Orogenic Research Articles

Detrital Zircon U-Pb Geochronology of River Sands from the Yulongkash and Karakash Rivers in the Hotan River Drainage System, Southwestern Tarim Basin: Implications for Sedimentary Provenance and Tectonic Evolution

The southwestern Tarim Basin, shaped by the far-field effects of the India-Eurasia collision, serves as a critical archive for reconstructing source-to-sink dynamics and tectonic evolution in a Cenozoic intracontinental foreland setting. This study presents detrital zircon U-Pb geochronology and trace element data from sands of the Yulongkash and Karakash Rivers, major tributaries of the Hotan River draining the West Kunlun Orogenic Belt. Our results reveal distinct provenance signatures between the two tributaries: Yulongkash river sands (HT1) exhibit dominant Triassic (~208 Ma) and Early Paleozoic (~418 Ma) zircon populations, sourced primarily from the South Kunlun and Tianshuihai terranes, whereas Karakash river sands (MY1) are characterized by Early Paleozoic (~460 Ma) and Precambrian zircons, reflecting predominant contributions from the North Kunlun Terrane. Integration with published datasets highlights systematic spatial variations in detrital zircon age spectra, controlled by bedrock heterogeneity, fluvial geomorphology, and sediment mixing efficiency. Furthermore, crustal thickness reconstructions based on zircon trace elements constrain the terminal closure of the Proto-Tethys Ocean to ~420–440 Ma (peak crustal thickness: ~80 km) and the Paleo-Tethys Ocean to the Late Triassic (~210 Ma). These findings not only refine the provenance framework of the Hotan River drainage system but also provide critical insights into the timing of Tethyan ocean closures and the tectonic evolution of the West Kunlun Orogenic Belt, emphasizing the utility of detrital zircon records in deciphering orogenic histories within complex intracontinental settings.

Shear-related gold mineralization in the Egyptian Nubian Shield, East African orogenic belt

Shear-related gold mineralization in the Egyptian Nubian Shield, East African orogenic belt

Early Cretaceous–Late Miocene Basin–Mountains Pattern in the Northeastern Margin of the Tibetan Plateau, NW China: Evidence From Detrital Zircon Chronology in the Lanzhou Basin

ABSTRACTThe basin‐mountain tectonic system along the northeastern margin of the Tibetan Plateau represents a structural signature formed through Cenozoic collision between the Indian and Eurasian plates and subsequent tectonic adjustments, though the mechanisms controlling its tectonic deformation and uplift remain subjects of ongoing scientific debate. The Cenozoic sedimentary sequences preserved in the Lanzhou Basin provide critical archives documenting both provenance variations and tectonic evolution of adjacent orogenic belts. In this study, we employed detrital zircon U–Pb geochronology combined with bulk sediment geochemical analysis (major and trace elements) to reconstruct source‐to‐sink relationships. Quantitative provenance discrimination was achieved through DZmix and DZstats modelling to determine relative contributions from potential source terrains. Analysis of the modelling results showed that During the Early Cretaceous and Late Palaeocene, the Indo‐Eurasian collision affected the West Qinling (50.3% contribution) and North Qilian (34.6%) orogen belts. A significant provenance shift occurred during the Eocene when large‐scale planation surfaces developed across the northeastern Tibetan Plateau margin, resulting in complete cessation of West Qinling‐derived sediments (3% contribution) to the Lanzhou Basin. Subsequent Early Oligocene stratigraphic records indicate resurgent West Qinling input (31%), marking its secondary uplift phase. Multiphase uplift‐denudation cycles characterised both Qilian and West Qinling domains throughout the Early Cretaceous to Late Miocene. Notably, spatiotemporal disparities emerged between North and South Qilian uplift histories, with differential exhumation timing and sediment routing generating distinct provenance signatures in basin fills.

Thermal structure of a Paleoproterozoic orogen: A case study from the Wutai–Fuping crustal section

Abstract Exhumed orogenic belts contain the only physical record of the processing of Earth’s crust during tectonic cycles and are therefore the critical regions where constraints on geodynamic processes can be developed. Reconstructing metamorphic field gradients and thermal modeling are key approaches for investigating this record. This study examines the thermal structure of the Wutai–Fuping crustal section within the Paleoproterozoic Trans-North China Orogen (TNCO). The crustal section records a decrease in metamorphic grade from the Fuping area in the southeast to the Wutai area in the northwest. The metamorphic pressure–temperature (P–T) evolution of high-grade metamorphism in this crustal section are well-established. However, constraints on mid- to low-grade metamorphism recorded in the crustal section are lacking. In this study, we constrain the petrochronology of the mid- to low-grade (epidote-amphibolite facies) metamorphic rocks through the application of phase equilibrium modeling, geothermobarometry, zircon SIMS U–Pb geochronology, and in situ garnet Lu–Hf geochronology. These datasets reveal peak P–T conditions of 0.6–0.8 GPa and 500–530 °C at 1888–1863 Ma. To put this new dataset in to a broader orogenic context and to understand its relationship to the timing of peak metamorphism at other crustal levels in the Wutai–Fuping crustal section, in situ garnet Lu–Hf geochronology was also collected from the higher-grade metamorphic rocks from the crustal section. The results yielded peak ages of 1899 ± 31 Ma for lower-amphibolite facies rocks from the Wutai Shizui Subgroup, 1872 ± 31 Ma for upper-amphibolite facies rocks from the Wanzi supracrustal rocks, and 1866 ± 29 Ma for granulite facies rocks from the Fuping TTG gneiss. Our data suggest that peak P–T conditions occurred at ca. 1.90–1.86 Ga across all metamorphic grades, defining a contemporaneous metamorphic field gradient varies from 25 to 18 °C/km with increasing depth from 20 to 50 km, which reflect the peak geotherm. Combined with metamorphic zircon and monazite U–Pb ages of 1.96–1.80 Ga previously reported in the Wutai–Fuping area, our updated dataset constrains the durations of the prograde, peak, and retrograde metamorphic stages. These occurred during 1.96–1.90 Ga, 1.90–1.86 Ga, and 1.86–1.80 Ga, respectively. The thermal structure of the peak stage and the duration of the prograde stage are supported by the results of one-dimensional thermal modeling. The metamorphic field gradient and the durations of the metamorphic stages may characterize the long-lived TNCO across multiple crustal levels.

Major post-collisional shear zones in the magnetotelluric models across the Slovakian Alpides, Bohemian Hercynides and Scandinavian Caledonides

One common phenomenon appears in the magnetotelluric models across the Western Carpathian Alpine, Bohemian Hercynian and Scandinavian Caledonian orogenic zones – significant deep subvertical orogen parallel conductive zones in the crust. On the basis of knowledge from the Western Carpathians, we interpret them as shear zones that were formed after the end of oceanic subduction and the subsequent collision between the continental blocks by the transition of the collisional tectonics to transpression. The deep shear zone allowed mineralized fluids and CO 2 , which formed a significant conductivity anomaly, to escape from the mantle. The occurrence of such large-scale orogen parallel shear zones in the investigated orogens points to the similarity of the kinematic regime in the orogens from different ages, at least in the Phanerozoic.

Analysis on the seismogenic processes of East Anatolian Fault Zone and surrounding areas constrained by horizontal shifts in disturbing potential and modeling the density contrasts

Abstract The Kahramanmaraş earthquakes on February 6, 2023, with magnitudes of 7.7 and 7.6, are considered the century's worst disaster in Türkiye. It was shown by these two main shocks that the East Anatolian Fault Zone not only often causes destructive earthquakes but also has a focus depth that is only about 10 km deep in the upper crust. The strength of the upper crust plays a crucial role in influencing the structures and fault zones of the upper crustal domain during seismic activities. This research explores the crustal deformation and structures of the East Anatolian Fault Zone and surrounding regions through gravity data and earthquake analysis. We began by calculating the radially averaged logarithmic amplitude spectrum of WGM12 (World Gravity Map 2012) isostatic residual gravity anomalies to determine the average depths of the deeper interfaces and the critical cut-off wavenumbers for filtering. The average depths of the Conrad discontinuity and the basement were determined to be 18 and 6.6 km, respectively, from the linear segments of the spectrum. A linear inversion method, specifically the weighted and damped minimum norm inverse solution, was applied to estimate density contrasts down to the Conrad depth. The present study thus carries out two-dimensional density contrast models of the East Anatolian Fault Zone and surrounding area in order to elucidate the structural discontinuities of the region. Furthermore, virtual deformation of the upper crust was mapped using horizontal shifts of the disturbing potential.

Timing of retrograde metamorphism in medium-pressure pelitic granulites of the Qianlishan Complex: insights from monazite-zircon U-Pb geochronology and phase equilibria modelling

Accurately determining the retrograde metamorphic ages of pelitic granulites is crucial for reconstructing their metamorphic evolution and understanding associated post-collisional extensional and subsequent exhumation processes in orogenic belts. This study integrates zircon and monazite geochronology with thermodynamic modelling to determine the retrograde metamorphic history of medium-pressure (MP) pelitic granulites in the Qianlishan Complex of the Khondalite Belt, North China Craton. Our findings show that all MP pelitic granulites follow similar clockwise pressure-temperature (P-T) trajectories, with precisely defined post-peak P-T conditions of 775°C–825°C and 4.9–6.5 kbar. U-Pb zircon dating via LA-ICP-MS on three MP granulites produced metamorphic ages of 1943 ± 18 Ma, 1931 ± 10 Ma, and 1941 ± 10 Ma. Similarly, monazite U-Pb analyses of the same samples yielded ages of 1932 ± 3 Ma, 1935 ± 3 Ma, and 1939 ± 3 Ma. A well-matched set of dates indicates a metamorphic episode at ∼1.93 Ga, which established a metamorphic period during the granulite-facies retrograde cooling phase. The geochronological studies of pelitic granulites from the Qianlishan Complex indicate that a peak-pressure metamorphic event took place between 1.96 and 1.94 Ga, with subsequent decompression and retrograde cooling occurring around 1.93 Ga. These findings reinforce the hypothesis that a continent-continent collision occurred in the Khondalite Belt around 1.95 Ga, followed by a rapid slab-breakoff at shallow depths, which triggered the uplift of pelitic granulites in the western Khondalite Belt to mid-crustal levels and their subsequent cooling around 1.93 Ga.

Geological Characteristics and Preliminary Genesis Exploration of the Sakay Gold Deposit in Vientiane, Laos

The Sakay gold deposit in Vientiane, Laos, is located in the Indochina landmass of the southeastern segment of the Tethys orogenic belt, specifically within the Vientiane-Pakse micro-landmass and the Vientiane-Pakse metallogenic belt. This area is regionally significant for the concentration of minerals such as gold, copper, and tin. The host rocks of the deposit are intermediate volcanic lavas and volcanic tuffs, occurring in near-east-west brittle shear structural fractures through hydrothermal filling and metasomatism. The ore exhibits granular texture, subhedral texture, porphyritic texture, and oriented polycrystalline texture, with structural features such as disseminated, vein-like, and cataclastic breccia. The main ore minerals are pyrite, sphalerite, galena, and chalcopyrite, while the gangue minerals are primarily quartz, calcite, and dolomite. Gold is mainly present as included gold or fissure gold within the crystal lattices and microfractures of minerals such as pyrite and sphalerite. Based on mineral assemblages and generation timing, the mineralization can be divided into three stages: arsenopyrite-pyrite-dolomite-quartz (I), sphalerite-galena-chalcopyrite-calcite (II), and siderite (III), with the latter stages often overlaying the former, showing evident cross-cutting and metasomatic phenomena. The surrounding rocks in the mining area are altered, mainly showing silicification, carbonatization, limonitization, sericitization, and chloritization. Preliminary studies suggest that this deposit is a low-temperature hydrothermal gold deposit within a brittle shear zone.

Finding the Hidden Orogeny—The Proterozoic Polymetamorphic History of Northern New Mexico

ABSTRACTPressure–temperature–time‐deformation histories provide key constraints on orogenic processes but can be affected by later overprinting. This is exemplified in the Proterozoic orogenic belts of southwestern Laurentia where competing tectonic models involve either a single progressive Mesoproterozoic event, the Picuris orogeny, or a polyorogenic history that also includes the ~1.65 Ga Mazatzal orogeny. We address this controversy with structural analysis and petrochronology in the type locality of the Picuris orogeny. Xenotime and monazite domains associated with the greenschist‐facies axial planar fabric of early F1 folds yield 1644 ± 11 Ma (xenotime) and 1641 ± 15 Ma (monazite) ages and 450°C–482°C temperatures recording metamorphism and shortening associated with the Mazatzal orogeny. This Palaeoproterozoic greenschist‐facies assemblage was overprinted by higher grade, protracted (1470–1350 Ma) tectonism that included the Picuris orogeny. Our results document the complex polyphase crustal assembly of Laurentia and highlight how petrochronology can effectively see through higher grade overprints to identify a more complete orogenic evolution.

Мониторинг деформаций перегонных туннелей метрополитена с применением нейросетевого подхода

The article discusses application of artificial neural networks and machine learning algorithms for monitoring of deformations in subway tunnels located in complex mining and geological conditions. Particular attention is given to industrial and environmental safety, as well as modern methods for measuring crustal deformations using GPS/GLONASS technologies, geodetic, and mine surveying. The main stages of artificial neural networks operation are described, i.e. the training based on the tunnel parameters and conditions, testing, validation, and operation to predict the potential deformations. The key neural network architectures are considered such as the deep, convolutional, and recurrent networks along with their data processing capabilities. Examples are provided of artificial neural networks used for data interpolation, hazardous zone recognition, and tunnel ring monitoring. The importance of high-quality initial data, including geometric parameters, physical material properties, climatic conditions, and historical data, is emphasized. Implementation of artificial neural networks can help to promptly identify risks, predict the deformation dynamics, and classify the deformation types, enabling timely measures to prevent emergencies.

Joint gravity and magnetic modelling for concealed mafic‐ultramafic intrusions in the Kalatongke Cu–Ni ore deposit, NW China

AbstractLocated in the north margin of the Central Asian Orogenic Belt (CAOB), the early‐Permian Kalatongke Cu–Ni sulphide Orefield is the largest Cu–Ni ore deposit in Xinjiang province, NW China. After more than 30 years’ exploitation, the reserved resources of copper and nickel in the Kalatongke deposit is in serious shortage. The Cu–Ni deposits are characterized by ore‐bearing mafic rock, small‐size intrusion clusters, high copper content (Cu/Ni ratios approximately 3:2), high PGE content and a widespread massive sulphide lens. It consists of 13 small mafic intrusions, most of which are concealed underground. Although the ultramafic rock, which is the main host rock in most of the Cu–Ni deposits in the world, has not yet been found in these intrusions, it is still supposed to have a high content ultramafic rock at greater depths with a much better ore‐bearing potential. The mafic‐ultramafic intrusions have significant gravity and magnetic anomalies, which are carefully processed in this paper to present the 3D spatial distribution of concealed intrusions, indicating the magma source and upwelling direction for a better understanding of the formation of magmatic sulphide deposits in terms of magma conduit system. The residual gravity and magnetic anomalies originated by deep ultramafic intrusions are extracted by applying the matched filter, whose response functions are determined from the logarithmic power spectrum curves. Then the 2.5D joint gravity and magnetic modelling strategy was performed on five profiles to present interpretative sections for the concealed ultramafic intrusions with possible magma intrusion history. The density and magnetization model derived from the gravity and magnetic data inversion were useful constraints in constructing the initial model. The joint modelling results indicate that the concealed ultramafic intrusions are largest and deepest near profile C–C′ and become smaller and shallower towards northwest direction until vanish on profile A–A′. The intrusion centre of is likely to be located near profile CC′, north to the lower part of Y3. Magma then upwelling in two opposite directions (NW and SE) along faults F2, F3 and F6–8 to form shallower intrusions. The final 3D geological model illustrates the validity of the gravity and magnetic data in obtaining quantitative representations of the concealed ore‐bearing ultramafic intrusions and associated conduit system. Due to the full‐coverage and wide availability of gravity and magnetic data, the joint modelling results can provide useful guidance for better locating the deep ore‐bearing ultramafic intrusions in the exploitation of magmatic sulphide deposits, especially in areas with limited drilling data.

Petrogenesis and tectonic implications of the Early Jurassic syenogranite in the northern section of Zhangguangcai Range, NE China: insights from geochronology, geochemistry, and Lu-Hf isotopes

The Lesser Xing’an-Zhangguangcai Range tectonic belt in northeastern China is located along the eastern margin of the Central Asian Orogenic Belt and serves as the key to understanding the tectonic transition between the Paleo-Asian Ocean and Paleo-Pacific regimes during the Early Mesozoic. This study presented the zircon U-Pb geochronology, Hf isotope, and whole-rock geochemistry of Early Jurassic syenogranites from the northern Zhangguangcailing Range. The LA-ICP-MS zircon dating result indicates a crystallization age of 194 ± 2 Ma. Integrated with regional data, this study confirmed that the Early Mesozoic magmatism in the region was concentrated in the Early Jurassic (180–200 Ma). The granites displayed typical arc-related features, including (1) high SiO2 (70.59–76.81 wt.%), alkali enrichment (Na2O + K2O = 7.65–8.38 wt.%), low Mg and Fe contents, classifying them as the high-K calc-alkaline metaluminous to weakly peraluminous (A/CNK = 0.99–1.04); (2) strong LREE enrichment with weak Eu anomalies (δEu = 0.44–0.81) and HREE depletion ((La/Yb)N = 3.38–16.17); and (3) enrichment in LILEs (Rb, K) with the corresponding depletion in HFSEs (Nb, Ta, and Ti). Harker diagrams showed negative correlations between SiO2 and MgO, TiO2, CaO, TFeO, P2O5, and Eu, indicating fractional crystallization involving amphibole, ilmenite, apatite, and feldspar. The zircon εHf(t) values (+2.7 to +5.0) and the corresponding Meso-to Neoproterozoic crustal model ages (TDM2 = 915–1067 Ma) suggested that the magma originated from partial melting of the Meso-Neoproterozoic mafic lower crust at amphibolite facies. The geochemical and isotopic data collectively identified these rocks as I-type granite. In a regional tectonic context, their formation was interpreted to reflect an active continental margin environment driven by the westward subduction of the Paleo-Pacific Plate during the Early Jurassic, potentially influenced by the closure of the Mudanjiang Ocean, a branch of the Paleo-Pacific.

Whole rock geochemistry, zircon U-Pb dating and Sr-Nd and Hf isotopic studies of Cretaceous granitoids from Southern Pamir, Tajikistan: insights into Pamir Plateau formation

ABSTRACT The Southern Pamir region, a critical part of the Alpine-Himalayan orogenic belt, exhibits a complex tectonomagmatic history that offers insights into the geodynamic evolution of the Pamir Plateau. This study presents comprehensive data on the Cretaceous granitoids from the Kyzylrabat area, including whole-rock geochemistry, zircon U-Pb geochronology and Sr-Nd-Hf isotopic analyses. The analysed granitoids are high-K calc-alkaline to shoshonitic, exhibiting A-type geochemical signatures. Zircon U-Pb ages range from 98.5 to 111.7 Ma, correlating well with contemporaneous volcanic activities. Isotopic data indicate a mixed magmatic origin involving a mantle-derived high-K magma and a crustal-derived felsic component. Petrogenetic analyses reveal co-magmatic trends and magma mixing processes, with geochemical evidence suggesting a mantle source metasomatized by subduction-related fluids. Geodynamic interpretations propose that the granitoids formed in an extensional back-arc setting during the northward subduction of the Shyok branch of the Neotethys Ocean. These findings provide critical constraints on the mid-Cretaceous tectonic and magmatic processes in the Southern Pamir, contributing to a deeper understanding of the orogenic plateau formation and evolution.

Relict Back‐Arc Basin Crustal Structure in the Western Greater Caucasus, Georgia

AbstractBack‐arc basins frequently form within subduction zones, creating sources of lithospheric weakness that can accommodate subsequent compressional deformation. The crustal structure of these basins, including whether they contain extended preexisting crust and/or new crust formed by seafloor spreading, can thus exert a major influence on strain partitioning in orogenic belts. Here, we present field observations, petrographic analyses, and major/trace element geochemical data from the Caucasus Basin, a back‐arc basin that initiated in continental lithosphere in the Jurassic and subsequently localized deformation in the present‐day Greater Caucasus during the latter stages of Cenozoic Arabia‐Eurasia continent‐continent collision. Our results reveal distinct lithologic and geochemical domains separated by south‐vergent thrust faults within the North Georgia fault system (NGFS) in the Republic of Georgia. Along the Enguri River, shallow intrusive and volcanic rocks are thrust over dominantly volcaniclastic cover, whereas along the Tskhenistskali River, intrusions into metasedimentary rocks are juxtaposed against volcanic flows. The presence of a minor depleted mantle geochemical signature in intrusive rocks from the Tskhenistskali traverse supports an episode of Jurassic seafloor spreading in the Caucasus Basin, with the resulting lithosphere facilitating Cenozoic basin closure by north‐dipping subduction during Arabia‐Eurasia collision. The Khaishi fault along the Enguri River and the Lentekhi fault along the Tskhenistskali river mark major juxtapositions in back‐arc crustal structure and may be components of the terminal suture indicating Caucasus Basin closure. Our results highlight how magmatic rocks in relict basin rocks can yield key insights into basin structure and orogenesis, even when no ophiolite is present.

Machine Learning and Big Data Mining Reveal Earth's Deep Time Crustal Thickness and Tectonic Evolution: A New Chemical Mohometry Approach

AbstractQuantitative analysis of crustal thickness evolution across deep time poses critical insights into the planet's geological history. It may help uncover new areas with potential critical mineral deposits and reveal the impacts of crustal thickness and elevation changes on the development of the atmosphere, hydrosphere, and biosphere. However, most existing estimation methods are restricted to arc‐related magmas, limiting their broader application. By mining extensive geochemical data from present‐day subduction zones, collision orogenic belts, and non‐subduction‐related intraplate igneous rock samples worldwide, along with their corresponding Moho depths during magmatism, we have developed a machine learning‐based mohometry linking geochemical data to Moho depth, which is universally applicable in reconstructing ancient orogenic systems' paleo‐crustal evolution and tracking complex tectonic histories in both spatial and temporal dimensions. Our novel mohometry model demonstrates robust performance, achieving an R2 of 0.937 and an Root Mean Squared Error of 4.3 km. Feature importance filtering highlights key geochemical proxies, allowing for accurate paleo‐crustal thickness estimation even when many elements are missing. Model validation in southern Tibet and the South China Block, regions characterized by well‐constrained crustal histories and complex tectonic processes, demonstrates its broad applicability. Reconstructed paleo‐crustal thickness records reveal a strong correlation between crustal thickening events and the formation of porphyry ore deposits, offering new insights for mineral exploration in ancient orogens subjected to significant surface erosion. By enabling the reconstruction of crustal thickness across geological timescales, this model enhances our understanding of Earth's internal dynamics and their interactions with surface processes, thereby advancing our comprehension of Earth's geological history.

Formation of the Heishan magmatic Ni-Cu sulfide deposit in the Central Asian Orogenic Belt: Implications from magma oxygen fugacity and sulfur isotopes

Formation of the Heishan magmatic Ni-Cu sulfide deposit in the Central Asian Orogenic Belt: Implications from magma oxygen fugacity and sulfur isotopes

The Djourdé-Sinassi magmatic-migmatitic complex, Northern Cameroon: a record of constriction and vertical extrusion of the Pan-African partially molten orogenic root.

The Djourdé-Sinassi magmatic-migmatitic complex is part of the juvenile Neoproterozoic Garoua Domain located in Northern Cameroon, surrounded by the Zalbi, Poli and Rey-Bouba greenstone belts, limited to the east by the sinistral Tcholliré-Banyo Shear zone and to the south by the Poli Thrust System. In the studied area, the Djourdé-Sinassi magmatic-migmatitic complex is subdivided into a western magmatic unit made of diorite, tonalite, granodiorite, with numerous enclaves of mafic and ultramafic rocks, and an eastern part dominated by metatexite migmatites enclosing ubiquitous mafic to ultramafic rafts. The plutonic rocks of the western unit display a subvertical magmatic fabric with variable trends. Locally, trains of hornblendite enclaves with lobate boundaries and dismembered into a network of felsic veins points to injection of mafic magma that mingled with a host magmatic mush and/or partially molten rocks. The migmatites display a foliation delineated by the alternation of leucosome and mesosome layers that are mainly subvertical and striking parallel to the alignment of the metric to kilometric size rafts of mafic and ultramafic rocks. A texturally continuous network of leucosome veins concordant to discordant relative to the syn-migmatitic foliation and the mineral assemblage attests for syntectonic melt segregation under granulite facies conditions (Hbl + Pl ± Bt ± Grt±Opx±Cpx ; peak: ≥800 °C/8–10 kbar). The magmatic fabric of plutonic rocks and the syn-migmatitic foliation are locally transposed into subvertical shear zones with a steeply plunging mineral and stretching lineation. N-S to NE-SW striking shear zones display sinistral kinematic criteria whereas E-W to WNW-ESE trending ones are dextral. These shear zones first developed in the presence of melt but then in solid-state during progressive retrogression from amphibolite to greenschist facies (Ab+Qtz + Ep ± Op ± Chl+Ser+Ep). These data suggest that the Djourdé-Sinassi magmatic-migmatitic complex has recorded reworking of a juvenile mafic crust into migmatites and plutonic rocks that formed the root of the Central African Orogenic Belt. This root has then been vertically extruded under a pure-shear dominated constrictional regime with vertical stretching in the presence of melt coeval with the injection of mantle-derived mafic magmas and was then progressively exhumed towards the surface. This deformation pattern is consistent with the position of the Sinassi complex surrounded by greenstone belts and on a larger scale, confined in between the West African – Congo cratons and Saharan metacraton.

Nappe tectonics in the Matomb-Hegba area, South-Central Cameroon: Implications on the tectonic evolution of the Yaoundé Group in the Central African Orogenic Belt

Nappe tectonics in the Matomb-Hegba area, South-Central Cameroon: Implications on the tectonic evolution of the Yaoundé Group in the Central African Orogenic Belt

The petrogenesis of plagiogranite of the Erenhot Ophiolite in the eastern Central Asian Orogenic Belt: A zircon Hf-O isotopic and whole-rock geochemical perspective

The petrogenesis of plagiogranite of the Erenhot Ophiolite in the eastern Central Asian Orogenic Belt: A zircon Hf-O isotopic and whole-rock geochemical perspective

Tectonic evolution of the Proto-Paleo-Tethys in the West Kunlun orogenic belt: Constraints from U-Pb geochronology of detrital zircons

Tectonic evolution of the Proto-Paleo-Tethys in the West Kunlun orogenic belt: Constraints from U-Pb geochronology of detrital zircons