Palaeopolyploidy promoted ancient adaptation of Tibetan sclerophyllous oaks to aridity and cold triggered by mountain uplift

Spatiotemporal evolution of the quartzofeldspathic gneisses of the Vinjamuru domain, Eastern Ghats Belt, India: Implications for the late Paleoproterozoic crustal growth in a craton-margin orogenic belt

Recognition of two significant gold mineralization events in the Jinshan mineral field of the Jiangnan orogenic belt, South China

Seismic constraints on the nature of the basement of the Junggar Basin, the southwestern Central Asian Orogenic Belt

Crustal thickening and delamination as drivers of adakite magmatism in the Adamawa–Yadé domain, Central African Orogenic Belt

Geodynamics of the Southern Central Asian orogenic belt: Insights from the mineral chemistry of pyroxenites in the Liuyuan ophiolite

Post-Collisional Ni Cu Mineralization in the late Devonian Binggounan Intrusion, North Qimantage (East Kunlun Orogenic Belt): Geochronological, Geochemical, and Petrogenetic Constraints

ABSTRACT Investigating the syn-exhumation magmatism can offer key clues to reveal the recycling of the continental crust and the relevant crust-mantle interactions in collisional orogens. This study focuses on a series of typical Silurian to Devonian A-type granitic intrusions in the East Kunlun Orogenic Belt (EKOB), which yield ages overlapping with the exhumation timing of eclogites. Those A-type granitic intrusions are represented by the Balong (~423 Ma) and Binggou (~391 Ma) syenogranites, and Yuejinshan (~391 Ma) granodiorites. All the granites have geochemical affinities to typical A-type granite, such as high ratios of Ga/Al and FeOt/(FeOt+MgO), and exhibit strong depletion of Ba, Sr, P, and Ti, relative to the N-MORB. The Balong and Binggou syenogranites have relatively high Y/Nb ratios and strong depletion of Nb, Ta, and Ti, belong to A2-type granites, while the Yuejinshan granodiorites have relatively low Y/Nb ratios and weak depletion of Nb, Ta, and Ti, belong to A1-type granites. Variations of geochemical and isotopic compositions indicate that the Balong and Binggou A2-type syenogranites were sourced from an ancient metasedimentary source dominated by the metamorphic greywackes, while the Yuejinshan A1-type granodiorites were derived from a mafic lower crust previously derived from an enriched lithosphere mantle. Incorporating our new results with a comprehensive dataset of Silurian to Devonian A-type granites identified in the EKOB, it can be concluded that slab break-off induced the upwelling of the asthenosphere mantle and the exhumation of the subducted continental crust, and then triggered extensive crustal melting during the Silurian to Devonian period. Melting of the returned continental crust under varying conditions of H2O content and pressure produced the Banglong and Binggou A2-type syenogranites, while the high-temperature melting of the mafic lower crust generated the Yuejinshan A1-type granodiorites.

Rock bursts are devastating hazards induced by the coupling of geological dynamic environments and mining-induced disturbances, which trigger a sudden release of energy when accumulated elastic strain exceeds the strength threshold of rock masses.As one of the key characterization parameters of the geological dynamic environment, the crustal deformation characteristics of the mining area can effectively reveal the dynamic evolution law of the overlying coal and rock mass structure from stress deformation to instability failure during the mining process of the underground working face.Based on the GNSS monitoring data of Junde mining area, through the analysis of the crustal deformation characteristics of Junde coal mine, it is determined that the crustal deformation of Junde coal mine area shows a trend of extrusion to the southeast as a whole, and its horizontal movement direction is consistent with the overall movement direction of the region as a whole, showing SEE direction, with an average movement rate of about 30mm / a ; By comparing the vertical time series of 3 # station with the time series of energy events, most of the time periods show the phenomenon of rising and falling at the same time. It is determined that when the energy background value is high (exceeding 100 events/day), if the GNSS station exhibits a rapid vertical subsidence reaching 30mm, the Junde Coal Mine faces a significantly increased probability of large-energy events. Through the analysis of the influence of the epicentral distance of the earthquake on the vertical movement of the crust and the characteristics of energy events, it is determined that the vertical rapid decline of GNSS stations is related to the epicentral distance. The farther the epicentral distance, the greater the rapid decline of GNSS stations before the occurrence of large energy events of the same magnitude.

Crustal deformation in central Japan occurs in a highly complex manner characterized by the Itoigawa-Shizuoka Tectonic Line (ISTL), the geologic boundary between the North American and the Eurasian plates. In addition, a prominent strain concentration zone, known as the Niigata-Kobe tectonic zone (NKTZ), has been identified by GNSS surveys. The existence of a volcanic chain introduces another complexity through its rheological heterogeneity. In this region, the spatial resolution and accuracy of strain rate mapping by conventional ground-based geodetic surveys have been limited by dense vegetation and rugged topography. Here, we integrate L-band InSAR data (2014-2023), which can resolve deformation in densely vegetated mountainous areas where ground-based measurements alone are spatially sparse, with GNSS data from a dense network (average spacing of [Formula: see text]) including private-sector stations, to generate a high-resolution interseismic strain rate map. We identify sharply localized strain rates along the northern ISTL ([Formula: see text]) and parts of the NKTZ ([Formula: see text]), which are of larger magnitude and more spatially confined than GNSS-only estimates. We also find a distinct strain rate concentration ([Formula: see text]) along the southern extension of the Hida Mountains volcanic zone. Some of these concentrated strain rate zones align with known active faults, while others do not (e.g., the southern extension of the Hida range). This study presents the first L-band InSAR-based strain rate map in a densely vegetated mountainous region, revealing the complex deformation style in volcanic arcs and providing new insights into strain accumulation processes.

Since the Cenozoic, the peripheral orogenic belts around the Junggar Basin have undergone substantia uplift in response to far-field deformation associated with the India-Asia collision. However, conventional geochronological methods commonly provide only indirect or insufficiently resolved constraints on the timing and geomorphic expression of late Cenozoic uplift and exhumation. Combustion metamorphic (CM) rocks, generated when coal seams are brought into shallow, oxygen-rich conditions during tectonic uplift and denudation and subsequently ignite spontaneously, offer a potential near-surface chronometer for these processes. In this study, we characterized coal maceral composition, rank, and spontaneous combustion tendency; documented the distribution, petrography, and mineral assemblages of CM rocks through field investigations, thin-section observation, and X-ray diffraction; and applied zircon (U-Th)/He dating to constrain the timing of CM rock formation. Three zircon grains define a tightly clustered Middle Pleistocene population with a weighted mean age of 0.63 ± 0.19 Ma, which we interpret as the principal timing of coal seam combustion and CM rock formation. Two older single-grain ages (8.7 ± 0.5 Ma and 87.7 ± 5.4 Ma) are treated cautiously as incompletely reset or inherited pre-combustion thermochronologic components rather than as independent combustion events. The spatial distribution and ages of CM rocks show a clear correspondence with late Cenozoic uplift and exhumation of the orogenic belt. These results demonstrate that zircon (U-Th)/He thermochronology of CM rocks can provide a useful chronological marker for near-surface tectonic processes and offers an additional approach for reconstructing late Cenozoic tectonic evolution in intracontinental orogenic settings.

The Zavkhan terrane (western Mongolia) sits in the core of the Central Asian Orogenic Belt and holds the key to understanding the evolution of the belt. However, the Neoproterozoic position of the Zavkhan terrane has remained contentious for a long time. Current models propose either a Siberian affinity, a peri-Siberian location, or an isolated paleogeographic position in the Paleo-Asian Ocean. These competing interpretations rely predominantly on tectonic and sedimentary evidence, with a notable lack of paleontological constraints. Here, we report Ediacaran large acanthomorphic acritarchs (LAAs) from the Shuurgat Formation at three sections in the Duruvlgin and Aldarkhaan areas of the northern Zavkhan terrane. Integrated with carbon isotope data from the same formation, these acritarchs support a stratigraphic correlation with the lower Doushantuo (Yangtze block) and Krol A (Lesser Himalaya) formations, indicating an early Ediacaran age. The Shuurgat LAA assemblage, comprising 24 species, shows high similarity to those of Yangtze block (South China) and Lesser Himalaya (northern India), and it shares a number of taxa that are common to, or even restricted to, these two blocks. Quantitative bioprovincial analysis of a global Ediacaran LAA database further confirms their inclusion within a single bioprovince. Together with comparable detrital zircon age spectra and stratigraphic sequences, these results support a close paleogeographic affinity of the Zavkhan terrane with the Yangtze block and Lesser Himalaya in the Ediacaran, challenging models invoking a Siberian connection.

Abstract The Precambrian basement of Madagascar hosts numerous yet poorly studied chromitite occurrences. The Ranomena deposit, a representative example in the North Toamasina chromite district, is hosted within lenticular mafic-ultramafic bodies of the Betsimisaraka/Anaboriana-Manampotsy domain. The chromitites exhibit disseminated to massive textures with cumulus chromite and orthopyroxene as the primary intercumulus silicate. Chromite compositions are high-Cr (Cr# mostly > 60) with elevated TiO2 (0.18–0.78 wt.%) and trace-element signatures (enrichments in Ti, Zn, Co, Mn, V, Sc; depletions in Ga, Ni) resembling those of stratiform chromitites. Whole-rock PGE patterns show relative enrichment in Os, Ir, Ru, and Rh over Pt and Pd, akin to the Lower Group chromitites of the Bushveld Complex. Zircons have been both identified in situ in thin sections and separated from mineral concentrates. Zircons from chromitite samples yield concordia U–Pb ages of 530.4 ± 2.2 Ma and 525.3 ± 2.3 Ma, respectively. Their δ18O values (4.7–6.1‰) and εHf(t) values (−5.4 to + 6.8) indicate variable degrees of crustal contamination. A binary mixing model suggests that the parental magmas formed from mantle-derived melts variably hybridized with crustal material (∼15–20% in the slightly earlier pulse). The Ranomena chromitites are coeval with post-collisional granitic magmatism in the central East African Orogen. We propose that they crystallized from mafic magmas generated during lithospheric delamination and asthenospheric upwelling in a post-collisional extensional setting, which may represent a previously unrecognized type of chromitite formation setting in orogenic belts.

Research subject. The Alambay ophiolite zone of the Salair Ridge (northwestern Altai–Sayan folded area, Central Asian Orogenic Belt), belonging to SSZ-type ophiolites. Aim . Determination of the formation age of magmatic rocks in the ophiolite zone. Establishing the age of the paleo-subduction zone initiation and the associated paleo-island arc system. Materials and methods . Zircons from plagiogranite (54°3’50.44” N, 85°45’0.22” E) and gabbro (54°0’46.67” N, 85°47’3.11” E) samples of the Upper Alambay gabbro-hyperbasite massif were dated using LA-ICP-MS on an Agilent 7900 quadrupole mass spectrometer at the Joint Innovation Center for Strategic Mineral Resources Exploration, School of Earth Resources, China University of Geosciences (Wuhan). Results . The weighted mean ²⁰⁷Pb/²⁰⁶Pb age of zircons from the plagiogranite sample (based on 18 analyses with common Pb correction) was 532.2 ± 3.9 Ma (MSWD = 0.84). The corresponding age for the gabbro sample was 530.6 ± 2.7 Ma (MSWD = 0.91). Conclusion . The suprasubduction ophiolites of the Alambay zone (Salair Ridge) formed in the Early Cambrian (≈530 ± 3 Ma). The subduction initiation in this sector of the Paleo-Asian Ocean can be estimated at ≈535–540 Ma. This age serves as a lower constraint for the formation of island-arc volcanic complexes in the Salair sector. Older rock assemblages in the region may represent accreted blocks to the Cambrian arc, likely located southwest of the Alambay zone. Volcanic arc complexes to the east should be younger, consistent with available data.

Tectonic–sedimentary responses during the Carboniferous–Permian transition in the western Ordos Basin: An integrated study from sedimentology, heavy mineral and detrital zircon geochronology

The Chiribiquete Mountains (Colombian Amazon) are a tepui-like (tabletop) mountain range. Here, we investigate the timing of surface uplift using regional geological data, analysis of sedimentary deposits within and near the mountains, and topographic analysis. We find that Early Miocene fluvio-lacustrine deposits of Andean provenance occur westwards of the Chiribiquete Mountains, whereas eastwards, fluvial deposits of Amazon Craton provenance occur. Onlap of Early Miocene deposits against the Ordovician basement rocks of the Chiribiquete Mountains, in combination with our provenance data, suggests that a proto-Chiribiquete Mountain chain existed by the Early Miocene. Reactivation of inherited basement faults since the Late Miocene likely led to increased surface uplift. Topographic analysis indicates the Chiribiquete Mountains tilt southwards, similar to, but with a higher tilt angle than neighbouring Early Miocene deposits. Based on the assumption that ~100 m of regional uplift of the Vaupés Arch, the tilting of the foreland deposits, and the local tilting of the Chiribiquete Mountains are coeval, we infer that the majority of surface uplift was achieved since the Late Miocene due to compression associated with Andean Mountain building. Regional uplift and/or Amazon drainage integration have since incised Early Miocene sediments by ~50 m, carving the characteristic terra firme plateaus between rivers. Thus, a low topographic barrier existed during the Early Miocene, which was significantly amplified since the Late Miocene. This implies that the origins of the modern tepui-like biome of the Chiribiquete Mountains date back to the earliest Neogene (or older), forming an exciting basis for further paleobiogeographic studies. • Sites E and W of the Chiribiquete Mountains were dated as Early Miocene. • Chiribiquete's E and W paleodrainages were disconnected in the Early Miocene. • A proto-Chiribiquete mountain range existed in the Early Miocene • Most surface uplift of the Chiribiquete Mountains occurred since the Late Miocene. • The origins of the Chiribiquete biome date back to the earliest Neogene (or older).

Three-dimensional crustal velocity and density structures around the eastern Central Asian orogenic belt and implications for the Solonker suture and metallogenic background

• Compiled data reveals lithium mineralization peak ages of 153–138 Ma in south China. • Granite generated from Mesoproterozoic continental crust with mantle-derived source. • Granites have large δ 7 Li values with negative correlation with Nb/Ta and Zr/Hf ratios. Eastern segment of Jiangnan orogenic belt in South China outcrops Mesozoic super-large and large granite type lithium (Li) deposits that are essential for comprehensive investigation of mechanism and peak ages of lithium mineralization. This study presents combined research results from geochronology, whole-rock geochemistry, Lu-Hf and Li isotopic compositions of the Dagang muscovite granite Li deposit. Zircon analyses from two muscovite granite samples yielded interpreted crystallization ages of 147 ± 0.9 Ma and 145 ± 1.4 Ma, respectively. By integrating previously reported data, three mineralization stages (153–138 Ma, 132–125 Ma and 108–100 Ma) are proposed in the eastern segment of Jiangnan orogenic belt, among which the 153–138 Ma and 132–125 Ma stages are indicative of the peak ages of Li mineralization and polymetallic mineralization, respectively. The Dagang muscovite granite sample show that SiO 2 exhibits good linear relationships with Na 2 O, K 2 O, Al 2 O 3 , Fe 2 O 3 T, MgO and Mg#, with exception of Li. The Lu-Hf isotopic compositions have large negative ɛ Hf (t) values ranging from −3.05 to −9.41, suggesting that the Dagang muscovite granite was generated from Mesoproterozoic continental crust with minor contributions of mantle-derived sources. Additionally, the granite samples show positive δ 7 Li values ranging from +2.54‰ ± 0.17‰ to +5.68‰ ± 0.13‰, which are not only negatively correlated with Zr/Hf and Nb/Ta ratios, but also consistent with that of the upper mantle (+4 ± 2‰). It is thus interpreted that the Li concentration of the Dagang muscovite granite type Li deposit was controlled by hydrothermal alteration and mantle-derived materials.

The tectonic affinity of the Shalazhashan Tectonic Zone in northern Alxa, NW China: Implication for the boundary of the southern Central Asian Orogenic Belt

Rapid crustal uplift during the Late Triassic in the Sulu orogenic belt, eastern China: Single-grain biotite Rb Sr isochron dating the Jiazishan syenite pluton