The Jurassic represents one of the most significant periods within the widespread Mesozoic magmatism of the Lhasa Block; however, its formation age and petrogenesis have led to controversy over the deep genetic mechanisms responsible for magmatism. To address this, we present new zircon geochronological, Hf isotopic and geochemical data for the Pairigang granite porphyries and granodiorites in the Tangjia area, southeastern Lhasa Block. The analysis results demonstrate that the Pairigang granites that intruded during 195–192 Ma (Early Jurassic) are characterized by marked light rare earth elements (LREEs) and large-ion lithophile element (LILE) enrichment, and display marked depletion in Nb and Ta, reflecting an affinity with arc magmatic rocks. The ε Hf ( t ) values (−7.33 to +1.47) and model ages indicate the involvement of both ancient crustal material and mantle-derived components. Based on the geochronological and geochemical analyses, this study suggests that the Early Jurassic Pairigang intrusive rocks are I-type granites, formed by the partial melting of mafic lower-crustal material and subsequent magma mixing with mantle-derived components. Combined with the previous studies, we propose that the Early Jurassic Pairigang granitic rocks resulted from the northward subduction of the Yarlung–Zangbo Neo-Tethyan Ocean. Variations in zircon Hf isotopes from Jurassic magmatic rocks across the Lhasa Block further indicate that the southeastern Lhasa Block represents an accretionary wedge system comprising juvenile crust formed during the evolution of the Tangjia–Sumdo Palaeo-Tethyan Ocean and the Yarlung–Zangbo Neo-Tethyan Ocean.
The Early Cretaceous (Albian) El Soplao Konservat-Lagerstätte, from Cantabria (northern Spain), provides unparalleled insights into late Mesozoic terrestrial ecosystems. The site stands out for yielding amber pieces with a blue–violet hue and abundant bioinclusions, which document a remarkably diverse arthropod assemblage. Many fossils exhibit anatomical fidelity down to microscopic structures, allowing detailed morphological and palaeoecological investigations. El Soplao amber preserves the oldest representatives of several major arthropod groups as well as compelling evidence, often direct, of behaviours and symbiotic interactions along the parasitism–mutualism spectrum between arthropods, insects and plants, and arthropods and vertebrates. Ongoing multidisciplinary research keeps expanding the palaeobiological knowledge on this remarkable locality, which represents one of the most important fossiliferous amber deposits in Europe.
This study investigates mafic microgranular enclaves (MMEs) within the Lingshan granite (Jiangxi Province, South China) through an integrated approach combining traditional geochemistry, macro-X-ray fluorescence (MA-XRF) mapping and X-ray computed tomography (X-CT). Zircon U–Pb ages and Hf isotopes indicate that the MMEs share similar crystallization ages and isotopic ratio with their host granite. X-CT imaging reveals similar short- and long-axis mineral orientations (biotite, hornblende, magnetite, ilmenite and some heavy minerals) between MMEs and host rock, supporting flow alignment of mafic magma globules within the felsic melt (globules of a more mafic magma injected into the felsic magma and subsequently mingled and mixed with it) rather than a restite, or early cumulate origin (the mineral orientations of MMEs in these models are nearly impossible to be consistent with those of the host granite). Whole-rock geochemistry exhibits non-linear trace element trends, which are inconsistent with simple magma mixing but rather an example of the chaotic nature of the mixing process. MA-XRF mapping further demonstrates enrichment of Fe, Mn, Ti, Y, Nb and Ca alongside depletion of Sr, K and Rb in MMEs, attributed to diffusion-driven exchange. The hybridization process weakened the A-type signature of the host granite, implying that some I-type granites may derive from A-type precursors, primarily through magma mixing. Notably, MMEs may sequester some critical ore-forming elements (e.g. Nb, Ta), potentially suppressing the metallogenic potential of the host granite. These findings may provide new constraints on magma differentiation processes and related mineralization mechanisms in South China's granitic systems.
CM chondrites record significant fluid–rock interaction in the early Solar System, yet whether their petrologic range reflects progressive hydration within a single parent body or sampling of multiple bodies remains debated. We present high-precision mass-independent Fe, Cr, and Ti isotope data (µ 54 Fe, µ 54 Cr, µ 50 Ti) for ten bulk CM1, CM2, and CM1/2 chondrites to constrain their formation and alteration history. Variability in µ 50 Ti values record heterogeneous distribution of refractory inclusions at sub-centimetre scales with a common chondrule–matrix reservoir. Bulk µ 54 Fe compositions are generally uniform, also supporting derivation from a common isotopic reservoir. However, several samples, independent of their degree of aqueous alteration, exhibit resolvable µ 54 Fe depletions. These shifts are best explained by two terrestrial weathering processes of preferential removal via leaching of chondritic alteration products and metals and the exchange of aqueous Fe in Antarctic fluids with chondritic Fe. While these results support derivation from a common isotopic reservoir for all CM chondrites, it remains unclear whether the CM chondrites sample a single or multiple CM parent bodie(s). This study highlights the need to account for terrestrial weathering effects when interpreting subtle µ 54 Fe variations in carbonaceous chondrites and additional mass-independent, refractory element isotopic analyses of CM1 chondrites.
This study investigates the apotropaic meaning of a fossil purchased in 1994 in the souk of Marrakesh. The specimen is an internal mould of an infaunal Jurassic bivalve ( Pleuromya cf. uniformis [J. Sowerby]) bearing a religious inscription in high relief, that has been identified as the Sunni formulation of the shahāda : ‘There is no god but Allāh, [and] Muḥammad is His Prophet.’ This represents the first documented example of a religious talisman carved onto a fossil within Islamic culture. Unlike a previously known Cretaceous belemnite from Palestine bearing non-religious incised Arabic script, the present specimen displays a clearly devotional and protective intent. Contextual and documentary evidence suggests that the fossil functioned as a talisman intended to neutralise the magical powers attributed to fossils by certain Berber tribes, for whom marine fossils were used in witchcraft and divination and were believed to possess vital qualities. The inscription of the shahāda can be interpreted as an act of Islamisation and resignification of fossils, affirming divine omnipotence and rejecting autonomous natural causality. The object was likely produced in the late nineteenth or early twentieth century, possibly in response to wider debates on evolution, using locally sourced Jurassic fossils from the Atlas Mountains.
This study defines the nature of the eastern boundary of the Gurla Mandhata core complex and assesses its significance in the broader context of along-strike termination of metamorphic core complexes. Integrated field mapping and monazite U–Th/Pb petrochronology constrain the magmatic and tectonometamorphic evolution of migmatitic rocks, leucogranitic dykes and sills, and the Chuwa Granite exposed along the eastern margin of the Gurla Mandhata core complex (NW Nepal Himalaya). The dykes and sills are interpreted as feeders to the Chuwa Granite, emplaced during crustal shortening and southward extrusion at ∼20–17 Ma. Migmatites record retrograde metamorphism from ∼18 to 14 Ma, and migmatization persisted until ∼14 Ma, coeval with onset of orogen-parallel extension in the Gurla Mandhata core complex. The Gurla Mandhata core complex and its eastern edge share a thermal pulse typical of southward extrusion of the Himalayan metamorphic core from ∼22 to 15 Ma. However, shear-sense differences from ∼15 to 13 Ma suggest the existence of a strain partitioning boundary at the eastern edge of the core complex, coinciding with the northward trace of the Indian basement Great Boundary Fault, which is interpreted to have reactivated and influenced the location of the core complex’ eastern termination.
The Neoproterozoic era marks a turning point in Earth history when the formation and breakup of supercontinent Rodinia drastically changed the configuration of plates and life environments. While most large cratons have been well placed within the Rodinia reconstructions through geological and paleomagnetic constraints, the former positions of many smaller micro-continents, such as those across the Asia region, remain poorly understood. Although the Tarim Craton played a vital role in linking the assembly and dispersal of the Rodinia supercontinent, a long-lasting controversy remains regarding the tectonic configuration of the Tarim Craton in the Rodinia mosaic. In this paper we synthesize the Meso- to Neoproterozoic stratigraphy and magmatism of the Tarim Craton and evaluate the current tectonic and paleogeographic models addressing the “Tarim geopuzzle” within Rodinia configuration. The Central Tianshan and Yili blocks are considered part of a Wilson Cycle evolution of the Tarim Craton during this time interval. Key geological features common to both the “ Great Tarim ” and western Laurentia include: 780–760 Ma mafic dike swarms along the northern edge of the Tarim Craton and the 780 Ma Gunbarrel Large Igneous Province; plume-driven continental rifting episode and synchronous basin initiation along conjugate margins; a Mesoproterozoic granitoid belt in Central Tianshan that is comparable to the ∼1.4 Ga Granite–Rhyolite Belt in southern Laurentia; compatible source-to-sink systems in Mesoproterozoic basins; and, coeval ∼650–615 Ma magmatism with rift-to-drift tectonics leading to passive margin development. Several key issues warrant focused investigation in future studies. These include the need to re-evaluate the ambiguous latest Mesoproterozoic Grenville-age orogeny in light of newly available zircon datasets; the nature and geodynamic significance of an Early Neoproterozoic intracontinental rifting event in southern Tarim that may record a two-stage rifting-amalgamation history within the core of Rodinia, involving initial separation from Australia followed by amalgamation with Laurentia; and, the significance of the apparent time lag (several tens of millions of years) between rift-to-drift tectonics and the paleomagnetically inferred Australia–Laurentia breakup. Addressing these issues will be critical for testing alternative paleogeographic reconstructions and for evaluating the viability of placing Tarim or other continental blocks in a core position within the Rodinia supercontinent.
We conducted high-pressure (1 GPa) melting experiments on a CM2 chondrite (MCY12002) across a temperature range of 1050–1400°C, with durations varying from 1 to 24 h, to investigate the onset of differentiation of hydrous (ice-bearing) planetary embryos in the early Solar System. Heating of the CM chondrite at near-solidus conditions results in the thermal decomposition of the hydrated minerals that comprise the matrix of the meteorite, and their metamorphic recrystallization into olivine crystals. The resulting mineral assemblages are composed of abundant olivine and scarce Al-rich–low-Ca pyroxene and kirschsteinite. Silicate glass is present in all experiments, increasing from less than 5 area% at 1050–1200°C to 16 area% at 1400°C. A sulfur-rich phase is also observed. The exceptionally high abundance of olivine can be interpreted as the combination of the initially high Mg content in phyllosilicates, correlated to the extent of aqueous alteration and the reducing oxygen fugacity conditions regulated by the devolatilization of the chondrite matrix. This latter process could explain the gap in oxygen fugacity between the most oxidized chondrites and the most oxidized achondrites, highlighting the impact of volatile loss during the early differentiation of CM-like bodies.
Magmatic microgranular enclaves of variable size and texture commonly occur as swarms within I-type batholiths. These enclave swarms provide a valuable opportunity to test competing hypotheses about enclave origin, as enclaves with variable textural features, mainly grain size, are spatially associated with new magmatic pulses related to a common pluton. In this study, the Pomarinho enclave swarm hosted within an I-type (328 ± 2.4 Ma) granodiorite of the Évora gneiss dome has been investigated. The Pomarinho enclave swarm is particularly well suited for this purpose, as quarrying has exposed the swarm in three dimensions, creating a natural laboratory to better understand relationships among enclaves and host granite, as well as among different enclave types, including single and double enclaves. Based mainly on field evidence but also using petrographic, mineralogical, geochemical and isotopic data, it was possible to infer an origin of enclaves. Field, petrographic and geochemical relations indicate that enclaves most probably derived from quenched magma conduit sidewalls rather than from fragmented syn-plutonic magma injections. We propose that shear induced by magma ascent physically eroded the sidewalls of the quenched conduit during during magma recharge, thereby facilitating the formation, transport and rounding of enclaves.
Reliable chronostratigraphic correlations for Precambrian cratons are critical for understanding associated tectonic processes and the environments in which early life evolved. This study examines implications of recent geochronological advances for the Statherian‒Tonian chronostratigraphic framework of the Greater North China Craton (GNCC), which encompasses the Langrim and Quanji-Central Qilian blocks, in addition to the traditional North China Craton (NCC). New age constraints subdivide the Statherian-Tonian stratigraphic record of the GNCC into three stages: ca. 1.78‒1.35, 1.35‒1.24, and 1.24‒0.80 Ga. Late Statherian deposition initiated in the Xionger Rift Basin and progressed toward an epicontinental carbonate sea covering the GNCC by ca. 1600 Ma. This corresponds with the initial breakup of Columbia that established evolutionary niches for early eukaryotes. An extensive ca. 1.35‒1.0 Ga depositional gap resulted from protracted collision, uplift, and erosion on the GNCC, associated with the Grenville-age, southward-migrating foreland basin in which black shales of the ca. 1.38 Ga Xiamaling Formation and related units were deposited. Between ca. 1240 and 800 Ma, deposition of carbonate-dominated successions indicates the development of an embayment on the Langrim Block (Pyeongnam Basin) that gradually expanded across the entire GNCC, corresponding to the rifting and breakup of Rodinia.
River incision rate data, together with an isostatic unloading model, have been used to constrain the origin of the ‘staircase’ of Pleistocene river terraces in the Lower Severn Valley. Previous studies show that terrace cyclicity is mainly controlled by climate change, while their ‘staircase’ pattern is the consequence of crustal uplift: variously accounted for by isostatic unloading, ductile flow in the lower crust and tectonics. Here, it is shown that crustal uplift can be explained by an isostatic unloading model that takes into account the generalized glaciation and deglaciation history of the British Isles, the topography of the Forest of Dean and Cotswold Hills, and the possibility of a lithosphere, rather than asthenosphere, stress relaxation. The model predicts that the flexural response to excavation (i.e. removal) of sediment by meltwater-charged rivers, or ice retreat, following a deglaciation event would be fast initially and then slow. In the Anglian ( c . 450 ka), believed to be the most significant such event, the response is rapid enough to explain the oldest and highest of the Lower Severn Valley terraces ( c . 60 m) and gentle enough to explain, with a small ‘boost’ from younger events, the height of the youngest and lowest of the terraces ( c . 20 m).
The Greater Barents Sea Basin (GBSB) is a unique area in the Arctic, as it hosts relatively well-preserved large-scale Cretaceous progradational wedges. Multiple regional studies document temporal and spatial variations in clinoform progradation directions and sedimentation styles across different parts of the GBSB and reveal a fundamental tectonically driven reorganization of drainage systems during the Early Cretaceous. This study uses an integrated source-to-sink approach combining regional seismic datasets with new detrital zircon U-Pb ages from the analysis of 11 samples spanning Valanginian to Campanian that are combined with seismic interpretation and mass balance calculations. This work presents a unified chronostratigraphic frame for the whole GBSB and correlates internal changes to large-scale plate tectonic events, and major volcanism, in the source area and the Arctic in general. It reveals that sediment input varied throughout the Cretaceous with low sediment input from local sources in the Late Jurassic-Hauterivian, which dramatically increased in the Barremian due to High Arctic large Igneous Province (HALIP) activity. Relatively high sediment input took place in the Albian-Cenomanian due to catchment reorganization, followed by relatively low sediment input in the Turonian-Coniacian with a last increase in the Campanian. A new provenance dataset, including new zircon data, confirms a catchment reorganization to a dominant northeasterly source, and constrains this change to the Aptian-Albian.
The age of mineralization in the North Pennine orefield is controversial, with age estimates ranging from Permian to Paleocene times. Here we present Nd-isotope data from a single large crystal of fluorite from the Boltsburn vein in Weardale that define an errochron with an apparent age of 155 +/- 21 Ma, indicating formation in the Upper Jurassic. Nd-isotope growth curves based on these data and published fluorite data from several other Alston block mineral veins intersect growth curves for the basement rocks (Skiddaw Group mudstones and Weardale granite) at the same age, confirming that the date is robust. Our proposed date coincides with a major phase of extension in the North Sea and with the time at which global sea-level reached its highest point in the Phanerozoic, possibly submerging the Alston block. Upper Jurassic extension may have reactivated older fractures of Variscan origin on the Alston block and allowed seawater to penetrate deep into the basement rocks to feed the hydrothermal circulation responsible for the mineral deposits. Mineralisation followed a long period of tectonic inactivity when global sea-level was generally low, and these two factors combined to inhibit hydrothermal circulation through the basement rocks. The temperature of the Weardale granite would have increased by radioactive decay during this period of inactivity.
Middle Neoproterozoic granitoids from the western margin of the Yangtze Block provide critical insights into crust-mantle interaction and crustal growth processes of the South China Block during Rodinia supercontinental cycles. Zircon U-Pb dating reveals that the Datian diorite and granite were emplaced contemporaneously at ca. 760–770 Ma. The Datian diorites exhibit variable SiO 2 (56.60–67.03%), high Mg # (49.32–55.18), medium Na 2 O+K 2 O (5.02–6.46), A/CNK (1.02–1.16) shows aluminum, and high Cr and Ni concentrations, while the granites show high SiO 2 (70.91–80.73%) and low MgO (0.11–0.67%), Na 2 O+K 2 O (4.72–8.52) shows a subalkaline series, A/CNK (0.86–1.22) indicates metaluminous to peraluminous. Both the diorite and granite are enriched in LILEs but depleted in HFSEs, resembling that of typical arc affinities. The diorites display moderate positive ε Hf (t) (+2.3 to +6.6) and mantle-like δ 18 O (4.95–6.30 ‰), while the granites exhibit similar ε Hf (t) compositions (+1.83 to +7.15) but low- δ 18 O (0.59–5.90‰) values. More importantly, the diorites display high Ba-Sr (Ba + Sr = 898 – 1720 ppm) signatures and characterized by amphibole-rich lithologies. These geochemical and isotopic signatures suggest that the parental magmas of the diorites were most likely generated by partial melting of the mantle wedge metasomatized by the subducted oceanic slab during the early stage, and subsequently the high Ba-Sr melts differentiate to generate the Datian diorite in a continental arc setting. The low- δ ¹⁸O granites were formed through partial melting of juvenile lower gabbroic crust that had been interpointed by high-temperature hydrothermal alteration. The high Ba-Sr granitoids share geochemical affinity with Archean sanukitoids, forming via amphibole-dominated fractional crystallization of fluid-metasomatized mantle. The development of mid-Neoproterozoic continental arcs along the margin of the Yangtze Block suggests that South China occupied a peripheral location in Rodinia.
In the Goiás Intra-Oceanic Arc System (Goiás IOAS), Brasília Orogen, Brazil, occurrences of porphyry-type mineral deposits have been identified. The most significant of these is the Chapada Cu–Au deposit (1056 Mt Cu @ 0.24% Au @ 0.12 g t –1 ). This deposit is related to metadiorites, orthogneisses and metavolcanic sedimentary rocks. This study aims to trace the igneous protolith source of the orthogneisses and to explore the impact of magmatism on the porphyry-type mineralization of the Goiás IOAS. The data obtained indicate that the orthogneisses represent two distinct magmatic series: one with a normal arc calc-alkaline (NCO) affinity, and the other with an adakitic (ADO) affinity. The NCO shows characteristics that suggest a source mantle metasomatized by slab-released fluids. They are geochemically and isotopically similar to metadiorites from the Chapada deposit, which suggests that they share a common mantle-derived magmatic origin. Evidence of mafic magma recharge suggests that the fertility of the system is related to addition of mantle-derived volatiles and incompatible elements. The ADO are distinct from the orthogneisses of the NCO and from the metadiorites of the Chapada deposits. They are not related to the Goiás IOAS mineralizing system.
Carpholite is indicative of blueschist facies conditions in metapelites. It is thought to be one of the main H 2 O carriers, contributing to the change in the mechanical properties of rocks deformed along plate interfaces. However, first-order parameters controlling the formation/preservation of carpholite in natural mineral assemblages are poorly constrained. We carried out forward modelling on a dataset of low blueschist facies metapelites, with the aim to elucidate which physio-chemical parameters govern the formation/preservation of carpholite in the observed mineral assemblages. Additionally, we attempted to evaluate the link between the hydrated phases in the mineral assemblages and the potentially released fluids during dehydration reactions. The results show that the formation/preservation of significant amounts of carpholite depends mainly on SiO 2 /Al 2 O 3 >2:1, and XMg [MgO/MgO + FeO total ] and A [Al 2 O 3 − 3 × K 2 O/Al 2 O 3 − 3 × K 2 O + FeO tot ] molar ratios of 0.40–0.60 and >0.40, respectively, and H 2 O-saturated conditions. Fe 3+ appears to have a minor role in carpholite stability. The amounts of fluids released by dehydration reactions along P–T paths typical of subduction zones are consistent for samples whose composition promote kaolinite, pyrophyllite and carpholite formation. Additionally, in samples with bulk compositions conducive to significant carpholite formation (>10 vol%), the predicted amount of potentially released aqueous fluids is higher than that predicted using a bulk composition that does not promote the abundant formation of this mineral. The implications for seismic behaviour are also discussed.
The occurrence of coesite has been observed to be contingent upon the presence of ultrahigh-pressure (UHP) metamorphic conditions. Nevertheless, its presence is limited due to reactions bound to UHP conditions, inherent instability and tendency for immediate recrystallization to quartz. This study aimed to better constrain the relationship between coesite, quartz and garnet in whiteschists from the Brossasco-Isasca Unit of the Dora-Maira Massif (Western Alps) based on detailed microstructural observations, electron backscatter diffraction (EBSD) and cathodoluminescence (CL) analyses. The microstructural observations enabled the differentiation of the four discrete microstructural stages of coesite to coesite-to-quartz transformation: (1) preserved primary coesite porphyroblasts, (2) the initial generation of palisade quartz, (3) the second generation of palisade quartz exhibiting indications of subsequent recrystallization, which resulted in (4) complete recrystallized matrix quartz. Based on the EBSD analysis, it is evident that the orientation of the quartz grains within all microstructures was driven solely by pressure relaxation, as they do not exhibit any preferred crystallographic orientation. After thoroughly examining the misorientation relationships of coesite, quartz and garnet, it was confirmed that no crystallographic relationships were identified between the investigated phases. CL images of the various quartz microstructures display homogeneous patterns. In contrast, coesite is distinctly more luminous. However, after a brief time interval, the high luminescence of coesite disappears and becomes indistinguishable from quartz. The observed luminosity may be associated with the elevated defect density of the coesite. Our results suggest that the recrystallization process of exhumed UHP complexes is not uniform, but comprises several definable steps that can be identified through detailed investigation.
CM chondrites are some of the most abundant meteorites and record evidence of aqueous alteration, thermal metamorphism and impacts on their parent bodies. Determining the size and number of CM chondrite parent bodies could shed light on the evolution of hydrated asteroids and how common CM-like material was in the early Solar System. Here, we combine thermal evolution modelling with the peak temperature distribution in the CM chondrite catalogue to constrain the parent body's early thermal history. In addition, we perform ultraviolet–visible–near-infrared (UV-vis-NIR) spectral comparisons to asteroids to understand the parent body's later collisional evolution. The timing of aqueous alteration and the number of heated CM chondrites is consistent with ≳50 km, low-temperature, aqueously altered parent body(ies) thermally metamorphosed by impacts. Spectra link the CM chondrites to hydrated, low-density asteroids and, combined with dynamical matches, limits the radii of surviving parent body(ies) to less than 150 km. Thermal modelling cannot determine the number of parent bodies, but the number of asteroids that are spectral or dynamical matches to CM chondrites supports that there were multiple parent bodies. Overall, our results suggest that one or more 50–100 km-radius planetesimals that accreted 3.5–4 Myr after calcium–aluminium-rich inclusion (CAI) formation could have produced the CM chondrites.
The Ediacaran-Cambrian transition archives the widespread disappearance of ‘Ediacaran-type’ soft-bodied biota and the appearance of most modern animal body plans, including a major diversification of skeletal animals and styles of animal-substrate interaction. Despite over a century of study, our ability to confidently reconstruct the series of macroevolutionary events that inform origination and extinction rates across the Ediacaran-Cambrian transition is challenged by underlying ambiguity in global stratigraphic correlation. Here, we review the chronology of events recorded by the successions that are currently the most temporally well-constrained, discuss major uncertainties, and use this perspective to reconstruct plausible global age frameworks for published biostratigraphic and chemostratigraphic data. Current models support minor temporal overlap of classically Ediacaran and Cambrian calcified animal fossils, aid assessments of eustatic sea-level and drivers of carbon isotope instability, contextualize regional datasets, and highlight the approaches required for further refinement. While there remains ~5 million years of uncertainty, holistic evaluation of existing chronostratigraphy suggests that the GSSP for the Ediacaran-Cambrian boundary falls between 538 and 533 Ma.
Granulite belts preserve fundamental records of lower-crustal processes and the tectonothermal evolution of ancient orogens, particularly during Paleoproterozoic supercontinent assembly. This study investigates the Novolândia Granulite Belt, Bacajá Domain, SE Amazonian Craton, through integrated field mapping, petrography, U–Pb zircon and monazite geochronology, and whole-rock Nd isotopes. The belt comprises aluminous, felsic and mafic granulite facies rocks variably affected by partial melting. Detrital zircon populations from aluminous granulites indicate Paleoarchean to Paleoproterozoic sources ( c. 3.3–2.3 Ga), suggesting sedimentary protoliths derived mainly from reworked ancient crust. Felsic and mafic granulites record ages of 2744 ± 21 and 2082 ± 7 Ma, respectively, interpreted as the best estimate of protolith crystallization. Metamorphic zircon and monazite ages define a protracted metamorphic event between 2.16 and 2.04 Ga, marked by multiple zircon growth episodes and late monazite crystallization, followed by a younger overprint at 1921 ± 16 Ma. Nd isotopic data yield predominantly negative ε Nd(t) values and Archean–Paleoproterozoic model ages, indicating extensive crustal reworking. The Novolândia Granulite Belt records the prolonged reworking of Archean crust near the Bacajá–Carajás boundary, reflecting a complex history of convergence, magmatism and granulite facies metamorphism related to the Paleoproterozoic Columbia assembly, similar to other granulite belts in Amazonian and West Africa cratons.
