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The major Precambrian crustal growth in the North China Craton (NCC) has been thought to have occurred at ∼2.5 Ga. Here we present secondary ion mass spectroscopy (SIMS) and laser ablation-inductively coupled mass spectrometry (LA-ICP-MS) zircon U-Pb ages and Hf isotope compositions from dioritic and tonalite-trondhjemite-granodiorite (TTG) gneisses of the Neoarchean-Paleoproterozoic metamorphic terrane in the central NCC. Zircons from the trondhjemitic samples yield emplacement ages at 2,702±7 and 2,722±9 Ma. Those from the dioritic gneiss yield an age of 2,704±14 Ma. The TTG gneisses are characterized by a Na-rich and K-poor (Na/K ratios=2.7, 2.6) nature; strongly fractionated rare earth element patterns ([La/Yb]N=35, 20); high Sr (418 ppm, 318 ppm) and Sr/Y (78, 49), low Y (5.4 ppm, 6.4 ppm) and YbN (3.0, 3.6); and low MgO (0.89%, 1.10%), Mg# (47, 42), Cr (39 ppm, 20 ppm), and Ni (11 ppm, 8 ppm), Nb/Ta (16, 12), which suggests that magmas were derived from the partial melting of a flatly subducted oceanic slab. The dioritic gneiss shows higher MgO (3.17%), Mg# (50), Cr (44 ppm) and Ni (40 ppm) and lower Sr/Y (22) and (La/Yb)N (8) ratios, which suggests contamination with mantle peridotite. All zircon grains from these Neoarchean gneisses yield high positive εHf (t) values that range from +3.5 to +7.7 and Hf model ages between 2.70 and 2.85 Ga. We propose that the widespread ∼2.5-Ga plutonic event found elsewhere in the NCC may represent a major reworking (melting) event, whereas the ∼2.7-Ga magmatism likely represents the main crustal growth of the NCC, comparable to those of other cratons worldwide.

The Precambrian history of the Lhasa terrane, southern Tibet is intensely debated, which hinders global plate tectonic reconstructions throughout the Proterozoic. Previous research on Precambrian basement has suggested that the Lhasa terrane originated from India or Africa, although the paucity of exposed pre‐Neoproterozoic rocks in the North Lhasa terrane (NL) has led to significant uncertainty. We document newly identified Neoarchean granites and Mesoproterozoic Guomangtso Suite from the NL. These pre‐Neoproterozoic rocks reveal a 2.62 Ga anorogenic rifting event and a 1.30–1.10 Ga transition from subduction to back‐arc extension, related to the 2.7–2.6 Ga rifting of the Pilbara Craton and the Proterozoic assembly between the North and West Australian Cratons, respectively. However, these tectono‐magmatic events have no equivalents in the South Lhasa terrane (SL). These observations suggest that the NL originated from Western Australia, and the NL and SL may have distinct origins. Plain Language Summary Constraining the origin and evolution of continental fragments plays a crucial role in validating the patterns in the growth of successive supercontinents. However, tracking the evolving paleogeographic position of these fragments, especially for those of Precambrian age without paleolongitude constraints, has proven difficult. We redefine the pre‐Neoproterozoic evolution of the Lhasa terrane, southern Tibet based on newly discovered Neoarchean and Mesoproterozoic rocks, which contain missing information about the pre‐Neoproterozoic evolution of the North Lhasa terrane (NL). We reveal the Neoarchean–Mesoproterozoic evolution of the NL and its affinity with Western Australia, which is clearly distinct from the Indian affinities of the South Lhasa terrane (SL) from the Paleoproterozoic to Mesoproterozoic. These findings suggest that the Lhasa terrane did not originate as a unified entity from India during the pre‐Neoproterozoic, as previously thought, but rather that the NL originated from Western Australia, with the NL and SL having distinct origins. Our study therefore shows for the first time key evidence identifying the origin of the NL before the Neoproterozoic. Key Points Newly identified 2.62 Ga granites in the North Lhasa terrane show affinity with the Pilbara Craton, Western Australia The 1.30–1.10 Ga Guomangtso Suite identified in North Lhasa documents the Proterozoic assembly of North and West Australian Cratons The North Lhasa terrane was connected with Western Australia before separating during the Neoproterozoic

Many paleoredox proxies indicate low-level and dynamic incipient oxygenation of Earth’s surface environments during the Neoarchean (2.8–2.5 Ga) before the Great Oxidation Event (GOE) at ∼2.4 Ga. The mode, tempo, and scale of these redox changes are poorly understood, because data from various locations and ages suggest both protracted and transient oxygenation. Here, we present bulk rock and kerogen-bound nitrogen isotope ratios as well as bulk rock selenium abundances and isotope ratios from drill cores sampled at high stratigraphic resolution through the Jeerinah Formation (∼2.66 Ga; Fortescue Group, Western Australia) to test for changes in the redox state of the surface environment. We find that both shallow and deep depositional facies in the Jeerinah Formation display episodes of positive primary δ15N values ranging from +4 to +6‰, recording aerobic nitrogen cycling that requires free O₂ in the upper water column. Moderate selenium enrichments up to 5.4 ppm in the near-shore core may indicate coincident oxidative weathering of sulfide minerals on land, although not to the extent seen in the younger Mt. McRae Shale that records a well-documented “whiff” of atmospheric oxygen at 2.5 Ga. Unlike the Mt. McRae Shale, Jeerinah selenium isotopes do not show a significant excursion concurrent with the positive δ15N values. Our data are thus most parsimoniously interpreted as evidence for transient surface ocean oxygenation lasting less than 50 My, extending over hundreds of kilometers, and occurring well before the GOE. The nitrogen isotope data clearly record nitrification and denitrification, providing the oldest firm evidence for these microbial metabolisms.

Archean rock exposures in the Yangtze Craton of South China are scarce and have been only studied in small-scale outcrops for understanding its early crustal evolution. Geological investigations have been carried out for three Neoarchean gneissic granitic plutons from the Dabie orogen in the northeastern margin of the Yangtze Craton. Zircon U-Pb geochronology constrains the emplacement of high-K monzogranite at 2645±30 Ma, high-K syenogranite at 2630±37 Ma and Na-rich granodiorite at 2497±29 Ma. These findings provide direct evidence for the existence of ∼2.7–2.5 Ga rocks in the Dabie orogen, which significantly contribute to the distribution and evolution of Neoarchean basement rocks in the Yangtze Craton. Zircon crystals from the three granite samples give ε Hf ( t ) values of −0.9 to 3.7, −4.2 to −0.4 and −4.7 to 0.1, respectively, corresponding to T DM2 ages of 3186–2909, 3372–3141 and 3297–3005 Ma. The magmatic zircons have δ 18 O values of 5.06±0.27‰ to 5.79 ±0.30‰ (average 5.59‰), 6.14±0.24 to 7.35±0.26‰ (average 6.87‰) and 5.95±0.17‰ to 7.09±0.17‰ (average 6.55‰), respectively. Considering the possible decrease of δ 18 O value due to the lead loss during post-crystallization alteration, the primary δ 18 O values might be substantially higher than those of the normal mantle zircon value ( δ 18 O=5.3±0.6‰). These isotopic data indicate that the Jiamiao Neoarchean granites were largely generated through reworking of Paleo-Mesoarchean basement rocks with a minor contribution of supracrustal material. Integrating our findings with previous results, we infer that the Archean-Paleoproterozoic complexes/terranes of the Yangtze Craton have distinct petrogenesis and the timings of the transition from Na-rich to high-K granites, crustal growth, and tectonothermal evolution before ∼2.0 Ga. However, all of them underwent metamorphism at about 2.0 Ga. These observations also reveal that the Yangtze Craton might comprise several microcontinents that evolved individually and collided to form a unified craton at ∼2.0 Ga, synchronous with the assembly of the Columbia supercontinent. However, the lack of relevant data from the southeastern Yangtze Craton may have a critical influence on this conclusion and should be solved in the future.

Emerging evidence suggests that atmospheric oxygen may have varied before rising irreversibly ∼2.4 billion years ago, during the Great Oxidation Event (GOE). Significantly, however, pre-GOE atmospheric aberrations toward more reducing conditions—featuring a methane-derived organic-haze—have recently been suggested, yet their occurrence, causes, and significance remain underexplored. To examine the role of haze formation in Earth’s history, we targeted an episode of inferred haze development. Our redox-controlled (Fespeciation) carbon- and sulfur-isotope record reveals sustained systematic stratigraphic covariance, precluding nonatmospheric explanations. Photochemical models corroborate this inference, showing Δ36S/Δ33S ratios are sensitive to the presence of haze. Exploiting existing age constraints, we estimate that organic haze developed rapidly, stabilizing within ∼0.3 ± 0.1 million years (Myr), and persisted for upward of ∼1.4 ± 0.4 Myr. Given these temporal constraints, and the elevated atmospheric CO₂ concentrations in the Archean, the sustained methane fluxes necessary for haze formation can only be reconciled with a biological source. Correlative δ13COrg and total organic carbon measurements support the interpretation that atmospheric haze was a transient response of the biosphere to increased nutrient availability, with methane fluxes controlled by the relative availability of organic carbon and sulfate. Elevated atmospheric methane concentrations during haze episodes would have expedited planetary hydrogen loss, with a single episode of haze development providing up to 2.6–18 × 1018 moles of O₂ equivalents to the Earth system. Our findings suggest the Neoarchean likely represented a unique state of the Earth system where haze development played a pivotal role in planetary oxidation, hastening the contingent biological innovations that followed.

Although the thermal evolution of the mantle before c. 3.0 Ga remains unclear, since c. 3.0 Ga secular cooling has dominated over heat production--this is time's arrow. By contrast, the thermal history of the crust, which is preserved in the record of metamorphism, is more complex. Heat to drive metamorphism is generated by radioactive decay and viscous dissipation, and is augmented by the influx of heat from the mantle. Notwithstanding that reliable data are sparse before the Neoarchean, we use a dataset of temperature (T), pressure (P) and thermobaric ratio (T/P at the metamorphic 'peak'), and age of metamorphism (t, the timing of the metamorphic 'peak') for rocks from 564 localities ranging in age from the Cenozoic to the Eoarchean eras to interrogate the crustal record of metamorphism as a proxy for the heat budget of the crust through time. On the basis of T/P, metamorphic rocks are classified into three natural groups: high T/P type (T/P >775°C/GPa, mean T/P ∼1105°C/GPa), including common and ultrahigh-temperature granulites, intermediate T/P type (T/P between 775 and 375°C/GPa, mean T/P ∼575°C/GPa), including high-pressure granulites and medium- and high-temperature eclogites, and low T/P type (T/P <375°C/GPa, mean T/P ∼255°C/GPa), including blueschists, low-temperature eclogites and ultrahigh-pressure metamorphic rocks. A monotonic increase in the P of intermediate T/P metamorphism from the Neoarchean to the Neoproterozoic reflects strengthening of the lithosphere during secular cooling of the mantle - this is also time's arrow. However, temporal variation in the P of intermediate T/P metamorphism and in the moving means of T and T/P of high T/P metamorphism, combined with the clustered age distribution, demonstrate the cyclicity of collisional orogenesis and cyclic variations in the heat budget of the crust superimposed on secular cooling since c. 3.0 Ga -this is time's cycle. A first cycle began with the widespread appearance/survival of intermediate T/P and high T/P metamorphism in the Neoarchean rock record coeval with amalgamation of dispersed blocks of lithosphere to form protocontinents. This cycle was terminated by the fragmentation of the protocontinents into cratons in the early Paleoproterozoic, which signalled the start of a new cycle. The second cycle continued with the progressive amalgamation of the cratons into the supercontinent Columbia and extended until the breakup of the supercontinent Rodinia in the Neoproterozoic. This cycle represented a period of relative tectonic and environmental stability, and perhaps reduced subduction during at least part of the cycle. During most of the Proterozoic the moving means for both T and T/P of high T/P metamorphism exceeded the arithmetic means, reflecting insulation of the mantle beneath the quasi-integrated lithosphere of Columbia and, after a limited reorganisation, Rodinia. The third cycle began with the steep decline in thermobaric ratios of high T/P metamorphism to their lowest value, synchronous with the breakup of Rodinia and the formation of Pannotia, and the widespread appearance/preservation of low T/P metamorphism in the rock record. The thermobaric ratios for high T/P metamorphism rise to another peak associated with the Pan-African event, again reflecting insulation of the mantle. The subsequent steep decline in thermobaric ratios of high T/P metamorphism associated with the breakup of Pangea at c. 0.175 Ga may indicate the start of a fourth cycle. The limited occurrence of high and intermediate T/P metamorphism before the Neoarchean suggests either that suitable tectonic environments to generate these types of metamorphism were not widely available before then or that the rate of survival was low. We interpret the first cycle to record stabilisation of subduction and the emergence of a network of plate boundaries in a plate tectonics regime once the balance between heat production and heat loss changed in favour of secular cooling, possibly as early as c. 3.0 Ga in some areas. This is inferred to have been a globally linked system by the early Paleoproterozoic, but whether it remained continuous to the present is unclear. The second cycle was characterised by stability from the formation of Columbia to the breakup of Rodinia, generating higher than average T and T/P of high T/P metamorphism. The third cycle reflects colder collisional orogenesis and deep subduction of the continental crust, features that are characteristic of modern plate tectonics, which became possible once the average temperature of the asthenospheric mantle had declined to <100°C warmer than the present day after c. 1.0 Ga.

Garnet is a common minor phase in S-type granites and pegmatites, but its petrogenesis remains poorly constrained. Garnet in these systems may have crystallized from the melt or it may represent inherited grains derived from the source or xenocrysts from the wall rocks. Although garnet has the potential to provide unique insights into the magmatic evolution and crystallization intervals of S-type granites and pegmatites, its geochemical and chronological record is underexplored. In this study, we investigate the Lu–Hf age and trace-element record of garnet in the Neoarchean Decelles Batholith (c. 2670–2620 Ma), southeastern Superior Craton, Canada. The batholith comprises one of the most voluminous granites in the region and was likely sourced from anatexis of the metasedimentary Pontiac Group at depth. Garnet Lu–Hf geochronology yielded ages between 2667.5 ± 3.9 and 2656.0 ± 7.1 Ma, overlapping with U–Pb monazite ages from the batholith and Lu–Hf ages from the host rocks. LA-ICP-MS trace-element mapping revealed well-preserved sharp oscillatory—locally sector—zoning in Li, P, Sc, Ti, Y, Zr, REE, Hf, Th, and U, contrasting with weak major element zoning. Garnet grains exhibit a core with concentric zoning and an overgrowth domain truncating core patterns, reflecting both trace-element uptake controlled by varying crystal growth rates, element supply and diffusion at the garnet-matrix interface in the presence of melt, and cation supply limitations due to co-crystallization of muscovite, monazite, apatite, and zircon. The data support a magmatic origin for garnet in the peraluminous granite and demonstrate that the oscillatory zoning can be diagnostic. Moreover, the new Lu–Hf garnet dates place new constraints on the timing of crystallization of the Decelles Batholith. This study provides new insights into the conditions of garnet crystallization in granitic systems and illustrates the versatility of garnet in constraining the onset and later evolution of peraluminous granitoid magmatism. Ultimately, our study underscores the necessity of case-by-case assessment of garnet origins in S-type granites, emphasizing trace-element mapping as a key tool for petrogenetic interpretation.

Here we examine how lithospheric thickening is affected by active surface sedimentation and erosion in geodynamic models of craton formation—an aspect that has been neglected in previous models even though cratons may be the first landmasses to emerge above sea level. In our two‐dimensional numerical models, inward horizontal velocities are imposed at the side boundaries of the model domain to induce thickening of the cratonic lithosphere by horizontal compression. Various rates of sedimentation and erosion are applied at the surface and the thickness of the lithosphere is monitored during the 50 Myr compression phase, and for 2 billion years after the imposed compression phase. In our models, surface processes act on the high‐relief surface topography of the mobile belts adjacent to the cratonic nucleus. Erosion in the mobile belts during the compression alters lithosphere geodynamics, increasing the thickness of the mobile belt lithosphere to depths capable of supporting diamond growth. This enhanced thickening in the mobile belt regions limits shortening and thickening of the cratonic nucleus and the lithospheric thickness can vary by up to 15 km between models with different surface process rates. Plain Language Summary The single most important event in Earth's history may have been the formation of cratons. These ancient continents have been preserved for billions of years due to their thick lithospheric keels, and they represent the first landmasses to rise above sea level, exposing the surface to erosion. As such, they are the platforms for terrestrial life. The removal and deposition of crustal material from cratons may have provided the impetus for the beginning of life on Earth and may have altered the progression of lithosphere deformation. Despite their significance, surface processes have largely been ignored in geodynamic models of craton formation. We present numerical models that fill this gap in the literature by exploring the effect of surface erosion and sedimentation on lithosphere thickening in a compressional regime. During the compression phase, high rates of erosion decrease thickening in the cratonic nucleus and enhance thickening in the weaker surrounding regions. Although the weaker material is unable to remain thick and stable for billions of years, unlike the cratonic nucleus, the lithosphere in these regions is momentarily in the diamond stability field—a result that does not happen in models with no active surface processes. Key Points Crustal thermal structure is a critical parameter that determines deformational style during lateral craton accretion High surface process rates hinder lithosphere thickening during compressional events, but the long‐term stability of cratons is unaffected Depleted mantle lithosphere is resistant to horizontal compression and fails to adequately thicken to the diamond stability field

The basalts within the greenstone belt worldwide serve as an ideal target to decipher the nature of Archean mantle sources and further to extend the understanding of the early stages of Earth’s evolution. To provide important insights into the issues, we carried out a detailed investigation of whole-rock geochemistry and Sm-Nd isotopes, and zircon U-Pb-Hf isotopes for the Late Neoarchean metamorphosed basalts in eastern Hebei, North China Craton. U-Pb isotopic dating using the LA-ICP-MS on zircons reveals that the basalts in eastern Hebei erupted at ca. 2.48–2.51 Ga and subsequently experienced multiple regional metamorphic events at 2 477 and 1 798 Ma, respectively. The metamorphosed basalts are featured by low SiO 2 , MgO, K 2 O + Na 2 O, and high FeO contents, endowed with the subalkaline and high-Fe tholeiitic affinities. The radiogenic initial Nd and Hf isotope values and correlations among V, Ni and Cr contents strongly imply that the basalts experienced significant clinopyroxene and olivine fractionation and minor crustal contamination during magma evolution. They are also characterized by the relatively low total REE contents and exhibit significant depletions to moderate enrichments in the LREE contents, indicating the derivation from a deep mantle source in an Archean proto-mantle plume setting.

The Neoarchean Qingyuan greenstone belt (QGB) is located at the northeastern margin of the North China Craton (NCC) and has experienced amphibolite- to granulite-facies metamorphism. The supracrustal rock assemblage is composed of biotite-hornblende (Bt-Hb) monzonitic gneiss, garnet-biotite-hornblende (Grt-Bt-Hb) monzonitic gneiss, Grt-Bt-Hb plagioclase gneiss, amphibolite and orthopyroxene-biotite-hornblende (Opx-Bt-Hb) plagioclase gneiss. This study involves thorough field and petrographic observations, whole-rock geochemistry and LA-ICP-MS zircon U‒Pb ages of these rocks to constrain the Neoarchean geodynamic setting of the QGB. Zircon U‒Pb dating indicates that these metavolcanic rocks formed during 2.57‒2.52 Ga and experienced subsequent regional metamorphism at 2.52‒2.47 Ga. Lithological and geochemical characteristics show that the QGB protoliths were tholeiitic to calc-alkaline basalts, andesites, dacites and rhyolites. The andesite-dacite-rhyolite assemblage exhibits high SiO 2 and Mg# values, low Yb and Y contents, strongly fractionated chondrite-normalized REE patterns and depletion in Nb, Ta, Ti and P, resembling Phanerozoic adakites. These geochemical characteristics suggest an origin from the partial melting of a subducted slab interacting with mantle wedge material. The tholeiitic to calc-alkaline basalts exhibit slightly LREE-enriched chondrite-normalized REE patterns and negative Nb and Ti anomalies, like island arc basalts. These basalts might have originated by partial melting of a mantle source affected by metasomatism from subduction-derived fluids and melts. The lithological associations and geochemical characteristics imply that the Qingyuan greenstone belt developed in a continental margin arc setting. Graphical abstract