Exhumation-induced stress triggers natural hydraulic fracturing, governing fluid overpressure limits in deeply buried strata. In the Sichuan Basin (South China), the geomechanical response of Lower Cambrian shale to multi-phase differential exhumation remains poorly quantified. We integrated apatite and zircon thermochronology, vitrinite reflectance, residual stratal thickness, and Skempton’s poroelastic model to reconstruct the exhumation and pore pressure history of the Qiongzhusi Formation. Results reveal a four-stage, northwestward-migrating exhumation since the Cretaceous, featuring severe uplift (3000–4000 m) along basin margins and the Weiyuan anticline, versus moderate uplift (2000–2500 m) in the Ziyang intra-basin area. This differential exhumation halted thermal evolution, establishing a spatial thermal maturity distribution (VR = 3.2%–4.0%) and a lower boundary at ∼5500 m, below which graphitization degrades rock properties. Crucially, differential exhumation magnitude and varying initial pore pressures at maximum burial (∼7000 m) governed stress trajectories during uplift. Driven by higher initial pressure, the moderately exhumed Ziyang area reached the natural fracturing threshold at 4100 m, significantly deeper than the heavily exhumed Weiyuan area (3250 m). These critical failure depths mechanistically define the upper limits for overpressure preservation, demonstrating that differential exhumation and poroelastic relaxation fundamentally control the vertical boundaries of overpressured shale compartments.

The relative tectonic activity of the Bafoussam–Mamfe Region (BMR) was assessed using morphometric and geomorphic approaches. Our investigations focused on 117 drainage sub-basins delineated from a 30 m resolution Digital Elevation Model (DEM) through Geographic Information System (GIS)-based techniques. Seven geomorphic indices (Re, Rr, Bs, AF, TTSF, Vf and HI) were computed to evaluate the influence of tectonic processes on basin morphology. In order to obtain a reliable assessment of relative tectonic activity, two complementary methods, the Index of Relative Active Tectonics (IAT) and the Analytical Hierarchy Process (AHP), were applied. The IAT results indicate four classes of relative tectonic activity (very high: ∼2.56%; high: ∼25.64%; moderate: ∼52.99% and low: ∼18.81%), whereas the AHP approach yields comparable distribution (very high: ∼9.40%; high: ∼38.90%; moderate: ∼35.04% and low: ∼16.66%). Both methods consistently reveal a predominance of moderate-to-high tectonic activity (approximately 81.19% and 83.34% for IAT and AHP, respectively). These results suggest that the morphology of the BMR is strongly controlled by active tectonics, likely driven by lithospheric mantle dynamics and upper crustal deformation associated with the Cameroon Volcanic Line (CVL), as well as the reactivation of inherited Pan-African structures. These processes collectively control the present-day landscape evolution of the region.

Regurgitalites (fossilized vomit) have been recognized as such for a century, but only recently they became better understood and systematically described. Centimetre-sized clumps containing tightly packed skeletal material of invertebrates (e.g. bivalves, serpulids and crinoids) and plant fragments are reported from well-core material offshore Norway for the first time. They occur in numerous wells with continuous cores through Middle to Upper Jurassic (Bathonian to Oxfordian) siliciclastic successions. The clumps mainly occur in delta-front deposits with records of salinity fluctuation due to incoming freshwater. This contrasts with their composition, consisting of stenohaline forms. The tight fabric, diverse composition, co-occurrence of fractured and complete organisms, and etched margins are consistent with an interpretation as regurgitalites. This biologically introduced allochthonous material differs from physically deposited skeletal concentrations (e.g. in storm layers) by their localized distribution (few centimetres). Delta-front environments are dynamic systems with a high sedimentation rate and frequent bioturbation. Consequently, the gastric pellets are subject of reworking and alteration, resulting in their disintegration or incorporation into burrows. An evaluation of potential producers of the regurgitalites – based on functional morphology and stomach content – infers that Cryptoclididae are most likely (although Hybodontiformes cannot be ruled out), which agrees with their abundance and stratigraphic distribution in the basin. Accordingly, these long-necked plesiosaurs were bottom-feeding on offshore epi-and infauna and regularly egested undigestible food remains nearshore, where it became preserved. The regurgitalites are ichnotaxonomically described as Vomitus igen. nov., including V. concha isp. nov., V. serpula isp. nov. and V. echinoderma isp. nov.

This study provides the first direct in situ U-Pb age for the Quilon Limestone in the Kerala Basin, integrating carbonate-cement geochronology with in situ 87Sr/86Sr isotope data. Laser ablation inductively coupled plasma mass spectrometry analyses yield a consistent lower-intercept age of 17.6 ± 1.3 Ma, placing deposition within the Early Miocene (Burdigalian). Slightly radiogenic Sr signatures indicate minor siliciclastic input during carbonate precipitation. The combined isotopic framework suggests short-lived carbonate deposition under reduced terrigenous influx and supports correlation with contemporaneous Sri Lankan carbonate platforms, reflecting Early Miocene sea-level fluctuations and regional paleogeographic connectivity.

This study presents an integrated study of remote sensing, fieldwork, petrographic, geochemical analyses and geotechnical properties of intrusive rocks in the Nikeiba area, South-Eastern Desert, Egypt. Gabal Nikeiba area is composed of Neoproterozoic rocks, including island-arc assemblages (mafic metavolcanics and metagabbro-diorite) and syn- (granodiorite and tonalite) to post-tectonic granitoids (syenogranite, alkali feldspar granite and quartz syenite), followed by post-granitic dikes of various compositions. PRISMA (PRecursore IperSpettrale della Missione Applicativa) hyperspectral data effectively delineated lithological units and structural features. The lithological discrimination serves as a spatial blueprint, ensuring that field sampling for geochemical analysis is optimized and geomechanical characterization is strategically targeted. The old magmatic phase is represented by a calc-alkaline series, typical of magmas formed in a subduction or continental collision setting. The post-collisional granites are subdivided into two magmatic phases, an older one including syenogranite and alkali feldspar granite, and a younger event includes quartz syenite. They have chemical signatures typical for A-type granites (i.e., high SiO2, K2O, Fe/Mg ratio, low CaO, MgO) which are associated with extensional tectonics, crustal melting and intraplate environments. Rare earth element (REE) patterns show light REE (LREE) enrichment and a distinct slope from LREEs to heavy REEs (HREEs). Bulk densities range from 2.48 to 2.7 g/cm3, with low porosity and water absorption, except for granodiorite. Quartz syenite and alkali feldspar granite exhibit superior physical properties and meet American Society for Testing and Materials (ASTM) C615 standards. Quartz syenite shows the highest mechanical strength and lowest abrasion, making it highly durable. Overall, quartz syenite is the most suitable candidate for dimensional stone applications.

Constraining the protolith ages and tectonic settings of metamorphic rocks is key to understanding the nature and evolution of orogenic belts. This paper presents a systematic study of leptite interlayers within extensively exposed layered marbles in the central South Tianshan Orogenic Belt. Based on field investigations, petrology, zircon U–Pb geochronology, and zircon trace‑element geochemistry, we constrain the depositional ages of the leptite and marble protoliths and evaluate their tectonic environment. The leptites occur as thin interbeds within medium‑ to thin‑bedded and banded marbles. Petrographic observations reveal a granoblastic texture composed predominantly of recrystallized quartz and calcite, suggesting that the leptites were derived from acidic tuff protoliths. Zircon U–Pb dating of two leptite samples yields protolith ages of 401.9 ± 2.7 Ma and 392.3 ± 1.3 Ma, recording two discrete volcanic ash‑fall events near the Early–Middle Devonian boundary. These ages constrain deposition of the regionally extensive marble succession to the Middle–Late Devonian. Inherited zircon ages of 480–503 Ma and c. 420 Ma point to earlier tectono‑magmatic events in the region. Zircon trace‑element signatures are consistent with derivation from volcanic eruptions in a subduction‑related magmatic arc setting. Accordingly, we propose that the South Tianshan region experienced arc magmatism during the Early–Middle Devonian, linked to subduction of the South Tianshan Ocean.

We present the analysis and summary of the results obtained by the application of 2-D integrated lithospheric modelling, assuming local isostasy, along 11 profiles that pass across the Carpathian-Pannonian region and their surrounding units. The results are illustrated on a new map of the lithosphere-asthenosphere boundary depth. The Carpathians are characterized by significant changes in the lithospheric thickness both across and along this mountain chain. The internal parts of the Carpathian arc are represented by moderately thickened lithosphere (∼140 km on average), whereas in their external parts LAB depth reaches up to 240 km. Along the Carpathians, the lithospheric thickness increases from the Western Carpathians (140–200) via the Eastern Carpathians (240 km) up to the Vrancea zone, where the largest LAB depth of 300 km is modelled. No lithosphere thickening was found in the westernmost part of the Western Carpathians. Here, the average thickness of the lithosphere is only ∼100 km. The thinnest lithosphere was modelled in the Pannonian Basin (60–100 km). In the Transylvanian Basin, it thickens from about 120 to 170 km. The other modelled areas are the East European Craton (100–180 km), the West European Palaeozoic platform (90–160 km), the Trans-European Suture Zone (150–240 km), the Apuseni Mts. (100–180 km), the Moesian Platform (160–200 km), the Balkanides (160–180 km) and the Srednogorie and Rhodopes area (140 km on average). The results clearly show that the variations of the LAB depth are modified not only by the age of the tectonic units but also by ongoing geodynamic processes.

The Tonto Group of the Grand Canyon is an archetypal record of prolonged sea-level rise and Cambrian biotic evolution. We use a Bayesian age modelling approach to quantify this unique chronostratigraphic record by combining high-precision detrital zircon maximum depositional ages with trilobite biostratigraphy and dynamic time-warped carbon isotope chemostratigraphy to create a vertical and lateral age model through the full stratigraphic sequence across the entire Grand Canyon transect. The results of this modelling test hypotheses related to epeirogenic versus eustatic mechanisms of transgression as well as the accuracy of the current global Cambrian geologic timescale. The Tapeats Sandstone of the Tonto Group is an iconic basal marker of the Sauk II transgression across the Great Unconformity; our age model reveals that its accumulation and distribution along the western Laurentian craton margin were influenced by local tectonics and base-level changes, in addition to global eustatic influences. Early Paleozoic tectonic subsidence of the western Laurentian cratonic margin in the Grand Canyon region did not occur until c. 504 Ma, later than previously thought. Our age model also facilitates numerical calibration of intercorrelated North American and global Cambrian stages and reallocation of time within the Cambrian that has implications for a faster tempo of early animal evolution and associated global carbon cycle perturbations. In addition to refining the depositional history of western Laurentia and the middle Cambrian (Miaolingian) timescale, our approach highlights the utility of data-integrative Bayesian age models for creating radioisotopically calibrated chronostratigraphies.

The Oued Feraguig Detrital Formation, exposed along the southern margin of the Lower Chelif Basin in northwestern Algeria, records the earliest marine deposits associated with the late Miocene transgression onto the Cretaceous substrate of the Beni Chougrane Massif. This study integrates sedimentological, ichnological and planktonic foraminiferal data to constrain the age, depositional environments and palaeogeographic significance of this transgressive succession. The formation is 80–90 m thick and unconformably overlies a weathered Upper Cretaceous substrate. Ten sedimentary facies were identified and grouped into two facies associations that record deposition from lower-shoreface to middle- and upper-shoreface environments. The basal conglomeratic deposits represent transgressive lags formed by erosion and reworking of the Cretaceous substrate during the initial phase of marine inundation. Up-section, the succession is dominated by well-sorted sandstones displaying planar lamination, planar and trough cross-stratification, hummocky and swaley cross-stratification, and local soft-sediment deformation structures. These features indicate deposition in a high-energy shoreface system influenced by waves and storms. The trace-fossil assemblage comprises 14 ichnotaxa and is dominated by vertically oriented dwelling burrows, including Ophiomorpha, Skolithos and Diplocraterion; this composition is consistent with the Skolithos ichnofacies. Subordinate horizontal traces record brief colonization during fair-weather intervals. Asteriacites stelliformis and Diplopodichnus biformis are reported from Algeria for the first time. Local development of oyster banks composed of Crassostrea gryphoides indicates short-lived phases of substrate stabilization within the shoreface system. Planktonic foraminiferal assemblages constrain the age of the formation to the early Tortonian, corresponding to planktonic foraminiferal subzones MMi9–MMi10 (ca. 11.54–10.55 Ma). These results refine the timing and sedimentary record of marine flooding along the southern margin of the Lower Chelif Basin and provide new insights into Miocene transgressive systems along structurally controlled basin margins in the western Mediterranean.

The Jurassic–Early Cretaceous fragmentation of Gondwana remains poorly constrained because alternative plate-kinematic models differ in their initial fits and in the interpretation of magma-rich, highly extended crust along southern Mozambique. This study integrates offshore geophysical observations with sedimentological, biostratigraphic and palaeobiogeographic evidence to distinguish direct constraints on marine connectivity from interpretations dependent on a particular reconstruction. Marine faunal exchange and sedimentary records indicate that a continuous trans-Gondwana seaway linking the western Tethys and Palaeo-Pacific through the proto-Weddell Sea system was established at approximately 145 Ma (late Tithonian), implying the loss of any remaining terrestrial connection between East and West Gondwana. Dinoflagellate-cyst assemblages and marine deposition in eastern Indian and western Australian basins indicate a first major terrestrial disconnection between Sri Lanka–India–Madagascar and Antarctica–Australia at approximately 134–133 Ma (latest Valanginian). These two age constraints are largely independent of any single plate model. Near magnetic chron M0r (∼121 Ma), some kinematic models retain a narrow Sri Lanka–Antarctica corridor. Major sea-level falls at approximately 121–120 Ma may have temporarily re-established terrestrial connectivity across shallow parts of this corridor without requiring tectonic re-closing. No direct geological evidence presently confirms such a connection, and its inferred final loss during the onset of transtension and asymmetric crustal accretion at approximately 119–120 Ma remains model-dependent. The synthesis provides a testable chronology for Gondwana fragmentation and distinguishes palaeogeographic inferences constrained directly by geological and fossil evidence from those dependent on plate-kinematic assumptions. It has implications for Southern Hemisphere biogeography, marine circulation and the interpretation of Cretaceous vicariant events.

The structural and metamorphic architecture of the Dora-Maira Massif has traditionally been interpreted as a stack of multiple tectonic slices, distinguished primarily on P–T peak conditions. New structural, lithostratigraphic and petrological data from the Permo–Mesozoic cover sequences of the northern-central Dora-Maira Massif allow a reassessment of the tectonic slices. Detrital zircon U-Pb geochronology constrains the Permian depositional age of garnet-chloritoid micaschist within the cover sequence, allowing a more robust reconstruction of the original extent and stratigraphic continuity of the sequence. Structural and petrological analyses show that both the Permo–Mesozoic cover and the underlying basement share the same Alpine P–T–d evolution, reaching ultra-high-pressure (UHP) conditions in the coesite-chloritoid-facies (530–560°C and 2.6–2.9 GPa). Newly identified coesite relicts support peak conditions inferred from thermodynamic modelling. Consequently, any significant detachment of cover from basement occurred after the Alpine metamorphic peak. Field mapping and geochronological constraints document a discontinuous Permian–Upper Cretaceous succession occurring either as deformed slices folded with the basement rocks or as partially detached slivers along the tectonic contact with the oceanic units. These results support a reinterpretation of the Dora-Maira Massif architecture and allow the merging of several previously defined small units into a single tectono-metamorphic unit. More broadly, our data suggest that basement–cover associations represent a key criterion for reconstructing the tectonic architecture of the Dora-Maira Massif. On this basis, and through comparison with existing studies, we propose a revised structural framework for the entire massif that reconciles field relationships with the wider extent of Alpine UHP metamorphism.

The extent to which interaction occurred between the proto-Iceland mantle plume and the continental lithospheric mantle (CLM) during establishment of the Palaeogene British and Irish Igneous Province (BIPIP) has wide-ranging and important implications, not least for understanding the nature and differentiation of the parental melts, models of contamination of primary magmas as well as base and precious metal mineralization. This study focuses on a rare Palaeogene-aged xenolithic dyke from Inver, NW Ireland. Geothermobarometric calculations indicate that spinel lherzolites from the Inver dyke represent relatively fertile, cold, deep CLM. The Al-in-olivine thermometer yields 865–974°C for two xenoliths studied in detail and equilibration pressures (using the Ca-in-olivine-clinopyroxene barometer) of 12–15 kbar. Oxygen fugacity calculations indicate relatively reducing conditions (Δlog f O2[QFM]) of −3.2 to −2.3, a characteristic not inconsistent with deeply sourced CLM materials. Thermobarometry on the dyke host rock suggests that its parental melt equilibrated with the mantle at 1326°C and 18.6 kbar, constraining the depth to the lithosphere-asthenosphere boundary at ∼43 Ma to ∼59 km. Taken together, these observations attest to the localized survival of relatively unmodified CLM following the main pulse of BIPIP magmatism at 61–58 Ma. The new constraints are permissive of magmatic mineral deposit formation or enhancement by exchange between locally metasomatized CLM and rising asthenospheric melts, but such processes may be localized, i.e. beneath individual igneous centres of activity.

The Tel’aobao uranium deposit, which was recently discovered within the oxidizing Huanhe Formation, northwestern Ordos Basin, represents a new stratigraphic target for uranium exploration. This paper investigates the ore genesis through petrological, geochemical and chronological analyses of various sandstone and mudstone samples. Results show that the ore-hosting strata, sourced from intermediate-acidic volcanic rocks, were deposited under the semi-arid and hot paleoclimatic conditions. The host sandstones exhibit several distinct characteristics: a limited initial reducing capacity, with total organic carbon (TOC) below 0.1% and total sulphur content (TSC) ranging from 0.002% to 0.074%; low kaolinite (averaging c. 8%) and chlorite content (averaging c. 13%); a high proportion of chlorite–smectite (43.7% to 70.3%) and illite–smectite mixed layers (40.5% to 53.6%); and elevated uranium content in both red and green non-mineralized sandstones, with averages of 6.8 and 7.46 ppm, respectively. In addition, these sandstones appear to have been altered by the ternary fluids system comprising oxidizing groundwater, reducing hydrocarbon and alkaline hydrothermal fluid, leading to the formation of some authigenic minerals and epigenetic indicators: uneven colour gradation, oxidized carbonaceous remnants, hematitization, pyritization, calcitization, chloritization, elevated acid-hydrolysed hydrocarbon content (24.6 to 6452 μL/kg) and pale-yellow fluorescence. The negative δ13CV-PDB (−7.6‰ to −1.1‰) and δ34S (−38.7‰ to −7‰) values support the occurrence of bacterial sulphate reduction (BSR), and abundant nano- to micro-sized coffinite (P-, Zr- or Y-bearing) and U-Ti aggregates are intimate related to pyrite, chlorite, sphalerite and iron oxides, reflecting two distinct mineralization mechanisms: low-temperature redox and thermochemical precipitation. Whole-ore U-Pb dating yields a reliable isochron age of 53.8 ± 6.3 Ma, whereas electron microprobe analysis traces a continuous dynamic mineralization process from 134.43 to 4.45 Ma. Based on these findings, a metallogenic model is proposed for this deposit: (1) uranium pre-enrichment during sedimentation stage; (2) secondary hydrocarbon reduction at the end of the Early Cretaceous; (3) regional interlayer oxidation-reduction mineralization from the Late Cretaceous to Eocene; and (4) hydrothermal reworking and deficient oxidation since the Oligocene. This research offers an effective vector for future uranium exploration within red-variegated strata.

A sample of an elongated, hollow, tube-like fulgurite (labelled NC-CH) was collected in the shorelines’ sand of Outer Banks, NC (USA). The goal of this study is to shed light on the origin of this material and phase transformations induced by lightning discharge. X-ray powder diffraction (XRPD) coupled with Rietveld quantitative phase analysis of the surrounding sand (NC-sand) identified quartz, plagioclase, biotite, cordierite and calcite. XRPD analysis of NC-CH revealed stishovite, absent in NC-sand, unequivocally confirmed through high-resolution XRPD and Rietveld quantitative phase analysis. The fulgurite exhibits a high X-ray amorphous abundance (85.3(4) wt%) compared to the sand (49.3(2) wt%), indicating melting and partial melting of primary minerals such as quartz, plagioclase, phyllosilicates and cordierite. Scanning electron microscopy (SEM) with energy dispersive spectrometry (EDS) revealed well-crystallized pyrite clusters (<1 µm) in NC-CH. Pyrite precipitation likely resulted from reducing conditions during sulfidation of ferromagnesian silicates in the presence of H2S fluids derived from hydrocarbons, water vapour and organosulfur compounds from burned organic matter. By investigating shock-impacted minerals at the nanometric scale, this study provides new insights into physicochemical constraints influencing mineral formation and phase transitions during extreme events such as lightning strikes or meteor impacts.

The uppermost Triassic Cotham Member of the Lilstock Formation preserves two regionally extensive microbialite horizons – the well-known stromatolitic Cotham Marble and the older, largely overlooked Estheria Bed – offering new insights into environmental change during the Rhaetian. Integrated field, facies and literature review data demonstrate that both horizons are far more geographically widespread than previously recognized, extending across multiple depocentres in southwest England and the English Midlands. The Estheria Bed comprises thrombolitic–stromatolitic bioherms with variable mesostructures, including vugs, grainstone infill and locally preserved lamination, indicating fluctuating hydrodynamic and early diagenetic conditions. The Cotham Marble exhibits a consistent architecture of laminated stromatolites and columnar branching forms, initiated by shallow burrows or borings and variably accompanied by Microtubus microfossils. Combined evidence from microbial fabrics, associated fauna, sedimentary structures, geochemistry and biomarker studies indicates deposition within a laterally extensive, shallow freshwater–brackish lagoon at least 9500 km2 in area. This lagoon experienced two mudstone-dominated packages culminating in microbialite formation. Together, the Cotham Marble and Estheria Bed provide useful horizons for regional correlation, revealing a dynamic lagoonal system sensitive to tectonic and hydrological change.

The Oi2b isotope event is a significant Late Oligocene global cooling period for which physical evidence and knowledge are scarce. It is represented by the glaciomarine Polonez Cove Formation (PCF) on King George Island (South Shetland Islands), the oldest and most intensively studied Cenozoic glacial deposit exposed on Antarctica. The PCF is overlain by the much less well-studied, slightly younger Boy Point Formation (BPF), which also preserves vital environmental information. The lithofacies are dominated by phases of coeval volcanism. Autogenic and allogenic processes are identified for the first time and used to determine the history of both formations. The PCF documents the ice terminus, its retreat and sub-polar thermal regime. The recession was followed by isostatic uplift, then by continuous sea level rise due to eustasy. The South Shetland Islands supported an ice dome probably detached from another on the Antarctic Peninsula and separated by at least seasonally open water (proto-Bransfield Strait). The existence of open water in the Weddell Sea explains the presence of erratics dumped by icebergs sourced from East Antarctica and the Antarctic Peninsula, and the study has enabled the configuration of Oi2b ice across Antarctica to be reconstructed for the first time. Rapid uplift terminated marine deposition, helping terrestrial ice to accumulate during a hitherto-unrecognized advance on King George Island. Wet-based ice of a further, slightly younger glacial was probably responsible for deep erosion that truncated the BPF and PCF, cutting >200 m down to present sea level.

Eo-Alpine metamorphism in the Western Carpathians is mostly recorded by low-to-medium grade rocks of the Veporic Superunit. However, the multimethod geochronological data from this key unit to understand Alpine evolution of the Western Carpathians are scarce. To better understand the timing of burial (subduction), peak conditions and post-peak exhumation, we applied in situ garnet Lu/Hf and mica Rb/Sr geochronology. Garnet yielded a somewhat imprecise, yet valid and geologically meaningful, age of ∼116 Ma interpreted as a record of subduction. In contrast, biotite Rb/Sr ages of ∼91 Ma and ∼75 Ma record resetting in the near-peak conditions upon the earliest stages of exhumation and fluid-aided re-equilibration, respectively. A white mica Rb/Sr dating also reflects Alpine disturbance of the isotopic system. The geochronologic data presented herein, together with the other already published geochronologic results, allow us to formulate a coherent subduction-exhumation model for the Veporic Superunit in an intracontinental setting. The upper plate for this subduction system would be a continental block belonging to Adria. We postulate that the rocks in question were subducted due to prior thinning of the continental crust, much as in the Eastern Alps, where the Lower Central Austroalpine units were subducted beneath the Adria plate. Altogether, these temporal and tectonic similarities demonstrate that the major allochthonous units in the Western Carpathians could indeed be equivalents to those defined in the Eastern Alps.

This study investigates the mineralogical and chemical composition of 25 slate samples and the petrography of four coarse-grained slates from seven sectors of the Carboniferous Culm Facies in the Malaguide (S Spain) and Ghomaride (N Morocco) domains (Betic Cordillera and Rif Chain). The succession comprises the lower Almogía Formation (Retamares and Greywacke-Slate members) and the upper Marbella Conglomerate Formation. Protoliths originated from shale sediments, consisting of quartz, feldspars, micas and Fe-oxides. An upward increase in quartz content, observed from the Malaguide to the Ghomaride domains, indicates increasing sediment maturity, due to erosion after a pre-depositional tectonic phase and sediment recycling. The rocks experienced post-burial very low-grade metamorphism (200–300°C). Geochemical signatures show increasing upward felsic components, decreasing mafic content, suggesting erosion of a volcanic arc and/or relict oceanic suture in the hinterland. Detrital chlorite and illite/muscovite testify low-grade metamorphic detrital signatures in the source area. Moderate oxidizing climatic conditions were dominant during sedimentation. Integrating our findings with recent researches, we propose that multiple Paleotethys Ocean branches separated the Paleo-Mesomediterranean microplate from the Iberian-Central French Domain, to the north, and from the Paleo-Atlas-Saharian Domain, to the south, during the Carboniferous. The Malaguide and Ghomaride domains, located along one of the southern Paleotethys branches, received detritus from a northern, pre-Carboniferous metamorphic zone, as well as, from an oceanic suture belt and/or magmatic arc. These hinterland source terranes were structured prior to Culm Facies deposition, which was subsequently structured during the latest Carboniferous Paleotethyan phase, contributing to the Pangaea final assembly.

Deccan volcanism in India represents one of the major continental flood basalt provinces on Earth. The drill holes of Continental Scientific Deep Drilling Project at Koyna in southern Deccan Province are unique in sampling a continuous subsurface stratigraphic record of the basalt down to basement. Element geochemistry of the 1251 m thick KBH-7 drill hole sequence shows that geochemistry alone cannot reliably demarcate discrete eruptive phases. However, geochemical logs of incompatible trace-element patterns and ratios, combined with multivariate statistical analysis, establish a subsurface succession comprising the Mahabaleshwar, Ambenali and Poladpur formations of the Wai Subgroup and the Bushe and Khandala formations of the Lonavala Subgroup directly overlying Archean basement. The older Kalsubai Subgroup is absent in the drill hole and this provides subsurface evidence for southward overstepping of older formations by younger formations in the Deccan Province. Palaeomagnetic inclination data from KBH-7 and nearby KBH-8 drill hole identify eight directional groups; each directional group may have erupted in short span of time (decades to centuries) relative to speed of secular variation. Considering the inferred lava-production rates, relative thicknesses of directional-group and non-directional lava sequences and the estimates of time lapsed for intermittent red boles formation, the main phase of Deccan eruption was likely to have occurred within a few thousand years (<4000–5000 years), in discrete phases, over a cumulative timescale of ∼200–300 ka.