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Due to the scarcity of rock samples, the Hadean Era predating 4 billion years ago (Ga) poses challenges in understanding geological processes like subaerial weathering and plate tectonics that are critical for the evolution of life. The Jack Hills zircon from Western Australia, the primary Hadean samples available, offer valuable insights into magma sources and tectonic genesis through trace element signatures. However, a consensus on these signatures has not been reached. To address this, we developed a machine learning classifier capable of deciphering the geochemical fingerprints of zircon. This allowed us to identify the oldest detrital zircon originating from sedimentary-derived "S-type" granites. Our results indicate the presence of S-type granites as early as 4.24 Ga, persisting throughout the Hadean into the Archean. Examining global detrital zircon across Earth's history reveals consistent supercontinent-like cycles from the present back to the Hadean. These findings suggest that a significant amount of Hadean continental crust was exposed, weathered into sediments, and incorporated into the magma sources of Jack Hills zircon. Only the early operation of both subaerial weathering and plate subduction can account for the prevalence of S-type granites we observe. Additionally, the periodic evolution of S-type granite proportions implies that subduction-driven tectonic cycles were active during the Hadean, at least around 4.2 Ga. The evidence thus points toward an early Earth resembling the modern Earth in terms of active tectonics and habitable surface conditions. This suggests the potential for life to originate in environments like warm ponds rather than extreme hydrothermal settings. [ABSTRACT FROM AUTHOR]

Continental alkaline magmatism has been suggested to play a significant role in releasing deep mantle carbon into the atmosphere, which can greatly impact the global climate. However, the temporal variations of alkaline magmatism and their potential to modulate climate over geologic time remain poorly constrained. The detrital zircon record is a frequently used proxy for tracking secular variations in particular magmatism. Here, we use a novel machine‐learning technique to discriminate zircon from carbonatites, kimberlites, and other alkaline rocks. A global compilation of detrital zircon yields continental alkaline magmatic flare‐ups between 1,050−850, 650−500, 250−200, and 50−0 Ma. Our estimates indicate relatively elevated contributions of total magmatic carbon outgassing from alkaline magmatism during the aforementioned magmatic flare‐ups. We infer that anomalous alkaline magmatism may influence global warming during specific intervals of geologic time, but when they are not that voluminous or persistent extensive arc magmatism may drive warming conditions. Plain Language Summary: The potential of volcanic CO2 emissions to modulate atmospheric CO2 levels and affect the environment of our planet has been recognized. Some specific volcanic types, such as continental arc volcanism, have been hypothesized to play a dominant role in driving long‐term climate change. Recently, the efficiency of continental alkaline magmatism in releasing carbon from the deep mantle to the atmosphere and its ability to influence Earth's climate is proposed for certain timescales and supported by empirical data. However, the quantitative estimation of the alkaline magmatic activity over geologic time and its general link to the global climate change remains poorly constrained. Here, we assess the alkaline magmatic variations based on the detrital zircon record and a novel machine‐learning model which could discriminate zircon from carbonatites, kimberlites and other related alkaline silicate rocks. The predictive result shows several peaks at 1,050−850, 650−500, 250−200, and 50−0 Ma, which is considered a minimum estimation due to the preservation bias of the detrital zircon record. Our estimates indicate that continental alkaline magmatism may influence global warming during specific intervals of geologic time such as the early Paleozoic and early Mesozoic. Key Points: Frequency of magmatic events can be assessed by a machine‐learning analysis of zirconContinental alkaline magmatism peaked between 1,050−850, 650−500, 250−200, and 50−0 MaAnomalous alkaline magmatism may contribute to global warming at certain times [ABSTRACT FROM AUTHOR]

The start of the Paleoproterozoic supercontinent cycle is typically taken as the initiation of orogenesis at ca. 2.1 Ga leading to the assembly of Earth's first supercontinent, Columbia. However, the dearth of ca. 2.5–2.2 Ga geological records makes it difficult to deduce tectonic factors during the onset of the Paleoproterozoic supercontinent cycle. The petrogenesis of tonalite–trondhjemite–granodiorite (TTG) provides useful proxies for tracing prevailing geodynamic regimes of early continental evolution. However, marked decreases of TTG and other magmatism occurred across the Archean–Paleoproterozoic transition and have previously precluded forming testable hypotheses. Early Paleoproterozoic TTGs have been identified in the North China Craton (NCC) and other cratons, which may represent the last major pulse of TTGs globally. Here we present low δ18O and δ30Si ca. 2.3 Ga TTGs from the NCC, together with thermodynamic modeling and compilation of stable O and Si isotopes for TTGs globally through time. The ca. 2.3 Ga TTGs were derived from the partial melting of Archean basaltic crust and give lighter average zircon δ18O (3.15 ± 0.35‰) and whole‐rock δ30Si values (−0.17 ± 0.08‰) than most Archean TTGs. Considering coeval mafic‐felsic igneous rocks, and lithospheric thinning since ca. 2.5 Ga based on estimated crustal thickness through the Neoarchean–Paleoproterozoic, we posit the onset of an intraplate rifting consistent with the anomalous low‐δ18O magmatism. Continental rifting of Archean cratons/supercratons plausibly hints at the formation of rifts driving subduction initiation as the veritable onset of the Paleoproterozoic supercontinent cycle. Plain Language Summary: The Earth's first supercontinent, Paleoproterozoic–Mesoproterozoic Columbia, likely began to form during ca. 2.1 Ga (billion years ago) orogenesis. However, the limited record of ca. 2.5–2.2 Ga magmatism makes it difficult to establish how exactly the Paleoproterozoic supercontinent cycle commenced. The tonalite–trondhjemite–granodiorite (TTG) series of felsic rocks forms the backbone of Archean cratons and can provide key constraints on the Earth's early tectonic evolution. Some early Paleoproterozoic TTGs occur in North China and other cratons, which may represent the last major TTG event globally, presenting the possibility to fulfill this role. Here we carry out zircon O and bulk‐rock Si isotopic analyses and thermodynamic modeling for these ca. 2.3 Ga TTGs, together with Si‐O‐Hf data compilation of TTGs globally through time. These ca. 2.3 Ga TTGs show lighter zircon O and bulk‐rock Si isotopes than those of Archean TTGs. They might be formed within‐plate, associated with lithospheric thinning and mantle‐crust remelting to form mafic‐felsic magmatism. We propose an intraplate rift setting for this early ca. 2.3 Ga magmatism, which drove the mobilism that led to the subsequent 2.1–1.8 Ga orogenesis and should be posited as the real start of the Paleoproterozoic supercontinent cycle. Key Points: Ca. 2.3 Ga tonalite–trondhjemite–granodiorite (TTG) in the North China Craton (NCC) shows the affinity of low‐pressure (LP) TTGs and contains low zircon δ18O and bulk‐rock δ30Si valuesCa. 2.3 Ga low δ18O and δ30Si TTG and coeval low‐δ18O magmatism herald the initiation of an intraplate rift settingSuch intraplate rifting hints at the formation of rifts driving subduction as the real onset of the Paleoproterozoic supercontinent cycle [ABSTRACT FROM AUTHOR]