sedimentary fill history of the huicheng basin in the west qinling mountains and associated...

SCIENCE CHINA Earth Sciences

© Science China Press and Springer-Verlag Berlin Heidelberg 2013 earth.scichina.com www.springerlink.com

*Corresponding author (email: [email protected])

• RESEARCH PAPER • doi: 10.1007/s11430-013-4607-4

doi: 10.1007/s11430-013-4607-4

Sedimentary fill history of the Huicheng Basin in the West Qinling Mountains and associated constraints on Mesozoic intracontinental

tectonic evolution

LI Wei1, DONG YunPeng1, GUO AnLin1, LIU XiaoMing1, LIU YiQun1, ZHA XianFeng2 & ZHANG KuaiLe1

1 State Key Laboratory of Continental Dynamics, Department of Geology, Northwest University, Xi’an 710069, China; 2 Xi’an Center of Geological Survey, China Geological Survey, Xi’an 710054, China

Received March 29, 2012; accepted August 27, 2012

The Qinling Orogenic Belt is divided commonly by the Fengxian-Taibai strike-slip shear zone and the Huicheng Basin into the East and West Qinling mountains, which show significant geological differences after the Indosinian orogeny. The Fengxian-Taibai fault zone and the Meso-Cenozoic Huicheng Basin, situated at the boundary of the East and West Qinling, provide a natural laboratory for tectonic analysis and sedimentological study of intracontinental tectonic evolution of the Qin-ling Orogenic Belt. In order to explain the dynamic development of the Huicheng Basin and elucidate its post-orogenic tecton-ic evolution at the junction of the East and West Qinling, we studied the geometry and kinematics of fault zones between the blocks of West Qinling, as well as the sedimentary fill history of the Huicheng Basin. First, we found that after the collisional orogeny in the Late Triassic, post-orogenic extensional collapse occurred in the Early and Middle Jurassic within the Qinling Orogenic Belt, resulting in a series of rift basins. Second, in the Late Jurassic and Early Cretaceous, a NE-SW compressive stress field caused large-scale sinistral strike-slip faults in the Qinling Orogenic Belt, causing intracontinental escape tectonics at the junction of the East and West Qinling, including eastward finite escape of the East Qinling micro-plate and southwest lateral escape of the Bikou Terrane. Meanwhile, the strike-slip-related Early Cretaceous sedimentary basin was formed with a right-order echelon arrangement in sinistral shear zones along the southern margin of the Huicheng fault. Overall during the Mesozoic, the Huicheng Basin and surrounding areas experienced four tectonic evolutionary stages, including extensional rift basin development in the Early and Middle Jurassic, intense compressive uplift in the Late Jurassic, formation of a strike-slip extensional basin in the Early Cretaceous, and compressive uplift in the Late Cretaceous.

the Qinling Orogenic Belt, the West Qinling, the Huicheng Basin, sedimentary filling, tectonic evolution, escape tectonics

Citation: Li W, Dong Y P, Guo A L, et al. Sedimentary fill history of the Huicheng Basin in the West Qinling Mountains and associated constraints on Meso-zoic intracontinental tectonic evolution. Science China: Earth Sciences, 2013, doi: 10.1007/s11430-013-4607-4

After the eventual closure of the Mianlue paleo-ocean [1, 2], the North and South China plates were fully amalgamated and the Qinling Orogenic Belt entered a stage of intraconti-nental tectonic development. To date, extensive studies have examined the Pre-Mesozoic evolution of the Qinling

Orogenic Belt, and substantial progress has been made in understanding the three-dimensional structure and orogenic processes, as well as associated kinematic mechanisms of the Qinling Orogenic Belt [2–15]. However, few studies have evaluated the intracontinental tectonic evolution of the Mesozoic and Cenozoic Qinling Orogenic Belt [16]. The Mesozoic and Cenozoic Huicheng Basin and its surround-ing fault zones at the boundary of the East and West Qinling

2 Li W, et al. Sci China Earth Sci January (2013) Vol.56 No.1

provide an excellent natural laboratory for assessing in-tracontinental tectonic evolution in the region since the Mesozoic.

1 Regional geology

The Qinling Orogenic Belt is oriented east-west and posi-tioned in the central Chinese mainland, separating the North China and the Yangtze Plates. It merges with the Dabie Orogenic Belt in the east and is divided into two branches in the west, designated as the Qilian and Kunlun orogenic belts, respectively.

The Qinling Mountains have experienced multiple oro-genic episodes over time, leading to the formation of a complex continental orogenic belt [17]. The associated three major tectonic stages include: (1) Neoarchean-Paleoprote- rozoic Precambrian basement formation and evolution; (2) Neoproterozoic-Triassic plate tectonic evolution; and (3) Mesozoic and Cenozoic intracontinental orogenesis and tectonic evolution [18]. Along the two suture zones of Shangdan and Mianlue, the Qinling Orogenic Belt can be divided into three major tectonic units, including the North China, the Yangtze Plate, and the intervening Qinling Mi-cro-plate [18].

At present, the Qinling Orogenic Belt is generally divided

into the East and West Qinling Mountains by the Fengxian- Taibai strike-slip shear zone and the Huicheng Basin [19]. The junction area of the Helan Mountains-Sichuan-Yunnan north-south tectonic belt [20, 21] and the Qinling Orogenic Belt lies at the boundary of the East and West Qinling, with distinct differences in crustal structure, gravity anomalies, depositional formations, and landscape characteristics on the two sides [22–24].

The Huicheng Basin developed in an intracontinental mountain basin upon folded Paleozoic and Triassic base-ment, extending from NEE to SWW. It is narrow in the east and broad in the west, with an east-west length of 210 km and a south-north width of 40 km (Figure 1).

2 The Huicheng Basin sedimentary filling characteristics

The Mesozoic Huicheng Basin comprises the Middle Juras-sic Longjiagou Formation (J2l) and the Lower Cretaceous Donghe Group (K1D). The Longjiagou Formation contains abundant Middle Jurassic bivalves, conchostracans (bi-valved crustaceans), and plant fossils, whereas the Donghe Group yields abundant Early Cretaceous plants and trace fossils.

Figure 1 Geology of the Huicheng Basin and its surrounding areas (modified from refs. [25, 26] and data1)–4)).

) Shaanxi Geological Survey. Regional Geological Survey Report and Geological Map of Hanzhong City (1:250000). 2004 2) Institute of Geological Survey, Chang'an University, Gansu Geological Survey. Regional Geological Survey Report and Geological Map of Tianshui

City (1:250000). 2004 3) Shaanxi Geological Survey. Regional Geological Survey Report and Geological Map of Baoji City (1:250000). 2003 4) Shaanxi Geological Survey. Regional Geological Survey Report and Geological Map of Lueyang County (1:250000). 2007

Li W, et al. Sci China Earth Sci January (2013) Vol.56 No.1 3

2.1 Longjiagou Formation sedimentary characteristics

The Longjiagou Formation (J2l) of the Huicheng Basin is distributed in middle and northern areas, Jiangluo Township, and in eastern areas, Ciba region of Liangdang County (Figure 1). The Longjiagou Formation is in fault contact with Mishuling intrusions in the northern Jiangluo region of the northern part of the basin, and in angular, unconforma-ble contact with the underlying Triassic strata in the south-ern Ciba region in the eastern part of the basin.

Lithologically the Longjiagou Formation mainly

is comprised of brown, gray and purple conglomerates, gray pebbly sandstones, coarse sandstones with shale interbeds and coal seams. A relatively complete profile of the Longjiagou Formation in the Huicheng Basin was obtained by field surveys of the Xipo Coal Mine profile in the Ciba region of Liangdang County, eastern Huicheng Basin; in Yanghe village in the Yushu region of Huixian County; and at Yanchuan river of the Jiangluo Township in the mid-Huicheng Basin (Figure 2).

The Longjiagou Formation is approximately 383 m thick

Figure 2 Interpretation of the Jurassic sedimentary sequence and depositional environment in the Huicheng Basin.


in the Xipo Coal Mine profile. Here (Figure 2(a)) the Longjiagou Formation is in unconformable contact with the underlying Lower Triassic Xipo Formation (T1x), which comprises gray-green-colored, thin limestones and calcare-ous slates with tight folding. The lower Longjiagou For-mation consists of dark gray-colored, thin-bedded mud-stones with thin-bedded, fine sandstone interbeds, with dark gray-colored, thin-bedded marls containing abundant fossils of the mussel Ferganoconcha (Figure 3(d)). The occurrence

of carbonaceous mudstones increases upwards, with phos-phorus iron ores observed in thin-bedded siltstones and abundant plant leaf fossils on bedding planes. Thus, the lower Longjiagou Formation is interpreted as lacustrine in origin. In contrast, the upper Longjiagou Formation con-tains a single horizon of light-gray, coarse pebbly sandstone, and medium-bedded, fine sandstones and purple-gray thin-bedded mudstones which gradually thinned, with parti-cle size from coarse to fine in multiple depositional cycles.

Figure 3 Photographs of Mesozoic clastic rocks in the Huicheng Basin. (a) Lower massive conglomerates of the Longjiagou Formation in Fuzhen Town-ship, Huixian County, lens cap (45 mm); (b) fine conglomerates of the Longjiagou Formation supported by massive grains, lens cap (55 mm); (c) thin-bedded marl and argillaceous siltstone interbeds of the Longjiagou Formation in the Xipo coal mine profile; (d) bivalve fossils in the marl facies of the Longjiagou Formation, coin (20 mm); (e) cretaceous Tianjiaba Formation in unconformable contact with the underlying Zhouqu Formation, geological hammer (35 cm); (f) tianjiaba Formation in unconformable contact with underlying Carboniferous strata at Xiaozaisi in Fengxian County; field view (ca. 50 m high and 70 m long).


The mudstones are primarily interbedded with gray-black thin-bedded carbonaceous mudstone and low-rank coal seams, interpreted as a meandering river depositional envi-ronment. Scour and fill erosion occurred between the coarse-grained sandstones and underlying mudstones, with low-angle oblique bedding developed in the sandstones. The lower sandstone profile is inferred as a channel bar and the upper thin-bedded mudstones are interpreted as floodplain deposits.

The Longjiagou Formation is approximately 1131－1383 m thick in the mid-north Huicheng Basin. With respect to the Yanghe village profile in Huixian County (Figure 2(c)), the Longjiagou Formation is in fault contact with the un-derlying Mishuling granodiorite, with basal conglomerates consisting of pebbly coarse sandstones. Associated con-glomerates mostly occurred as massive rocks with no sig-nificant bedding. The conglomerate gravels are character-ized by poor sorting, subangular-angular morphology and are supported by a matrix of coarse-grained sandstones (Figure 3(a)). The conglomerate gravels range in diameter from 0.5 to 2 cm, with a maximum size of 6 cm× 4 cm. They primarily consist of K-feldspar phenocrysts, quartz gravels and granitic gravels derived from weathering of the underlying granodiorites, with large suspended granitic clasts occasionally found filling in the topographic lows. This basal conglomerate is interpreted as the rapid accumu-lation product of piedmont weathering, and formed from debris flows [27]. Lithologically the lower part of the pro-file occurs as a belt of gray-purple colored, thickly bedded, massive conglomerates with purple-red silty mudstones. These conglomerate gravels are subangular-angular, sup-ported by a matrix of sandstone with parallel bedding, and are interpreted as alluvial fan facies debris-flow deposits. These strata grade upwards in the middle part of the profile to light gray colored, moderately thickly bedded conglom-erates with interbeds of purple-red colored, moderately to thinly bedded sandstones. The conglomerates are lenticular in geometry, and the gravels are subrounded, grain- supported and imbricated. The gravel layer is generally 1.5– 2.0 m thick, with overlying pebbly sandstones interbedded with muddy siltstones. This gravel layer is interpreted as alluvial fan related gravelly-braided channel deposits. The upper pebbly coarse sandstones are interpreted as channel sandbar deposits. The lithology of the upper part of the pro-file is moderately to thinly bedded conglomerate interbed-ded with thin-bedded siltstone. This conglomerate is in ero-sional contact with the underlying sandstone, with scour surfaces commonly observed. The conglomerates are most-ly lenticular and the gravels are in an imbricate arrangement with parallel bedding, interpreted as braided channel depos-its. The upper part of the profile consisting of relatively thinly bedded muddy siltstone is interpreted as flood plain deposits.

A facies analysis of the depositional environment of the Jurassic profiles in different regions of the Huicheng Basin

(Figure 2) showed that in the western part of the basin, the Middle Jurassic Longjiagou Formation transitioned from a lower massive conglomerate facies to an upper moderately to thinly bedded glutenite. Laterally from north to south, sedimentary grain size varied from coarse to fine and the sedimentary facies transitioned from alluvial fans to braided rivers adjacent to the basin provenance area. Furthermore, in the eastern part of the basin, grain size is much finer and the lower lacustrine facies transitioned to an upper facies representing meandering rivers, indicating that this region was potentially the center of the basin. These facies charac-teristics indicate that the distribution characteristics of the sedimentary facies were potentially controlled by the boundary fault [28].

2.2 Donghe Group sedimentary characteristics

Outcrops of the Donghe Group occur throughout the Huicheng Basin. Stratigraphic logging was conducted in Fengxian County and Liangdang County in the eastern ba-sin, as well as in Chengxian County and Kangxian County in the western basin (Figure 1). Based on paleontological assemblages, lithologic associations, and sedimentary char-acteristics, the Donghe group was divided, from bottom to top, into the Tianjiaba Formation (K1t), Zhoujiawan For-mation (K1z), and Jishan Formation (K1z) [29]. The Donghe Group is in unconformable contact or fault contact with the underlying strata of different ages. In the northeastern mar-gin of the basin, the Tianjiaba Formation is in unconforma-ble contact with the underlying Carboniferous Sixiakou Formation (C2-3s) in the Longkou Township of Fengxian County, and in unconformable contact with the underlying Triassic Xipo Formation (T1x) in the Xipo Coal Mine pro-file of Liangdang County. In the southwestern basin, the Tianjiaba Formation is in unconformable contact with un-derlying Silurian rocks (Figure 3(e)), and the Donghe Group is unconformable with the overlying Neogene Gansu Group.

2.2.1 Tianjiaba Formation

The Tianjiaba Formation occurs as a set of purple thick-bedded conglomerates, approximately 240–925 m thick in the eastern part of the basin, and approximately 727 m thick in the Jifeng mountain profile in the southwestern part of the basin. In the northeastern basin, the Lumusi pro-file in Yangjiazhuang (Lianghe Township, Fengxian County) and the Qiaotou profile in Fengxian County (Figure 4(a), (c)) reveal that the Tianjiaba Formation is in unconformable contact with the underlying carbonaceous slates of the Car-boniferous Sixiakou Formation (C1－2s). The Tianjiaba For-mation occurs as a purple massive breccia with angular and platy gravels of mixed sizes (maximum dimensions 30 cm× 40 cm × 60 cm). The gravels are cemented by muddy con-stituents and are matrix-supported, with no significant bed-ding. The gravels are all gray-black carbonaceous slates, interpreted as debris flow deposits based on their sedimen-


Figure 4 Interpretation of the Cretaceous sedimentary sequences and depositional environment of the Huicheng Basin (same legend as Figure 2).

tary structures and lithological association. The Tianjiaba Formation occurs as a purple, thickly bedded massive con-glomerate in the Qiaotou region in the Longkou Township of Fengxian County. The gravels were subangular-angular, poorly sorted, matrix supported and faintly bedded. The gravels consist primarily of silty slates and phyllites (Figure 5(a), 5(c)), and in places show an imbricate structure. The gravels become rounded upwards (sub-angular to subrounded) and occur in lenticular mudstones, interpreted as debris flow deposits.

In the western basin, the Jifeng mountain profile in Chengxian County was selected for detailed examination (Figure 4(e)). The Tianjiaba Formation is in angular, un-conformable contact with the underlying Silurian Zhouqu Formation (S2z) (Figure 3(f)). The lithology of the underly-ing strata is gray-green thinly bedded slate and phyllite. The Tianjiaba Formation constitutes a massive glutenite above the unconformity surface, with tectonic development of erosional fill on the contact surface. The gravelly conglom-erate above the unconformity surface comprises subangular to subrounded clasts of mainly slate and phyllite. The grav-els are supported by a matrix of poorly sorted purple sand-stone (maximum 10 cm × 15 cm, generally 4–6 cm). The

lower part of this formation consists of thickly bedded mas-sive conglomerates, sandy conglomerates alternating with mudstones, and lenticular sandstones. The gravels are faint-ly bedded, and contain some imbricated conglomeratic ho-rizons, interpreted as alluvial fan facies debris-flow deposits. The upper part of the formation contains purple, moderate to thickly bedded sandy conglomerates interbedded with sandstones, which feature parallel- and cross-bedding, in-terpreted as alluvial fan-fan margin-braided river deposits.

2.2.2 Zhoujiawan Formation

The Zhoujiawan Formation is in conformable contact with both the underlying and overlying strata. It is approximately 155 m thick in Fengxian County in the eastern basin. For example, in the Lumusi profile of the Yangjiazhuang region in Lianghe Township, Fengxian County (Figure 4(c)), the lower part of the formation comprises moderate to thickly bedded pebble conglomerates, pebbly coarse sandstones, sandstones interbedded with thinly bedded pebbly siltstones, and mudstones. The rounded conglomeratic gravels are generally 0.5–2 cm in diameter, with clasts supported by a sandy matrix. The gravels preserve an imbricate structure with parallel bedding. Scour and fill structures commonly


Figure 5 Photographs of Cretaceous clastic rocks and fold deformation. (a) Debris flow deposits of the Tianjiaba Formation at Xiaozaisi, lens cap diameter 55 mm; (b) imbricate sedimentary conglomerates of the Tianjiaba Formation at the Chan River, pencil length 12 cm; (c) massive grain-supported conglom-erates of the Tianjiaba Formation at the Xiaozaisi with an imbricate structure, geological hammer 35 cm; (d) channel scour and fill structures of the Lower Cretaceous Zhoujiawan Formation at the Lumusi; (e) gray thinly bedded mudstone and siltstone interbeds of the Lower Cretaceous Jishan Formation at the Jifeng mountain; (f) fold deformation and asymmetric folds of Cretaceous sandstones at the Banfangzi, with a nearly horizontal axis and a gently north-dipping axial surface.

occur in the lower portions of the conglomerates (Figure 5(d)), with trough cross-bedding observed in the fine- grained sandstones. These deposits are interpreted as grav-elly-braided river channel deposits. Moreover, the thinly bedded sandstones and mudstones are inferred as floodplain deposits. The upper part of the formation consists of moder-ately bedded pebbly sandstones, fine sandstones and silt-stones, as well as multiple depositional cycles of mudstones with variable grain size content. The basal sandstone of each depositional cycle, as well as the underlying mud-

stones, reveal scour surfaces. The lower portion of the sand-stone units feature trough cross-bedding, whereas the upper parts contain siltstone and mudstone interbeds. The mud-stones are horizontally bedded. The upper part of the for-mation has an obvious dual-texture in the vertical profile, interpreted as meandering river deposits.

In the western basin, the Zhoujiawan Formation contain-ing the Jifeng mountain profile in southwestern Chengxian County is approximately 638 m thick. The well-exposed Jifeng mountain profile (Figure 4(e)) contains gray-purple


sandy conglomerates, sandstones and gray thinly to moder-ately bedded siltstones with mudstone interbeds containing calcareous nodules, showing multiple coarse-to-fine deposi-tional cycles of conglomerate-sandstone and siltstone- mudstone horizons. Scour and fill structures occur between the sandy conglomerate and the underlying mudstones. The conglomeratic gravels are subrounded-rounded and showed both matrix and grain supported stratigraphic intervals. We can see that trough cross-bedded sandstones occur in the lower, sand ripple cross-bedded siltstone and horizontal bedded mudstone occur in the upper in each sedimentary cycle. The dual nature of such depositional cycles was dis-tinct, and is interpreted as meandering river deposits based on the sedimentary structures and stratigraphic associations.

2.2.3 Jishan Formation

The Jishan Formation is in conformable contact with the underlying Zhoujiawan Formation, and in unconformable contact with the overlying brown-red conglomerates and mudstones of the Gansu Group. The Jishan Formation is absent in the eastern basin and is presently distributed in the northern and southern sides of the western basin. It is ap-proximately 1190 m thick on the southern side. Taking the Jifeng Mountain profile as an example (Figure 4(e)), the overall rock association is black-gray and gray-green mud-stone, muddy siltstone with sandstone interbeds, conglom-erate, carbonaceous shale, coal seams and limestone. This formation comprises dark mudstones and muddy siltstones with coal seams and limestone interbeds. Associated mud-stones and siltstones mostly contain horizontal bedding. The above features suggest that the Jishan Formation is domi-nated by lacustrine sediments. Along the Shixia-Erlangmiao in northern Chengxian County in the western basin, the Jishan Formation is in angular, unconformable contact with the underlying thinly bedded limestone of the Lower Trias-sic Xipo Formation (T1x). The lithology of the Jishan For-mation consists of purple thickly bedded massive conglomerate, with subangular gravels and poor sorting. This for-mation is dominated by limestone gravels, with matrix sup-ported sand-argillaceous cements, and thus is interpreted as alluvial fan debris-flow deposits. Marginal facies deposition indicates that the northern basin was adjacent to the prove-nance.

In the eastern basin, the Donghe Group transitions from thickly bedded massive conglomerates to fluvial sandstones and mudstone associations of the Zhoujiawan Formation. In the western basin, the Donghe Group transitions from mas-sive conglomeratic facies of the Zhoujiawan Formation to lacustrine facies deposition of the Jishan Formation. Later-ally (south-to-north), the sediment grain size varies from coarse to fine, and the sedimentary facies shift from alluvial fan to lacustrine facies. The Cretaceous sedimentary facies are significantly asymmetrical, with alluvial fan facies in the east and lacustrine facies in western areas of the basin. Overall, the depocenter of the basin migrated from east to

west through time.

3 Sediment provenance

Basin sediments function as the link connecting the basin with adjoining mountains. Thus, basin sediment provenance analysis can effectively reveal exhumation processes and tectonic uplift events in mountains of the provenance area [30]. A direct and effective method for basin sediment provenance analysis is to perform statistical analysis of conglomerate gravels using the imbricate structure of flat pebble conglomerate in conglomerates and to reconstruct the paleocurrent direction of oblique bedding in sandstones [31, 32]. During measurement and data collection of paleo-currents, we collected 20–30 data measurements from each location and correspondingly performed a horizontal cor-rection. For statistical analysis of the gravels, selected con-glomerate outcrops (1–2 m2) were divided into square areas with 10-cm spacing. Statistical analysis was performed on gravels with a diameter > 2 cm using the random throw-ing-dot method.

3.1 Basin paleocurrents

The Longjiagou Formation in the northern Jiangluo region of the middle Huicheng Basin consists primarily of coarse clastic conglomerates, sandy conglomerates and sandstone deposits, in an east-to-west zonal distribution of the basal conglomerates along the northern border of the basin. Our measurements of the imbricated flat pebbles of the Longjiagou Formation conglomerates and paleocurrent re-construction of the oblique bedding in middle-upper sand-stones show that the paleocurrent direction was in the north-south or east-west direction on the northern margin of the Jurassic Huicheng Basin, and that the paleocurrent di-rection was NNW-SSE or west-east in the eastern basin (Figure 6). The paleocurrent directions of the Jurassic con-glomerates indicate that the early provenance was the northern basin areas, whereas for the central basin fluvial and lacustrine facies, the provenance was the northern and western basin areas.

The Cretaceous paleocurrent direction was NNE-SSW on the northeastern basin margin and south-north on the southwestern basin margin, indicating that the sedimentary provenance was from these areas during the Cretaceous (Figure 7).

3.2 Conglomerate composition

The conglomerate gravels provide important evidence for elucidating sedimentary provenance and uplift and exhuma-tion processes in the provenance areas [33], as well as sup-ply favorable supporting evidence for paleocurrent analysis


Figure 6 Distribution, paleocurrent direction and gravel composition of Jurassic conglomerates in the Huicheng Basin.

Figure 7 Distribution, paleocurrent direction and gravel composition of Cretaceous conglomerates in the Huicheng Basin.

results. To determine the provenance and associated spatial and temporal changes in paleocurrent directions, we sys-tematically and statistically analyzed the conglomerate gravels in different layers or areas during stratigraphic log-ging.

(1) Jurassic. At the northern margin of the basin, gravels in the basal conglomerate portion of the Longjiagou For-mation were dominated by feldspar phenocrysts, quartz crystal phenocrysts and granitic gravels. The composition of the conglomeratic gravels was similar to that of the under-lying Mishuling granodiorite. The amount of feldspar phenocrysts and quartz crystal phenocrysts gradually decreased, whereas the occurrence of sandstone boulders increased within the gravels up-profile (Figure 6), indicating that with the development of the basin and away from the provenance area, gravel composition came from the inner basin. In the

Xipo Coal Mine profile at the eastern margin of the basin, the Longjiagou Formation is in unconformable contact with the underlying Lower Triassic Xipo Formation, with basal conglomerate gravels mainly dominated by limestones, sandstones and mudstones (Figure 6). The composition of limestone is the same as the lithology of the underlying Lower Triassic Xipo Formation, indicating the provenance is the underlying Triassic Xipo Formation. Collectively the paleocurrent analysis implies that the Jurassic sediment provenance was situated in the northwestern and southern parts of the basin, and that the Mishuling intrusions were the primary provenance of the lower conglomerates of the Longjiagou Formation.

(2) Cretaceous. In the northern part of the eastern basin (Longkou of Fengxian County and Lumusi of Lianghe Township), the conglomerate gravels of the lower Tianjiaba


Formation of the Donghe Group mainly include slates, phyllites and shales, consistent with similar rock types found in the Carboniferous Sixiakou Formation in the northern basin. In the southern part of the eastern basin (Xipo Coal Mine profile), the conglomerate gravels mainly constitute limestones and siltstones, consistent with the composition of the underlying Triassic Xipo Formation. Gravel composition statistics indicate that the eastern basin provenance is Carboniferous metamorphic rocks from northern areas and from Triassic sediments in the southern part of the eastern basin.

The conglomerates of the Jishan Formation at Erlang-miao in the northern part of the western basin are composed primarily of limestones, sandstones and chert, similar in lithology to the underlying Triassic Xipo Formation in the northern part of the western basin. Overall, reconstruction of associated paleocurrent directions suggests that the provenance was from the northern basin. In the southern part of the western basin (Chanba region), the conglomerate gravels of the Tianjiaba Formation are composed mainly of slate, the derived from the Silurian Zhouqu Formation (S2z) in the south. Collectively the reconstruction of associated paleocurrent directions and sedimentary zircon provenance tracers [34] indicate that the provenance was from the southern Huicheng Basin.

Statistical comparisons of the conglomerate gravel com-positions on the southern and northern sides of the eastern and western basin reveal that the Cretaceous sedimentary provenances were in the southern and northern basin, con-sistent with reconstructed paleocurrents.

4 Origin of the Huicheng Basin

4.1 Basin margins and adjacent fault zones

4.1.1 The Huicheng fault (F1)

The Huicheng fault is distributed in a NNE direction across the Taibai, Fengxian, Liangdang, Huixian and Chengxian counties, curved in a SSW direction in Wudu to the west, and eventually extended to Zhouqu and Wenxian in the northwest. The Huicheng fault divides the Taibai and Baoji magmatic body in the eastern profile and in the central pro-file occurs as the northern boundary fault of the Mesozoic basin in Fengxian, Huixian and Chengxian. Based on the 1:250000 Lueyang geological survey report, the western profile of the Huicheng fault, known as the Xijiaji- Zuojiaping fault, was formed during the major orogenic period within the East Qunlun-Qinling Orogenic Belt (In-dosinian) 4) and experienced multiple inheritance events.

4.1.2 Mianlue fault zone (F2)

The Mianlue fault zone refers to a series of faults between the Zhuangyuanbei fault along the northern boundary and the Kangxian-Lueyang fault at the southern boundary. This

fault zone crossed Wenxian, Maqu, and Huashixia to reach the southern Kunlun tectonic belt in the west, and crossed Shiquan and Gaochuan along the Bashan Arc to reach the southern Dabie margin [18]. The Mianlue fault zone fea-tured multi-phase activity [35, 36]. The first phase was north-south thrust ductile shearing, which reflects the struc-tural deformation caused by the Indosinian collision and subduction of the Qinling Orogenic Belt. The second phase was in the Late Triassic intracontinental sinistral ductile shearing after the collision, superimposed with late brittle sinistral shearing. The last phase was brittle dextral shearing, which cross-cut the early tectonic deformation.

4.1.3 Yangpingguan-Ningshan fault zone (F3)

The Yangpingguan-Ningshan fault zone is oriented in an east-west direction, and consists of the Qingchuan- Yangpingguan fault in the west and the Ningshan fault in the east. It extends to the Qingchuan-Yangpingguan fault in the west and southwest, merges with the Shanyang-Feng- zhen fault in the east, and further connects with the Shang-dan fault in the vicinity of Xixia [25]. The Ningshan fault zone developed in the Mesozoic, with multi-phase activity, including early sinistral ductile shearing in the Middle-Late Jurassic and late sinistral brittle shearing in the Early Cre-taceous [37]. The Qingchuan-Yangpingguan fault originated from Pingwu in the west, crossed Qingchan and Yang-pingguan and reached Mianxian in the east, further merging with the Mianlue fault zone. The fault was approximately 250 km in length and 500–700 m in width, with a general north-east direction of 60°–65° and a general northwest-dip of 60°–70°. The fault was formed in the Late Triassic, fol-lowed by multi-phase tectonic activity [9, 38, 39].

4.2 Origin of the Huicheng Basin

In this study, we attempt to explain the origin of the Huicheng Basin by studying its sedimentary fill processes and geometrical, kinematic, chronological analyses of the basin margins and adjacent major boundary faults in com-bination with regional geological background. Below we discuss the origin of the basin during different stages since the Jurassic strata are in unconformable contact underlying and overlying strata, and Jurassic and Cretaceous strata be-long to different depositional cycles.

4.2.1 Origin of the Jurassic Huicheng Basin

In Jiangluo-Youlongchuan region of Huixian County on the northern side of the basin, the basal conglomerates of the Longjiagou Formation are in normal fault contact with the underlying Mishuling intrusions. The fault is approximately 0.5–1 m in width with a steep southward dip and an attitude of 195°∠76°. The footwall of the fault is composed of Mishuling light-gray massive quartz diorites with a medium to coarse-grained fabric, in which K-feldspar phenocrysts were observed. In terms of topographic relief and geo-


morphic expression, the footwall occurs as a steep positive terrain, displaying fault scarp features. The hanging wall is composed of basal conglomerates of the Longjiagou For-mation and primarily consists of long phenocrysts, quartz phenocrysts and diorite gravels, resulting from rapid accu-mulation of footwall rock weathering products. There are highly-dipped striation lineations that step towards the basin on the cross-section, with distinct mirror characteristics. Together the striations and stepped features as well as the contact relationships between geological bodies of different ages on both sides of the basin suggest that this fault was a steeply-dipping normal fault. In addition, at the northern boundary of the Lisi profile on the upper Yanchuan River west of the fault, basal conglomerates of the Longjiagou Formation were in normal fault contact with the geological body on the northern side (attitude: 175°∠72°). The recon-struction of paleostress state based on fault striae and cross-section data at different points along the fault suggest that the principal compressive stress σ1 was nearly vertical (average σ1=29°∠76°) and σ2 was horizontal (average 274°∠06°), consistent with the fault strike, whereas σ3 was nearly horizontal (average 183°∠13°), consistent with the fault trend (Figure 8).

Reconstruction of the boundary fault paleostress field shows that the basin in Middle Jurassic time was undergo-ing nearly north-south extension. Together the fault proper-ties on the northern side of the basin, and changes in prove-nance, synsedimentary normal faults and Jurassic sedimen-tary facies, collectively suggest that the Jurassic Huicheng Basin was an intermittently subsiding montane basin formed under the control of a steeply-dipping south- southeast normal fault on its northern side. The fault crossed horizontal alluvial fan deposits adjacent to the northern side of the basin, braided river deposits in the central basin area, and lacustrine coal-bearing sedimentary deposits in the dis-tal region. The associated basin fill pattern (Figure 9) was similar to that of Miall’s alluvial basin model [40].

4.2.2 Origin of the Cretaceous basin

In the northern Huicheng Basin, the Huicheng fault retained

more late sinistral shearing. The fault is nearly vertical, with nearly horizontal striae and a plunge angle of generally <30°. In the Dabanping region of Wudu County, the fault strike becomes arcuate, bending to the southwest and ex-tending to the northeast. On the curved southwestern side of the fault strike line, the fault is steeply north-dipping and the hanging wall is oblique to the southwest. Because of a lack of datable minerals in the brittle fault zone (owing to deformation), the duration of brittle fault activity was in-stead estimated based on crosscutting relationships between associated geological bodies. In the Jiangluo region on the northern side, the fault cut the Middle Jurassic and Triassic strata via sinistral shearing, and it controlled the Early Cre-taceous deposition in the Huicheng Basin. Therefore, we suggest that the fault along the northern side of the basin occurred sinistral shearing during the Early Cretaceous.

In the Early Cretaceous, the Huicheng fault on the north-ern margin of the Huicheng Basin and the Yangpingguan- Ningshan fault on the southern margin of the eastern Qin-ling micro-plate together formed a huge sinistral strike-slip fault system [26, 37]. Despite the multi-phase activity of the fault, faults formed under the same stress field display cer-tain matching relationships. Statistical analyses of lineations, the fault plane within two fault zones, and reconstruction of the paleostress field collectively suggest NE-SW compres-sion (Figure 10), consistent with the tectonic background of strong NNE-SSW compression in the Early Cretaceous Qinling region [41, 42]. In this stress field, a series of north- trending rift segments inevitably formed in the interval be-tween the two NEE-SWW trending sinistral strike-slip faults. Meanwhile, the geological blocks at the junction of East and West Qinling adjusted to the NE-SW compression induced shortening deformation via relative motion along the block boundary fault zone. The northern margin of the northeastern Yangtze Plate squeezed into the Qinling tec-tonic belt with clockwise rotation, leading to the southwestern lateral escape of Bikou Terrane. In contrast, the East Qinling micro-plate was restricted by northern and southern stable blocks, and therefore showed limited east-

Figure 8 Reconstruction of the middle Jurassic tectonic stress field (lower hemisphere stereographic projection).


Figure 9 Jurassic basin fill mode (modified from ref. [40]).

ward escape relative to the West Qinling [35] (Figure 10). The Early Cretaceous Huicheng Basin spread as a nearly

NEE-SWW, narrow strip belt, narrow in the east and wide in the west. The basin spreading direction is consistent with the regional NE-SW compressional tectonic stress field, distributed along internal tensile cracks in a huge strike-slip fault zone. The eastward escape of the East Qinling micro-

plate along the Huicheng fault caused stretching on the trailing edge, further resulting in the depositional basin nar-rowing in the east and widening in the west. The distribu-tion of basin depositional facies, from eastern conglomerate facies to western lacustrine facies, as well as migration of the depositional center from west to east, all indicates con-trol of depositional facies and depocenter position by strike-slip motion on the boundary fault.

5 Discussion of regional tectonic evolution

As mentioned above, the Qinling region entered the in-traplate tectonic evolution stage after the Late Triassic. Since the Jurassic, sedimentary strata within the Qinling Orogenic Belt on its northern and southern sides (Table 1) recorded detailed geological information regarding evolu-tion of the basin-mountain system.

(1) Jurassic. At the southern margin of Ordos Basin in the northern Qinling Orogenic Belt, several formations were deposited, including the Lower Jurassic Fuxian, the Middle Jurassic Zhiluo and Anding, as well as the Upper Jurassic Fenfanghe formations. Among these, the Lower Jurassic

Figure 10 Analysis of the brittle fracture tectonic stresses in the Huicheng Basin and adjacent areas, and origin of the Cretaceous basin.


was in unconformable contact with the underlying Triassic. Basin analysis and paleogeographic reconstruction have shown that the Early-Middle Jurassic deposits were not lim-ited to the Ordos Basin, but extended to the east and west [43, 44]. In the Early-Middle Jurassic, a major north-south depo-sitional sag formed in northern China. Growing evidence suggests a weak regionally extensional tectonic setting from nearly south-north to NNE-SSW during this period [45].

In addition to the sedimentary record of the Middle Ju-rassic Longjiagou Formation in the Huicheng Basin within the Qinling Orogenic Belt, strata of the Lower-Middle Ju-rassic Tanlihe Formation and Middle Jurassic Chenjia-zhuang and Huomaidi formations were deposited in the Tianshui region on the northern side of the Qinling Oroge- nic Belt. Associated basal coarse clastic conglomerates transitioned upward to continental acidic volcanic rocks and sedimentary clastic rocks with coal seams, in angular, un-conformable contact with the underlying strata2). In the northern Mianlue tectonic zone, the Lower-Middle Jurassic Baitianba, Qianfoya, and Hongshuigou formations are in angular, unconformable contact with underlying strata and deposited along the Mianlue, Jiangkou, and Jiudianliang faults in Mianxian and Liuba counties in South Qinling. The Jurassic deposits gradually transitioned from lower alluvial fan-fluvial coarse clastic sediments upwards to upper lacus-trine-deltaic facies and fine-grained sediments with coal seams1), suggesting the Jurassic basin was an extensional rift basin. Jurassic deposits also suggest the Huicheng Basin as a relative accumulation rift basin. Statistical analysis of the lower conglomerate composition of the Longjiagou Formation showed that the provenance was the northern Mishuling intrusions, and that the rock age was 213 ± 3 Ma [46]. These indicate that the Qinling Orogenic Belt was up-lifted and the orogeny occurred prior to Jurassic deposition, splitting the Qinling Mountains into their southern and northern parts. In the Early-Middle Jurassic, the Qinling Mountains and surrounding areas were associated with re-gional extension, such that the Qinling Orogenic Belt inter-nally collapsed, resulting in a series of internal rift basins along the nascent fault zone.

(2) Late Jurassic. The Upper Jurassic Fenfanghe For-mation was deposited in the Ordos Basin on the northern

side of the Qinling Orogenic Belt, in unconformable contact with the underlying Middle Jurassic3). Tectonic deformation and depositional analysis shows that the Ordos Basin was under strong, multi-directional compressive stress, and the sedimentary provenance was situated in the marginal mountains [45, 47]. The provenance of the northern Sichuan Basin in the southern Qinling Orogenic Belt was derived mainly from the Hannan-Micang Mountains in the north, and the Daba Mountains in the east [48]. During this period, the Sichuan Basin was also subject to multi-directional compressive and aggradational stresses [49]. There is a lack of the Late Jurassic deposits in the Qinling Orogenic Belt, and the Lower Cretaceous rocks are in unconformable con-tact with underlying strata of different ages. Together the analyses of the Late Jurassic tectonic deformation in the Qinling tectonic belt [41, 42, 50] shows that strong com-pression and uplift occurred in the Late Jurassic Qinling Mountains, which likely became the intracontinental oro-genic belt dividing the southern and northern Qinling Mountains.

(3) Early Cretaceous. In the northern and central parts of the Qinling Orogenic Belt, the Lower Cretaceous Zhidan Group, the Liupanshan Group, and the Donghe Group are in angular unconformable contact with the underlying strata. A series of rift basins [51] were developed in the south-western and western margins of the Ordos Basin. The Early Cretaceous sedimentary basin largely extended along the early faults within the Qinling Orogenic Belt. In addition, a series of sinistral strike-slip faults were developed within the Qin- ling Orogenic Belt, forming a huge NEE-SWW sinistral strike-slip shearing. In the NE-SW compressive stress field, compressive strike-slip occurred and formed a series of sinistral strike-slip-related echelon Cretaceous sedimentary basins in the shear zone.

(4) Late Cretaceous: The eastern and western Qinling re-gions underwent rapid uplift [52, 53]. Intense fold (Figure 4(f)) and thrust nappes occurred in Early Cretaceous strata in the Heihebanfangzi area within the Qinling Orogenic Belt, but there is a general lack of the Upper Cretaceous rocks in the Qinling region. The Cenozoic strata are unconformable with the underlying Upper Cretaceous rocks of different

Table 1 Stratigraphic framework and tectonic evolution of the Mesozoic Qinling orogenic belt and adjacent areas

Southern edge of

Ordos Basin Northwestern margin of

Sichuan Basin Qinling orogenic belt Tectonic evolution of the Qinling orogenic belt

Upper Cretaceous Missing Missing Missing

Tectonic evolution of intracontinental

Extrusion uplift Lower Cretaceous Zhidan Gr./

Liupanshan Gr. Chengqiangyan Gr.

Donghe Gr. Extrusion slip- strike–slip related extensional

basins Upper Jurassic Fenfanghe Fm.

Lianhuagou Fm. Suining Fm.

Missing

Middle Jurassic Zhiluo Fm. Anding Fm.

Shaximiao Fm. Qianfoyan Fm.

Longjiagou Fm. Stretching after the orogenic-rift basin

Lower Jurassic Fuxian Fm. Baitianba Fm. Missing

Underlying strata Triassic Triassic Mishuling rock /Lower Triassic

The end of the orogeny 215–200 Ma [2]

Mishuling rock age 213±3 Ma [46]

∧∧∧∧∧∧∧∧∧∧∧∧∧∧∧∧∧∧∧∧∧

∧∧∧∧∧∧∧∧∧∧∧∧∧∧∧∧∧∧∧∧∧

∧∧∧∧∧∧∧∧∧∧∧∧∧∧∧∧∧∧∧∧∧

∧∧∧∧∧∧∧∧∧∧∧∧∧∧∧∧∧∧∧∧∧

∧∧∧∧∧∧∧∧∧∧∧∧∧∧∧∧∧∧∧∧∧

∧∧∧∧∧∧∧∧∧∧∧∧∧∧∧∧∧∧∧∧∧


ages, indicating that the Qinling region was experiencing uplift and exhumation during this period.

6 Conclusions

Our study of the Mesozoic sedimentary record and the ad-jacent fault zones of the Huicheng Basin shows that:

(1) Following the Late Triassic collisional orogeny, the Qinling Orogenic Belt experienced extensional collapse in the Early-Middle Jurassic, resulting in the formation of a series of rift basins.

(2) In the Late Jurassic-Early Cretaceous, large-scale sinistral strike-slip faults were developed under the NE-SW compressive stress field of the Qinling Orogenic Belt, lead-ing to an intracontinental escape structure at the junction of eastern and northern Qinling region, east finite escape of eastern Qinling, and southwestern escape of the Bikou Ter-rane. Meanwhile, the Early Cretaceous depositional basin related to strike-slip extension developed in a right-stepping echelon arrangement in the sinistral strike-slip fault zone.

(3) From the Mesozoic, the Huicheng Basin and its adja-cent areas have experienced four tectonic evolutionary stages, including an Early-Middle Jurassic extensional rift basin development stage, a Late Jurassic strong compres-sional and uplift stage, an Early Cretaceous strike-slip and extensional basin formation stage, and a Late Cretaceous compression and uplift stage.

This research was supported by National Natural Science Foundation of China (Grant Nos. 40802051 & 41190074) and MOST Special Fund from the State Key Laboratory of Continental Dynamics, Northwest University. The authors gratefully acknowledge Prof. Hongfu Liu (Northwestern Uni-versity) and Haiping Li (Shaanxi Institute of Regional Geology and Miner-al Resources) for generous help with field work. We are also indebted to the reviewers for their critical and constructive comments, which substan-tially improved an early version of the manuscript.

1 Zhang G W, Dong Y P, Lai S C, et al. Mianlue tectonic zone and Mianlue suture zone on southern margin of Qinling-Dabie orogenic belt. Sci China Ser D-Earth Sci, 2004, 47: 300–316

2 Dong Y P, Zhang G W, Franz N, et al. Tectonic evolution of the Qin-ling orogen, China: Review and synthesis. J Asian Earth Sci, 2011, 41: 213–237

3 Xu Z Q, Lu Y L, Tang Y Q, et al. Formation of the Composite East-ern Qinling Chains (in Chinese). Beijing: China Environmental Sci-ence Press, 1988. 1–160

4 Zhang G W, Zhang B R, Yuan X C, et al. Qinling Orogenic Belt and Continent Dynamics (in Chinese). Beijing: Science Press, 2001. 286–303

5 Gao S, Zhang B R, Wang D P, et al. Geochemical evidence for the Proterozoic tectonic evolution of the Qinling Orogenic Belt and its adjacent margins of the North China and Yangtze cratons. Precam-brian Res, 1996, 80: 23–48

6 Gao S, Zhang B R, Jin Z M, et al. Lower crustal delamination in the Qinling-Dabie orogenic belt. Sci China Ser D-Earth Sci, 1999, 42: 423–433

7 Zhang H F, Zhang B R, Zhao Z D, et al. Continental crust subduction and collision along Shangdan Tectonic Belt of East Qinling, China —Evidence from Pb, Nd and Sr isotopes of granitoids. Sci China Ser

D-Earth Sci, 1996, 39: 273–282 8 Meng Q R, Zhang G W. Geologic framework and tectonic evolution

of the Qinling orogen, central China. Tectonophysics, 2000, 323: 183–196

9 Wang E Q, Meng Q R, Chen Z L, et al. Early Mesozoic left-lateral movement along the LongMen Shan fault belt and its tectonic impli-cations (in Chinese with English abstract). Earth Sci Front, 2001, 8: 375–384

10 Ratschbacher L, Hacker B R, Calvert A, et al. Tectonics of the Qin-ling (Central China): Ectonostratigraphy, geochronology, and defor-mation history. Tectonophysics 2003, 366: 1–53

11 Liu S F, Ronald S, Zhang G W. Mesozoic sedimentary basin devel-opment and tectonic implication, northern Yangtze Block, Eastern China: Record of continent–continent collision. J Asian Earth Sci, 2005, 25: 9–27

12 Li S Z, Kusky T M, Wang L, et al. Collision leading to multiple-stage large-scale extrusion in the Qinling orogen: Insights from the Mi-anlue suture. Gondwana Res, 2007, 12: 121–143

13 Faure M, Wei L, Monié P, et al. Palaeozoic collision between the North and South China blocks, Triassic intracontinental tectonics, and the problem of the ultrahigh-pressure metamorphism. C R Geosci, 2008, 340: 139–150

14 Xu, J F, Zhang B R, Han Y W, et al. Geochemistry of the Mian-Lue ophiolites in the Qinling Mountains, central China: Constraints on the evolution of the Qinling orogenic belt and collision of the North and South China Cratons. J Asian Earth Sci, 2008, 32: 336–347

15 Wang Z Q, Yan Q R, et al. Geochemical constrains on the prove-nance and depositional setting of the Devonian Liuling group, East Qinling Mountanis, Central China: Implications for the tectonic evo-lution of the Qinling orogenic belt. J Sediment Res, 2012, 82: 9–24

16 Meng Q R, Wang E C, Hu J M. Mesozoic sedimentary evolution of the northwest Sichuan basin: Implication for continued clockwise ro-tation of the South China block. Geol Soc Am Bull, 2005, 117: 396–410

17 Zhang G W, Meng Q R, Yu Z P, et al. Orogenesis and dynamics of the Qinling Orogen. Sci China Ser D-Earth Sci, 1996, 39: 225–234

18 Zhang G W, Meng Q R, Lai S C. Tectonics and structure of Qinling orogenic belt. Sci China Ser B-Chem, 1995, 38: 1379–1394

19 Zhang G W, Guo A L, Yao A P. Western Qinling-Songpan continen-tal tectonic node in China’s continental tectonics (in Chinese with English abstract). Earth Sci Front, 2004, 11: 23–32

20 Ma X Y. Outline of Lithospheric Dynamics of China—Explanation of Lithospheric Dynamics Map in China and Offshore Areas (1:4000000) (in Chinese). Beijing: Geological Publishing House, 1987. 1–76

21 Zhang G W, Guo A L, Dong Y P, et al. The relationship of the Helan-Chuandian N-S tectonic zone and eastern Tibetan Plateau in Chinese continent and its dynamics (in Chinese). In: Wu F Y, Fan H R, Chen F K, eds. Petrology and Geodynamics Conference, Hang-zhou, Zhejiang, 2005. 4–6

22 Yuan X C, Xu M C, Tang W B, et al. Eastern Qinling seismic reflec-tion profiling (in Chinese with English abstract). Chin J Geophys, 1994, 37: 749–758

23 Zhang G W, Guo A L, Liu F T, et al. The three-dimensional structure of Qinling orogenic belt and its dynamics analysis. Sci China Ser D-Earth Sci, 1996, 26(Suppl): 1–6

24 Yang Z H, Guo J F, Su S R, et al. New advances in the geological study of the Qinling orogen (in Chinese with English abstract). Geol China, 2002, 29: 246–256

25 Zhang E P, Niu D Y, Huo Y G, et al. Geological Map of Qin-ling-Dabie Mountains and Adjacent Region of the People’s Republic of China (1:1000000). Beijing: Geological Publishing House, 1992

26 Zhang G W, Chen J Y, Yuan X C, et al. Tectonic Map of Qinling Orogenic belt (1:1000000). Beijing: Science Press, 1996

27 Stanley A S, Victor R B, Margaret F B, et al. Alluvial Fan Flooding. Washington D C: National Academy Press, 1996. 1–182

28 Mack G H, Seager W R. Tectonic control on facies distribution of the Camp Rice and Palomas Formations (Pliocene-Pleistocene) in the southern Rio Grande rift. Geol Soc Am Bull, 1990, 102: 45–53


29 Qi H, Liu Z J, Zhang Z F, et al. Early Cretaceous stratigraphy in the Huicheng Basin (in Chinese with English abstract). Northwest Geol, 1979, 4: 86–100

30 Liu S F, Zhang G W. Fundamental ideas, contents and methods in study of basin and mountain relationships (in Chinese with English abstract). Earth Sci Front , 2005, 12: 101–111

31 Rust B R. Pebble orientation in fluvial sediments. J Sedimen Petrol, 1972, 42: 384–388

32 Allen P A, Allen J R. Basin Analysis: Principles and Applications, 2nd ed. Oxford: Blackwell Science, 2005. 219–348

33 Hendrix M S, Graham S A, Amory J Y, et al. Noyon Uul (King Mountain) Syncline, southern Mongolia: Lower Mesozoic sedimen-tary record of the tectonic amalgamation of central Asia. Geol Soc Am Bull, 1996, 108: 1256–1274

34 Zhang Y L, Wang Z Q. Provenance analysis of Early Cretaceous Huixian-Chengxian basin, western Qinling orogenic belt, China: Constraints from zircon U-Pb geochronology (in Chinese with Eng-lish abstract). Geol Bull China, 2011, 30: 37–50

35 Li S Z, Zhang G W, Li Y L, et al. Deformation and orogeny of the Mian-Lue suture zone in the Qinling orogenic belt (in Chinese with English abstract). Acta Geol Sin, 2002, 76: 469–483

36 Chen H, Hu J M, Wu G L, et al. Study on the intracontinental defor-mation of the Mian-Lue suture belt, western Qinling (in Chinese with English abstract). Acta Petrol Sin, 2010, 26: 1277–1288

37 Hu J M, Meng Q R, Chen H, et al. Tentonic evolution and implica-tion of Ningshan Fault in the central part of Qinling Orogen (in Chi- nese with English abstract). Acta Petrol Sin, 2011, 27: 657–671

38 Wang Q W, Liang B, Xie Q X, et al. Research on microstructures and deformation conditions of the Qinchuan Fault Zone (in Chinese with English abstract). J Mineral Petrol, 2000, 20: 87–90

39 Li Y, Zhou R J, Densmore A L, et al. Geomorphic and sedimentary evidence for reversion of strike-slip direction in Longmen Shan Fault Zone (in Chinese with English abstract). J Mineral Petrol, 2006, 26: 26–34

40 Miall A D. Alluvial sedimentary basins: Tectonic setting and basin architecture. In: Miall A D, ed. Sedimentation and Tectonics in Allu-vial Basins. Geol Assoc Can Spec Paper, 1981, 23: 1–33

41 Dong S W, Shi W, Zhang Y Q, et al. The tectonic stress field in the Dabashan orogen resulting from late Mesozoic intra-continental orogeny (in Chinese with English abstract). Acta Geosci Sin, 2010, 31: 769–780

42 Dong S W, Zhang Y Q, Chen X H, et al. The formation and deforma-tional characteristics of east Asia multi-direction convergent Tectonic system in late Jurassic (in Chinese with English abstract). Acta Ge-osci Sin, 2008, 29: 306–317

43 Liu C Y, Zhao H G, Wang F, et al.Attributes of the Mesozoic struc-ture on the west margin of the Ordos Basin (in Chinese with English abstract). Acta Geol Sin, 2005, 79: 737–747

44 Cheng S T, Huang Y Q, Fu X H. Paleogeography reconstruction of the Early-Middle Jurassic large Ordos basin and development and evolution of continental downwarping. Acta Sedimentol Sin, 1997, 4: 43–49

45 Zhang Y Q, Liao C Z, Shi W, et al. On the Jurassic deformation in and around the Ordos Basin, North China (in Chinese with English abstract). Earth Sci Front, 2007, 14: 182–196

46 Qin J F, Lai S C, Grapes R, et al. Geochemical evidence for origin of magma mixing for the Triassic monzonitic granite and its enclaves at Mishuling in the Qinling orogen (central China). Lithos, 2009, 112: 259–276

47 Dong S W, Li T D, Zhong D L, et al. Recent progress and perspective of the research on J-K east Asian multi: Direction convergent tecton-ics (in Chinese with English abstract). Bull NSFC, 2009, 5: 281–286

48 Liu Y S, Guo Z F, Liang X W, et al. Tectonic significance of sand-stones and coupling relation of basin and mountain in the late Trias-sic-Jurassic in the middle and upper Yangze region (in Chinese with English abstract). Petrol Geol Exper, 2006, 28: 201–205

49 Zhang Y Q, Dong S W, Li J H, et al. Mesozoic muti-direction com-pressional tectonics and formation-reformation of Sichuan Basin (in Chinese with English abstract). Geol China, 2011, 38: 233–250

50 Hu J M, Shi W, Qu H J, et al. Mesozoic deformation of Dabashan curvilinear structural belt of Qinling orogen (in Chinese with English abstract). Earth Sci Front, 2009, 16: 49–68

51 Zhang Y Q, Shi W, Liao C Z, et al. Fault kinematic analysis and change in late Mesozoic tectonic stress regimes in the peripheral zones of the Ordos basin, north China (in Chinese with English ab-stract). Acta Geol Sin, 2006, 80: 639–647

52 Guo J J, Han W F, Li X F. The cenozoic tectonic evolution of the West Qinling: Constraints on the uplift and deformation of the Qing-hai-Tibet Plateau. Earth Sci Front, 2009, 16: 215–225

53 Wan J L, Wang Y, Li Q, et al. Apatite fission track study of Taibai Mountain uplift in the Mesozoic-Cenozoic (in Chinese with English abstract). Nuclear Tech, 2005, 28: 712–716

sedimentary fill history of the huicheng basin in the west qinling mountains and associated...

Documents