediment.
Geol., 336, 26–35, 2016.
Bhatia, M. R.: Plate tectonics and geochemical composition of sandstones, J.
Geol., 91, 611–627, 1983.
Bhatia, M. R. and Crook, K. A. W.: Trace element characteristics of
graywackes and tectonic setting discrimination of sedimentary basin,
Contrib. Mineral. Petrol., 92, 181–193, 1986.Cai, Y. L., Ouyang, F., Luo, X. R., Zhang, Z. L., Wen, M. L., Luo, X. N.,
and Tang, R.: Geochemical Characteristics and Constraints on Provenance,
Tectonic Setting, and Paleoweathering of Middle Jurassic Zhiluo Formation
Sandstones in the Northwest Ordos Basin, North-Central China, Minerals,
12, 603, 10.3390/min12050603, 2022.
Cao, J., Yang, R. F., Yin, W., Hu, G., Bian, L. Z., and Fu, X. G.: Mechanism
of Organic Matter Accumulation in Residual Bay Environments: The Early
Cretaceous Qiangtang Basin, Tibet, Energ. Fuels, 32, 1024–1037, 2018.Cao, L., Zhang, Z. H., Zhao, J. Z., Jin, X., Li, H., Li, J. Y., and Wei, X.
D.: Discussion on the applicability of Th / U ratio for evaluating the
paleoredox conditions of lacustrine basins, Int. J. Coal Geol., 248, 103868, 10.1016/j.coal.2021.103868,
2021.
Carroll, A., Liang, Y. H., Graham, S., Xiao, X. H., Hendrix, S., Chu, J. C.,
and McKnight, L.: Junggar basin, northwest China: trapped Late Paleozoic
Ocean, Tectonophysics, 181, 1–14, 1990.
Carroll, A., Graham, S., Hendrix, M., Ying, D., and Zhou, D.: Late Paleozoic
tectonic amalgamation of northwestern China: sedimentary record of the
northern Tarim, northwestern Turpan, and southern Junggar basins, Geol. Soc.
Am. Bull., 107, 571–594, 1995.
Chen. X., Niu, R. J., and Cheng, J. H.: The Sequence stratigraphy of Middle
Permian-Triassic in Turpan-Hami Basin, Xinjiang, Pet. Geol., 24, 494–497,
2003.
Deditius, A.: Arsenic Environmental Geochemistry, Mineralogy, and
Microbiology, Rev. Mineral. Geochem., 79, 1905–1907, 2015.
Essefi, E.: Geochemistry and mineralogy of the sebkha Oum El Khialate
evaporites mixtures, southeastern Tunisia, Resour. Geol., 71, 242–249,
2021.
Floyd, P. A. and Leveridge, B. E.: Tectonic environment of the Devonian
Gramscatho Basin, South cornwall: framework mode and geochemical evidence
from turibiditic sandstones, J. Geol. Soc., 144,
531–542, 1987.
Gehrels, G. E., Valencia, V. A., and Ruiz, J.: Enhanced precision,
accuracy,efficiency, and spatial resolution of U-Pb ages by laser
ablation-multicollector-inductively coupled plasma-massspectrometry,
Geochem. Geophy. Geosy., 9, 1–13, 2008.
Glaser, K. S., Miller, C. K., Johnson, G. M., Kleinberg, R. L., and
Pennington, W. D.: Seeking the sweet spot: Reservoir and completion quality
in organic shales, Oilfield Rev., 25, 16–29, 2014.
Greene, T. J., Carroll, A. R., Wartes, M., Graham, S. A., and Wooden, J. L.:
Integrated provenance analysis of a complex orogenic terrane: Mesozoic
uplift of the Bogda Shan and inception of the Turpan-Hami Basin, NW China,
J. Sediment. Res., 75, 251–267, 2005.
Guo, Z., Zhang, Z., Wu, C., Fang, S., and Zhang, R.: The Mesozoic and
Cenozoic exhumation history of Tianshan and comparative studies to the
junggar and Altai mountains, Acta Geol. Sin., 80, 1–15, 2006.
Hatch, J. R. and Leventhal, J. S.: Relationship between inferred redox
potential of the depositional environment and geochemistry of the Upper
Pennsylvanian (Missourian) Stark shale member of the Dennis Limestone,
Wabaunsee County, Kansas, USA, Chem. Geol., 99, 65–82, 1992.
Herkat, M. and Ladjal, A.: Paleobathymetry of foraminiferal assemblages
from the Pliocene of the Western Sahel (North-Algeria), Palaeogeogr.
Palaeocl., 374, 144–163, 2013.
Hu, F., Meng, Q., and Liu, Z.: Mineralogy and element geochemistry of oil
shales in the Lower Cretaceous Qingshankou Formation of the southern
Songliao Basin, northeast China: implications of provenance, tectonic
setting, and paleoenvironment, ACS Earth Space Chem., 5, 365–380, 2021.
Ji, H., Tao, H., Wang, Q., Qiu, Z., Ma, D., Qiu, J., and Liao P.: Early to
middle Jurassic tectonic evolution of the Bogda mountains, northwest China:
evidence from sedimentology and detrital zircon geochronology, J. Asian
Earth Sci., 153, 57–74, 2018.
Jiang, S. H., Li, S. Z., Somerville, I. D., Lei, J. P., and Yang, H. Y.:
Carboniferous-Permian tectonic evolution and sedimentation of the
Turpan-Hami Basin, NW China: Implications for the closure of the Paleo-Asian
Ocean, J. Asian Earth Sci., 113, 644–655, 2015.
Kidder, D. L. and Erwin, D. H.: Secular distribution of biogenic silica
through the phanerozoic: Comparison of silica-replaced fossils and bedded
cherts at the series level, J. Geol., 109, 509–522, 2001.
Korobkin, V. V. and Buslov, M. M.: Tectonics and geodynamics of the western
Central Asian Fold Belt (Kazakhstan Paleozoides), Russ. Geol.
Geophys., 52, 1600–1618, 2011.Taylor, S. R. and McLennan, S. M.: The Continental Crust: Its Composition and Evolution, Blackwell Scientific Publications, Oxford, 10.1017/S0016756800032167, 1985.
Kroonenberg, S. B.: Effect of provenance, sorting and weathering on the
geochemistry of fluvial sands from different tectonic and climatic
environments, in: Proceedings of the 29th International Geological Congress,
Part A, Kyoto, Japan, 24 August–3 September 1992, 69, 81, Kyoto, Japan, 851052, edited by: Kumon, F. and Yu, K. M., 1992.Lerman, A. and Baccini, P.: Lakes: Chemisty, Geology, Physics,
Springer-Verlag, New York, 10.1007/978-1-4757-1152-3. 1978.
Li, C. M., Liu, J. T., Ni, L. B., and Fan, S. W.: Characteristics of deep
geological structure and petroleum exploration prospect in Turpan-Hami
Basin, China Petroleum Exploration, 26, 44–57, 2021 (in Chinese with
English abstract).
Li, L., Qu, Y. Q., Meng, Q. R., and Wu, G. L.: Gravity Flow Sedimentation:
Theoretical Studies and Field Identification, Acta Sedimentol. Sin.,
29, 677–688, 2011.Li, R. B.: Filling characteristic and research significance of Permian in
Tainan Depression of Tuha Basin, Journal of Jilin University, Earth Science
Edition, 49, 1518–1528, 10.13278/j.cnki.jjuese.20180243, 2019.
Li, Y. J., Sun, P. C., Liu, Z. J., Yao, S. Q., Xu, Y. B., and Liu, R.:
Geochemistry of the Permian Oil Shale in the Northern Bogda Mountain,
Junggar Basin, Northwest China: Implications for Weathering, Provenance, and
Tectonic Setting, ACS Earth Space Chem., 4, 1332–1348, 2020.
Li, W., Hu, J., Li, D., Liu, J., Sun, Y., and Liang, J.: Analysis of the
late Paleozoic and Mesozoic paleocurrents and It's constructional
significance of the northern Bogdashan, Xinjiang, Acta Sedimentol. Sin.,
25, 283–292, 2007.Li, Y. L., Shan, X., Gelwick, K. D., Yu, X. H., Jin, L. N., Yao, Z. Q., Li,
S. L., and Yang, S. Y.: Permian mountain building in the bogda mountains of
NW China, Int. Geol. Rev., 64, 2048270, 10.1080/00206814.2022.2048270, 2022.
Liu, D., Zhang, C., Yao, E., Song, Y., Jiang, Z., and Luo, Q.: What
generated the Late Permian to Triassic unconformities in the southern
Junggar Basin and western Turpan Basin; tectonic uplift, or increasing
aridity?, Palaeogeogr. Palaeocl., 468, 1–17, 2017.
Liu, D., Kong, X., Zhang, C., Wang, J., Yang, D., Liu, X., Wang, X., and
Song, Y.: Provenance and geochemistry of Lower to Middle Permian strata in
the southern Junggar and Turpan basins: a terrestrial record from
mid-latitude NE Pangea,
Palaeogeogr. Palaeocl., 495, 259–277, 2018.
Liu, G. and Zhou, D.: Application of microelements analysis in identifying
sedimentary environment-taking Qianjiang Formation in the Jiang Han Basin as
a example, Pet. Geo. Exp., 29, 307–311, 2007 (in Chinese with English
abstract).
Maravelis, A. G., Offler, R., Pantopoulos, G., and Collins, W. J.:
Provenance and tectonic setting of the Early Permian sedimentary succession
in the southern edge of the Sydney Basin, eastern Australia, Geol. J.,
56, 2258–2276, 2021.
McLennan, S. M., Taylor, S. R., and Kröner, A.: Geochemical evolution of
Archean shales from South Africa I: The Swaziland and Ponggola Supergroups,
Precambrian Res., 22, 93–124, 1983.
McLennan, S. M., Hemming, S., McDaniel, D. K., and Hanson, G. N.: Geochemical
approaches to sedimentation, provenance, and tectonics, Spec. Pap. Geol.
Soc. Am., 284, 21–40, 1993.
Mei, X., Li, X. J., Mi, P. P., Zhao, L., Wang, Z. B., Zhong, H. X., Yang, H.,
Huang, X. T., He, M. Y., Xiong, W., and Zhang, Y.: Distribution regularity and
sedimentary differentiation patterns of China seas surface sediments,
Geol. China, 47, 1447–1462, 2020 (in Chinese with English abstract).
Miao, H., Wang, Y. B., Zhao, S. H., Guo, J. Y., Ni, X. M., Gong, X, Zhang,
Y. J., and Li, J. H.: Geochemistry and Organic Petrology of Middle Per-mian
Source Rocks in Taibei Sag, Turpan-Hami Basin, China: Implication for
Organic Matter Enrichment, ACS Omega, 6, 31578–31594, 2021.
Miao, H., Wang, Y. B., Guo, J. Y., Fu, Y., and Li, J. H.: Weathering
correction and hydrocarbon generation and expulsion
potential of Taodonggou Group source rocks in Taibei Sag in Turpan-Hami
Basin, Petrol. Geol. Oilfield Dev. Daq., 42, 22–32,
2023.
Miao, H., Wang, Y. B., Guo, J. Y., Han, W. L., and Gong, X.: Evaluation of
Middle Permian source rocks of the Taodonggou Group in the Turpan Hami
Basin, Geophys. Prospect. Petrol., 61, 733–742, 2022a (in
Chinese with English abstract).
Miao, H., Wang, Y. B., He, C., Li, J. H., Zhang, W., Zhang, Y. J., and Gong,
X.: Fault development characteristics and reservoir control in Chengbei
fault step zone,Bohai Bay Basin, Lithol. Reserv., 34, 105–115,
2022b (in Chinese with an English abstract).
Miao, H., Wang, Y. B., Ma, Z. T., Guo, J. Y., and Zhang, Y. J.: Generalized
Deltalog R model with spontaneous potential and its application in
predicting total organ carbon content, J. Min. Sci.
Technol., 7, 417–426, 2022c (in Chinese with English abstract).
Miao, J. Y., Zhou, L. F., Deng, K., Li, J. F., Han, Z. Y., and Bu, Z. Q.:
Organic Matters from Middle Permain Source rocks of Northern Xinjiang and
Their Relationships with Sedimentary environments, Geochemica, 6, 551–560,
2004 (in Chinese with English abstract).
Nesbitt, H. W. and Young, G. M.: Prediction of some weathering trends of
plutonic and volcanic rocks based on thermodynamic and kinetic
considerations, Geochim. Cosmochim. Ac., 48, 1523–1534, 1984.
Novikov, I. S.: Reconstructing the stages of orogeny around the Junggar
basin from the lithostratigraphy of Late Paleozoic, Mesozoic, and Cenozoic
sediments, Russ. Geol. Geophys., 54, 138–152, 2013.
Obrist-Farner, J., Yang, W., and Hu, X. F.: Nonmarine time-stratigraphy in a
rift setting: an example from the Mid-Permian lower Quanzijie low-order
cycle Bogda Mountains, NW China, J. Palaeogeogr., 4, 27–51, 2015.
Pinto, L., Munoz, C., Nalpas, T., and Charrier, R.: Role of sedimentation
during basin inversion in analogue modelling, J. Struct. Geol.,
32, 554–565, 2010.Rollinson, H. R.: Using Geochemical Data: Evaluation, Presentation,
Interpretation, Longman Scientific Technical, New York, 10.4324/9781315845548, 1993.
Rosenthal, Y., Lam, P., Boyle, E. A., and Thomson, J.: Authigenic cadmium
enrichments in suboxic sediments: precipitation and postdepositional
mobility – sciencedirect, Earth Planet. Sc. Lett., 132,
99–111, 1995.
Roser, B. P. and Korsch, R. J.: Provenance Signatures of Sandstone-mudstone
suites determined using discriminant functiom analysis of major-element
data, Chem. Geol., 67, 119–139, 1988.
Ross, D. J. K. and Bustin, R. M.: Investigating the use of sedimentary
geochemical proxies for paleoenvironment interpretation of thermally mature
organic-rich strata: Examples from the Devonian–Mississippian shales,
Western Can. Sediment. Basin Chem. Geol., 260, 1–19, 2009.
Schoepfer, S. D., Shen, J., Wei, H. Y., Tyson, R. V., Ingall, E., and Algeo,
T. J.: Total organic carbon, organic phosphorus, and biogenic barium fluxes
as proxies for paleomarine productivity, Earth Sci. Rev., 149, 23–52, 2015.
Shao, L., Li, W. H., and Yuan, M. S.: Characteristic of sandstone and its
tectonic implications of the Turpan Basin, Acta Sediment. Sin.,
17, 435–441, 1999.
Shao, L., Stattegger, K., and Garbe-Schoenberg, C.: Sandstone petrology and
geochemistry of the Turpan Basin (NW China): implications for the tectonic
evolution of a Continental Basin, J. Sediment. Res., 71,
37–49, 2001 (in Chinese with English abstract).Shi, J., Zou, Y. R., Cai, Y. L., Zhan, Z. W., Sun, J. N., Liang, T., and
Peng, P. A.: Organic matter enrichment of the Chang 7 member in the Ordos
Basin: Insights from chemometrics and element geochemistry, Mar. Petrol.
Geol., 134, 105306, 10.1016/j.marpetgeo.2021.105404, 2021.Shi, Y. Q, Ji, H. C., Yu, J. W, Xiang, P. F., Yang, Z. B., and Liu, D. D.:
Provenance and sedimentary evolution from the Middle Permian to Early
Triassic around the Bogda Mountain, NW China: A tectonic inversion
responding to the consolidation of Pangea, Mar. Pet. Geol., 114, 104169, 10.1016/j.marpetgeo.2021.105404,
2020.
Shu, L., Wang, B., Zhu, W., Guo, Z., Charvet, J., and Zhang, Y.: Timing of
initiation of extension in the Tianshan, based on structural, geochemical
and geochronological analyses of bimodal volcanism and olistostrome in the
Bogda Shan (NW China), Int. J. Earth Sci., 100, 1647–1663, 2011.
Song, J., Bao, Z., Zhao, X. M., Gao, Y. S., Song, X. M., Zhu, Y. Z., Deng,
J., Liu, W., Wang, Z. C., Ming, C. D., Meng, Q. K., Zhang, L., Mao, S. W.,
Zhang, Y. L., Yu, X., and Wei, M. Y.: Sedimentology and geochemistry of
Middle–Upper Permian in northwestern Turpan–Hami Basin, China: Implication
for depositional environments and petroleum geology, Energ. Explor.
Exploit., 36, 910–941, 2018.
Sun, G. and Liu, Y.: The preliminary analysis of the uplift time of Bogda
Mountain, Xinjiang, Northwest China, Acta Sedimentol. Sin., 27, 487–491,
2009.
Tang, W., Zhang, Z., Li, J., Li, K., Chen, Y., and Guo, Z.: Late Paleozoic
to Jurassic tectonic evolution of the Bogda area (northwest China): evidence
from detrital zircon U–Pb geochronology, Tectonophysics, 626, 144–156,
2014.Taylor, S. R. and Mclennan, S. M.: The continental crust: Its composition
and evolution, Blackwell Science Publications, Oxford, 10.1017/S0016756800032167, 1985.
Thorpe, C. L., Law, G. T. W., Boothman, C., Lloyd, J. R., Burke, I. T., and
Morris, K.: The Synergistic Effects of High Nitrate Concentrations on
Sediment Bioreduction, Geomicrobiol. J., 29, 484–493, 2012.
Tian, J. Q., Liu, J. Z., Zhang, Z. B., and Cong, F. Y.: Hydrocarbon-generating
potential, depositional environments, and organisms of the Middle Permian
Tarlong Formation in the Turpan-Hami Basin, northwestern China, GSA Bull.,
129, 1252–1265, 2017.
Tribovillard, N. P., Desprairies, A., Lallier?verges, E., Bertrand, P.,
Moureau, N., Ramdani, A., and Ramanampiso, L.: Geochemical study of
organic-matter rich cycles from the Kimmeridge Clay Formation of Yorkshire
(UK): productivity versus anoxia, Palaeogeogr. Palaeocl., 108, 165–181, 1994.
Tribovillard, N., Algeo, T. J., Lyons, T., and Riboulleau, A.: Trace metals
as paleoredox and paleoproductivity proxies: an update, Chem. Geol.,
232, 12–32, 2006.
Tribovillard, N., Algeo, T. J., Baudin, F., and Riboulleau, A.: Analysis of
marine environmental conditions based on molybdenum–uranium
covariation – applications to Mesozoic paleoceanography, Chem. Geol.,
324, 46–58, 2012.
Wartes, M. A., Carroll, A. R., and Greene, T. J.: Permian sedimentary record
of the Turpan-Hami basin and adjacent regions, northwest China: Constraints
on postamalgamation tectonic evolution, Geol. Soc. Am.
Bull., 114, 131–152, 2002.Wang, A., Wang, Z., Liu, J., Xu, N., and Li, H.: The Sr / Ba ratio response to
salinity in clastic sediments of the Yangtze River Delta, Chem. Geol., 559,
119923, 10.1016/j.chemgeo.2020.119923, 2021.Wang, J., Cao, Y. C., Wang, X. T., Liu, K. Y., Wang, Z. K., and Xu, Q. S.:
Sedimentological constraints on the initial uplift of the West Bogda
Mountains in Mid-Permian, Sci. Rep., 8, 1453, 10.1038/s41598-018-19856-3, 2018a.
Wang, J., Wu, C., Li, Z., Zhu, W., Zhou, T., Wu, J., and Wang, J.: The
tectonic evolution of the Bogda region from Late Carboniferous to Triassic
time: evidence from detrital zircon U–Pb geochronology and sandstone
petrography, Geol. Mag., 155, 1063–1088, 2018b.
Wang, J., Wu, C., Zhou, T., Zhu, W., Zhou, Y., Jiang, X., and Yang, D.:
Source-to-Sink analysis of a transtensional rift Basin from syn-rift to
uplift stages, J. Sediment. Res., 89, 335–352, 2019.Wang, J. L., Wu, C. D., Zhou, T. Q., Zhu, W., Li, X. Y., and Zhang, T.:
Source and sink evolution of a Permian–Triassic rift–drift basin in the
southern Central Asian Orogenic Belt: Perspectives on sedimentary
geochemistry and heavy mineral analysis, J. Asian Earth Sci.,
181, 103905, 10.1016/j.jseaes.2019.103905, 2019.
Wang, L.: Sediment flux and mechanism for the uplifting of the mountain
system around the Junggar inland basin Sediment, Geol. Tethyan Geol., 16,
39–46, 1996.
Wang, Y.: Mixed Sedimentary Characteristics and Pattern of the Fan Delta in
the Middle Permian Taerlanggou Profile, Xinjiang Province Acta
Sediment. Sin., 37, 922–933, 2019 (in Chinese with English
abstract).Wang, Z. W., Yu, F., Wang, J., Fu, X. G., Chen, W. B., Zeng, S. Q., and
Song, C. Y.: Palaeoenvironment evolution and organic matter accumulation of
the Upper Triassic mudstone from the eastern Qiangtang Basin (Tibet),
eastern Tethys, Mar. Petrol. Geol., 130, 105113, 10.1016/j.marpetgeo.2021.105113, 2021.
Wronkiewicz, D. J. and Condie, K. C.: Geochemistry of archean shales from
the witwatersrand supergroup, south Africa: Source-area weathering and
provenance, Geochim. Cosmochim. Ac., 51, 2401–2416, 1987.
Wei, H., Chen, D. Z., Wang, J. G., Yu, H., and Tucker, M. E.: Organic
accumulation in the lower Chihsia Formation (Middle Permian) of South China:
Constraints from pyrite morphology and multiple geochemical proxies,
Palaeogeogr. Palaeocl., 353, 73–86, 2012.
Wei, X. X.: Middle-Late Permian fossil woods from Northern Tuha Basin:
Implications for Palaeoclimate, MS thesis, Wuhan, China university of
Geosciences, 2015 (in Chinese with English abstract).
Wu, C., Li, H. W., Sheng, S. Z., Chen, T., Shi, X. F., and Jiang, M. L.:
Characteristics and main controlling factors of hydrocarbon accumulation of
Permian-Triassic in Lukeqin structural zone, Tuha Basin, China Petrol.
Explor., 26, 137–148, 2021 (in Chinese with English abstract).
Xiong, X. H. and Xiao, J. F.: Geochemical Indicators of Sedimentary
Environments – A Summary, Earth Environ., 39, 405–414, 2011 (in
Chinese with English abstract).Xu, C., Shan, X. L., Lin, H. M., Hao, G. L., Liu, P., Wang, X. D., Shen, M.
R., Rexiti, Y., Li, K., Li, Z. S., Wang, X. M., Du, X. D., Zhang, Z. W., Jia,
P. M., and He, W. T.: The formation of early Eocene organic-rich mudstone in
the western Pearl River Mouth Basin, South China: Insight from paleoclimate
and hydrothermal activity, Int. J. Coal Geol., 253,
103957, 10.1016/j.coal.2022.103957, 2022.
Xu, H. Y.: Characteristics of Permian Dark Fine-Grained Sedimentary rocks and
their shale oil and gas Sigificance in the Northern Margin of Turpan-Hami
Basin, MS thesis, Xi'an: Chang'an University, 2022 (in Chinese with English
abstract).
Yang, W., Feng, Q., Liu, Y. Q., Tabor, N., Miggins, D., Crowley, J. L., Lin,
J. Y., and Thomas, S.: Depositional environments and cyclo- and
chronostratigraphy of uppermost Carboniferous–Lower Triassic
fluvial–lacustrine deposits, southern Bogda Mountains, NW China – A
terrestrial paleoclimatic record of mid-latitude NE Pangea, Glob.
Planet. Change, 73, 15–113, 2010.
Yang, Y., Song, C., and He, S.: Jurassic tectonostratigraphic evolution of
the Junggar basin, NW China: a record of Mesozoic intraplate deformation in
Central Asia, Tectonics, 34, 86–115, 2015.
You, J., Liu, Y., Zhou, D., Zheng, Q., Vasichenko, K., and Chen, Z.:
Activity of hydrothermal fluid at the bottom of a lake and its influence on
the development of high-quality source rocks: Triassic Yanchang Formation,
southern Ordos Basin, China, Austr. J. Earth Sci., 67,
115–128, 2019.Yu, Y., Cai, H. L., Yin, T. J., Zhang, X. Q., Xu, H., Huang, Y. R., and Cao,
T. T.: Sedimentary Characteristics and Depositional Model of Lacustrine
Gravity Flow Deposits: A case study of the Cretaceous Pointe Indienne
Formation of Block A, Lower Congo Basin, Acta Sediment. Sin.,
40, 34–46, 2022.
Zhang, C., He, D., Wu, X., Shi, X., Luo, J., Wang, B., Yang, G, Guan, S.,
and Zhao, X.: Formation and evolution of multicycle superimposed basins in
Junggar Basin, China Petrol. Exp., 11, 47–58, 2006.
Zhang, K., Song, Y., Jiang, S., Jiang, Z. X., Jia, C. Z., Huang, Y. Z., Wen,
M., Liu, W. W., Xie, X. L., Liu, T. L., Wang, P. F., Shan, C. A., and Wu, Y.
H.: Mechanism analysis of organic matter enrichment in different sedimentary
backgrounds: A case study of the Lower Cambrian and the Upper
Ordovician-Lower Silurian, in Yangtze region, Mar. Petrol. Geol., 99,
488–497, 2019.
Zhang, S., Liu, C., Bai, J., Wang, J., Ma, M., Guan, Y., and Peng, H.:
Provenance variability of the Triassic strata in the Turpan-Hami basin:
detrital zircon record of Indosinian tectonic reactivation in eastern
Tianshan, Acta Geol. Sin., 93, 1850–1868, 2019.
Zhang, S. C., Zhang, B. M., Bian, L. C., Jing, Z. J., Wang, D. R., Zhang, X.
Y., Gao, Z. Y., and Chen, J. F.: Development constraints of marine source
rocks in China, Earth Sci. Front., 12, 39–48, 2005 (in Chinese with
English abstract).Zhao, B. S., Li, R. X., Qin, X. L., Wang, N., Zhou, W., Khaled, A., Zhao,
D., Zhang, Y. N., Wu, X. L., and Liu, Q.: Geochemical characteristics and
mechanism of organic matter accumulation of marine-continental transitional
shale of the lower permian Shanxi Formation, southeastern Ordos Basin, north
China, J. Petrol. Sci. Eng., 205, 108815, 10.1016/j.petrol.2021.108815, 2021.Zhao, R., Zhang, J. Y., Zhou, C. M., Zhang, Z. J., Chen, S., Stockli, D.F.,
Olariu, C., Steel, R., and Wang, H.: Tectonic evolution of
Tianshan-Bogda-Kelameili mountains, clastic wedge basin infill and
chronostratigraphic divisions in the source-to-sink systems of
Permian-Jurassic, southern Junggar Basin, Mar. Petrol. Geol., 114, 104200, 10.1016/j.marpetgeo.2019.104200,
2020.
Zhu, X., Wang, B, Chen, Y., and Liu, H. S.: Constraining the
Intracontinental Tectonics of the SW Central Asian Orogenic Belt by the
Early Permian Paleomagnetic Pole for the Turfan-Hami Block, J.
Geophys. Res.-Sol. Ea., 124, 12366–12387, 2019.