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The Sichuan Basin was a part of the Yangtze Carbonate Platform (YCP) during the Cambrian–Ordovician, and marine carbonates were deposited in the basin during this interval. Although previous studies have evaluated the paleogeography, paleoclimate and paleoecology of this basin, they have primarily focused on the paleoecology and biological evolution in the basin; however, analysis of paleogeography and paleoclimate is lacking. This study integrated outcrop sedimentological and magnetic fabric data to document sedimentary differentiation and anisotropy of magnetic susceptibility (AMS) within the YCP. The aims of this study were to infer paleowind directions during each epoch of the Cambrian–Ordovician and to constrain the paleogeographic location of the YCP. The northwestern, central and southeastern sides of the YCP were characterized by high-energy deposition (e.g. sub-angular to rounded intraclasts), medium-energy deposition (e.g. sub-angular to sub-rounded intraclasts) and low-energy deposition (e.g. angular to sub-angular intraclasts), respectively. The centroid D-Kmax values for the Early, Middle and Late Cambrian were 116° ± 52°, 145° ± 57° and 159° ± 62° from the present north, respectively; corresponding values for the Early, Middle and Late Ordovician were 169° ± 70°, 139° ± 73° and 91° ± 68° from the present north, respectively. Sedimentary differentiation and AMS results indicated that the prevailing wind directions during the Early Cambrian, Middle Cambrian, Late Cambrian, Early Ordovician, Middle Ordovician and Late Ordovician were 296° ± 52°, 325° ± 57°, 339° ± 62°, 349° ± 70°, 319° ± 73° and 271° ± 68° from the present north, respectively. The present study provides evidence for the location of the YCP during the Cambrian–Ordovician via the correspondence between the paleowind directions over the YCP and the trade winds in the Northern and Southern hemispheres. The novelty of this study lies in the following aspects: (1) it integrates microfacies and AMS analyses to establish paleowind patterns; (2) it constrains the paleo-hemispheric location of the YCP during the Cambrian–Ordovician; and (3) it provides a reference for further studies of the paleoclimate and paleogeography of the YCP during the Cambrian–Ordovician. [ABSTRACT FROM AUTHOR]

The Bikou Terrane, located at the conjunction of the Longmenshan fold-thrust belt and the west Qinling orogenic belt in centeral China, was involved in the Late Triassic collision between the South China and North China blocks. The Bikou Terrane has preserved crucial information on structural geometry and kinematics of Triassic tectonics, and is therefore of great importance for reconstructing the Paleo-Tethyan evolutionary history. However, multi-phase tectonic events of the Bikou Terrane are unsettled. This work presents detailed structural analysis based on both the field and laboratory works, which reveals three phases of deformation events in Bikou and its adjacent areas, including top-to-the-SW shearing related to SW-ward thrusting (DI) mainly to the north of the Bikou Terrane, top-to-the-NNW shearing related to NNW-ward thrusting (DII) in the Bikou Terrane, and strike-slip faulting (DIII) locally developed in the northern Bikou Terrane. Anisotropy of magnetic susceptibility (AMS) study and related structural analysis not only support the multiphase deformation but also reveal a gradual transition from the DII-related magnetic fabrics to the DIII-related magnetic fabrics in the Bikou Terrane. Integrating published geochronological data, it is constrained that DI occurred at ca. 237-225 Ma, DII occurred at ca. 224-219 Ma, and DIII possibly occurred during the Early Cretaceous. Based on regional tectonics, the DI event corresponds to the collision between the South Qinling block and the Bikou Terrane, and the DII event reflects the intracontinental amalgamation between the Bikou Terrane and the Yangtze block, which indicates a Late Triassic successive amalgamation from the North China block to the South China block. Intracontinental adjustment represented by the strike-slip (DIII event) occurred after the final amalgamation between the North China and South China blocks. By applying AMS on deciphering structural geometry and multiphase deformation, our study suggests that AMS is a useful tool for structural analysis. [ABSTRACT FROM AUTHOR]

In many modern deep‐water slope environments, deposits formed by bottom currents (contourites) are rather common. However, reports on ancient contourites in deep‐water environments are scarce and most of them remain contentious. Based on the study of high‐resolution sedimentological, sedimentary geological and magnetic fabric characteristics, this study presents the key evidence of bottom current activity in the Middle Ordovician Kelimoli Formation from the western margin of the North China craton, and reconstructs the deep‐sea circulation pattern and the direction of deep‐water bottom currents in the middle and low latitudes during the Middle Ordovician. Six typical carbonate microfacies are identified in the Kelimoli Formation, which can be grouped into three sedimentary facies types related to the main interpreted depositional processes (bottom current, undifferentiated bottom current and hemipelagic settling, and hemipelagic settling). The evidence of bottom current deposits are five‐fold. Firstly, it is possible to observe a variety of traction current structures, which mainly represent bed‐load‐dominated transport of sediments. Secondly, there are multi‐scale inverse grading and bi‐grading, as well as inversely‐graded and normally‐graded sedimentary sequences, which reflect the periodic change of bottom current activity. Thirdly, gradual or sharp contact boundaries and small internal erosional surfaces indicate omission surfaces caused by the oscillating variation of bottom current velocity. Fourthly, the continuous rhythmic change of sedimentary fabrics on the microscopic scale reflects sustained, waxing and waning current intensities. Fifthly, the anisotropy of magnetic susceptibility reveals the microscopic fabric characteristics of imbricated magnetic grains, which represent the continuous action of directional current, and the restored palaeocurrent direction indicates that the current is mainly parallel to the slope strike. After the palaeo‐north correction of the North China craton clockwise rotation of 120° to 150° since the Ordovician, anisotropy of magnetic susceptibility shows that the direction of bottom current in the study area is towards the north‐east/east. Therefore, it is speculated that there was a clockwise deep‐water circulation in the middle and low latitudes of the southern hemisphere during the Ordovician. This study not only provides sedimentological evidence for the Ordovician bottom current activity, but also contributes to a better understanding of the Ordovician palaeoceanographical environment, especially the Middle Ordovician deep‐sea circulation pattern. [ABSTRACT FROM AUTHOR]

We theoretically provide a magnetic phase diagram for the single-layer (SL) CrBr3, which could be effectively tuned by both strain engineering and charge doping in SL-CrBr3. Through systematical first-principles calculations and Heisenberg model Hamiltonian simulations, three different magnetic phases in SL-CrBr3, which are off-plane ferromagnetic, in-plane ferromagnetic and in-plane NĂ©el-antiferromagnetic phases, are found in the strain and charge doping regimes we studied. Furthermore, our results show that higher order Heisenberg exchange parameters and anisotropy exchange parameters should be taken into account for accurately illustrating the magnetic phase transition in SL-CrBr3. As a result, we find from the SpinW simulation that the Curie temperature is about T c = 38.4 K, which is well consistent with the experimental result 34 K [ Nano Lett. 19 3138 (2019)]. The findings here may be confirmed in future experiments, and may be useful for the potential applications of SL-CrBr3 in spintronics field. [ABSTRACT FROM AUTHOR]

Internal structures of the pluton may provide key information on magma emplacement mechanism and the relationship with regional tectonics. We present a case study on the Late Triassic Gaoqiao pluton from South Qinling Belt, which was emplaced under a syn‐collisional setting. Multi‐approaches including zircon U–Pb geochronology, field and microstructural observations, anisotropy of magnetic susceptibility analysis was conducted to reconstruct the growth process of the pluton and to investigate the internal structures. Zircon U–Pb geochronology reveals that the pluton is a composite intrusion which was constructed by two successive units with distinct ages (~220 and ~210 Ma). Field observations show that the Gaoqiao pluton and its country rocks recorded abundant evidences of syn‐plutonic deformations, indicating a syn‐tectonic emplacement. Microstructural observations show that the internal fabrics were mainly acquired during the stage from magma flow to high‐T solid‐state deformation. The fabric distributions display 'onion‐skin' patterns on the pluton scale, which are characterized by zoned foliations and lineations. Combined with the syn‐collisional convergence setting, we propose a tectonic‐controlled incremental growth model for the pluton, in which the pluton was successively constructed by the Fujiahe unit and the Hetaoping unit, and the emplacement process of the pluton was controlled by the regional deformation with sinistral transpressional kinematics. Furthermore, the internal fabric patterns of the Gaoqiao pluton were probably formed by tectonic‐controlled helical magma flow, which appears to be common in fabric formation of many other plutons with similar features. [ABSTRACT FROM AUTHOR]

Central Asia loess deposits can yield detailed records of aridification across the Asian interior, as well as the atmospheric circulation. In this study, we presented grain size, heavy mineral assemblage, rock magnetism and anisotropy of magnetic susceptibility of a loess section in the Tacheng Basin in Xinjiang region, NW China. The results of anisotropy of magnetic susceptibility indicated that a near-surface SE wind prevailed in the Tacheng area since Marine Isotope Stage (MIS) 3, while a near-surface SW prevailing wind developed during MIS3b. We inferred that the change of wind direction was due to glacial advance during MIS3b. Combining the result of anisotropy of magnetic susceptibility with grain size, heavy mineral assemblage data and previously published low-field mass susceptibility revealed that dust transported by the near-surface SW wind had a greater ability to enhance magnetic susceptibility and higher amphibole/epidote ratio. Additionally, a strong Siberian High during Heinrich Event (H)5 at ca. 48 ka blocked the advection of moisture into the region via mid-latitude westerlies, causing glacial recession and the weakening of the prevailing SW wind. Our study has implications for identifying changes in paleo-wind direction and dust source, which can aid understanding of the influence of westerlies and the Siberian High on dust accumulation, as well as their interactions. [ABSTRACT FROM AUTHOR]

• HTS composite conductors containing stacked HTS tapes are considered to manufacture TF coils in CFETR magnetic system. • The anisotropy of magnetic field of the TF coils is studied. The magnetic field in the different direction is computed in the normal conditions and the fault conditions. • Providing a reference for designing HTS TF magnets. High temperature superconductors (HTS) have been developed over the years and have the better performance. Some conceptual HTS composite conductors have been designed for high field magnets, such as fusion magnets. The magnetic field environment in which the magnet is located must be determined to ensure the safety of the HTS magnet. In this paper, we study the magnetic field distribution of the China Fusion Engineering Test Reactor (CFETR) magnetic system under two plasma equilibrium shapes. In the CFETR magnetic system, HTS composite conductors containing stacked HTS tapes are considered to manufacture the toroidal field (TF) coils. The critical current is related to the direction of the magnetic field in HTS tapes, so we focus on the anisotropy of magnetic field of the TF coils. Sometimes, TF coils of the CFETR magnetic system may operate under fault conditions. Two possible fault conditions are considered: the short circuit in one TF coil and the unprotected quench in one TF coil. We evaluate the magnetic performance of the CFETR magnetic system under fault conditions and also analyze the magnetic field of the TF coils in different directions under fault conditions by the finite element method. This provides a reference for the design of the HTS TF magnets. [ABSTRACT FROM AUTHOR]

The Tarim Basin was in the lower latitudes during the Cambrian-Ordovician, during which it experienced marine carbonate platform deposition. Although the platform is in the Trade Winds belt, the specific prevailing quantitative paleowind direction remains uncertain. This study integrated drill core and outcrop sedimentological data with outcrop magnetic fabric data to document sedimentary differentiation and anisotropy of magnetic susceptibility (AMS) within the Tarim Carbonate Platform (TCP). The aims of this study were to infer paleowind directions during each epoch of the Cambrian-Ordovician and to constrain the paleogeographic location of the TCP. The characteristics of the south, central, and northern sides of the platform were indicative of high-energy deposition (e.g., sub-angular to sub-rounded intraclasts with sparite cements), medium-energy deposition (e.g., angular to sub-rounded intraclasts with microspar and sparite cements), and low-energy deposition (e.g., angular to sub-angular intraclasts with microspar cements), respectively. AMS measurements yielded mean paleocurrent directions for the Early, Middle, and Late Cambrian of 226° ± 42°, 207° ± 43°, and 193° ± 36° from present north, respectively, whereas those for the Early, Middle, and Late Ordovician were 178° ± 39°, 165° ± 43°, and 155° ± 52° from present north, respectively. The results of sedimentary differentiation and AMS indicated that the prevailing wind directions of the Early Cambrian, Middle Cambrian, Late Cambrian, Early Ordovician, Middle Ordovician, and Late Ordovician were 226° ± 42°, 207° ± 43°, 193° ± 36°, 178° ± 39°, 165° ± 43°, and 155° ± 52° from present north, respectively. Since the TCP has rotated clockwise by ∼90° since the Ordovician, the paleowind directions of the Early, Middle, and Late Cambrian were 146° ± 42°, 117° ± 43°, and 103° ± 36° from paleo-north, respectively. The paleowind directions of the Early, Middle, and Late Ordovician were 88° ± 39°, 75° ± 43°, and 65° ± 52° from paleo-north, respectively. The TCP shifted from Southern Hemisphere to the Northern Hemisphere from the Early Cambrian to the Late Ordovician. The TCP was close to the Equator during the Early Ordovician. The novelty of this study related to: (1) integrating microfacies and AMS analyses to establish paleowind patterns; (2) constraining the paleo-hemispheric location of the TCP during the Cambrian-Ordovician; (3) providing references for the further study of paleoclimate and paleogeography of the TCP during the Cambrian-Ordovician. • Quantitative measurements of sediment properties across the platform were documented. • Quantitative measurements of anisotropy of magnetic susceptibility across the platform were documented. • Quantitative paleowind directions of the platform were reconstructed during the Cambrian-Ordovician. • Paleo-hemispheric location of Tarim Block was constrained during Cambrian-Ordovician. • An integrated methodology of standard petrographic and magnetic anisotropy data. [ABSTRACT FROM AUTHOR]

To understand the post-orogenic tectonics related to collision between the North China Craton (NCC) and the South China Block (SCB), the Northern Sulu massif is a representative area. It experienced a complex evolution marked by exhumation of ultra-high-pressure metamorphism rocks, migmatization, and alkaline magmatism in the Latest Triassic, and felsic magmatism in the Late Jurassic. In this contribution, we carried out a combined study including structural analysis, anisotropy of magnetic susceptibility (AMS), and gravity survey on the Northern Sulu massif. According to our structural analysis, it is interpreted as an extensional dome, exhibiting dominantly SE-dipping foliations in its east and center and NW-dipping ones closer to its northwestern margin, NW-SE mineral and stretching lineations, and top-to-the-NW kinematics. The Latest Triassic pyroxene syenite has dominantly SE-dipping mesoscopic/magnetic foliations, NW-SE magnetic lineations, and wedge shape at depth, and the Latest Triassic quartz syenite has variable magnetic fabric. Considering geometric relations of plutons and country rocks, the former is a " syn -kinematic" pluton, while the latter post-dates the regional tectonics, constraining the timing of the top-to-the-NW shearing at 220–210 Ma. Compared with the syn-orogenic tectonic events, the Latest Triassic ductile deformation points to a NW-SE extension related to lithospheric delamination. Late Jurassic isotropic monzogranite is characterized by "onion-skin" magnetic foliations with NE-SW trending magnetic lineations, and NE- or SW-ward decrease of thickness at depth. On the basis of regional understanding, we link its emplacement with the Late Jurassic NE-SW extensional tectonics attributed to the oblique subduction of the Paleo-Pacific plate. Such two episodes of crustal extensions with magmatism reformed the crustal architecture of the SE-margin of the NCC, which considerably facilitated stress-transmission from plate-boundary to intraplate during the development of subsequent Late Mesozoic intracontinental deformations. • Recognition of syn - to post-tectonic syenite precisely constrains timing of ductile deformation. • Multidisciplinary study reveals two episodes of extension in Sulu UHP orogen at Mesozoic. • Crustal extension weakening crust helped subsequent intracontinental deformations. [ABSTRACT FROM AUTHOR]

The Cretaceous extensional province of the South China Block (SCB), and the decratonization-induced extension in the North China Block (NCB), were both controlled by the Late Mesozoic subduction of the Izanagi/Paleo-Pacific Plate. Different from the metamorphic core complexes exhuming deep crustal rocks of the NCB, extension of the SCB is expressed by numerous half-graben basins and detachment of upper-middle crustal rocks, but its mode and mechanism remain unclarified. At the westernmost of this extensional province, the Early Paleozoic Yuechengling-Miao'ershan Massif, composed of the ductilely deformed Yuechengling pluton and undeformed Miao'ershan pluton, records Late Mesozoic detachment and exhumation. Magnetic fabrics of the western Yuechengling pluton are consistent with structural fabrics, while the NE-SW trending magnetic lineation and NE-SW striking magnetic foliation of the Miao'ershan pluton and the undeformed Yuechengling pluton reflect a pre-existing magma flow structure. Integrating our structural observation, anisotropy of magnetic susceptibility (AMS) results with gravity modeling, we reveal the deep geometry of the extensional dome and restore the original structure before the Late Mesozoic Ziyuan detachment. The mode of extension argues for a single batholith split into two separate massifs, thinning the crust of the central SCB. The shallow-dipping Ziyuan detachment fault (10°-30°) may account for the large horizontal extension but low exhumation of mid-crustal rocks in the SCB, in contrast to the large exhumation of deep crustal rocks in the NCB. • Magnetic fabrics and gravity modeling help structural restoration. • The Ziyuan detachment fault cuts and splits the batholith into two individual plutons. • Low angled <30° stretching accounts for the lower exhumation of the SCB than the NCB. [ABSTRACT FROM AUTHOR]

Hydraulic fracturing is an effective stimulation method for the economic development of tight-gas reservoirs in which extremely low matrix permeability requires complex fracture networks. Petrophysical/mechanical experiments and XRD/SEM analyses demonstrate that volcanic sedimentary rock is characterized by developed natural fracture, strong brittleness, stress sensitivity, AE activity, weak anisotropy, and fluid sensitivity. Fracability index is often utilized as a key parameter to evaluate the ability to generate fracture networks. In this study, a new systematic experimental approach and a new mathematical model are established for the comprehensive evaluation of the fracability of tight-gas formations. These two methods integrate natural fracture, stress sensitivity, rock anisotropic nature, AE activity and crack density. The results indicate that the fracability index (FI) and the calculated crack density (CRD) are positively linearly correlated. The method is successfully applied to evaluate the fracability of the Yingtai gas field in northeast China. [ABSTRACT FROM AUTHOR]

Magma flow directions for 6 Late Cretaceous mafic dyke swarms exposed in coastal southeastern China (SE China) were analyzed using anisotropy of magnetic susceptibility (AMS) and field evidence. Normal AMS fabrics are predominant. The AMS of the dyke swarms originates mainly from the distribution anisotropy of intersertal magnetite that crystallized during late stage magma flow or after the magma cooled. The AMS fabrics record tectonic stress combined with magma flow. Sub-vertical to vertical magma flow is inferred from symmetrical imbricated magnetic foliations of dyke walls and field evidence for 5 dyke swarms. The inferred (sub-) vertical flow directions also indicate that the magma chambers were probably just beneath the sampled locations. Low anisotropy degree, different orientations of principal AMS axes, and asymmetrical magnetic foliations of normal fabrics oblique to dyke walls indicate syntectonic emplacement of the Late Cretaceous dyke swarms under an extensional tectonic regime caused by Paleo-Pacific plate subduction. [ABSTRACT FROM AUTHOR]

Anisotropy of magnetic susceptibility (AMS) of Chinese loess is considered to be an effective tool for determining paleowind direction. However, the relationship between AMS and the paleowind direction is still a matter of debate. This study reports the results of AMS measurements of Chinese loess deposited during the last glacial period on slopes of varying slope angles and orientations. The sites are located on the Chinese Loess Plateau, in West Qinling, and on the eastern margin of Qilian Mountain. The results show that within the same region, magnetic lineations are clustered along similar orientations despite differences in slope exposure and slope angle, but that different regions exhibit different directions of magnetic lineation. These results suggest that the alignment of the magnetic grains during deposition of the eolian deposits was determined by air circulation rather than by water flow on the surface of the slopes, and therefore that the AMS of Chinese loess can be used to determine paleowind directions. In addition, our results indicate that the AMS of Chinese loess is determined mainly by the patterns of regional surface wind flow that occurred during dust accumulation rather than by the uniform pattern of large-scale atmospheric circulation. In addition, since wind direction is influenced significantly by regional topography, the AMS of Chinese loess may have the potential to detect significant changes in past regional topography. [ABSTRACT FROM AUTHOR]

[Display omitted] • The Dongguashan quartz-diorite stock was built by multiple magma pulses. • Early magma pulse was guided by inherited NE-SW-trending structure in country rock. • Late magma pulse emplacement was assisted by regional extensional regime. • Eastward magma emplace might control location of skarnization in stock eastern sideable 1. We present a study on the Dongguashan quartz diorite stock which is the largest Early Cretaceous intrusion associated with skarn-porphyry polymetallic ore deposit in the Tongling Ore Cluster, Middle-Lower Yangtze Metallogenic Belt in East China. The Dongguashan quartz diorite show massive texture without obvious foliation, and intrusive contact was locally observed inside of the stock. The anisotropy of magnetic susceptibility (AMS) results of the stock show two distinct groups. The Group I (G-I) is dominated by NE-SW-striking magnetic foliation with variably oriented magnetic lineation. The Group II (G-II) that intruded into G-I is characterized by steep NW-SE-striking magnetic foliation and lineation, which are parallel to the vein-like orebody developed in the stock. The 3D geometrical modelling of the stock displays a triangular shape in plan-view with an eastward bulge and irregular stock boundary in the eastern side and the contact surface is steeper in the west than that in the east, denoting that the stock was constructed with an eastward magma accretion trend. Furthermore, the Dongguashan quartz diorite has a wide range of composition and geochronological data, suggesting a multiple magma pulses emplacement model. Accordingly, we propose that the Dongguashan stock was constructed by at least two stages magma pulses. The earlier stage magma pulses intruded along the NE-SW-striking pre-emplacement structures in the country rock and partly intruded into the lithological and mechanical discontinuous interfaces which yielded the stratabound skarn orebody. The eastward magma accretion produced a highly deformed and longer heated country rock on the eastern side of the stock, favoring the orebody development along the eastern stock-country rock contact interface. The late-stage magma pulse and the parallelism among the trend of magnetic foliation of G-II, extensional structure and vein-like orebody suggest that the vein-type orebodies may controlled by both magma emplacement and regional tectonics. [ABSTRACT FROM AUTHOR]

[Display omitted] • A Late Jurassic extension was recoganized in previous thought long time contraction Yanshan belt. • Structural geology, geophysics and geochemistry data of pluton provide firm evidences. • The "Yanshan-A Movement" is constrained at 172–164 Ma instead of a wide range from 172 to150 Ma. • The geodynamics could be ascribed to the oblique subduction of the Izanagi plate. The Yanshan fold and thrust belt (YFTB) was built up by multiple contractional events, namely the "Yanshan Movement", which was traditionally subdivided into the "Yanshan-A" and "Yanshan-B". In contrast with the better constraint on "Yanshan-B" (ca.140 Ma), the timing of "Yanshan-A" is still in dispute. The Middle Jurassic contraction (172–160 Ma) was widely accepted, however, whether this contraction can last into 150 Ma is still unclear. In this article, to clarify the Late Jurassic tectonic regime in the YFTB, a multidisciplinary study, including structural geology, Anisotropy of Magnetic Susceptibility (AMS), gravity modeling, geochronology, and geochemistry, has been carried out to investigate the emplacement mechanism of the Siganding pluton (ca. 161–157 Ma) in the northern Beijing area. The magma was predominantly derived from the Precambrian continental lower crust. The magnetic foliations are pluton margin-parallel and outward dipping, resembling the fabric pattern of magmatic dome. The NE-SW striking magnetic lineations and NW-SE linear feeder zones revealed by gravity modeling indicate that the emplacement of the Siganding pluton was controlled by a weak NE-SW crustal stretching interpreted as a regional tectonic extension. Considering that the Late Jurassic (164–153 Ma) NE-SW oriented extension structures are not only documented in the YFTB, but also the entire eastern NCC, hereby we propose that the "Yanshan-A" is constrained at 172–164 Ma, instead of a wide range from the Middle Jurassic to Late Jurassic (172–150 Ma) as argued by previous workers. The extension could be ascribed to the oblique subduction of the Izanagi plate. [ABSTRACT FROM AUTHOR]

It is well known that the Dabie-Sulu orogenic belt resulted from the northward continental subduction of the South China Block (SCB) beneath the North China Block (NCB) during the Triassic. Correlating the deformation events recorded in the subducted and overriding plates is essential to understand its tectonic evolution, but related deformation is poorly documented in the overriding plate. In this contribution, we present detailed structural analysis, anisotropy of magnetic susceptibility (AMS), and geochronological data in the Linsishan unit of the Jiaobei massif, the overriding plate of the Sulu orogenic belt. The Linsishan unit preserves a significant ductile deformation characterized by NNW-, NE-, or SE-dipping foliations with NE–SW trending mineral lineations. Coupling mesoscopic and magnetic fabrics augment the NE–SW linear structures. The NE-dipping monoclinal structures with top-to-SW kinematics could be interpreted as a SW-directed thrusting, the deformation temperature of which is 350–450 °C according to the quartz c-axis fabrics. The timing of deformation is constrained to be 223–221 Ma based on 40Ar/39Ar dating of the deformed rocks and linked with a syn -collisional stage in the Sulu orogenic belt. Combining these new results with previous works, we propose a three-stage evolution model for the Sulu orogenic belt, namely (1) subducted SCB experienced ultra-high pressure (UHP) metamorphism before 230 Ma; (2) SW-directed thrusting was developed in the overriding plate, coeval with the syn -collisional exhumation of UHP rocks during 230–220 Ma; (3) post-collisional migmatization, magmatism, extension, and UHP rocks exhumation took place at 220–205 Ma. • Late Triassic SW-directed thrusting is reported in the overriding plate of Sulu belt. • New data improve our understanding of tectonic evolution of Sulu orogenic belt. • Structural and AMS data are combined to understand the geometry of gneissic domain. [ABSTRACT FROM AUTHOR]

The South Dabashan Belt at the northern margin of the South China Block is a typical arcuate-shaped orogenic belt in western China. Its formation and evolution are important for understanding the collisional orogeny and intracontinental deformation in the South Qinling Orogen and its foreland basin. Anisotropy of magnetic susceptibility (AMS) can provide fabric patterns which can be used to discuss the strain of the South Dabashan Belt. Rock magnetism reveals that paramagnetic minerals dominate magnetic susceptibility and some ferromagnetic minerals also exist. Magnetic fabrics of Triassic and Jurassic strata are essentially type II fabric with well-developed magnetic lineation; further, they rarely show sedimentary fabric, indicating the early stage of the deformation processes. Magnetic fabrics show that early horizontal shortening strain is characterised by a radial pattern in the South Dabashan Belt. Our results indicate that the Chengkou Fault initially formed as a normal fault with arcuate shape during the opening of the Mianlue Ocean and has a controlling effect on the formation of the curved fold-and-thrust belt. Then, the later shortening strain overprints the previous deformation but barely changes the curvature of the Chengkou Fault. • AMS recorded early LPS orientations with a radial pattern. • Chengkou Fault initially formed as a normal fault with arcuate shape. • Chengkou Fault controls the formation of the arcuate South Dabashan Belt. [ABSTRACT FROM AUTHOR]

• A multidisciplinary investigation indicates Late Triassic tectonic setting in the northern NCC. • The Wangtufang pluton was built by an earlier diorite and a later lopolith-like syenogranite. • The NW-SE oriented syenogranite dykes in the diorite are interpreted as tension gashes. • The Wangtufang pluton emplaced during a Late Triassic NE-SW trending extensional setting. To better understand Late Triassic tectonic setting in the northern North China Craton (NCC), the emplacement mechanism of the Wangtufang pluton, which recorded the synmagmatic regional tectonic signature, has been investigated. Zircon U-Pb ages, and Hf isotopic data, and whole-rock geochemical analyses suggest that the Late Triassic Wangtufang pluton composed of syenogranite and diorite is derived from partial melting of lower crust with some depleted mantle components. Both the syenogranite and diorite appear isotropic. Anisotropy of magnetic susceptibility and gravity studies have been carried out to characterize internal fabrics and shape of the pluton. The diorite forms just thin remnants above the syenogranite. The syenogranite with a series of NW-SE trending dykes intruded into the diorite and its country rocks. In the syenogranite, the gently dipping magnetic foliations strike nearly parallel to the pluton border. The shallow plunging magnetic lineations mainly strike NE–SW. Combining NE-SW trending elongated subsurface shape with central root, unflat bottom, and moderate- to high- inward dipping sidewalls, the syenogranite could be considered as a lopolith-like intrusion. The syenogranite was likely emplaced by inflation of magma pulses from its central conduit and built up by floor depression. Emplacement of the syenogranite was in an extensional setting, considering: (1) the NE–SW striking magnetic lineation, (2) the NE–SW trending elongated subsurface pluton shape, and (3) the orthogonal NW–SE striking syenogranitic dykes considered as tension gashes during the NE–SW trending extension. The Wangtufang pluton provides reliable arguments to the Late Triassic intracontinental extensional setting already suggested in the northern NCC. [ABSTRACT FROM AUTHOR]

The Shanganning Carbonate Platform (SCP) of the North China Craton (NCC) was located in the Trade Winds belt during the Cambrian, which influenced its facies development. In recent years, numerous drillcores have been recovered from these units, but the depositional environments and facies architecture of this large (~2.0 × 105 km2) carbonate platform system have not yet been reported in detail. In this study, we integrate sedimentological and magnetic fabric data collected from outcrops and drillcores in order to document variation in microfacies and facies associations within the SCP, to infer paleowind directions and constrain the paleogeographic location of the SCP, and to evaluate eolian controls on platform development. This analysis documented numerous carbonate microfacies belonging to six fabric types (mudstone, wackestone, packstone, grainstone, framestone, and dolostone) along with rarer siliciclastic sediments. These microfacies belong to facies associations representing tidal flat, open platform, platform margin, slope, and deep basinal depositional environments. Anisotropy of magnetic susceptibility (AMS) measurements yielded mean paleocurrent directions for the Early, Middle, and Late Cambrian of 114°, 63°, and 83° (± ~30°) from paleo-north, respectively, that were relatively consistent for 12 out of 13 platform-margin sites, all vectors being corrected for a post-Cambrian ~150° clockwise rotation of the NCC. These wind orientations are consistent with the SCP shifting from south of the paleo-Equator in the Early Cambrian to north of it by the Middle Cambrian. Paleo-Trade Winds influenced facies patterns across the platform, producing a distinct windward-leeward zonation. The windward margin is characterized by well-sorted oolitic grainstone, as well as (favositids) coral and (dasycladacean) algal-sponge framestone, and the leeward margin by poorly-sorted oolitic wackestone-grainstone and fine bioclastic sediments. The present study is innovative in 1) integrating microfacies and AMS analyses in order to establish paleowind patterns and influences on an ancient carbonate platform, 2) documenting windward-leeward variation in quantifiable sediment properties across the SCP, and 3) constraining the paleo-hemispheric location of the NCC during the Cambrian. • Analysis of microfacies and depositional environments of Cambrian in Ordos Basin • Quantitative measurements of sediment properties across the platform were documented. • Paleo-hemispheric location of North China Craton was constrained during Cambrian. • Paleo-Trade Winds influenced windward versus leeward facies zonation patterns. • An integrated methodology of magnetic anisotropy and standard petrographic data [ABSTRACT FROM AUTHOR]