The end-Triassic mass extinction (ETME) was one of the most severe biotic crises of the Phanerozoic, driven by environmental changes linked to Central Atlantic Magmatic Province volcanism. While the ETME is a well-studied event, its expression in organic-walled phytoplankton, particularly acritarchs, remains relatively unexplored. Palynological analysis of the Prees 2 borehole, NW England (West Midlands), spanning from the upper Rhaetian to the lower Sinemurian, reveals exceptionally diverse aquatic palynomorph assemblages. The aquatic palynological assemblages, in the context of ammonite, miospore and lithostratigraphic data, show how phytoplankton communities responded to stress and subsequent stabilization. In the upper Rhaetian, the dominance of xerophytic coniferous pollen reflects warm, semi-arid palaeoenvironmental conditions, while euryhaline palynomorphs are in a nearshore environment. Subsequent phases show increased terrestrial humidity as evidenced by the palynoflora, coinciding with reduced aquatic diversity in an assemblage adapted to low-oxygen conditions. The base of the Hettangian is marked by sustained Cheirolepidiaceae dominance and a transition from short-spined Micrhystridid occurrences (reflecting low-oxygen conditions) progressing to an increased aquatic morphological diversity phase. This latter phase includes alterations in acritarch assemblages and the proliferation of dinoflagellate cysts, indicating a shift from a proximal shallow-water to a shelf palaeoenvironmental setting. Our findings demonstrate that acritarchs are valuable indicators of palaeoenvironmental change, capturing transient ‘bloom’ phases linked to post-extinction instability and offering new insights into Early Jurassic palaeoecology and recovery following the ETME.

The extent to which continental acidity during the Early Triassic varied with latitude remains insufficiently constrained, despite its relevance for understanding environmental stress and biotic recovery patterns across the Smithian–Spathian boundary (SSB). We examined the abundance, textures and compositions of strontium-rich hydrated aluminium phosphate–sulphate (APS) minerals in 179 continental samples spanning tropical to high paleolatitudes in both hemispheres. APS minerals display broadly comparable early-diagenetic features across sections, indicating formation shortly after deposition under acidic meteoric conditions. Their distribution suggests a latitudinal trend: APS contents commonly exceed 0.1 vol.% in equatorial western peri-Tethyan basins, where faunal and floral records are sparse during the SSB, whereas concentrations decrease towards higher latitudes and are rare beyond ∼40° in both hemispheres. This pattern does not appear to correlate with lithological or textural variability and may reflect spatial differences in the intensity or duration of acidification linked to Siberian Traps volcanism. Equatorial basins thus likely experienced more prolonged or recurrent acidic episodes, whereas higher-latitude areas may have been subject to comparatively attenuated effects, potentially contributing to earlier ecological recovery. These results provide a useful framework for evaluating continental acidification and its environmental implications during the interval following the end-Permian mass extinction (EPME).

The present study investigates the novel occurrence of rare garnet-aluminosilicate-bearing metapelitic enclaves from the Western Lohit Plutonic Complex in the Dibang Valley, Arunachal Pradesh, Northeastern India. Textural, mineralogical, thermobarometric and phase equilibrium modelling analyses reveal a complex polymetamorphic evolution characterized by two distinct stages. The first stage corresponds to a pre-Himalayan low-pressure, high-temperature event likely linked to Cretaceous magmatism, evidenced by relict andalusite porphyroblasts. The second stage reflects Barrovian-type Himalayan metamorphism associated with India-Asia collision, marked by peak assemblages of garnet, kyanite and melt formed near the solidus. Thermobarometric studies estimate near-peak metamorphic conditions at approximately 650 ± 25 °C and 7–9 kbar. Consistently, Pressure-temperature phase equilibrium modelling indicates that garnet core compositions record an initial metamorphic event at lower pressure (∼5.5 kbar) and temperature (∼550 °C), reflecting prograde burial prior to peak conditions. Peak metamorphic conditions, constrained by pressure-temperature phase equilibrium modelling, are estimated at approximately 670 °C and 8.5 kbar. Microstructural observations indicate muscovite-dehydration melting is the primary mechanism for incipient melt generation in the studied metapelite, with the melt largely retained within the rock. Ti-in-biotite thermometry reveals cooling temperatures of 560–590 °C during final exhumation. The rocks experienced a clockwise P–T path involving prograde burial, near-isothermal decompression and retrograde cooling, consistent with thrust duplexing and exhumation along the Lohit thrust shear zone. These findings provide new constraints on the metamorphic evolution and partial melting processes during Himalayan orogenesis in the northern Indo-Burma region.

A 10 m-thick and laterally extensive, mixed siliciclastic–carbonate heterolithic unit occurs between coastal quartz arenites (Banaganapalle Formation) and open marine outer-shelf carbonate platform (Narji Limestone) in the Mesoproterozoic Kurnool sea, India. While the dynamics of mixed siliciclastic–carbonate systems are well studied in the Phanerozoic, comparable Proterozoic examples remain poorly documented and are notably absent from the Indian subcontinent. High-resolution stratigraphic, facies, and petrographic analyses of this heterolithic unit reveal a progressive transition from outer-shelf to storm-dominated middle-to inner-shelf settings, periodically disrupted by episodic high-energy depositional events. Two distinct mixing modes are identified: (i) lithofacies to microscopic-scale strata mixing (Punctuated Mixing), linked to high-frequency sea-level oscillations, and (ii) bed-scale compositional mixing (In-Situ Mixing) of nearshore siliciclastics and subtidal carbonate mud. These findings demonstrate that repeated siliciclastic influx did not inhibit contemporaneous carbonate precipitation, documenting previously unrecognized mixed sedimentation between the Banaganapalle siliciclastics and the Narji carbonates, and advancing understanding of mixed-system dynamics in Proterozoic sedimentary rocks. The widespread occurrence of mixed heteroliths in the Kurnool sub-basin is interpreted to have formed during a phase of rapid subsidence that drove marine transgression, plausibly associated with a rise in sea-level, linked to post-Columbia breakup. Lithostratigraphically correlative heterolithic intervals in the intracratonic Bhima, Pranhita–Godavari and Kurnool basins suggest a regionally extensive, basin-wide Mesoproterozoic transgressive event across the Southern Indian Block. This heterolithic deposit may provide a key stratigraphic marker for regional correlation and yield new insights about the resilience of a Proterozoic non-skeletal carbonate factory and its interaction with episodic siliciclastic input.

The Álamo Complex, part of the Galician–Castilian Lineament within the Central Iberian Zone, lies between the Ollo de Sapo Domain and the Schist–Greywacke Complex. It comprises six tectonometamorphic sectors dominated by psammitic–pelitic metasediments (MTS), gneisses, migmatites, leucogranites and tourmaline-rich rocks. Zircon U–Pb dating identifies three Ediacaran partial melting events (∼628, 584 and 549 Ma) that occurred under high-pressure conditions within the kyanite stability field. These contrast with a low-pressure Variscan partial melting episode (∼310–315 Ma). Orthogneisses and leucogranites dated at ∼482–465 Ma record Cambro–Ordovician magmatism, characterized by abundant inherited Ediacaran zircon cores, indicating significant crustal recycling. Petrographic and geochemical similarities, together with shared zircon inheritance patterns, link the Álamo Complex with the Ollo de Sapo Domain and other segments of the Galician–Castilian Lineament, suggesting a common magmatic evolution. Tourmaline-rich rocks likely formed by boron metasomatism initiated during the Ediacaran and enhanced by recurrent partial melting. Variscan magmatism is represented by intrusive mafic and granitic bodies (∼307–311 Ma) and tourmaline-bearing leucogranites, reflecting continued reworking of Ediacaran crust into the Late Palaeozoic. These results shed light on the crustal evolution of Central Iberia.

Minute hybodont shark teeth from uppermost Albian–lower Cenomanian (mid-Cretaceous) continental deposits of Djebel Amour (Saharan Atlas, Algeria) are described. They are assigned to a new genus and species of Lonchidiidae, Lonchidionoides trifurcatum. Similar teeth recently reported from the Early Cretaceous of Brazil are here referred to as Lonchidionoides sp. The heterodont dentition of Lonchidionoides is characterized by clutching anterior teeth with a tricuspid crown and larger crushing posterior teeth with less individualized cusps. Lateral teeth show an intermediate morphology. The two occurrences of this non-marine hybodontiform genus may reflect the existence of a large ancestral distribution area that was divided during the opening of the South Atlantic, as previously suggested for several groups of cartilaginous and bony fishes.

Recent palaeobiological studies have emphasized the need for interpretations of the fossil record to consider spatial changes in environmental conditions (e.g. topography, climate). Establishing the role the environment plays in determining the distributions of extinct and existing organisms is complicated by biological evolution. Using available observations to ‘see through’ the randomness of biological evolution to determine contributions from environmental change is not trivial because of the sparsity of the fossil record, lack of precise information about rates of evolution, and because we obviously cannot physically re-run the evolutionary history that resulted in modern biodiversity or the fossil record. To address these issues, we establish scales and scenarios in which spatial environmental change is manifested in records of the number of species in a given area (richness) generated by eco-evolutionary simulation. Evolutionary processes that are likely to be random on the timescales of environmental change are included. Signals of environmental change that are likely to be hidden by the effects of ‘noisy’ evolutionary processes and those likely to emerge are identified. The ‘experiment of life’ is simulated many times, producing statistical insights. Results show that the spatial rate of environmental change is strongly correlated with species richness when the ability of organisms to disperse is high. Interaction between scale, dispersal and environmental structure is shown to determine both statistical and spatial distributions of richness. As a proof-of-concept, we compare predictions to bird species richness. The results emphasize the need to consider the randomness of evolution when interpreting the observations of extinct or present life on Earth.

Deposits of thick volcanic and volcaniclastic series can be interpreted as either related to regional tectonics (commonly extensional or transtensional tectonics) or local volcanic mechanisms (caldera collapse). In order to distinguish between these two end-member mechanisms, we propose the use of magnetic techniques, namely analysis of Anisotropy of Magnetic Susceptibility (AMS) and paleomagnetism, and analysis of geological structures. These techniques have been applied to the Estac Basin (Central Pyrenees), an inverted Late Carboniferous–Permian basin now involved in the antiformal stack of the Pyrenean belt. AMS data provide directions of flow of volcanic rocks that can be interpreted in terms of palaeo-slopes and therefore can be related to structures contemporary with deposition and Late Carboniferous–Permian volcanic activity. The maximum of the magnetic lineation (i.e. volcanic paleoflow) direction is bimodal, with (i) an absolute maximum (as occurring in most South-Pyrenean Late Carboniferous–Permian basins) along a WNW–ESE direction and (ii) a secondary magnetic lineation along an N–S direction. Paleomagnetic data obtained from the volcanic products show a primary magnetization or early remagnetization compatible with the Late Carboniferous–Permian paleomagnetic reference direction and allow us to reconstruct an early folding probably related to the warping of the basin. The magnetic and structural data can be interpreted according to a volcano-tectonic subsidence model in which E–W faults played a major role and caldera collapse contributed to the important thickness of the volcaniclastic deposits.

Garnet-bearing silicic volcanic rocks are rare in fossil orogens and usually record a transient stage from regional compression to extension. This study reports newly identified 839 ± 3 Ma garnet-bearing dacitic volcanic rocks associated with the Fuchuan ophiolite complex (FOC) in the eastern Jiangnan Orogen (JO), Southeast China. The presence of these unusual rocks provides new constraints on the late Neoproterozoic tectonic evolution of the orogen.

The garnet-bearing dacitic volcanic rocks of the garnets are weakly peraluminous and exhibit trace element and Nd isotopic signatures similar to those of post-orogenic, strongly peraluminous granites in the eastern JO, indicating a similar crustal source. The garnets are almandine-rich (76–79 wt%) and characterized by low CaO (<2.5 wt%), MnO (<2.6 wt%) and TiO2 (<0.1 wt%), consistent with garnets in peraluminous S-type volcanic rocks globally. Integrated petrological, geochemical and zircon Hf isotopic evidence indicates that the primary magma originated from partial melting of a heterogeneous lower-crustal source, comprising both juvenile basaltic and ancient pelitic components. High zircon saturation temperatures (>900°C) further imply the heating of coeval underplating mantle-derived mafic magma, analogous to the mechanism forming ‘hot granites’.

Integrating our findings with regional geology, we propose that the garnet-bearing dacitic volcanic rocks associated with the FOC formed in an ensialic back-arc basin along the southeastern margin of the Yangtze Craton. The occurrence of the garnet-bearing magmatism records the onset of back-arc extension, likely following the ∼880–860 Ma arc–continent collision and subsequent subduction polarity reversal.

The Curaco Batholith, located in Northern Patagonia (Argentina), is a Late Triassic-Early Jurassic composite intrusive body comprising monzogranites, granodiorites, diorites, granite porphyry, muscovite-bearing leucogranites, mylonites, and andesitic-rhyolitic dikes. This study integrates field mapping, petrographic-microstructural observations, rock magnetic data, and anisotropy of magnetic susceptibility (AMS) analyses across these different facies to investigate the emplacement history of the Curaco batholith within an E-W-trending deformation area. Microstructural analysis allowed classification into three categories: (1) magmatic, encompassing sub-magmatic to high-temperature solid-state, (2) medium-temperature solid-state, and (3) low-temperature solid-state. These were systematically correlated with AMS data. The magnetic fabrics in most lithologies exhibit general NW-SE-trending foliations with subhorizontal to moderately plunging lineations, consistent across the batholith. AMS fabrics within and around the La Seña and Pangaré shear zones share this orientation but display variable dips and lineation plunges. The observed parallelism between magnetic and mesoscopic fabrics, including microgranular enclaves, syn-plutonic dikes, and magmatic foliations in granitic rocks, suggests that strain was recorded progressively during crystallization. The coherent alignment of magmatic, solid-state, and AMS fabrics supports a syn-tectonic emplacement model. At the regional scale, the batholith developed under E-W dextral strike-slip tectonics, whereas at the local scale, emplacement occurred within a right-stepping releasing stepover, producing transtensional conditions. This deformation pattern reflects continuous strain during magma cooling, from magmatic flow to solid-state deformation at progressively lower temperatures, ultimately approaching the brittle-ductile transition. The Curaco Batholith thus records the emplacement of a syn-extensional magma body during the early stages of Gondwana break-up, providing insights into magmatism-transtension interactions in continental settings.