Large-scale crustal growth driven by LIP magmatism during the Paleoproterozoic

Domain: earth_science
Published: 2025-11-28
Editorial outcome: major_revision

Abstract
The evolution of Earth’s continental crust is crucial for understanding geodynamics, climate regulation, and the origins of life. The Paleoproterozoic, marked by the Great Oxidation Event and the consolidation of plate tectonics, was a critical interval for continental growth. While arc magmatism dominates crust formation in the Phanerozoic, its role in earlier Earth history remains uncertain. Three silicic LIPs in the Amazon Craton were emplaced at regular ~90-100 million-year intervals (1980 Ma, 1880 Ma, and 1790 Ma), producing high-temperature (>750°C) silicic magmas derived from lower crust (~45 km thick). Our findings demonstrate that LIPs contributed significantly to continental crustal growth through deep-crustal partial melting of Archean-Rhyacian crust. We highlight that silicic LIP magmatism was a fundamental driver of continental differentiation and long-term stability during the Paleoproterozoic.

Introduction
Earth’s geodynamic and continental crustal evolution is a critical issue considering its implications for climate conditions and the inception of life since the erosion of silicate rocks drives the stabilization of liquid water at Earth’s surface by consuming atmospheric CO2. To understand this evolution, we must assess both when and how plate tectonics took place and the processes responsible for the creation of continental crust. The onset of plate tectonics as a local or global system, powered by the negative buoyancy of old dense oceanic lithosphere sinking into weaker ductile asthenosphere in subduction zones, dates back to Hadean or the end of Archean. In addition, there are two divergent hypotheses regarding the compositional evolution of the continental crust through time. A uniformitarian view based on geochemical and Hadean zircon data suggests that silicic continental crust was already formed in the Hadean, and nearly constant crustal silica compositions prevailed since the early Archean. An alternative view, based on tectonic/metamorphic asymmetry, magmatic associations, and geochemistry, proposes that the early Earth was composed of a mafic crust, evolving towards more intermediate compositions from 3.1 Ga to 2.5 Ga.

At the beginning of the Paleoproterozoic, the Great Oxidation Event occurred during the period between 2.4 Ga and 2.0 Ga, accompanied by decreased deposition of banded iron formation and a concomitant increase in atmospheric O2 levels. This time interval partially overlaps with a global decline in magmatism, orogenic activity, and passive margin sedimentation from 2.3 Ga to 2.2 Ga, interpreted as a tectono-magmatic lull, possibly linked to a phase of stagnant-lid tectonics. The end of the Rhyacian (~2.2 Ga) to the Statherian (1.8 Ga–1.6 Ga) is characterized by multiple orogenic belts surrounding Archean cratons. Rhyacian domains, including those of the Amazon and West African cratons, are dominated by granite-basalt-komatiite associations. Eclogites and ophiolites, considered ‘plate tectonic indicators’, are common features of these belts, including the Svecofennian, Kola-Karelia, and Birimian. The period from the Late-Rhyacian to the Statherian includes anachronic events of rift-drift, accretionary and collisional orogenies in most Paleoproterozoic belts, with episodes of silicic additions to the continental crust. An exception to these belts is the Late-Rhyacian to Statherian record of the Amazon Craton in South America. This is a key area to investigate mechanisms of crustal growth and a potential relationship with subduction, since no plate tectonic indicators have been identified. Instead, the period from 2.0 Ga to 1.74 Ga in this crustal segment is marked by the emplacement of large igneous provinces with an extensive bimodal igneous association. Peaks in magmatic activity within these provinces occurred at approximately 90 to 100 Myr intervals, specifically around 1.98 Ga, 1.88 Ga, and 1.79 Ga, accompanied by the emplacement of basaltic radial dyke swarms and sill complexes. These silicic LIPs are key to unraveling the tectonic evolution of the Amazon Craton, evaluating effective mechanisms of continental crust formation, and testing the theory of a global interconnected network of plate boundaries during the Paleoproterozoic.

The Amazon Craton spans approximately 6,500,000 km², making it the largest continuous exposure of Archean, Paleoproterozoic, and Mesoproterozoic crust in South America. It is bounded by the Andes and partially concealed by Andean foreland basins to the west and Neoproterozoic mobile belts to the east. The craton is divided into the Guyana Shield in the north and the Central Brazil Shield in the south, separated by the overlying Phanerozoic Amazonas Basin. Paleomagnetic reconstructions indicate a connection between the Amazon and West African cratons around ~2.0 Ga, following the 2.2–2.0 Ga Transamazon-Birimian Orogeny. At 1.78 Ga, paleomagnetic models suggest a connection between Amazonia, West Africa, and Baltica, forming the South America-Baltica (SAMBA) configuration. The SAMBA model is considered the core of the Columbia Supercontinent, with other cratonic blocks likely accreted to this extensive continental landmass, even though some researchers dispute that Amazonia/West Africa was never part of Columbia.

The geological framework of the Amazon Craton consists of Archean provinces considered the craton’s central nuclei, represented by the Central Amazonian Province (>2.3 Ga), bounded by progressively younger Paleoproterozoic provinces. Archean segments (Mesoarchean to Neoarchean) outcrop in the eastern portion of the Central Brazil Shield, and at the east and west boundaries of the Guyana Shield. Archean crust is indirectly observed beneath most of the Central Brazil Shield and part of the Guyana Shield. The distribution of Archean crust is evidenced as an isotopic provinciality that divides the Amazon Craton into an eastern segment, characterized by Archean Nd TDM ages and the most negative εNd(t) values, and a western segment, where Rhyacian to Orosirian Nd TDM ages and slightly negative to slightly positive εNd(t) values predominate.

Archean provinces in the Amazon and West African cratons are bounded by high-grade metamorphic belts, greenstone belts, tonalite-trondhjemite-granodiorite (TTG) to charnockite suites, and high-Mg-K granite suites from the Rhyacian to Orosirian (2.2–1.95 Ga). These form a 1500 km-long NNW-SSE belt in the northern Guyana Shield and occur as several fragments in the Central Brazil Shield. This orogenic event, widespread across both the Amazon and West African cratons, is related to the Transamazonian Orogeny in South America. Orosirian to Stenian provinces have been interpreted as NW-trending orogenic belts characterized by continuous arc accretion and soft-collision events to the west of the Archean-Rhyacian cores at 2.03 Ga–1.87 Ga, 1.83 Ga–1.52 Ga, 1.55 Ga–1.3 Ga, and 1.3 Ga–1.0 Ga. Parallel accretionary orogens were matched with orogens from Baltica and Laurentia, and paleomagnetic correlations linked them with Amazonia, giving rise to the Great Proterozoic Accretionary Orogen, thought to be generated by almost continuous subduction over time. Nevertheless, the record of plate tectonic indicators in the Amazon Craton comprises a 1460–1440 Ma ophiolite in the Sunsás Belt, that post-dates Paleoproterozoic belts and pre-dates the late Mesoproterozoic events (1.2–0.95 Ga). These events are correlated with the Grenville-type orogens related to the collision of Amazonia and Laurentia.

Large Paleoproterozoic linear volcano-plutonic belts across the Amazon Craton are composed of silicic-dominant igneous rocks, mostly granitoids and rhyolitic ignimbrites with calc-alkaline I-type to A-type affinities, that intrude and overlie Archean, Rhyacian, and Eo-Orosirian terranes. They have been previously interpreted as part of distinct magmatic arcs or related to post-collisional events, conforming with the orogenic evolution of the Amazon Craton provinces during the Paleoproterozoic. The main arguments favoring magmatic arc settings involve: (i) geochemical features, such as the occurrence of high-K calc-alkaline rocks with negative Nb-Ta anomalies, (ii) slightly juvenile Nd isotope signatures, (iii) genetic association with Au-Cu(-Mo) and Cu-Mo epithermal and sparse porphyry mineralization, and (iv) regional crystallization/Nd TDM age zonation. All these features are also likely to occur in LIP-SLIP settings, and several other features from these belts, such as radial dyke swarms, high-volume igneous events with short duration, bi-modal compositions, and older surrounding crust, are typical of intraplate LIP magmatism. Further, three separate LIP/Silicic LIP events have been interpreted, based on their preserved areal extent, the short duration of igneous activity, and correlation with tholeiitic basaltic radial dyke swarms:

1) The ‘early Orosirian’ Orocaima Silicic LIP in the central part of the Guyana Shield has more than 0.4 M km², an approximate duration of ~53 Myr, and peak magmatism at 1.98 Ga, representing the first cycle of large-scale silicic magmatism, referred to here as Cycle 1. This Silicic LIP occurs spatially and temporally close to the Yanomami LIP, represented by 1.98 Ga radiating dyke swarms, which are composed of tholeiitic basalts derived from an OIB-like primary melts and form an arrangement pointing to a plume center near the SW margin of proto-Amazonia;

2) The ‘late Orosirian’ Uatumã Silicic LIP that occur over Archean terranes and the Transamazonian belts along the Guyana and Central Brazil shields, has nearly 1 M km², an approximate duration of ~47 Myr, with peak magmatism at 1.88 Ga, representing the second cycle of large-scale magmatism at around 1.88 Ga (Cycle 2). The silicic magmatism is locally associated with charnockites, enderbites, rapakivi granites and gabbros, being also recorded in NW-trending bimodal dyke swarms. The age of this magmatism correlates with worldwide basaltic dyke swarms associated with several LIPs;

3) The Statherian Western Amazonia Igneous Belt, which occurs only within the Central Brazil Shield, generally intrudes the Rhyacian to Orosirian basement, with at least 0.4 M km², a peak of magmatism at 1.78 Ga, and a duration between 45 and 50 Myr. The SLIP is associated with high- and low-Ti tholeiitic basaltic dyke swarms in the Central Brazil Shield and is synchronous with the 1.79 Ga Avanavero LIP in the Guyana Shield. This LIP is represented by a sill complex in the Guyana Shield and by radiating dyke swarms in both Amazon and West African cratons, composed of E-MORB-like tholeiitic high- and low-Ti basalts whose arrangement points to a plume center in the Tuareg Shield. This represents the third cycle of large-scale magmatism (Cycle 3).

In this study, we analyze zircon U-Pb, Lu-Hf, and trace element data from representative volcanic rocks across each of these Large Igneous Provinces to interpret the geodynamic processes driving the repeated cyclic eruptions of voluminous magmas during the Paleoproterozoic. Our findings are compared to the crustal evolution of the Amazon Craton, serving as an example of mechanisms responsible for large-scale continental crust growth.

Results
Age of volcanic rocks
To determine crystallization and inherited age ranges along with zircon trace element compositions, we analyzed 15 samples representative of Paleoproterozoic LIPs from the Amazon Craton. Field and petrographic description, along with location in more detailed geological maps, are present in Supplementary Data 3. The analyses were conducted on 370 previously imaged zircon grains (Supplementary Data 4). Sample selection criteria focused on key lithostratigraphic units with well-established geological contexts and well-characterized whole-rock geochemistry. Crystallization ages were obtained by weighted mean of 207Pb/206Pb dates. Ages interpreted as inherited are reported as concordant (>95%) zircon 207Pb/206Pb apparent ages of single grains. The complete dataset is presented in the Supplementary Data 5.

Six samples of Cycle 1 were collected along the northern boundary of Brazil and Venezuela in the Guyana Shield (three samples from the I-type Surumu Group and one sample from the A-type Cachoeira da Ilha Formation) and near the Tapajós Gold Province in the Central Brazil Shield (two samples from the I-type Vila Riozinho Formation). The three samples from the Surumu Group yield crystallization ages of 1987±4 Ma, 1995±5|8 Ma, and 1996±4 Ma, with inherited ages ranging from 2307 Ma to 2021 Ma. The sample from the Cachoeira da Ilha Formation produces a crystallization age of 2011±4 Ma, with inherited ages between 2097 Ma and 2061 Ma. The two samples from the Vila Riozinho Formation yield ages of 1989±4 Ma and 1982±3 Ma, with inherited ages ranging from 2049 Ma to 2026 Ma.

Three samples from Cycle 2 were collected from both the Guyana Shield (one sample from the I-type Jatapu Formation) and the Central Brazil Shield (two samples from the A-type Moraes de Almeida Formation). The sample from the Jatapu Formation yields an age of 1890±4|8 Ma, with inherited grains dating from 2135 Ma to 1976 Ma. The Moraes de Almeida Formation samples produced ages of 1882±6 Ma and 1893±4|5 Ma, with inherited ages ranging from 2042 Ma to 1922 Ma.

Six samples from Cycle 3 were obtained from the lowermost (four samples from the A-type Colíder Group) and uppermost (two samples from the A-type Pedro Sara Formation) stratigraphic units of the Western Amazonia Igneous Belt. The Colíder Group samples yield ages of 1814±3 Ma, 1796±4|7 Ma, 1795±5 Ma, and 1792±4 Ma, with inherited ages ranging from 1971 Ma to 1829 Ma. Two samples from the Pedro Sara Formation provided ages of 1762±4 Ma and 1755±4 Ma, with inherited grains ranging from 2852 Ma to 1810 Ma.

Zircon composition, crystallization conditions, and source-depth
Zircons from all three cycles exhibit similar compositions, characterized by high concentrations of Hf, Nb, Ta, Y, Th, and P, consistent with those of granitoids and dolerites. Their mean Th/U and Yb/Sm are approximately 1 and 20, respectively. Chondrite-normalized trace element patterns reveal negative anomalies for La, Pr, Eu, Nb, and Ti, coupled with positive anomalies for Th, U, Hf, and Ta. The mean rare earth element (REE) content of the zircons is ~1000 ppm, with chondrite-normalized REE patterns displaying positive Ce and Sm anomalies and a notable enrichment of heavy REE compared to light REE (Supplementary Data 6).

Trace element geochemistry of zircons provides insights into their source rock composition and crystallization environment. Zircons formed from garnet-bearing sources exhibit lower heavy REE concentrations due to garnet’s affinity for these elements during partial melting, resulting in flatter chondrite-normalized heavy REE patterns. Compared to zircons from high-temperature, high-pressure metamorphic rocks equilibrated with garnet, the igneous zircons analyzed here display Yb(n), Yb/Ce(n), and Yb/Tb(n) similar to those of lower crustal material (Fig. 3A, B). This source interpretation is consistent with field evidence indicating that melts for cycles 1 and 3 were generated from HT-UHT garnet-bearing migmatites and granulites at lower continental crustal levels.

To estimate crustal thickness for each studied magmatic cycle, we applied the chemical mohometry model, by using a large dataset of geochemical data available from the literature. Data were filtered to exclude major and mobile trace elements sensitive to hydrothermal alteration processes. The results yielded Moho depths at 46.3 km during Cycle 1, 46.4 km during Cycle 2, and 43.6 km during Cycle 3 (Supplementary Data 7), which corresponds to a ‘normal’ continental crust thickness, close to the ~40 km average. The depth of zircon crystallization was estimated by the model utilizing the ¹⁷⁶Lu/¹⁷⁷Hf ratio of individual grains as a pressure proxy. Given the inherent uncertainty of single-zircon pressure determinations, Kernel Density Estimate (KDE) curves were used for more robust analysis. The KDE plots reveal peaks at approximately 8.4 kbar for Cycles 1 and 2, and 7.4 kbar for Cycle 3 (Fig. 3C). Assuming a pressure gradient of 3.5 kbar/km, these pressures corresponded to crystallization depths of ~29 km for Cycles 1 and 2 and ~27 km for Cycle 3, consistent with field evidence and zircon trace element data indicating sources within the lower continental crust.

Calculated Ti-in-zircon crystallization temperatures range from 650°C to 950°C, with most samples clustering between 780°C and 820°C. Using zircon-melt partitioning of cerium, fO2 conditions for single zircon grain crystallization were estimated. Results indicate a range from reducing conditions at ΔQFM −2 to oxidizing conditions up to ΔQFM+7, correlating with mineral assemblages that include biotite ± amphibole ± Fe-Ti oxides. Cycle 1 shows a progressive transition from more oxidizing conditions before 2000 Ma to more reducing conditions afterward. Cycle 2 spans fO2 conditions between ΔQFM+3 and −3, with no clear age-related trend. Cycle 3 zircons (1810–1780 Ma), primarily associated with biotite ± amphibole ± Fe-Ti oxide-bearing rocks, formed under dominantly oxidizing conditions. In contrast, zircons from the youngest Pedro Sara Formation (~1760–1755 Ma), composed of clinopyroxene ± orthopyroxene ± Fe-Ti oxides, crystallized under more reducing conditions (Fig. 3D).

Hf isotopic signatures from Paleoarchean to Tonian in the Amazon Craton
In addition to previously published datasets including detrital and igneous zircon age and Hf isotopes, we present 172 coupled zircon U-Pb and Lu-Hf analyses from 15 volcanic rock samples representing the three Paleoproterozoic igneous cycles. Reference values for the chondritic uniform reservoir (CHUR) are from, whereas those for the depleted mantle (DM) are from. Evolution lines for a typical Archean mafic source and products of TTG remelting were anchored at 2200 Ma, representing the major episode of crust recycling during the Transamazonian Orogeny, and at 3500 Ma, closest to the oldest Nd TDM age found for Cycle 2 igneous rocks and the oldest zircon in the literature dataset, representing the oldest hypothetical recycled crustal source. Literature data for each Cycle represent primarily intrusive granitoids along with a few volcanic samples. The combined analysis of our data and published datasets reveals distinct trends in Hf isotope compositions for each cycle (Fig. 4).

Cycle 1 zircons exhibit a range from supra-chondritic radiogenic signatures, with εHf(t) values reaching +10 and close to the Depleted Mantle (DM) evolution curve, to less radiogenic signatures with εHf(t) values as low as −12, as observed in the εNd(t) vs. U-Pb age space. Our data, obtained in samples from the Guyana Shield agree with data obtained for volcanic and plutonic rocks of the same age from the Central Brazil Shield. Primary sub-populations for Cycle 1, identified in KDE plots, display peaks at −5.4 and +2.7. Cycle 2 zircons display a bimodal distribution of εHf(t) values. One subset shows radiogenic signatures, clustering near −0.9 and reaching up to +5, and another subset has predominantly unradiogenic signatures, with εHf(t) values clustering around −15 and reaching as low as −20. The most unradiogenic signatures were obtained for zircons of Cycle 2-related granitoids intruding the Archean provinces of the AC. Granitoids intruding Archean crustal segments within the eastern Amazon Craton display strongly negative εHf(t), εNd(t), and Archean Nd TDM ages, mirroring the most negative εHf(t) values of Fig. 4, suggesting the origin of the least radiogenic Hf values linked to significant Archean crustal reworking. They also follow the evolution of Archean crust, as observed in detrital zircon sets obtained for Amazon River sands and Paleoproterozoic sedimentary units. Cycle 3 zircons from this study and from the literature range from slightly radiogenic signatures, with a peak at +0.68, with εHf(t) values reaching +5 (resembling the behavior of εNd for literature data of this Cycle), to values as low as −10.

Methods
U-Pb and trace element measurements
Instrumentation-Photon Machines Excite Excimer 193 nm laser ablation unit coupled to a Nu Instruments, Nu Plasma P3D multicollector inductively coupled plasma-mass spectrometer (for detailed methodology see refs. 70, 71).

Operating conditions - samples were analyzed for 20 seconds using a fluence of 1.5 J/cm2, a frequency of 4 Hz, and spot size of 20 µm diameter, resulting in crater depths of ~7 µm. Utilizing a standard-sample bracketing technique, analyses of reference materials with known isotopic compositions were measured before and after each set of seven unknown analyses.

Data reduction protocols and secondary zircon standards - corrections for baseline, instrumental drift, mass bias, down-hole fractionation and age and trace element concentration calculations were carried out using Iolite v. 4.1. ‘91500’ zircon (1065.4±0.3 Ma 207Pb/206Pb ID-TIMS age and 1062.4±0.4 Ma 206Pb/238U ID-TIMS age) served as the primary reference zircon to monitor and correct for mass bias as well as Pb/U down-hole fractionation and to calibrate trace element concentration data, while ‘GJ-1’ zircon (608.5±0.4 Ma 207Pb/206Pb and 601.7±1.3 Ma 206Pb/238U ID-TIMS ages), OG1 (206Pb/238U ages of 3440.7±3.2 Ma and 3463.3±3.6 Ma respectively), ‘Plešovice’ (337.13±0.37 Ma 206Pb/238U ID-TIMS age, Temora-2 (416.75±0.24 Ma 206Pb/238U ID-TIMS age) were treated as unknowns to assess accuracy and precision. The following U-Pb concordia dates were obtained for secondary reference zircons: 91500: 1064±2 Ma, MSWD=1.7 (n=47); GJ-1: 603±3 Ma, MSWD= 0.6 (n=7); Temora-2: 420±2 Ma, MSWD=1.7 (n=7); Plešovice: 335±1 Ma, MSWD=0.65 (n=7). An age of 3466±6 Ma, MSWD= 0.06 (n=7) was obtained from the 207Pb/206Pb weighted mean for OG1.

The kernel density estimation and histogram of zircon U–Pb ages, Concordia, and weighted mean date plots were calculated in IsoplotR using the 238U and 235U decay constants of ref. 78. All uncertainties are quoted at the 95% confidence or 2s level and include contributions from the external reproducibility of the primary reference material for the 207Pb/206Pb and 206Pb/238U ratios; results are summarized in the Supplementary Data 5. Based on the long-term reproducibility of multiple secondary reference zircons, trace element concentrations are accurate to 5% (2σ).

Lu-Hf measurements
Hf isotopes in zircon were measured in situ by LA-MC-ICP-MS at UCSB. Methods used in this study are similar to those used by ref. 79.

Operating conditions - ablation spots were placed over the original U–Pb analysis spots to obtain Hf compositions that correspond to the measured U–Pb date of the zircon. A laser spot size of 50 μm, a fluence of 1.5 J/cm², and a pulse rate of 15 Hz were used to ablate samples for 30 s, with a 45 s delay between analyses to allow washout. Masses 171–180 inclusive were measured on 10 Faraday cups at 1 a.m.u. spacing.

Data reduction protocols and secondary zircon standards - data were reduced using Iolite v 4.1. Natural ratios of 176Yb/173Yb = 0.79621880 and 176Lu/175Lu = 0.0265681 were used to subtract isobaric interferences of 176Yb and 176Lu on 176Hf. The Yb mass bias factor was calculated using a natural 173Yb/171Yb ratio of 1.13268580 and was used to correct for both Yb and Lu mass bias. A natural 179Hf/177Hf ratio of 0.7325 was used to calculate the Hf mass bias factor. Interference and mass-bias corrected 176Hf/177Hf ratios were further normalized to ‘Plešovice’ reference zircon (assuming a 176Hf/177Hf value of 0.282482±13). To assess accuracy and precision, natural ('91500’, ‘GJ-1’, ‘Plešovice’, 'Temora-2’, and ‘Mud Tank’) reference zircons were run concurrently and treated as unknowns. The weighted mean corrected 176Hf/177Hf values (±2 SD) obtained for the secondary reference materials are: 0.282312±22, MSWD=1.3 (n=12) for 91500, 0.282006±23, MSWD = 1.7 (n=9) for GJ-1, 0.282483±13, MSWD = 0.36 (n=13) for Plešovice. 0.282671±24, MSWD=1.8 (n=13) for Temora-2 and 0.282500±18, MSWD = 2 (n=11) for Mud tank in good agreement with preferred values.

Reference parameters - epsilon Hf at time t for each analysis was calculated from the inferred crystallization age for each sample (except for inherited grains, from which spot ages were used), using a 176Lu decay constant of 1.867 × 10-11 a-1 and CHUR values of. Reference materials used for monitoring trace-element data quality were NIST 612 and BHVO glasses.

Peer review rounds
[{"round": 1, "reviewer_comments": {"reviewer_1": "Dear Simões et al.,\nYour manuscript \"Large-scale crustal growth determined by LIP magmatism during the Paleoproterozoic,\" examines the role\nof Large Igneous Provinces (LIPs) in the Paleoproterozoic crustal growth of the Amazonian Craton. The study bases its\ninterpretations and conclusions on a significant set of zircon U-Pb, Lu-Hf, and trace element data from volcanic rocks, taken\nas representative of three Paleoproterozoic silicic LIPs, along with compilations from the literature. However, substantial\nrevisions are required to improve clarity, methodological rigor, and the interpretation of results before the paper can be\nconsidered for publication.\nI have subdivided my review into two parts: analytical data and the manuscript. The detailed review of both parts can be\nfound, respectively, in the attached word files “Revision_SuppMaterial” and “Revision_Manuscript.”\nWhen reviewing a manuscript with isotopic data, my first step is always to check the reference materials and attempt to\nreproduce the figures and age calculations. The isotopic data for reference materials are in excellent agreement with\naccepted values. However, I encountered several discrepancies that need to be addressed to ensure reproducibility and\nclarity of the results of the studied.\nMy main concern is that the plots and age calculations presented for the studied samples are not reproducible. Although the\ncalculated ages are consistent within uncertainty, the plots differ. The possible reasons for this are explained in more detail\nin the attached word file “Revision_SuppMaterial.”. You must ensure that the data presented can be reproduced by the\nreviewers (and future readers). The supplementary data tables need to be updated to ensure clarity, reproducibility, and\nproper interpretation of the data.\nRegarding the manuscript, nearly all sections, including some figures, need substantial revisions. Please refer to the\ndetailed review in the attached word file “Revision_Manuscript.”\nTo summarize, the revised version should:\ni) ensure full reproducibility of the figures presented in this study by completing the reported data of the studied samples and\nproviding the data resulting from literature compilation;\nii) provide CL images of representative zircons of each samples, with location of the analysed spots.\niii) improve the visualization of some figures and, importantly, include geological maps;\niv) most importantly, explore whether the role of the LIPs in the crustal growth of the Amazon Craton necessarily contradicts\nthe currently accepted accretionary orogenic model. Rather than dismissing one process in favour of the other, the\nmanuscript could discuss how both may have contributed to the crustal growth of the Amazon Craton.\nI believe the suggested modifications in the word files are feasible within the current scope of your manuscript and would\nsignificantly strengthen its contribution to the debate on the role of LIPs in the Paleoproterozoic crustal growth of the Amazon\nCraton.\nGiven the number of revisions needed to clarify inconsistencies, improve data presentation, and deepen the discussion, my\nrecommendation is major revision.", "reviewer_2": "The manuscript \"Large-scale crustal growth determined by LIP magmatism during the Paleoproterozoic” submitted for\npublication in Nature Communications, was evaluated. The manuscript presents a critical and original discussion about the\nevolution of Orosirian LIPs in Amazonian craton, focusing on its importance to crustal growth. The manuscript is well\npresented, structured, and concise. In general, it is well written and illustrated, and based in a current literature. The Abstract\nsummarizes the general questions and conclusions of the manuscript. The manuscript presents new geochemistry, isotopic\n(U-Pb and Lu-Hf) and Ti-thermometry data for zircon, but discussion about tectonic aspects are almost absent. All along the\nmanuscript, the authors use the term “Amazon craton”. The correct expression is “Amazonian craton”, as it was initially\nproposed by Almeida et al. (1981) to define the same region and setting.\nThe main constraint of the manuscript is the lack of tectonic evidence, among others, compatible with SLIP setting for the\nstudy regions. Sometimes, only geochemistry data lead to dubious conclusions. According to the chemical composition of\nthe rocks (mainly calc-alkaline to shoshonitic, high-K, I-type to A-type), it is possible to accept these rocks as occurring in\npre- to post-collisional, as well as in an intraplate (fissural) environment. In fact, several authors argue magmatic arc setting\nfor the rocks included in the three cycles proposed in the manuscript. It is the case of Fraga et al. (2020, 2024) for the\nOrocaima Igneous Belt (cycle 1); Almeida et al. (2001), Vasquez et al. (2002), Santos et al. (2004), Juliani et al. (2013),\nFernandes and Juliani (2019) for the Tapajós and Iriri-Xingu domains (cycles 1 and 2), and Cordani and Teixeira (2007) for\nJuruena region (cycle 3). In the manuscript, the SLIP-related setting is accepted for all regions without discussion. Arc\nmagmatic and intraplate events may simultaneously or sequentially happen, since well-arranged in the space and time. For\ninstance, in the Tapajos domain, where rocks from cycles 1 and 2 occur, and also magmatic arcs are argued, it is necessary\nreconstruct the tectonic history, fit both cycles and prove if they are true SLIPs. In summary, I am not against the SLIP\nhypothesis, but it is necessary show evidence in a comprehensive geological setting. They could be shown in tables or as\nSupplementary Material.\nAnother discussion needing to be enlarged concerns the extensions and the representations of the three cycles in Figure 1.\nIn the Tapajos and Iriri-Xingu domains (southeastern part of the craton), rocks from both cycles 1 and 2 occur. In my point of\nview, it is not possible separate two different domains, as it is shown in Figure 1, because in some areas there are both\ncycles, side-to-side, overlaying or cross-cutting one over the other. The same is true to Peixoto de Azevedo domain,\nsurrounded by rocks from cycle 3, where rocks from cycle 2 is also present. Additionally, a 1.88 Ga granite magmatism is\nspread in the Carajas domain, extreme southeastern part or the craton. This magmatism has been correlated to Uatuma\nSLIP, present in the adjacent Iriri-Xingu and Tapajos domains. In line 331, a rock from cycle 2 occurring in Tucuma area\n(Carajas Province) is exampled, but it is not shown in figure 1. I suggest including as Supplementary Material a map\npresenting all sample locations, which data were used in the manuscript."}, "author_response": "Response to Referees\nLarge-scale crustal growth determined by LIP magmatism during the\nPaleoproterozoic\nMatheus S. Simões, Carlos A. Sommer, Marcelo L. Vasquez, Lucas M.M. Rossetti, John M. Cottle, Túlio A.\nMendes, Andrew R.C. Kylander-Clark\nResponse to reviewer 1 – Part I\nIntroduction\nLines 27-30: “The period from the Late-Rhyacian to the 27 Statherian includes anachronic events\nof rift-drift, accretionary and collisional orogenies in most Paleoproterozoic belts, with episodes\nof silicic additions to the continental crust. An exception to these belts is the Late-Rhyacian to\nStatherian record of the Amazon Craton in South America.”\nWhy is the Amazon Craton record an exception? As you mention further down, in the geological\ncontext, the evolution of the Amazon Craton has long been interpreted as the result of\nsouthwestward continental growth, characterized by the continuous migration of tectonic and\nmagmatic processes from an ancient Archean core in the east. This process is thought to have\noccurred through successive magmatic arcs accreted along the southwestern margin of the\ncraton or the development of a long-lived accretionary belt (e.g., Tassinari and Macambira,\n1999; Santos et al., 2000; Cordani and Teixeira, 2007; Scandolara et al., 2017; Trevisan et al.,\n2021; Motta et al., 2022), in line with the broader concept of the Great Proterozoic Accretionary\nOrogen (Condie, 2013).\nWe appreciate this initial comment and understand its relevance. However, we\nemphasize that the introduction is intended to frame the broader rationale of the\nmanuscript. The question of “why the Amazon Craton is an exception” is addressed\nprogressively throughout the text.\nTo provide further context, we have included a new supplementary table (Supplementary\nTable 2) in the revised manuscript that summarizes arguments supporting or challenging\nboth LIP- and subduction-related models. In brief, the first three references cited by the\nreviewer are regional in scope and primarily rely on age rejuvenation and variations in\nisotopic ratios from different systems. Recent studies, along with our new data, suggest\nthat such patterns are not universally applicable—exceptions exist, and the association\nof geochronological provinces with orogenic activity remains a subject of ongoing debate\nin the context of the Amazon Craton (AC) and should not be treated as an “a priori truth”.\nFor instance, Scandolara et al. (2017) present a detailed study of a portion of the AC\nproposing an arc-related setting without any direct evidence of subduction. Their\ninterpretation is based on airborne magnetic data from remote, inaccessible areas\n(interpreted as thrusts without field evidence) and geochemical signatures (high-K calc-\nalkaline rocks with negative Nb-Ta anomalies), which can also occur in intraplate\nenvironments.\nIn contrast, Barros et al. (2009) and Rizzotto et al. (2019) offer a different interpretation\nof the same rock units. These works emphasize the bimodal nature of the magmatism\nbased on the geochemistry of igneous rocks, and on the proposal of a metamorphic core\ncomplex formed in an extensional tectonic setting.\nRegarding the contributions of Trevisan and Motta, we acknowledge that their work offers\nvaluable new data and insightful reinterpretations. Nonetheless, the same geochemical\nparameters invoked in support of arc settings—high-K calc-alkaline signatures, negative\nNb-Ta anomalies, and tectonic discrimination diagrams—do not provide unequivocal\nevidence for subduction. Moreover, the occurrence of porphyry-like mineralization is\ntypical of Phanerozoic arc environments, but is not diagnostic of an arc setting, as similar\nmineralization is observed in silicic LIPs such as the Sierra Madre Occidental (Camprubí\net al., 2017 - http://dx.doi.org/10.1016/j.oregeorev.2016.01.006).\nSeveral of these debates have already been highlighted in prior literature (e.g., Rizzotto\net al. works) and the presence of silicic LIPs within the Amazon Craton has been\npreviously proposed based on robust datasets (e.g., Teixeira et al., 2019). Therefore, we\nmaintain that our interpretation of the existing literature, combined with new data\npresented herein, is scientifically well supported and consistent with ongoing discussions\nin the field.\nLines 31-33: This is a key area to investigate mechanisms of crustal growth and a potential\nrelationship with subduction since no plate tectonic indicators have been identified. Instead,\nthe period from 2.0 Ga Ma to 1.74 Ga Ma in this crustal segment is marked by the emplacement\nof large igneous provinces with an extensive bimodal igneous association.\nThis sentence likely needs rephrasing, as many will disagree with its current wording. What do\nthe authors consider to be “plate tectonic indicators”? Arc-related geochemical signatures in\nPaleo- to Mesoproterozoic magmatic rocks, along with increasingly positive εNd and εHf values\nwith decreasing U-Pb crystallization ages away from the craton are typical characteristics of\naccretionary orogens. Additionally, “instead” may not be the most appropriate transition. A\nmore suitable alternative would be: \"Between 2.0 and 1.74 Ga, the Amazon Craton also records\nthe emplacement of large igneous provinces with extensive bimodal magmatism.\"\nIt is possible that some researchers may disagree with our statement regarding Plate\nTectonic Indicators (PTIs) in the Amazon Craton. However, such disagreement does not,\nin itself, constitute a compelling reason to rephrase the statement. As outlined by Stern\n(2023), PTIs include features such as ophiolites, eclogites, passive continental margins,\ntall collisional mountains, paleomagnetic constraints, hydrous fluid-sensitive ore\ndeposits, S-type granites, and deep crustal geophysical imaging.\nIn contrast, arc-like geochemical signatures and isotopic zonation alone are not definitive\nevidence of arc-related tectonic settings (e.g., Ewart et al., 1992 -\nhttps://doi.org/10.1017/S0263593300008002). In our work and several others (e.g.,\nMotta et al., 2022), there is evidence of extensively negative εNd and εHf values, so the\nargument on these features is not consensually valid. High-K calc-alkaline rocks, for\ninstance, can also form in intraplate environments, along with A-type magmatism (Bryan,\n2007; Ewart et al., 1992; Ferrari et al., 2018). Moreover, isotopic zonation can arise within\nblocks of continental crust that have been repeatedly intruded by both mafic and silicic\nmagmas. These intrusive events may reset low-temperature isotopic systems or modify\nthe underlying mantle composition, thus shifting εNd and TDM model ages over time (Lu\net al., 2024 - https://doi.org/10.1029/2024GL108715).\nI will return to this point later, but I believe a key aspect of the manuscript should focus on\nwhether the presence of LIPs/SLIPs necessarily contradicts the widely accepted accretionary\norogeny model for the evolution of the Amazon Craton. Alternatively, could these processes be\nreconciled? If so, craton growth could be understood as the result of both mechanisms—\nhorizontal growth through accretionary processes and vertical growth associated with the\nemplacement of LIPs/SLIPs away from the craton margin (subduction zone). As noted by Teixeira\net al. (2019), LIPs/SLIPs “appear to accompany the stepwise accretionary crustal growth of\nAmazonia,” and several other authors have linked them to slab retreat events.\nWe agree that these processes can be complementary. In our manuscript, several rock\nunits dated between 2200 and 2020 Ma—such as those from Cuiú-Cuiú, Jacareacanga,\nand the Guyana Shield— which are already interpreted as products of orogenic activity\nrelated to the Transamazon Orogeny in the literature, remain with this interpretation. This\norogenic episode is further supported by the presence of a plate tectonic indicator\n(ophiolite) in the West African Craton. Without this phase of orogenesis, the necessary\nconditions for subsequent silicic LIP magmatism would likely not have been achieved.\nRegarding slab retreat events, we respectfully note that clear evidence of subducted\nslabs—aside from the recognized ophiolites at ~2150 Ma and ~1460 Ma—is lacking. The\nproposed accretionary models are not currently supported by sufficiently compelling\ndata, and as such, we do not consider there to be a strong scientific basis for adopting\nthese models as the default interpretation.\nGeological context of the Amazon Craton\nGeneral comment:\nThis section would greatly benefit from a simplified geological map of the Amazon Craton. It is\nextremely difficult to follow the text without a figure (and I am rather familiar with the Amazon\nCraton).\nThe figure should display: i) the main tectonic provinces of the Amazon Craton, with their ages\nindicated in the legend; the superposition of the studied SLIPs; iii) the locations of the analysed\nsamples. Additionally, since the \"SAMBA\" model is referenced, it would be useful to include it\nas an inset within the geological map.\nA new figure (Fig. 1a) was made using the SAMBA model and the geological map of the\nAmazon Craton (Fig. 1b) with emphasis on the studied magmatic provinces, as\nsuggested.\nFurthermore, given that you have a detailed map of the Guiana Shield (current Fig. 4), it would\nbe appropriate to provide a similar one for the Central Brazil Shield, as most of the studied\nsamples come from this area.\nA detailed map of the Guyana Shield is not included in the paper solely to indicate sample\nlocations. Rather, it was specifically compiled to highlight Rhyacian dome-and-keel\nstructures, orogeny-related rocks, and large igneous provinces (LIPs). Since the Central\nBrazil Shield does not display Rhyacian dome-and-keel structures, a detailed\nrepresentation of this area was deemed unnecessary for the purposes of this manuscript.\nNevertheless, geological maps with sample location are now presented as\nsupplementary material (Supplementary Data 1).\nLines 59-53: “The distribution of Archean crust is evidenced as an isotopic provinciality that\ndivides the Amazon Craton into an eastern segment, characterized by Archean Nd depleted\nmantle model (TDM) ages and the most negative εNd(t) values, and a western segment, where\nRhyacian to Orosirian Nd TDM ages and slightly negative to slightly positive εNd(t) values\npredominate (Fig. 1a, b).”\nThis figure does not seem to be the most appropriate choice for this section. A Nd TDM age map\nis not necessary to highlight the Archean crust and the Paleo- to Mesoproterozoic provinces; a\ngeological map is much more effective. To enhance clarity, as mentioned earlier, the SLIPs and\nsample locations should be plotted on a geological map, rather than on an Nd TDM age or εNd(t)\nmap.\nWe acknowledge that Nd isotope maps are valuable for illustrating the progressive\nrejuvenation of the underlying crust and mantle throughout each magmatic cycle. We\nincluded geological maps with sample location as supplementary material\n(Supplementary Data 1).\nComments about Fig. 1:\n“The database for contour construction is sourced from 27 and 21.”\ni) Reference '27', Condie et al., 2021, does not include any Nd isotopic data. Similarly, '21', Motta\net al., 2022, only provides Nd data for the Central-Brazil Shield. Could the authors clarify the\nsource of the remaining data?\nThe correct reference of Nd isotope data is Puetz and Condie (2021) Volume 10, Issue\n4, July 2019, Pages 1305-1326– Multimidia component 3. This is now corrected in the\ntext and references.\nii) If the data is from different sources, did the authors confirm that the TDM ages were all\ncalculated using the same Depleted Mantle model? If not, they should consider recalculating\nthem for consistency.\nThe dataset from Puetz and Condie (2021) includes a tab detailing the specific models\nused for isotopic calculations, while the Motta et al. (2022) compilation presents values\nas originally reported by each author. We agree that applying a uniform model across all\ndatasets would enhance consistency. However, the degree of variation introduced by\nusing different depleted mantle (DM) models does not significantly affect the overall\ninterpretation of the map. The spatial patterns and isotopic variations remain valid, and\nthe data from the Central Brazil Shield show good correlation with those from the Guiana\nShield, as illustrated in the figures.\niii) The Nd data used should be provided as supplementary material (figures must be\nreproducible by the reviewers and future readers). The figure should also include the sample\npositions so that the reader can assess the sample density and distribution.\nThe isotope data used for the map is now presented as a new supplementary table\n(Supplementary Table 1), as suggested.\niv) The software used and the interpolation method applied for generating the data in the figure\nshould be specified.\nThis is now specified in the figure capture, as suggested.\nLines 75-79: “Nevertheless, the record of plate tectonic indicators in the Amazon Craton\ncomprise a 1460-1440 Ma ophiolite in the Sunsás Belt, that post-dates Paleoproterozoic belts\nand pre-dates the late Mesoproterozoic events (1.2 – 0.95 Ga). These events are correlated with\nthe Grenville-type orogens related to the collision of Amazonia and Laurentia”.\nI’m not sure why the authors included this or what they intend to convey with this text.\nLines 79-82: Further, the proposition of Orosirian-Statherian orogenic belts in the Amazon\nCraton does not match with some important surface geological relationships, including two\nOrosirian and one Statherian igneous belts exhibiting N-S and E-W, NW-SE and E-W trends that\nconflict with the parallel NW-SE orogenic provinces.”\nI don’t fully understand the sentence. From the regional geological maps provided by other\nauthors (since this manuscript does not include one), it is very clear that the provinces are\ngenerally oriented in a NW-SE direction. This orientation is well-documented and widely\naccepted in the published literature. If the authors are suggesting a different orientation, they\nshould provide evidence to support this claim.\nThe igneous belts are now more clearly depicted in Figure 1b. We are not suggesting\nthat the geochronological provinces are not oriented NW–SE. Rather, we are highlighting\nthat “two Orosirian and one Statherian igneous belts exhibit N–S, E–W, and NW–SE to\nE–W trends that contrast with the parallel NW–SE orientation of the orogenic provinces.”\nIn this context, our point is that these igneous belts do not share the same structural\ntrends as the geochronological provinces.\nOrosirian and Statherian igneous belts:\nIt is essential to provide at least a brief description of the geology of each of the igneous belts.\nAre there notable differences between them, or are they very similar? As it currently stands,\nwithout referring to the literature, all I know is that there are three Paleoproterozoic SLIPs in the\nAmazon Craton and their respective ages, nothing more. The lithologies they encompass, their\nrelationships with one another, etc, remain unclear.\nWe enhanced their description in the ‘Orosirian and Statherian Igneous Belts’ section.\nDetailed lithostratigraphic review is also presented by Teixeira et al. (2019) and we feel\nit is not necessary to fully repeat it.\nYou analysed 15 volcanic rocks, mostly ignimbrites, from three SLIPs. While the supplementary\nmaterial lists the geological unit of each sample, there is no context provided. The reader is left\nuncertain about the nature of these formations, whether they are associated with sedimentary\nrocks, how they relate to the calc-alkaline I-type to A-type plutonic rocks, and so on. There is a\nsignificant lack of geological context. In addition, there is an absence of field and petrographic\nphotos of the samples. While the field constraints might be well-established, and I don’t doubt\nthat, this information is not conveyed in the manuscript.\nA full report with field and petrographic descriptions along with geological maps for each\nsampled region is now presented as new supplementary material (Supplementary Data\n1).\nResults\nAge of volcanic rocks\nPlease refer to the comments in the separate Word file regarding the U-Pb data. Additionally, I\nbelieve this section would benefit from a figure comparing your data with previously published\ndata from the literature.\nZircon composition, crystallization conditions and source-depth\nThe calculated Ti-in-zircon crystallization temperatures (which are not presented as a figure in\nthe manuscript or as a supplementary figure) and ΔQFM values should be provided in the\nsupplementary data table. Additionally, is there any correlation between these values and the\nU-Pb ages and εHf(i) values of the analysed zircons? Additional insights may be gained from this.\nCalculated temperature and oxygen fugacity data are now presented in the\nsupplementary material (Supplementary Table 3).\nLines 175-178: “To estimate crustal thickness for each studied magmatic cycle we applied the\nchemical mohometry model, by using a large dataset of geochemical data available from the\nliterature. Data was filtered to exclude major and mobile trace elements sensitive to\nhydrothermal alteration processes.”\nData should be presented as supplementary material as it must be available to the reviewers to\nensure the calculations are correct.\nGeochemical data are now presented in supplementary material (Supplementary Table\n4) the models are presented in the Supplementary Data 4.\nLines 180-184: KDE plots of the depth estimate proxy using the ¹⁷⁶Lu/¹⁷⁷Hf ratio are not\npresented as a figure in the manuscript or as a supplementary figure. Results could/should be\npresented in the supplementary data table.\nThis is now presented in a figure along the manuscript and as supplementary material\n(Supplementary Table 3).\nComment on Figures 2b and 2c: if I am not mistaken, the fields were created by the users. If this\nis the case, I believe the data compiled from the literature to construct the fields should be\nprovided as supplementary data to allow the reviewers to verify the data and ensure the\naccuracy of the figures.\nThis is now presented in the supplementary material (Supplementary Table 4).\nHf isotopic signatures from Paleoarchean to 201 Tonian in the Amazon Craton\nLines 201-204: “In addition to previously published datasets including detrital and igneous zircon\nage and Hf 203 isotopes, we present 172 coupled zircon U-Pb and Lu-Hf analyses from 15\nvolcanic rock samples representing the three Paleoproterozoic igneous cycles.”\nReference 27, Condie et al. 2021, does not include any Hf isotopic data. Compiled Hf data should\nbe provided as supplementary material and references indicated.\nThis is now included as supplementary material as suggested (Supplementary Table 5).\nLines 216-244: This part of the text focus on interpretation and implications rather than the\npresentation of the results, therefore, it would be more appropriate to move this content to the\ndiscussion section.\nThis is now in the discussion section, as suggested.\nComments of figure 3:\ni) Detrital and igneous zircon Hf data from the literature are currently presented as grey circles.\nThey should be represented with different symbols for clarity. Igneous zircon should be\nsymbolized according to their geological unit or, alternatively, tectonic province to provide more\ncontext and facilitate interpretation.\nSince igneous zircon represented less than 20% of the literature data and were obtained\nfor few geological units we decided to remove it from this figure.\nii) What exactly do the literature data for Cycle 1, Cycle 2, and Cycle 3 represent? Why are they\nseparated from the general \"detrital and igneous (literature)\" data? Given that you only\nanalysed volcanic rocks, mainly ignimbrites from each of the SLIPs, how do these volcanic rocks'\nHf compositions compare to the plutonic rocks of each SLIP? Are there any notable differences\nor similarities between them that could provide additional insights into the geochemical\ncharacteristics or tectonic settings of these regions?\nWe added some new sentences in this part, but different isotopic compositions are only\nfound for Cycle 2, and this difference was explored and partially interpreted in the text.\niii) For example, zircon from the three analysed volcanic samples of the Uatamã SLIP (Cycle 2)\nshow a relatively restricted range of εHf(i) values, from -6.7 to +1.7, with an average value of -\n2.0. However, the \"Cycle 2 literature\" data shows a major cluster at -15.0. What lithologies does\nthis cluster represent? Are they the same as the more radiogenic cluster or are they different?\nWhy do the Uatamã SLIP rocks reach much more enriched (more negative) εHf(i) values,\napproaching the evolution trend of the Archean crust as defined by the \"detrital and igneous (literature)\"\nzircon? (By the way, what exactly do these Archean \"detrital and igneous (literature)\"\nrepresent? Igneous rocks from Carajás? Archean detrital zircon from younger sequences?)\nWe added more information about that.\nOn another note, how do the Hf isotopic data from this study and the literature compilation\ncompare with the Nd data from the literature? You compiled Nd data for the Amazon Craton, as\nshown in Fig. 1. Why not compare the two datasets? Do they show similar or divergent trends?\nThis could provide further insights into the evolution of the Amazon Craton.\nWe added an inset with Nd isotope data from the literature in Figure 3 and presented the\ncomparison of the two datasets along the text.\niv) It is unclear what the starting point ages are for the C-F2, TTG, and KREEP, and why those\nparticular ages were chosen. Please specify the rationale behind these age selections.\nThis is now explained along the text.\nv) The references for the 'previously published zircon ages' used to construct the KDE diagram\nmust be provided. Additionally, the compilation of age data, coordinates, and other relevant\ninformation should be included as supplementary material to ensure transparency and allow for\nreproducibility.\nThis is now inserted as supplementary material (Supplementary Table 5). ‘Previously\npublished zircon ages’ are the same used to constrain Lu-Hf data in the same diagram.\nDiscussion\nChanges in structure and composition of the Amazon Craton crust\nThe discussion of the Hf data should be moved to this section, and should be discussed along\nwith the Nd isotopic data.\nIt has been moved to discussion section and is discussed along with Nd data, as\nsuggested.\nLines 292-293: “The isotope composition of silicic igneous rocks reveals that the proportion of\nreworked crust during magmatism was highly dependent on the availability of pre-existing\ncrustal material.”\nWhile this statement might be valid for Cycle 3 rocks, as you explain in lines 296 to 299, it does\nnot explain the differences observed between Cycle 2 and Cycle 1. Although there is no available\nprojection of the Hf-analysed samples on a geological map, the existing projection on the Nd\nTDM age map suggests that both Cycle 1 and Cycle 2 rocks are spatially associated with Archean\ncrust, whereas Cycle 3 rocks, further west, overlie a region characterized by predominantly\nPaleoproterozoic Nd TDM ages. If Cycle 1 and Cycle 2 broadly overlap spatially, their availability\nof pre-existing crustal material and its characteristics should be comparable. However, the\nisotopic results indicate that Cycle 2 rocks have incorporated significantly more evolved crustal\nmaterial than Cycle 1.\nThis is because there are no Hf analyses on Cycle 1 rocks overlying the Archean\ndomains (e.g., Iriri-Xingu domain). Nevertheless, this is demonstrated in the new Nd data\ninset on the same figure.\nCycle 3 rocks exhibit an εHf(i) range identical to that of Cycle 1. Identical εHf(i) values for two\nmagmatic events of distinct ages suggest either an increase in the juvenile component and/or a\nreduction in the influence of the Archean crust in the younger cycle. Given the apparent overall\ncorrespondence between the Nd and Hf isotopic data (as seen in both Fig. 1 of this study and\nFig. 8 of Motta et al., 2022), and also that Cycle 3 rocks are located west of the Cycle 1 and 2\nrocks (i.e., further away from the Archean core), the data strongly suggest that Cycle 3 rocks\nwere emplaced in a distinct crustal “structure” (either younger crust or thinned Archean\nbasement) compared to Cycles 1 and 2.\nThis suggestion is now incorporated into the main text.\nComments on Figure 5: i) There are no KDEs shown on the right side of the figure. ii) The\nabbreviations MU, MC, UC, and SM are not indicated in the figure.\nKDE’s are inserted in a revised figure 2 (now figure 3), abbreviations are now inserted\nwithin the figure 5 (now figure 6).\nRepeated Cycles of Mantle-Derived Magmatism at ~95 Myr Intervals\nComments on Figure 6: i) Fig. 6A and B are exchanged. ii) Sources of data from the literature\nmust be indicated in the figure caption. Compiled data should be made available as\nsupplementary material.\nFigures are now with the correct order in the capture and the compilation is inserted as\nsupplementary material (Supplementary Table 5).\nCrustal growth by intraplate igneous events during the Paleoproterozoic\nLines 411-416: \"Prior to this, from the Orosirian to the Statherian, no clear evidence of\nsubduction events exists within the Amazon Craton following the Rhyacian Transamazonian-\nEburnean-Birimian orogenies. Instead, crustal growth during this interval was primarily driven\nby large igneous province (LIP) events. A potential exception is the proposed Statherian arc\nmagmatism in the Rio Negro Province; however, this interpretation remains unsupported by\ndefinitive plate tectonic indicators.\"\nThis is a classic case where the phrase \"absence of evidence is not evidence of absence\" applies.\nThe absence of “definitive plate tectonic indicators” could be due to a true lack of subduction or\nsimply because of an incomplete record (ophiolite sequences and high-pressure rocks are not\nvery common in the Paleoproterozoic).\nIn the initial version of the manuscript, we included some elements of positive evidence\nfor a non–plate tectonic regime, but these were not sufficiently emphasized. In this\nrevised version, we have clarified the distinction between negative evidence—which, on\nits own, corresponds to the type of argument being invoked in your comment—and\npositive evidence, which complements the negative evidence and strengthens our\noverall interpretation.\nThe assertion that crustal growth during the Orosirian-Statherian was \"primarily driven by LIP\nevents\" is a strong claim that requires robust evidence. While the authors correctly highlight the\nimportance of LIPs in crustal growth, they do not sufficiently address the geochemical and\nisotopic trends that are commonly associated with accretionary orogens, such as the\nsouthwestward decrease in crystallization ages and TDM model ages observed in the magmatic\nrocks of the Paleoproterozoic Ventuari-Tapajós and Rio Negro-Juruena belts, which in addition\nexhibit arc-related geochemical signatures . This pattern is a hallmark of long-lived accretionary\norogens from the Proterozoic to the Phanerozoic (e.g., Bahlburg et al., 2023 and references\ntherein) and should not be dismissed without a compelling alternative explanation.\nWe acknowledge that this statement should not be taken as an established truth. It is not\ntypical for arc settings to exhibit features such as radial dyke swarms, bimodal\nmagmatism, and the dominance of A-type silicic magmatism. Moreover, decrease in\ncrystallization ages and TDM model ages are not exclusive indicators of arc-related\nprocesses; they may also reflect basement features. For example, even in arc settings,\nspatial isotopic variation may be attributed to different crustal and mantle sources\n(Kagami et al., 1992 - https://doi.org/10.1007/BF00310452).\nFor instance, during Cycle 3, we observe TDM model ages spanning the Rhyacian and\nArchean, which suggest reworking of ancient crust and melting of a Rhyacian mantle\nsource. Additionally, the presence of Orosirian TDM model ages may reflect either the\nmelting of previously formed Cycle 2 crust or mantle rejuvenation processes. These\nobservations reinforce the complexity of the tectonic and igneous evolution and caution\nagainst attributing such features solely to arc settings.\nInstead of positioning LIP magmatism in opposition to accretionary tectonics, the authors should\nexplore how these processes may have interacted. Could the emplacement of LIPs have played\na role in modifying an accretionary orogen? Is there geochemical evidence suggesting interplay\nbetween plume-derived and arc-related magmatism? These are the types of questions that\ncould provide a more nuanced and comprehensive interpretation of the Amazon Craton's\nevolution. A more balanced discussion would acknowledge the role of LIPs while evaluating\nwhether they necessarily contradict an accretionary orogenic model. Rather than dismissing one\nprocess in favour of the other, the manuscript could explore how both may have contributed to\ncrustal growth of the Amazon Craton.\nWe fully agree with the importance of seeking balanced interpretations regarding the\nAmazon Craton (AC). Naturally, accretionary and collisional events played a role in the\nAC’s tectonic evolution, and we do not dismiss their occurrence. As highlighted in the\nnew supplementary table, several regions of the AC with Rhyacian to Statherian ages\nnow present stronger evidence for intraplate magmatism, even in areas that were initially\ndescribed as magmatic arcs. The historical view of geochronological provinces is a\nhallmark for understanding crustal evolution of the AC. Orogenic model-based solutions\nwere a solid response to primarily geosyncline theory-based models. Nevertheless,\nthere were some flaws adopted for reaffirming these models in some places. However,\nsome key assumptions used to reinforce these models warrant reconsideration.\nOne major limitation lies in the interpretation of whole-rock geochemistry:\n1. Most silicic rocks are naturally enriched in K₂ O and plot within the high-K to\nshoshonitic fields on petrological diagrams. So, not an argument for magmatic\narc setting.\n2. These diagrams have often been used to support Andean-type magmatism\nwithout incorporating A-, I-, or S-type granitoid classification diagrams and\nwithout considering the geochemistry and evolution of coeval mafic magmatism.\n3. A significant volume of these high-K silicic rocks is demonstrably A-type in\ncharacter, as already established in previous studies, and therefore does not\nrequire detailed demonstration in this manuscript.\n4. The common association of I-type calc-alkaline or tonalite-granodiorite-diorite\nsuites (contemporaneous to A-type magmatism) with arc settings has often been\nmisapplied. The main misconception regards the lack of detailed geological\nmapping. For example, single plutons in intraplate settings may record multiple\nintrusive pulses, alternating between syeno- to monzogranites with A-type affinity\nand granodiorites/tonalites with I-type affinity—as observed, for example, in the\nLavras do Sul (Gastal et al. 2015 - 10.1590/23174889201500020004) and São\nSepé (Gastal and Ferreira, 2013 - 10.22456/1807-9806.43440) granites of the\nNeoproterozoic Sul-Riograndense Shield.\n5. Furthermore, many igneous suites—coeval with known A-type magmatism—\nconsist of high-K, calc-alkaline I-type granitoids, which are not exclusive to arc\nsettings, and can also be generated by high-grade metamorphism of deeply buried\ncontinental crust and subsequent attendant water-fluxed melting of crustal\nlithologies (Janousek et al., 2023 - 10.1016/j.jog.2022.101960).\nA second flawed assumption involves the interpretation of age zonation in zircon U–Pb\ndata and Nd isotopic signatures as indicative of accretion. The first interpretation of\nCordani et al., Tassinari and Macambira, Santos et al., Cordani and Teixeira, assume\nisotopic zonation across the NW-trending geochronological provinces. Nevertheless, no\nclear age/isotope ratio zonation is observed for Cycle 1, which is dominantly E-W\ntrending in the Guyana Shield. For Cycle 2, there is no crystallization age zonation, and\nthe Nd isotopic signatures are evidently influenced by underlying Archean or Rhyacian–\nSiderian crust (Semblano et al., 2016 - 10.11606/issn.2316-9095.v16i3p19-38; Teixeira\net al., 2017 - 10.1016/j.jsames.2017.09.017, and many references from works at eastern\nAC). Cycle 3 is also E-W trending and exhibits strong evidence for extensional, bimodal\nmagmatic activity and coeval ultra-high temperature (UHT) metamorphism (Rizzotto et\nal., 2019 10.1016/j.jsames.2019.01.003, Benetti et al., 2024 - link). Nd isotopes and\ninherited zircons points to a reworked Orosirian crust with local Archean substrate. Later\ndeformation and metamorphic overprints correspond to younger tectonic events\nunrelated to the timing of LIP emplacement (Almeida et al., 2022 - 10.29396/jgsb),\nas illustrated in Figure 6.\nBy stating this, we are not invalidating the geochronological province models. On the\ncontrary, they remain highly valuable for identifying the crustal or mantle sources\nunderlying LIP magmatism. Our work does not seek to directly challenge these models.\nResponse to Referees\nLarge-scale crustal growth determined by LIP magmatism during the\nPaleoproterozoic\nMatheus S. Simões, Carlos A. Sommer, Marcelo L. Vasquez, Lucas M.M. Rossetti, John M. Cottle, Túlio A.\nMendes, Andrew R.C. Kylander-Clark\nResponse to reviewer 1 – Part II\nComments on the data and figures presented in the supplementary table:\n1) When reviewing a manuscript with geochronology data, my first step is always to check the\nreference materials and to attempt reproducing the figures and age calculations. Results from\nthe reference materials are in excellent agreement with the accepted values.\nUsing Isoplot-R and following the same conditions outlined in the Methods section, I tested the\ndata reported in the supplementary table for the studied samples. While the calculated ages\nagree within uncertainty, I cannot reproduce the age results and diagrams presented by the\nauthors: the plots differ. Below, I provide an example for sample VR05, though this issue applies\nto all samples. As shown, the calculated ages are consistent within uncertainty, but the plots\nthemselves are different.\nWhile this discrepancy does not affect the overall results of the manuscript, because the\ncalculated ages usually overlap within uncertainty, it is important that any reader should be able\nto reproduce the figures presented by the authors. This is an issue and should be addressed.\nI am not sure about the cause of these differences. One possibility is that the authors may have\nplotted the diagrams using the 207/235 and 206/238 ratios, rather than the 238/206 and\n207/206 ratios reported in the table, meaning that the results calculated by Iolite are producing\nslightly inconsistent isotopic ratios (this is a known issue of Iolite). However, this is just a guess,\nas the 207/235 ratio is not included in the data table, and I cannot confirm this. Depending on\nhow the 207/235 ratio was calculated (mean of ratios versus ratio of means), this could explain\nthe discrepancies observed.\nUsing sample VR05 as an example, we carefully retraced the plotting procedure and\nidentified a possible cause for the age differences. The analytical errors in our data table\nare reported as 2σ (absolute), so all diagrams were generated using the ‘Input errors’\nsetting as ‘2se (abs)’ in IsoplotR.\nHowever, when we plotted VR05 using the ‘1se (abs)’ option (as shown in the figure\nbelow), we obtained the same result as you did. This indicates that the discrepancy\narises from selecting the incorrect input error setting during plotting. Therefore, we\nbelieve that the mismatch in results is due to this choice in the ‘Input errors’ parameter\nand we recommend you try to use 2se (abs) as input.\nAuthors should report the U-Pb isotopic data as follows:\n206Pb/204Pb (or % of common Pb), 207Pb/235U, 206Pb/238U, rho, 207Pb/206Pb, 238U/206Pb, rho,\n232Th/238U.\nThe complete dataset, arranged as requested, is now included in the revised supplementary\nmaterial (Supplementary Table 3).\nPlot for sample VR05 reported in supplementary table:\nPlot for the same sample VR05 with data from columns B to F:\n(Note that in the plot above, I did not reject the youngest and oldest analyses. To obtain an\nacceptable MSWD I would have had to reject more than 2.)\n2) Furthermore:\n Please indicate the type of concordance used (e.g., % difference between the ²⁰⁶Pb/²³⁸U\nand ²⁰⁷Pb/²⁰⁶Pb ages, concordia distance, etc.). The authors appear to have used\nconcordia distance (or a similar approach), but this should be explicitly stated.\nThis is now stated on the Supplementary Table 3.\n3) When examining the data for each individual sample, many of the rejected analyses could be\ninterpreted as either significantly older and discordant grains (xenocrysts or inherited cores) or\ngrains affected by common Pb. However, common Pb estimation is not provided in the data\ntable, nor are CL images that could clarify whether these analyses correspond to inherited cores.\nCL images of representative zircons of each sample should be provided.\nZircon CL images are now inserted as supplementary material (Supplementary\nData 3).\n Building on the above, when plotting the data for all samples, the common Pb\nhypothesis seems unlikely, as most data align along discordia lines toward geologically\nmeaningful ages (those younger than 2.2 Ga). In contrast, analyses older than 2.2 Ga are\nmore scattered and usually highly discordant (except for PB07A_8: 2852 Ma), making\ntheir ²⁰⁷Pb/²⁰⁶Pb ages questionable.\n4) A potential approach for the treatment of U-Pb data could be considered. As noted by\nVermeesch (2021, Geoscience Frontiers 12, 843–850), “volcanic rocks often exhibit positively\nskewed age distributions with a short tail of syn-eruptive U–Pb ages and a long tail of pre-\neruptive or xenocrystic ages.”. In such cases, the maximum likelihood age model (minimum age\non radialplot of Isoplot-R) might be a good alternative for determining the crystallization age, as\nit statistically rejects possible xenocrystic ages. This automated method is likely more accurate\nfor identifying inherited grains than manually removing analyses by visual inspection. This is\nparticularly relevant for Paleoproterozoic rocks, where a conservative 1% uncertainty\ncorresponds to approximately ± 20 Ma, leading to inevitable overlap between crystallization\nages and slightly older xenocrysts (e.g., see comments on sample GLR-35 below).\nSome comments on the data of a few samples:\nSample LA-01:\n Grains LA01_17 and 18 overlap with the main group and, therefore, should not be\nconsidered as inherited. They should be included in the weighted mean 207Pb/206Pb\nand concordia age calculations. Based on the rejection criteria indicated in the\nsupplementary table (concordance > 0.95), grain LA01_10 could also be included in the\nweighted mean 207Pb/206Pb age calculation.\n Grain LA01_19 (2064 ± 19 Ma) should be considered as an inherited grain as it aligns\nwith LA01_3 (2061 ± 23 Ma) and 13 (2061 ± 22 Ma).\n Grains LA01_20, 24 and 25 seem affected by common Pb.\nWe recalculated the ages after your recommendations, MSWD raised to 2 and the age\nof the entire population became older. By using the radial plot, we obtained one tail with\n1971 ± 13, which is geologically more meaningful for a crystallization/eruption age. This\nis now explained in the text and the figures were replaced in the Supplementary Table\n3.\nSample PA-34:\nThe reported MSWD of 3.4 the weighted mean concordia age (2002.3 ± 3.2/6.3 Ma) exceeds the\nrange of acceptable MSWD values for n = 19 at 2 sigma level. The weighted mean 207/206 age\nshould be the preferred age (1996 ± 4 Ma, MSWD = 0.87).\nOk, this is now fixed.\nSample TM43:\nUsing the 15 analyses selected by the authors to calculate the weighted mean ²⁰⁷Pb/²⁰⁶Pb age,\nI obtain a lower MSWD value of 1.3, compared to the reported 2.5 in the data table. This suggests\nthat the weighted mean ²⁰⁷Pb/²⁰⁶Pb age should be preferred over the weighted mean concordia\nage.\nThis is probably because the analytical errors in our data table are reported as 2σ\n(absolute), so all diagrams were generated using the ‘Input errors’ setting as ‘2se (abs)’\nin IsoplotR.\nSample MA-02:\nSimilarly to the sample above, using the 22 analyses selected by the authors to calculate the\nweighted mean ²⁰⁷Pb/²⁰⁶Pb age, I obtain a lower MSWD value of 0.56, compared to the reported\nin the data table. In any case, both of these MSWD values are statistically more reliable than\nthe MSWD of 4 reported for the weighted mean Concordia age, which was chosen as the\npreferred age by the authors. Given this, the weighted mean ²⁰⁷Pb/²⁰⁶Pb age should be preferred\nover the weighted mean Concordia age.\nOk, this is now fixed.\n1.6\nSample GLR-35:\n The statistical parameters of the three “age” types provided clearly indicated that the\ncalculated dates are not statistically sound:\no concordia age (n = 23): MSWD = 6.8 and p = 0 (for concordance and\nequivalence);\no weighted mean 207/206 age (n = 23): MSWD = 4.8, p = 0);\no weighted mean concordia age (n = 20): MSWD = 3, p = 0).\nThe three analyses, considered inherited by the authors, are represented in grey. However, both\nthe MSWD values and visual inspection of the diagram clearly indicate the presence of more\nthan one population of analyses within the green group.\n Considering that the 23 analyses are all nearly concordant, we can use the radial plot\nfunction of Isoplot-R to assess the presence of more than one age component. The\nalgorithm indicates the presence of two distinct age components within the 23\nanalyses, one at 1795 ± 6 Ma and an older one at 1830.6 ± 8.9 Ma. From the plot, it is\nclear that analyses older than 1820 Ma belong to the older component.\n Considering analyses older than 1820 Ma as inherited (GLR35_8, GLR35_16, GLR35_19,\nGLR35_22, GLR35_24, in addition to the 3 selected by the authors), we can calculate a\nweighted mean 207/206 age of 1795.2 ± 5.6 Ma (MSWD = 0.82, p = 0.66) for the younger\ngroup.\n Using the MLA algorithm, we obtain an identical age of 1794 ± 7 Ma.\nOk, we used the younger tail in the radial plot as the preferred age.\nRadial plot (finite mixtures = auto)\nRadial plot (finite mixtures = minimum)\nSample PGR27:\n The authors consider only the existence of one inherited grain (PGR27_25). However,\ninspection of the Concordia diagram clearly indicates the presence of more inherited\ngrains. Excluding analyses PGR27_8 and PGR27_9, which have very large uncertainties,\nit is clear that there are at least four analyses that are older than the main group.\n This is clearly depicted in the radial plot, which shows a younger population with a\nweighted mean 207/206 age of 1791 ± 5 Ma and an older one at 1840.4 ± 9.9 Ma.\nOk, we used the younger tail in the radial plot as the preferred age.\nSample SS-39:\nRejecting analyses SS39A_23 and SS39A_25 results in a statistically more robust concordia age\n(considering MSWD and p for concordance and equivalence).\nOk, we used this concordia instead of the earlier one.\nSample PB07A:\n Analyses PB07A_18 and PB07A_24 are not represented in the diagrams and were not\nused in the calculations; however, this is not indicated in the data table.\n From the inspection of the Concordia diagram, it is clear that, apart from grain\nPB07A_8 (2852 ± 17 Ma), there are other xenocrysts. This is also evident from the statistical\nparameters reported by the authors for the Concordia age, where MSWD = 5.1 and p = 0 (for\nconcordance and equivalence) clearly point to excess scatter. Indeed, the radial plot indicates\nthe presence of an older group comprising 4 analyses with a weighted mean 7/6 age of 1814 ±\nthe latter group yields an excellent age of 1761.3 ± 3.9 Ma (MSWD = 1.1, p = 0.28, for\nconcordance and equivalence).\nThis does not differ very much from our weighted mean concordia age of 1760.8 ± 3.3\n(MSWD = 1.4, N = 17, p = 0.37).\nSample PB09A:\n This is a sample where the differences between the plots constructed for the same\nanalyses with the data reported in the supplementary table (left) and the plot presented\nby the authors (right) differ significantly (see figures below). From the inspection of the\ndiagram and the 7/6 ages (1810 ± 21 Ma and 1796 ± 22 Ma), it is clear that the two\nanalyses in red on the left diagram are older than the main group (ages around 1760\nMa). This difference is not depicted in the diagram presented by the authors (right),\nwhich raises questions regarding the validity of the plots.\n As I mentioned before, while this does not have major implications for the calculation\nof the crystallization ages of the studied samples, since the final age differences overlap\nwithin uncertainty and therefore do not affect the conclusions of the study, it does\nindicate that something is wrong. While I can't be 100% sure that this is the cause of the\nissue, my guess is that it has to do with the fact that users plotted the diagrams using\nthe 207/235 (not reported in the data table) and 206/238 ratios, meaning that the\nresults calculated by Iolite are producing slightly inconsistent isotopic ratios (this is a\nknown issue of Iolite).\n Considering the data presented in the data table, which is the one I have access to,\nthis sample as an inherited component with a WM 7/6 age of 1803 ± 16 Ma and a crystallization\nage of 1758.6 ± 5.4 Ma (WM 7/6 age of the youngest group); the latter overlap with the\nConcordia age of 1758 ± 4 Ma (MSWD = 1.4, p = 0.07; excluding the most discordant analysis\nPB09_21).\nOk, we recalculated the ages and presented it in a revised table with the diagrams\n(Supplementary Table 3).\nconcordia_age::: 175 8 ± 4 Ma (n:::17)\nMSWIJ. 0 .0041'11-.-4'1-1-.-4.'-P=l-x-\"I-•'-0.-9-5'-1 -0.-0-5-8-1-0-.0-7-2\no\nie\n170-0\no\n\"o'\n21\nie\n16 50\ng)\no\n4 . 0 4. 2 4 . 4 4. 6 4 . 8 5. 0\n2 07p b/ 2 J SU\nResponse to Referees\nLarge-scale crustal growth determined by LIP magmatism during the\nPaleoproterozoic\nMatheus S. Simões, Carlos A. Sommer, Marcelo L. Vasquez, Lucas M.M. Rossetti, John M. Cottle, Túlio A.\nMendes, Andrew R.C. Kylander-Clark\nResponse to reviewer 2\nReviewer #2 (Remarks to the Author):\nThe main constraint of the manuscript is the lack of tectonic evidence, among others,\ncompatible with SLIP setting for the study regions. Sometimes, only geochemistry data\nlead to dubious conclusions. According to the chemical composition of the rocks\n(mainly calc-alkaline to shoshonitic, high-K, I-type to A-type), it is possible to accept\nthese rocks as occurring in pre- to post-collisional, as well as in an intraplate (fissural)\nenvironment. In fact, several authors argue magmatic arc setting for the rocks included\nin the three cycles proposed in the manuscript. It is the case of Fraga et al. (2020,\n2024) for the Orocaima Igneous Belt (cycle 1); Almeida et al. (2001), Vasquez et al.\n(2002), Santos et al. (2004), Juliani et al. (2013), Fernandes and Juliani (2019) for the\nTapajós and Iriri-Xingu domains (cycles 1 and 2), and Cordani and Teixeira (2007) for\nJuruena region (cycle 3).\nIn the manuscript, the SLIP-related setting is accepted for all regions without\ndiscussion. Arc magmatic and intraplate events may simultaneously or sequentially\nhappen, since well-arranged in the space and time. For instance, in the Tapajos\ndomain, where rocks from cycles 1 and 2 occur, and also magmatic arcs are argued, it\nis necessary reconstruct the tectonic history, fit both cycles and prove if they are true\nSLIPs. In summary, I am not against the SLIP hypothesis, but it is necessary show\nevidence in a comprehensive geological setting. They could be shown in tables or as\nSupplementary Material.\nTo provide further context, we have included a new supplementary table in the revised\nmanuscript that summarizes arguments supporting or challenging both LIP- and\nsubduction-related models.\nWe fully agree with the importance of seeking balanced interpretations regarding the\nAmazon Craton (AC). Naturally, accretionary and collisional events played a role in the\nAC’s tectonic evolution, and we do not dismiss their occurrence. As highlighted in the\nnew supplementary table, several regions of the AC with Rhyacian to Statherian ages\nnow present stronger evidence for intraplate magmatism, even in areas that were initially\ndescribed as magmatic arcs. The historical view of geochronological provinces is a\nhallmark for understanding crustal evolution of the AC. Orogenic model-based solutions\nwere a solid response to primarily geosyncline theory-based models. Nevertheless, there\nwere some flaws adopted for reaffirming these models. However, some key assumptions\nused to reinforce these models warrant reconsideration.\nOne major limitation lies in the interpretation of whole-rock geochemistry:\n1. Most silicic rocks are naturally enriched in K₂ O and plot within the high-K to\nshoshonitic fields on petrological diagrams. So, not an argument for magmatic\narc setting.\n2. These diagrams have often been used to support Andean-type magmatism\nwithout incorporating A-, I-, or S-type granitoid classification diagrams and\nwithout considering the geochemistry and evolution of coeval mafic magmatism.\n3. A significant volume of these high-K silicic rocks is demonstrably A-type in\ncharacter, as already established in previous studies, and therefore does not\nrequire detailed demonstration in this manuscript.\n4. The common association of I-type calc-alkaline or tonalite-granodiorite-diorite\nsuites (contemporaneous to A-type magmatism) with arc settings has often been\nmisapplied. The main misconception regards the lack of detailed\ngeological mapping. For example, single plutons in intraplate settings may\nrecord multiple intrusive pulses, alternating between syeno- to monzogranites\nwith A-type affinity and granodiorites/tonalites with I-type affinity—as observed,\nfor example, in the Lavras do Sul (Gastal et al. 2015 -\n10.1590/23174889201500020004) and São Sepé (Gastal and Ferreira, 2013 -\n10.22456/1807-9806.43440) granites of the Neoproterozoic Sul-Riograndense\nShield.\n5. Furthermore, many igneous suites—coeval with known A-type magmatism—\nconsist of high-K, calc-alkaline I-type granitoids, which are not exclusive to arc\nsettings, and can also be generated by high-grade metamorphism of deeply\nburied continental crust and subsequent attendant water-fluxed melting of\ncrustal lithologies (Janousek et al., 2023 - 10.1016/j.jog.2022.101960).\nA second flawed assumption involves the interpretation of age zonation in zircon U–Pb\ndata and Nd isotopic signatures as indicative of accretion. The first interpretation of\nCordani et al., Tassinari and Macambira, Santos et al., Cordani and Teixeira, assume\nisotopic zonation across the (generally) NW-trending geochronological provinces.\nNevertheless, no clear age/isotope ratio zonation is observed for Cycle 1, which is\ndominantly E-W trending in the Guyana Shield. For cycle 2, there is no age zonation,\nand the Nd isotopic signatures are evidently influenced by underlying Archean or\nRhyacian–Siderian crust (Semblano et al., 2016 - 10.11606/issn.2316-9095.v16i3p19-\n38; Teixeira et al., 2017 - 10.1016/j.jsames.2017.09.017, and many references from\nworks at eastern AC). Cycle 3 is also E-W trending and exhibits strong evidence for\nextensional, bimodal magmatic activity and coeval ultra-high temperature (UHT)\nmetamorphism (Rizzotto et al., 2019 10.1016/j.jsames.2019.01.003, Benetti et al., 2024\n- link). Nd isotopes and inherited zircons points to a reworked Orosirian crust with local\nArchean substrate. Later deformation and metamorphic overprints correspond to\nyounger tectonic events unrelated to the timing of LIP emplacement (Almeida et al.,\n2022 - 10.29396/jgsb), as illustrated in Figure 6.\nAnother discussion needing to be enlarged concerns the extensions and the\nrepresentations of the three cycles in Figure 1. In the Tapajos and Iriri-Xingu domains\n(southeastern part of the craton), rocks from both cycles 1 and 2 occur. In my point of\nview, it is not possible separate two different domains, as it is shown in Figure 1,\nbecause in some areas there are both cycles, side-to-side, overlaying or cross-cutting\none over the other. The same is true to Peixoto de Azevedo domain, surrounded by\nrocks from cycle 3, where rocks from cycle 2 is also present. Additionally, a 1.88 Ga\ngranite magmatism is spread in the Carajas domain, extreme southeastern part or the\ncraton. This magmatism has been correlated to Uatuma SLIP, present in the adjacent\nIriri-Xingu and Tapajos domains. In line 331, a rock from cycle 2 occurring in Tucuma\narea (Carajas Province) is exampled, but it is not shown in figure 1. I suggest including\nas Supplementary Material a map presenting all sample locations, which data were\nused in the manuscript.\nWe acknowledge that several aspects of geological mapping may be limited by the scale\nof the maps presented. Nevertheless, we carefully reviewed all the points raised here\nand confirmed that they are indeed represented on the geological map. To improve\nclarity, we have included a new Figure 1 in the revised manuscript, where the geological\noutlines are more precisely constrained. Additionally, detailed geological maps showing\nsample locations and descriptions are now provided in the Supplementary Data 1 file."}, {"round": 2, "reviewer_comments": {"reviewer_2": "The reviewed manuscript “Large-scale crustal growth determined by LIP magmatism during the Paleoproterozoic”, was\nevaluated. The manuscript has been substantially improved, especially with the inclusion of new maps and supplementary\nmaterial. Now, it is clearer, precise and denser. However, I have some additional comments, hoping the manuscript to be\nbetter.\n- I suggest including in the title “Amazonian Craton”, since the object of the manuscript is exclusive over this region.\n- Indeed, in my first review, in according to Stratigraphic code, I suggested replacing “Amazon Craton” by “Amazonian\nCraton”, term originally proposed by Almeida et al. (1981) to define the same region and setting. This point was not\ncommented by the authors.\n- The new “Arc vs LIP” table summarizes a comprehensive characteristic set helping the discussion about the tectonic\nsetting. However, it is possible to see that they are not conclusive, in special, concerning poorly known regions, as we have\nin the Amazonia Craton. For instance, considering this constraint, the debate Arc vs LIP is not a crucial obstacle to advance\nthe discussion. The main aspects to support the manuscript approach are the huge magma volumes with age, isotope and\nchemistry compositions nearly well determined.\n- Concerning this aspect, I believe that the statement “…since no plate tectonic indicators have been identified” (line 71) is\ntoo strong to the actual level of geological knowledge of the Amazonian Craton.\n- In Fig. 1, why were the Paraguá and Rio Apa domains excluded from the Amazonian Craton? Most authors accept\nParaguá domain as allochthonous block, but it is not a reason the exclude it. For example, the Archean Imataca and Amapá\nblocks probably are also allochthonous, but were considered as part of the craton.\n- In relation to the geochronological provinces, it is important to highlight that not all of them are considered as orogenic belts\n(line 132). It is the case of the Carajás domain, as well as the Iriri-Xingu and Erepecuru-Trombetas domains, all of them\nincluded in the Central Amazonia Province. Moreover, the NW-trend Iriri-Xingu and Erepecuru-Trombetas domains are\nalmost fully composed by rocks from cycles 1 and 2.\n- Still concerning the geochronological provinces, not all of them are NW-trending orientation (see Response for Reviewer\n2). It is true for provinces younger than 2,0 Ga, but it is not the case of the Maroni-Itacaiunas Province (Guiana Shield).\n- I disagree that the “…the Orosirian-Statherian orogenic belts do not match the orientation of N-S and E-W Orosirian-\nStatherian igneous belt” (lines 132 and 133). Cycles 1 occurs in the E-W Maroni-Itacaiunas Province, as well as in the NW\nCentral Amazonia Province, this last one completely composed of rocks from the cycles 1 and 2. Cycle 3 crops out in E-W\nsouthern part of the Rio Negro-Juruena Province. However, it doesn’t matter if the igneous and orogenic belts match or not.\nThe SLIP magmas could utilize previous regional structures to penetrate the upper crust.\n- In regard to lines 533-535, there are several authors reporting evidence of plate tectonics in the Rio Negro Province (e.g.\nAlmeida et al. 2022 (https://doi.org/10.1080/00206814.2021.2025158), and reference therein.\n- Reference 340 (line 252) and fig. 2d (line 269) do not appear in the manuscript.", "reviewer_3": "Simões et al., 2025. Nature Comm.\nGeneral comments\nThe manuscript convincingly argues that LIPs were major contributors to Paleoproterozoic crustal growth. However, has this\nnot been shown previously by for example the work of reference 12–14?\nThe idea of mantle cyclicity at ~95 Myr intervals aligns well with emerging models of deep Earth dynamics. (Just be honest\nwith the ages here)\nIt places the Amazon Craton in a global context through correlations with West Africa, Baltica, and others—strengthening the\ncase for a broader LIP-linked geodynamic system.\nI am a bit puzzled why the authors only use, and base their discussion on, Nd model ages, when their own data is zircon Hf\ndata and model ages can be calculated from these data. Is there a reason for this? The authors claim to have calculated two\nstage model ages (although undefined) but do not present them or seem to use them.\nThe abstract could benefit from more clarity by directly stating the key finding: that LIPs contributed significantly to crustal\ngrowth via deep-crustal partial melting.\nThe discussion could be better segmented to explicitly highlight contrasts between arc and LIP-related crust formation\nmodels.\nWhile the authors argue for intraplate LIP-driven crust formation, the paper could further address counterarguments from\nproponents of arc-dominated growth models.\nThe interpretation of zircon trace elements as direct indicators of source pressure and temperature, though accepted, would\nbenefit from more explicit discussion of uncertainties and assumptions.\nComments on data\nI cannot recreate the εHf values for the data.\nThe authors do not define what values for, for example CHUR was used. (Bouvier et al., 2008)?\nUsing the same decay constant and bouvier CHUR values I get quite substantially different εHf values than the authors. This\nis VERY concerning! Even using other (common) CHUR values I doubt I would get the same values as the authors.\nIn several places (for example row 28 (VR05-1)) there are Hf/Hfi data and a calculated εHf value. But for that analyses (and\nseveral more) there are no raw data in columns CF–CO. The table is generally very confusing and difficult to decipher. εHf\nvalues are calculated for zircon with no data and vice versa.\nEven though not stated the εHf values seem to be calculated at the individual zircon dates (based on spot locations on figure\n4). This has been shown multiple times that this is in accurate. See for example Whitehouse and Kemp (2010, Geol. Soc.\nSpec. Pub. London).\nεHf values should always be calculated at the interpreted age of igneous crystallisation.\nThe “preferred age” for several samples according to the summary table on tab Sample identification state that they prefer\nand use the “concordia weighted mean age”. What is that? Either it’s a concordia age or a weighted mean age. And if a\nweighted mean age, then it needs to be defined as for example 207Pb/206Pb or similar. If this is a weighted mean of\nindividual Concordia dates (which is unconventional, but would be ok) this needs to be explained, and the individual\nconcordia dates should be added to the data column in the supplementary table.\nThe only form of explanation is found on lines 201–202: “Ages are reported here as the maximum likelihood estimate with its\nanalytical uncertainty/analytical uncertainty with dispersion.\nFurthermore: 6/7 weighted mean in Supp. table 2. Tab “Sample identification” should be 7/6 I assume.\nOGC εHf = +0.6 ± 0.2 2s (Kemp et al., 2017), in this study the results come out to: ~+2.7- 2.5 units too high. Is this data\ncorrect?\nSome reference zircon have data for Hf in column T–W, but some only in row CF and forward. What is the difference here?\nOGC have no calculated εHf values, but there is raw data. It’s all very confusing, and the fact that these reference zircon are\ngiving the incorrect values combined with the unreadable table makes me worried.\n(However, the data in row CF in the “data” tab does not seem to be the measured values, as this doesn’t make sense for any\nof the reference zircon) This needs to be marked more clearly so that one can check the data quality of the reference\nmaterial.\n“To assess accuracy and precision, natural (91500’,‘Mud Tank’, and GJ-1) and synthetic (MunZirc-1, -3, and -4) reference\nzircons were run concurrently and treated as unknowns.”\nThis data is nowhere to be found! At least not for Mud Tank and MUN zircon.\nWhat lab was used for these isotope analyses? The machines are listed, but not what lab.\nHow was the primary standard values for zircon Hf data checked? Against JMC-475? Not reported. Also, the 178Hf/177Hf is\nhigher than usual in these analyses. A mean value of all analyses is 1.4677 when the reported value is 1.4772 for, for\nexample JMC-475. All individual analyses have a 178Hf/177Hf > than 1.4772. Please comment on this.\nWhat was used in the Yb correction? Among the data presented in the table there is no zircon with high Yb which would be\nusable for Yb corrections. OGC would be good. Mud Tank would be good. MUN would be ok. But none of this data is\npresented.\nIndividual line comments\nLine 14: The rise of plate tectonics in the Paleoproterozoic. A LOT of studies would argue against this, but here its stated as\na truth. This needs to be addressed.\nLine 65: There are basically no 2.2 Ga rock in Fennoscandia. To find 2.2 Ga old bedrock in the region, you only find it in the\neastern and northern parts, specifically within the Karelian Craton, in areas of Finland and Russian Karelia (In this paper the\nKola-Karelian) where Paleoproterozoic supracrustal sequences, often associated with early rifting events, are preserved.\nLines 74–75: Why 95 Myrs.? The timespan between these magmatic episodes are 100, 100 and 110 Ma.\nLine 158: Is negative Nb-Ta anomalies really likely to be present in LIPs? You need either significant crustal contamination\nduring magma ascent and emplacement, or\nfractionation of Ti-bearing minerals within the magmatic system. I would rephrase this sentence.\nLine 209–: Results are written in past tense (yielded) but these analyses still yield. Hence, this should be in present tense\n(yield).\nLine 231: Add these ratios as columns in supplementary table to easily check. A mean Th/U of 1 is very high.\nAlso, the word “ratios” is redundant as the Th/U and Yb/Sm are ratios. Hence, this reads “ratio ratio”.\nLines 291–295: Statement requires references.\nLine 300: What DM was used? What CHUR values were used?\nLines 303-304: “Primary sub-populations for Cycle 1, identified in KDE plots, occur at -5.4 and +2.7.” 1. What does this\nmean? 2. Occur?\nLine 305: clustering at -0.89 is very specific, please rephrase.\nLine 306: haspredominantly (missing space)\nLine 311: Figure 3? Should be figure 4, right?\nLine 315: What is clustering here at the specific value of +0.68? All data? Some of the data? It doesn’t look like a tight\ncluster. If this is a mean value I assume the MSWD is rather high if all data is included. If all data is not included, then this\nneeds to be stated.\nOh, now I saw the curve in the figure. So this is a peak, not a cluster… Please explain this more carefully.\nFig. 4: What DM was used in the model age calculations for Nd data?\nLine 444: These are not only zircon U-Pb dates. Baddeleyite have been used to date at least a few of these, which is\napparent even from the titles of the references.\nLine 446: Well. The time difference between the direct ages of the dykes are 100–110 Myrs. The difference between the\nzircon peaks, which I assume have an uncertainty that overlaps the baddeleyite/zircon ages of the dykes might be ca. 95\nMyrs. But these are peaks, not direct ages. I think the authors needs to be more up front about this. Ca 100 Ma is still a good\nmatch to your harmonic mantle cycles, but it would be a stronger argument if based on the direct dates presenting the\n“actual” age gaps. However, the age interval presented and forwarded in the cited reference [58] is NOT 94 Myrs but 90\nMyrs. So, now the difference is going from 95–94 to from 100 (or 110) Myrs to 90, which is not as strong of a match.\nLine 452: This is not ref [58] but rather the work of: S.J. Puetz, K.C. Condie\nTime series analysis of mantle cycles Part I: The geologic record in zircons, large igneous provinces and mantle lithosphere\nGeosci. Front., 10 (2019), pp. 1305-1326, 10.1016/j.gsf.2019.04.002\nThese authors claim mantel cyclicity of ca 93 and 187 Myrs.\nLine 466: You present data, not evidence. Evidence is a very strong word choice. I would suggest rephrasing.\nLines 480–488: Recent studies have shown, using several different basis of evidence that there is a lot of water in the\nmantle. Hence, I would strongly argue that subduction is NOT a prerequisite for the generation of silicic magma.\nSee for example papers below.\n1. Schmandt, B., & Jacobsen, S. D. (2014). Dehydration melting at the top of the lower mantle. Science, 344(6189), 1259-\n1262.\n2. Pearson, D. G., Brenker, F. E., Nestola, F., McNeill, J., Nasdala, L., Hutchison, B. J., ... & Stachel, T. (2014). Hydrous\nmantle transition zone indicated by ringwoodite from Brazilian diamond. Nature, 507(7491), 221-224.\n3. Wang, W., Schmandt, B., & Hu, J. (2025, forthcoming or recent). Water Stored in the Mantle for Millions of Years May Be\nLinked to Continental Volcanism.\n4. Bolfan-Casanova, N. (2018). Water in the Earth's mantle. Mineralogical Magazine, 69(3), 229-257.\nIn summary, the scientific consensus over the last decade has solidified the understanding that the Earth's mantle,\nparticularly the transition zone, is a vast reservoir of water, likely holding several times the volume of our surface oceans.\nThis understanding is built on a multidisciplinary approach combining seismology, high-pressure mineral physics, and\ngeochemistry.\nFigure. 1A. The colour difference between the eclogite and ophiolites are too small. I would recommend changing these (or\none of these) colours.\nFigure. 2. I cannot find dyke swarm C2 in the figure.\nFigure 3C. Are the error bars 1 or 2 sigma?\nFigure 4. The authors mention second stage TDM ages. These are: 1. Not defined by 176Lu/177Hf for the second stage. 2.\nThey are not presented anywhere.\nFigure 5. Why are charnokites and 2.11–2.08 granitic magmatism denoted using magma blobs instead of squares like other\nmagmatic events/intrusions, like for example the 2.0–1.93 Grnaulite, charnokite, high T/P gneisses?\nFigure 6. The evolution of the figures from A–Dare not discussed. Please expand the figure caption to guide the reader what\nis happening in the transition between these stages.\nFigure 7. The colour difference between the greenstone belts and cycle 1 is too small in (B)."}, "author_response": "Response to Referees\nLarge-scale crustal growth determined by LIP magmatism during the\nPaleoproterozoic\nMatheus S. Simões, Carlos A. Sommer, Marcelo L. Vasquez, Lucas M.M. Rossetti, John M. Cottle, Túlio A.\nMendes, Andrew R.C. Kylander-Clark\nResponse to reviewer 1 – Part II\nComments on the data and figures presented in the supplementary table:\n1) When reviewing a manuscript with geochronology data, my first step is always to check the\nreference materials and to attempt reproducing the figures and age calculations. Results from\nthe reference materials are in excellent agreement with the accepted values.\nUsing Isoplot-R and following the same conditions outlined in the Methods section, I tested the\ndata reported in the supplementary table for the studied samples. While the calculated ages\nagree within uncertainty, I cannot reproduce the age results and diagrams presented by the\nauthors: the plots differ. Below, I provide an example for sample VR05, though this issue applies\nto all samples. As shown, the calculated ages are consistent within uncertainty, but the plots\nthemselves are different.\nWhile this discrepancy does not affect the overall results of the manuscript, because the\ncalculated ages usually overlap within uncertainty, it is important that any reader should be able\nto reproduce the figures presented by the authors. This is an issue and should be addressed.\nI am not sure about the cause of these differences. One possibility is that the authors may have\nplotted the diagrams using the 207/235 and 206/238 ratios, rather than the 238/206 and\n207/206 ratios reported in the table, meaning that the results calculated by Iolite are producing\nslightly inconsistent isotopic ratios (this is a known issue of Iolite). However, this is just a guess,\nas the 207/235 ratio is not included in the data table, and I cannot confirm this. Depending on\nhow the 207/235 ratio was calculated (mean of ratios versus ratio of means), this could explain\nthe discrepancies observed.\nUsing sample VR05 as an example, we carefully retraced the plotting procedure and\nidentified a possible cause for the age differences. The analytical errors in our data table\nare reported as 2σ (absolute), so all diagrams were generated using the ‘Input errors’\nsetting as ‘2se (abs)’ in IsoplotR.\nHowever, when we plotted VR05 using the ‘1se (abs)’ option (as shown in the figure\nbelow), we obtained the same result as you did. This indicates that the discrepancy\narises from selecting the incorrect input error setting during plotting. Therefore, we\nbelieve that the mismatch in results is due to this choice in the ‘Input errors’ parameter\nand we recommend you try to use 2se (abs) as input.\nAuthors should report the U-Pb isotopic data as follows:\n206Pb/204Pb (or % of common Pb), 207Pb/235U, 206Pb/238U, rho, 207Pb/206Pb, 238U/206Pb, rho,\n232Th/238U.\nThe complete dataset, arranged as requested, is now included in the revised supplementary\nmaterial (Supplementary Table 3).\nPlot for sample VR05 reported in supplementary table:\nPlot for the same sample VR05 with data from columns B to F:\n(Note that in the plot above, I did not reject the youngest and oldest analyses. To obtain an\nacceptable MSWD I would have had to reject more than 2.)\n2) Furthermore:\n Please indicate the type of concordance used (e.g., % difference between the ²⁰⁶Pb/²³⁸U\nand ²⁰⁷Pb/²³⁶Pb ages, concordia distance, etc.). The authors appear to have used\nconcordia distance (or a similar approach), but this should be explicitly stated.\nThis is now stated on the Supplementary Table 3.\n3) When examining the data for each individual sample, many of the rejected analyses could be\ninterpreted as either significantly older and discordant grains (xenocrysts or inherited cores) or\ngrains affected by common Pb. However, common Pb estimation is not provided in the data\ntable, nor are CL images that could clarify whether these analyses correspond to inherited cores.\nCL images of representative zircons of each sample should be provided.\nZircon CL images are now inserted as supplementary material (Supplementary\nData 3).\n Building on the above, when plotting the data for all samples, the common Pb\nhypothesis seems unlikely, as most data align along discordia lines toward geologically\nmeaningful ages (those younger than 2.2 Ga). In contrast, analyses older than 2.2 Ga are\nmore scattered and usually highly discordant (except for PB07A_8: 2852 Ma), making\ntheir ²⁰⁷Pb/²⁰⁶Pb ages questionable.\n4) A potential approach for the treatment of U-Pb data could be considered. As noted by\nVermeesch (2021, Geoscience Frontiers 12, 843–850), “volcanic rocks often exhibit positively\nskewed age distributions with a short tail of syn-eruptive U–Pb ages and a long tail of pre-\neruptive or xenocrystic ages.”. In such cases, the maximum likelihood age model (minimum age\non radialplot of Isoplot-R) might be a good alternative for determining the crystallization age, as\nit statistically rejects possible xenocrystic ages. This automated method is likely more accurate\nfor identifying inherited grains than manually removing analyses by visual inspection. This is\nparticularly relevant for Paleoproterozoic rocks, where a conservative 1% uncertainty\ncorresponds to approximately ± 20 Ma, leading to inevitable overlap between crystallization\nages and slightly older xenocrysts (e.g., see comments on sample GLR-35 below).\nSome comments on the data of a few samples:\nSample LA-01:\n Grains LA01_17 and 18 overlap with the main group and, therefore, should not be\nconsidered as inherited. They should be included in the weighted mean 207Pb/206Pb\nand concordia age calculations. Based on the rejection criteria indicated in the\nsupplementary table (concordance > 0.95), grain LA01_10 could also be included in the\nweighted mean 207Pb/206Pb age calculation.\n Grain LA01_19 (2064 ± 19 Ma) should be considered as an inherited grain as it aligns\nwith LA01_3 (2061 ± 23 Ma) and 13 (2061 ± 22 Ma).\n Grains LA01_20, 24 and 25 seem affected by common Pb.\nWe recalculated the ages after your recommendations, MSWD raised to 2 and the age\nof the entire population became older. By using the radial plot, we obtained one tail with\n1971 ± 13, which is geologically more meaningful for a crystallization/eruption age. This\nis now explained in the text and the figures were replaced in the Supplementary Table\n3.\nSample PA-34:\nThe reported MSWD of 3.4 the weighted mean concordia age (2002.3 ± 3.2/6.3 Ma) exceeds the\nrange of acceptable MSWD values for n = 19 at 2 sigma level. The weighted mean 207/206 age\nshould be the preferred age (1996 ± 4 Ma, MSWD = 0.87).\nOk, this is now fixed.\nSample TM43:\nUsing the 15 analyses selected by the authors to calculate the weighted mean ²⁰⁷Pb/²⁰⁶Pb age,\nI obtain a lower MSWD value of 1.3, compared to the reported 2.5 in the data table. This suggests\nthat the weighted mean ²⁰⁷Pb/²⁰⁶Pb age should be preferred over the weighted mean concordia\nage.\nThis is probably because the analytical errors in our data table are reported as 2σ\n(absolute), so all diagrams were generated using the ‘Input errors’ setting as ‘2se (abs)’\nin IsoplotR.\nSample MA-02:\nSimilarly to the sample above, using the 22 analyses selected by the authors to calculate the\nweighted mean ²⁰⁷Pb/²⁰⁶Pb age, I obtain a lower MSWD value of 0.56, compared to the reported\nin the data table. In any case, both of these MSWD values are statistically more reliable than\nthe MSWD of 4 reported for the weighted mean Concordia age, which was chosen as the\npreferred age by the authors. Given this, the weighted mean ²⁰⁷Pb/²⁰⁶Pb age should be preferred\nover the weighted mean Concordia age.\nOk, this is now fixed.\n1.6\nSample GLR-35:\n The statistical parameters of the three “age” types provided clearly indicated that the\ncalculated dates are not statistically sound:\no concordia age (n = 23): MSWD = 6.8 and p = 0 (for concordance and\nequivalence);\no weighted mean 207/206 age (n = 23): MSWD = 4.8, p = 0);\no weighted mean concordia age (n = 20): MSWD = 3, p = 0).\nThe three analyses, considered inherited by the authors, are represented in grey. However, both\nthe MSWD values and visual inspection of the diagram clearly indicate the presence of more\nthan one population of analyses within the green group.\n Considering that the 23 analyses are all nearly concordant, we can use the radial plot\nfunction of Isoplot-R to assess the presence of more than one age component. The\nalgorithm indicates the presence of two distinct age components within the 23\nanalyses, one at 1795 ± 6 Ma and an older one at 1830.6 ± 8.9 Ma. From the plot, it is\nclear that analyses older than 1820 Ma belong to the older component.\n Considering analyses older than 1820 Ma as inherited (GLR35_8, GLR35_16, GLR35_19,\nGLR35_22, GLR35_24, in addition to the 3 selected by the authors), we can calculate a\nweighted mean 207/206 age of 1795.2 ± 5.6 Ma (MSWD = 0.82, p = 0.66) for the younger\ngroup.\n Using the MLA algorithm, we obtain an identical age of 1794 ± 7 Ma.\nOk, we used the younger tail in the radial plot as the preferred age.\nRadial plot (finite mixtures = auto)\nRadial plot (finite mixtures = minimum)\nSample PGR27:\n The authors consider only the existence of one inherited grain (PGR27_25). However,\ninspection of the Concordia diagram clearly indicates the presence of more inherited\ngrains. Excluding analyses PGR27_8 and PGR27_9, which have very large uncertainties,\nit is clear that there are at least four analyses that are older than the main group.\n This is clearly depicted in the radial plot, which shows a younger population with a\nweighted mean 207/206 age of 1791 ± 5 Ma and an older one at 1840.4 ± 9.9 Ma.\nOk, we used the younger tail in the radial plot as the preferred age.\nSample SS-39:\nRejecting analyses SS39A_23 and SS39A_25 results in a statistically more robust concordia age\n(considering MSWD and p for concordance and equivalence).\nOk, we used this concordia instead of the earlier one.\nSample PB07A:\n Analyses PB07A_18 and PB07A_24 are not represented in the diagrams and were not\nused in the calculations; however, this is not indicated in the data table.\n From the inspection of the Concordia diagram, it is clear that, apart from grain\nPB07A_8 (2852 ± 17 Ma), there are other xenocrysts. This is also evident from the statistical\nparameters reported by the authors for the Concordia age, where MSWD = 5.1 and p = 0 (for\nconcordance and equivalence) clearly point to excess scatter. Indeed, the radial plot indicates\nthe presence of an older group comprising 4 analyses with a weighted mean 7/6 age of 1814 ±\nthe latter group yields an excellent age of 1761.3 ± 3.9 Ma (MSWD = 1.1, p = 0.28, for\nconcordance and equivalence).\nThis does not differ very much from our weighted mean concordia age of 1760.8 ± 3.3\n(MSWD = 1.4, N = 17, p = 0.37).\nSample PB09A:\n This is a sample where the differences between the plots constructed for the same\nanalyses with the data reported in the supplementary table (left) and the plot presented\nby the authors (right) differ significantly (see figures below). From the inspection of the\ndiagram and the 7/6 ages (1810 ± 21 Ma and 1796 ± 22 Ma), it is clear that the two\nanalyses in red on the left diagram are older than the main group (ages around 1760\nMa). This difference is not depicted in the diagram presented by the authors (right),\nwhich raises questions regarding the validity of the plots.\n As I mentioned before, while this does not have major implications for the calculation\nof the crystallization ages of the studied samples, since the final age differences overlap\nwithin uncertainty and therefore do not affect the conclusions of the study, it does\nindicate that something is wrong. While I can't be 100% sure that this is the cause of the\nissue, my guess is that it has to do with the fact that users plotted the diagrams using\nthe 207/235 (not reported in the data table) and 206/238 ratios, meaning that the\nresults calculated by Iolite are producing slightly inconsistent isotopic ratios (this is a\nknown issue of Iolite).\n Considering the data presented in the data table, which is the one I have access to,\nthis sample as an inherited component with a WM 7/6 age of 1803 ± 16 Ma and a crystallization\nage of 1758.6 ± 5.4 Ma (WM 7/6 age of the youngest group); the latter overlap with the\nConcordia age of 1758 ± 4 Ma (MSWD = 1.4, p = 0.07; excluding the most discordant analysis\nPB09_21).\nOk, we recalculated the ages and presented it in a revised table with the diagrams\n(Supplementary Table 3).\nconcordia_age::: 175 8 ± 4 Ma (n:::17)\nMSWIJ. 0 .0041'11-.-4'1-1-.-4.'-P=l-x-\"I-•'-0.-9-5'-1 -0.-0-5-8-1-0-.0-7-2\no\nie\n170-0\no\n\"o'\n21\nie\n16 50\ng)\no\n4 . 0 4. 2 4 . 4 4. 6 4 . 8 5. 0\n2 07p b/ 2 J SU\nResponse to Referees\nLarge-scale crustal growth determined by LIP magmatism during the\nPaleoproterozoic\nMatheus S. Simões, Carlos A. Sommer, Marcelo L. Vasquez, Lucas M.M. Rossetti, John M. Cottle, Túlio A.\nMendes, Andrew R.C. Kylander-Clark\nResponse to reviewer 2\nReviewer #2 (Remarks to the Author):\nThe main constraint of the manuscript is the lack of tectonic evidence, among others,\ncompatible with SLIP setting for the study regions. Sometimes, only geochemistry data\nlead to dubious conclusions. According to the chemical composition of the rocks\n(mainly calc-alkaline to shoshonitic, high-K, I-type to A-type), it is possible to accept\nthese rocks as occurring in pre- to post-collisional, as well as in an intraplate (fissural)\nenvironment. In fact, several authors argue magmatic arc setting for the rocks included\nin the three cycles proposed in the manuscript. It is the case of Fraga et al. (2020,\n2024) for the Orocaima Igneous Belt (cycle 1); Almeida et al. (2001), Vasquez et al.\n(2002), Santos et al. (2004), Juliani et al. (2013), Fernandes and Juliani (2019) for the\nTapajós and Iriri-Xingu domains (cycles 1 and 2), and Cordani and Teixeira (2007) for\nJuruena region (cycle 3).\nIn the manuscript, the SLIP-related setting is accepted for all regions without\ndiscussion. Arc magmatic and intraplate events may simultaneously or sequentially\nhappen, since well-arranged in the space and time. For instance, in the Tapajos\ndomain, where rocks from cycles 1 and 2 occur, and also magmatic arcs are argued, it\nis necessary reconstruct the tectonic history, fit both cycles and prove if they are true\nSLIPs. In summary, I am not against the SLIP hypothesis, but it is necessary show\nevidence in a comprehensive geological setting. They could be shown in tables or as\nSupplementary Material.\nTo provide further context, we have included a new supplementary table in the revised\nmanuscript that summarizes arguments supporting or challenging both LIP- and\nsubduction-related models.\nWe fully agree with the importance of seeking balanced interpretations regarding the\nAmazon Craton (AC). Naturally, accretionary and collisional events played a role in the\nAC’s tectonic evolution, and we do not dismiss their occurrence. As highlighted in the\nnew supplementary table, several regions of the AC with Rhyacian to Statherian ages\nnow present stronger evidence for intraplate magmatism, even in areas that were initially\ndescribed as magmatic arcs. The historical view of geochronological provinces is a\nhallmark for understanding crustal evolution of the AC. Orogenic model-based solutions\nwere a solid response to primarily geosyncline theory-based models. Nevertheless, there\nwere some flaws adopted for reaffirming these models. However, some key assumptions\nused to reinforce these models warrant reconsideration.\nOne major limitation lies in the interpretation of whole-rock geochemistry:\n1. Most silicic rocks are naturally enriched in K₂ O and plot within the high-K to\nshoshonitic fields on petrological diagrams. So, not an argument for magmatic\narc setting.\n2. These diagrams have often been used to support Andean-type magmatism\nwithout incorporating A-, I-, or S-type granitoid classification diagrams and\nwithout considering the geochemistry and evolution of coeval mafic magmatism.\n3. A significant volume of these high-K silicic rocks is demonstrably A-type in\ncharacter, as already established in previous studies, and therefore does not\nrequire detailed demonstration in this manuscript.\n4. The common association of I-type calc-alkaline or tonalite-granodiorite-diorite\nsuites (contemporaneous to A-type magmatism) with arc settings has often been\nmisapplied. The main misconception regards the lack of detailed\ngeological mapping. For example, single plutons in intraplate settings may\nrecord multiple intrusive pulses, alternating between syeno- to monzogranites\nwith A-type affinity and granodiorites/tonalites with I-type affinity—as observed,\nfor example, in the Lavras do Sul (Gastal et al. 2015 -\n10.1590/23174889201500020004) and São Sepé (Gastal and Ferreira, 2013 -\n10.22456/1807-9806.43440) granites of the Neoproterozoic Sul-Riograndense\nShield.\n5. Furthermore, many igneous suites—coeval with known A-type magmatism—\nconsist of high-K, calc-alkaline I-type granitoids, which are not exclusive to arc\nsettings, and can also be generated by high-grade metamorphism of deeply\nburied continental crust and subsequent attendant water-fluxed melting of\ncrustal lithologies (Janousek et al., 2023 - 10.1016/j.jog.2022.101960).\nA second flawed assumption involves the interpretation of age zonation in zircon U–Pb\ndata and Nd isotopic signatures as indicative of accretion. The first interpretation of\nCordani et al., Tassinari and Macambira, Santos et al., Cordani and Teixeira, assume\nisotopic zonation across the (generally) NW-trending geochronological provinces.\nNevertheless, no clear age/isotope ratio zonation is observed for Cycle 1, which is\ndominantly E-W trending in the Guyana Shield. For cycle 2, there is no age zonation,\nand the Nd isotopic signatures are evidently influenced by underlying Archean or\nRhyacian–Siderian crust (Semblano et al., 2016 - 10.11606/issn.2316-9095.v16i3p19-\n38; Teixeira et al., 2017 - 10.1016/j.jsames.2017.09.017, and many references from\nworks at eastern AC). Cycle 3 is also E-W trending and exhibits strong evidence for\nextensional, bimodal magmatic activity and coeval ultra-high temperature (UHT)\nmetamorphism (Rizzotto et al., 2019 10.1016/j.jsames.2019.01.003, Benetti et al., 2024\n- link). Nd isotopes and inherited zircons points to a reworked Orosirian crust with local\nArchean substrate. Later deformation and metamorphic overprints correspond to\nyounger tectonic events unrelated to the timing of LIP emplacement (Almeida et al.,\n2022 - 10.29396/jgsb), as illustrated in Figure 6.\nAnother discussion needing to be enlarged concerns the extensions and the\nrepresentations of the three cycles in Figure 1. In the Tapajos and Iriri-Xingu domains\n(southeastern part of the craton), rocks from both cycles 1 and 2 occur. In my point of\nview, it is not possible separate two different domains, as it is shown in Figure 1,\nbecause in some areas there are both cycles, side-to-side, overlaying or cross-cutting\none over the other. The same is true to Peixoto de Azevedo domain, surrounded by\nrocks from cycle 3, where rocks from cycle 2 is also present. Additionally, a 1.88 Ga\ngranite magmatism is spread in the Carajas domain, extreme southeastern part or the\ncraton. This magmatism has been correlated to Uatuma SLIP, present in the adjacent\nIriri-Xingu and Tapajos domains. In line 331, a rock from cycle 2 occurring in Tucuma\narea (Carajas Province) is exampled, but it is not shown in figure 1. I suggest including\nas Supplementary Material a map presenting all sample locations, which data were\nused in the manuscript.\nWe acknowledge that several aspects of geological mapping may be limited by the scale\nof the maps presented. Nevertheless, we carefully reviewed all the points raised here\nand confirmed that they are indeed represented on the geological map. To improve\nclarity, we have included a new Figure 1 in the revised manuscript, where the geological\noutlines are more precisely constrained. Additionally, detailed geological maps showing\nsample locations and descriptions are now provided in the Supplementary Data 1 file.\nReviewer #2 (Remarks to the Author):\nThe reviewed manuscript “Large-scale crustal growth determined by LIP magmatism\nduring the Paleoproterozoic”, was evaluated. The manuscript has been substantially\nimproved, especially with the inclusion of new maps and supplementary material. Now,\nit is clearer, precise and denser. However, I have some additional comments, hoping\nthe manuscript to be better.\n- I suggest including in the title “Amazonian Craton”, since the object of the manuscript\nis exclusive over this region.\n- Indeed, in my first review, in according to Stratigraphic code, I suggested replacing\n“Amazon Craton” by “Amazonian Craton”, term originally proposed by Almeida et al.\n(1981) to define the same region and setting. This point was not commented by the\nauthors.\nWe apologize for not addressing this point earlier.\nThe term Amazonian Craton was first proposed by F.F.M. Almeida and colleagues in\ntheir landmark 1981 paper. In my view (first author), Almeida remains one of Brazil’s\nmost influential geologists. His earlier work in the southeast Amazon (Almeida &\nNogueira Filho, 1968) was fundamental for clarifying the region’s complex geology\nalong the Aripuanã river, which was often misinterpreted by later studies that\noverlooked his contributions. His research on the Trindade and Fernando de Noronha\nislands continues to inform interpretations of volcanic architecture, and several of his\nother works remain foundational for understanding Brazil’s geology. I highlight this\nbackground to express my deep respect for his legacy.\nA later review by Santos (2003) argued—convincingly, in my view—that we should\navoid adjectives when naming tectonic units, otherwise we would end up with terms\nsuch as “Sanfranciscan Craton,” “Kaapvaalian Craton,” “Superiorian Craton,” or\n“Yilgarnian Craton.” The International Stratigraphic Code (Murphy & Salvador, 2008;\nhttps://stratigraphy.org/guide/defs) does not provide guidance on this issue either, since\nit applies to litho-, bio-, chrono-, and magnetostratigraphy, not to tectonic nomenclature.\nIn practice, the literature shows no consensus or problem: some international papers\nuse Amazonian, others Amazon. For these reasons, I chose to retain the usage in our\nmanuscript. I acknowledge the reviewer’s concern, but I believe it is a matter of\nconvention rather than correctness, and I trust the editors will consider it within the\nbroader scientific context as referees.\n- The new “Arc vs LIP” table summarizes a comprehensive characteristic set helping\nthe discussion about the tectonic setting. However, it is possible to see that they are\nnot conclusive, in special, concerning poorly known regions, as we have in the\nAmazonia Craton. For instance, considering this constraint, the debate Arc vs LIP is not\na crucial obstacle to advance the discussion. The main aspects to support the\nmanuscript approach are the huge magma volumes with age, isotope and\nchemistry compositions nearly well determined.\nWe understand that the table, prepared following a suggestion, is not definitive—\nparticularly given uncertainties in poorly known regions. However, it is informative and\nhelps readers draw their own conclusions. Nevertheless, we are open to suggestions\nand, if requested, we can delete this from the Supplementary Material.\n- Concerning this aspect, I believe that the statement “…since no plate tectonic\nindicators have been identified” (line 71) is too strong to the actual level of geological\nknowledge of the Amazonian Craton.\nAlthough geological knowledge of remote Amazonian regions is limited, this has not\nprevented the proposal of diverse tectonic models. Our interpretation of PTIs relies on\nmajor advances over the last two decades—airborne geophysics, geochronology,\ngeochemistry, isotope studies, and fieldwork—that have revealed features such as\nophiolite sequences (Rizzotto & Harmann, 2012). Naturally, future discoveries of plate\ntectonic indicators for the 2.0–1.74 Ga interval may lead to revised interpretations.\n- In Fig. 1, why were the Paraguá and Rio Apa domains excluded from the Amazonian\nCraton? Most authors accept Paraguá domain as allochthonous block, but it is not a\nreason the exclude it. For example, the Archean Imataca and Amapá blocks probably\nare also allochthonous, but were considered as part of the craton.\nWe have no problem with Paraguá and Rio Apa, including these units in the geological\nmap would not best illustrate the LIP–SLIP units and dyke swarms concentrated in the\nmain area of the Amazon Craton.\nSo, understanding that the way it is shown in the Figure Caption caused a confusion,\nwe rephrased that: “(B) Chronostratigraphic map of the Amazon Craton (the southern\nParaguá and Rio Apa domains are not shown in this figure, as their inclusion would alter the\nmap scale and reduce the detail of the LIP–SLIP units and sample locations)”\n- In relation to the geochronological provinces, it is important to highlight that not all of\nthem are considered as orogenic belts (line 132). It is the case of the Carajás domain,\nas well as the Iriri-Xingu and Erepecuru-Trombetas domains, all of them included in the\nCentral Amazonia Province. Moreover, the NW-trend Iriri-Xingu and Erepecuru-\nTrombetas domains are almost fully composed by rocks from cycles 1 and 2.\nWe agree with the reviewer. The original sentence was not adding anything to the\npaper, so we deleted it.\n- Still concerning the geochronological provinces, not all of them are NW-trending\norientation (see Response for Reviewer 2). It is true for provinces younger than 2,0 Ga,\nbut it is not the case of the Maroni-Itacaiunas Province (Guiana Shield).\nWe understand this may arise from the former phrase we have deleted. Nevertheless,\nMaroni-Itacaiúnas, Ventuari-Tapajós, Rio Negro-Juruena, Rondonian-San Ignácio and\nSunsás are NW-trending (we can call it SE-trending also, but I think it is the same),\nas seen below (from Cordani et al., 2009):\n- I disagree that the “…the Orosirian-Statherian orogenic belts do not match the\norientation of N-S and E-W Orosirian-Statherian igneous belt” (lines 132 and 133).\nCycles 1 occurs in the E-W Maroni-Itacaiunas Province, as well as in the NW Central\nAmazonia Province, this last one completely composed of rocks from the cycles 1 and\n2. Cycle 3 crops out in E-W southern part of the Rio Negro-Juruena Province.\nHowever, it doesn’t matter if the igneous and orogenic belts match or not. The SLIP\nmagmas could utilize previous regional structures to penetrate the upper crust.\nWe agree with the reviewer. The original sentence was not adding anything to the\npaper, so we deleted it.\n- In regard to lines 533-535, there are several authors reporting evidence of plate\ntectonics in the Rio Negro Province (e.g. Almeida et al. 2022\n(https://doi.org/10.1080/00206814.2021.2025158), and reference therein.\nThis is already cited in the paper: ‘A potential exception is the proposed Statherian arc\nmagmatism in the Rio Negro Province16; which lack definitive plate tectonic indicators\nbut also lack positive evidence for the absence of plate tectonics.’, but we added the\nreference.\n- Reference 340 (line 252) and fig. 2d (line 269) do not appear in the manuscript.\nThis was a misprint and should be fig. 3d. Now fixed, thanks.\nGeneral comments\nThe manuscript convincingly argues that LIPs were major contributors to\nPaleoproterozoic crustal growth. However, has this not been shown previously by for\nexample the work of reference 12–14?\nWe agree that refs. 12–14 are landmarks for recognizing LIP activity in the Amazon\nCraton, but none develops a craton-scale synthesis arguing that LIPs were the primary\ndrivers of Paleoproterozoic crustal growth. Specifically: (12) Klein et al. (2012) first\nrecognized a silicic LIP at 1.88–1.87 Ga but treated a subset of the record and did not\nevaluate crustal growth at craton scale; (13) Rizzotto et al. (2019) reinterpreted the\nsouthwestern Amazon Craton and shifted the discussion away from purely accretionary\nmodels, yet it was not intended as a craton-wide treatment of Statherian magmatism;\n(14) Ibañez-Mejía et al. (2025) documents a ca. 1.98 Ga LIP, focusing largely on mafic\nmagmatism rather than silicic components and without a continent-scale crustal growth\nframework.\nIn summary, these three works are hallmarks, but they do not integrate craton-scale\nmodels and do not argue in favor of LIPs as crust builders during the Paleoproterozoic.\nThe idea of mantle cyclicity at ~95 Myr intervals aligns well with emerging models of\ndeep Earth dynamics. (Just be honest with the ages here)\nIt places the Amazon Craton in a global context through correlations with West Africa,\nBaltica, and others—strengthening the case for a broader LIP-linked geodynamic\nsystem.\nI am a bit puzzled why the authors only use, and base their discussion on, Nd model\nages, when their own data is zircon Hf data and model ages can be calculated from\nthese data. Is there a reason for this?\nWe prefer not to use Hf TDM ages because it has been demonstrated in several\npapers it can produce artificial age ranges depending on the chosen source.\nBea et al. (2018) - https://doi.org/10.1016/j.chemgeo.2017.11.034\nVeervort and Camp (2016) - http://dx.doi.org/10.1016/j.chemgeo.2016.01.023\nThe authors claim to have calculated two stage model ages (although undefined) but\ndo not present them or seem to use them.\nTwo stage model ages were calculated for literature Nd isotope data and the\ncalculations were made by the referred authors. No model ages were used for Hf in this\npaper.\nThe abstract could benefit from more clarity by directly stating the key finding: that LIPs\ncontributed significantly to crustal growth via deep-crustal partial melting.\nWe agree, now revised.\nThe discussion could be better segmented to explicitly highlight contrasts between arc\nand LIP-related crust formation models.\nPlease, take a look at the first two paragraphs of the last section. We improved the LIP\ncrust formation models and avoided flooding the paragraphs with detailed explanations\nwhich are already (and very well) discussed in the literature.\nWhile the authors argue for intraplate LIP-driven crust formation, the paper could\nfurther address counterarguments from proponents of arc-dominated growth models.\nThis represents a case of “difficult ground” (Sun Tzu), as one of the reviewers is\npresumably from Brazil. To address this, we added a paragraph drawing on\nSupplementary Table 2 (Arc versus LIP), but we avoided an extensive discussion so as\nnot to risk overemphasizing potentially contentious interpretations.\n‘Earlier interpretations of subduction episodes following the Transamazonian–Birimian\nOrogeny were based on arguments such as juvenile Nd signatures in granitoids and gneiss²⁶,\ncalc-alkaline geochemical signatures in tonalites and monzogranites (Santos et al., 2004),\n“porphyry-like” gold deposits (Juliani et al., 2021), and regional zonation of\ncrystallization/metamorphism ages coupled with Nd model ages¹⁶. Nevertheless, many of\nthese features are also found in Phanerozoic silicic LIP provinces (Ewart et al., 1992; Bryan,\n2007; Camprubí et al., 2017). In contrast, diagnostic features such as large-scale radial dyke\nswarms, bimodal igneous compositions, and the short-lived nature of voluminous magmatism\nacross vast regions are not typical of arc-related settings (Ducea et al., 2025).’\nThe interpretation of zircon trace elements as direct indicators of source pressure and\ntemperature, though accepted, would benefit from more explicit discussion of\nuncertainties and assumptions.\nWe also felt this section needed some improvement. Now this is slightly less\ninterpretative when describing the data and we added two references that corroborate\nwith field evidence of the sources (HT-UHT garnet-bearing granulite/migmatite).\nCompared to zircons from high-temperature, high-pressure metamorphic rocks equilibrated\nwith garnet, the igneous zircons analyzed here display Yb , Yb/Ce and Yb/Tb similar to\n(n) (n) (n)\nthose of lower crustal material37(Fig. 3a, b). This source interpretation is consistent with field\nevidence indicating that melts for cycles 1 and 3 were generated from HT-UHT garnet-bearing\nmigmatites and granulites at lower continental crustal levels38,39.\nAssuming a pressure gradient of 3.5 kbar/km, these pressures corresponded to\ncrystallization depths of ~29 km for Cycles 1 and 2 and ~27 km for Cycle 3, consistent\nwith field evidence and zircon trace-element data indicating sources within the lower\ncontinental crust.\nComments on data\nFirstly, we would like to thank you for the detailed revision of the original data. Had this\nnot been done, and the paper eventually accepted, it would have lost credibility. Your\nreview gave us the opportunity to demonstrate the robustness of our data in an\norganized and transparent way.\nSecondly, we apologize for the problems with the dataset. The main issue stemmed\nfrom an incorrect reorganization of the original spreadsheet, which resulted in several\nrow offsets and confusion between reference material data. Also, there was a problem\nwith the methods section which is now fixed.\nTo address this, we carefully traced the dataset back to the original spreadsheet and\nrestarted the review process from the beginning. We believe this has resolved the\ninconsistencies, and we now proceed to respond to the reviewer’s comments in detail\nbelow.\nI cannot recreate the εHf values for the data.\nThe authors do not define what values for, for example CHUR was used. (Bouvier et\nal., 2008)?\nThis is now indicated in the methods section. We used Bouvier et al. (2008) values.\nεHf = (176Hf/177Hf / (0.282785-0.0336*(EXP(0.01867*0.001*AGE)-1)))-1)*10000\ni\n176Hf/177Hf = (176Hf/177Hf - (176Lu/177Hf*(EXP(0.01867 * 0.001*AGE)-1)))\ni\nUsing the same decay constant and bouvier CHUR values I get quite substantially\ndifferent εHf values than the authors. This is VERY concerning! Even using other\n(common) CHUR values I doubt I would get the same values as the authors.\nAfter considering this comment, we recalculated all εHf values using the parameters of\nBouvier et al. (2008). The results differed by only 0.1 epsilon units from our previous\ncalculations. Since this matches what the reviewer should obtain, we are confident that\nthis issue is now resolved.\nIn several places (for example row 28 (VR05-1)) there are Hf/Hfi data and a calculated\nεHf value. But for that analyses (and several more) there are no raw data in columns\nCF–CO. The table is generally very confusing and difficult to decipher. εHf values are\ncalculated for zircon with no data and vice versa.\nWe apologize for the errors. When preparing the table for the manuscript, some data\nbecame offset from the original spreadsheet. In addition, the original dataset itself\ncontained a few mismatches (notably one involving OGC and Tem2). We have carefully\nreviewed and corrected these issues, and we believe the dataset is now accurate.\nEven though not stated the εHf values seem to be calculated at the individual zircon\ndates (based on spot locations on figure 4). This has been shown multiple times that\nthis is in accurate. See for example Whitehouse and Kemp (2010, Geol. Soc. Spec.\nPub. London).\nεHf values should always be calculated at the interpreted age of igneous crystallisation.\nWe agree with this comment and have therefore recalculated all individual εHf values\nusing the interpreted igneous crystallization ages. For grains interpreted as inherited,\nhowever, we retained their individual zircon 207Pb/206Pb ages. This is now explained in\nthe methods section.\nThe “preferred age” for several samples according to the summary table on tab Sample\nidentification state that they prefer and use the “concordia weighted mean age”. What\nis that? Either it’s a concordia age or a weighted mean age. And if a weighted mean\nage, then it needs to be defined as for example 207Pb/206Pb or similar. If this is a\nweighted mean of individual Concordia dates (which is unconventional, but would be\nok) this needs to be explained, and the individual concordia dates should be added to\nthe data column in the supplementary table.\nThe only form of explanation is found on lines 201–202: “Ages are reported here as the\nmaximum likelihood estimate with its analytical uncertainty/analytical uncertainty with\ndispersion.\nThis problem originated from our initial interpretations and was further complicated by a\nreviewer’s suggestion to use radial plots. We have now adopted the weighted mean of\n207Pb/206Pb dates as the most reliable age estimate. This choice is supported by the\nhigh accuracy of the 207Pb/206Pb age of OG reference material. The Supplementary\nMaterial has been updated accordingly.\nFurthermore: 6/7 weighted mean in Supp. table 2. Tab “Sample identification” should\nbe 7/6 I assume.\nOk, corrected.\nOGC εHf = +0.6 ± 0.2 2s (Kemp et al., 2017), in this study the results come out to:\n~+2.7- 2.5 units too high. Is this data correct?\nSome reference zircon have data for Hf in column T–W, but some only in row CF and\nforward. What is the difference here? OGC have no calculated εHf values, but there is\nraw data. It’s all very confusing, and the fact that these reference zircon are\ngiving the incorrect values combined with the unreadable table makes me worried.\n(However, the data in row CF in the “data” tab does not seem to be the measured\nvalues, as this doesn’t make sense for any of the reference zircon) This needs to be\nmarked more clearly so that one can check the data quality of the reference\nmaterial.\nThe issues with OG and the overall confusion involving row offsets and mismatched or\nmissing reference material data stemmed from the incorrect reorganization of the\noriginal spreadsheet and from a lack of clarity (and some misprints) in the methods\nsection.\nWhen we performed the Hf analyses, we used different reference materials than for the\nU-Pb analyses. In some cases, the same material was analyzed for both systems, but\nothers were exclusive to one technique (e.g., OG was used only for U-Pb, while Mud\nTank was used only for Hf). This distinction is now clearly explained in the methods\nsection and the Supplementary Material spreadsheet has been reorganized to properly\nreflect these datasets.\n“To assess accuracy and precision, natural (91500’,‘Mud Tank’, and GJ-1) and\nsynthetic (MunZirc-1, -3, and -4) reference zircons were run concurrently and treated\nas unknowns.”\nThis data is nowhere to be found! At least not for Mud Tank and MUN zircon.\nAlso caused by imprecise information in the original methods section. To be crystal-\nclear:\nU-Pb was performed on GJ-1; OG1; Plešovice and Temora-2\nLu-Hf was performed on 91500, GJ-1, Plešovice, Mud Tank and Temora-2.\nThis is now explained in the methods section (with obtained ages and isotope ratios)\nand organized in the Supplementary Material spreadsheet.\nWhat lab was used for these isotope analyses? The machines are listed, but not what\nlab.\nHow was the primary standard values for zircon Hf data checked? Against JMC-475?\nNot reported. Also, the 178Hf/177Hf is higher than usual in these analyses. A mean\nvalue of all analyses is 1.4677 when the reported value is 1.4772 for, for example JMC-\n475. All individual analyses have a 178Hf/177Hf > than 1.4772. Please comment on\nthis.\nWe inserted the LASS-UCSB in the methods section.\nYes, the mean value is for 178Hf/177Hf in our dataset is 1.46773 and the median is\n1.46760. However, we disagree that the accepted value for JMC-475 is 1.4772, as it\nhas been reported as 1.467254 (e.g., Choi et al. 2013 - https://doi.org/10.1186/2093-\n3371-4-1). Our average differs by ~0.0004 from this reported value, most likely due to\nminor gain calibration effects.\nFor the other Hf isotopic ratios, we normalize the Plesovice zircon. The 178Hf/177Hf ratio,\nhowever, is internally standardized and therefore not normalized to Plesovice. Its slight\ndeviation from the accepted value is attributed to the gain calibration offset. Importantly,\nthe accuracy of our 176Hf/177Hf ratios is confirmed by the secondary reference materials\n(91500, Mud Tank, Temora-2, and GJ-1), all of which fall within uncertainty of their\naccepted values.\nWhat was used in the Yb correction? Among the data presented in the table there is no\nzircon with high Yb which would be usable for Yb corrections. OGC would be good.\nMud Tank would be good. MUN would be ok. But none of this data is presented.\nWe use Plesovice zircon to correct for Yb interference (and any associated offset in\nHf). As demonstrated by the reference materials with strongly contrasting Yb contents\n(e.g., Temora-2 with >150,000 ppm Yb, and GJ-1 with ~34,000 ppm Yb), the corrected\n176Hf/177Hf values fall within uncertainty of their accepted values. Reference materials\nfor low 176Yb/177Hf were Mudtank, GJ-1 and Plesovice. For high 176Yb/177Hf we used\n91500 and Temora-2.\nIndividual line comments\nLine 14: The rise of plate tectonics in the Paleoproterozoic. A LOT of studies would\nargue against this, but here its stated as a truth. This needs to be addressed.\nWe agree. Replaced ‘rise’ by ‘consolidation’.\nLine 65: There are basically no 2.2 Ga rock in Fennoscandia. To find 2.2 Ga old\nbedrock in the region, you only find it in the eastern and northern parts, specifically\nwithin the Karelian Craton, in areas of Finland and Russian Karelia (In this paper the\nKola-Karelian) where Paleoproterozoic supracrustal sequences, often associated with\nearly rifting events, are preserved.\nOk, Fennoscandia is now excluded from this phrase.\nLines 74–75: Why 95 Myrs.? The timespan between these magmatic episodes are 100,\n100 and 110 Ma.\nOk, 1980 – 1880 = 100 Myr and 1880 – 1790 = 90 Myr.\nReplaced by ‘Peaks in magmatic activity within these provinces occurred at\napproximately 90 to 100 Myr intervals’\nLine 158: Is negative Nb-Ta anomalies really likely to be present in LIPs? You need\neither significant crustal contamination during magma ascent and emplacement, or\nfractionation of Ti-bearing minerals within the magmatic system. I would rephrase this\nsentence.\nApparent arc signatures, such as negative Nb-Ta anomalies are very common, mainly\nin low-Ti tholeiites from LIPs. There is a sub-chapter in Ernst (2014) – Geochemistry of\nLIPs (https://doi.org/10.1017/CBO9781139025300.010), resuming additional causes for\nit:\n(1) partial melting of heterogeneous subcontinental lithospheric mantle (SCLM; e.g.\nGallagher and Hawkesworth, 1992; Jourdan et al., 2007a, 2009);\n(2) partial melting of variably depleted and hydrated mantle, inferred to be within the\nlithosphere (Turner and Hawkesworth,1995);\n(3) partial melting of lithospheric mantle that has previously been modified by\nsubduction-related fluids (e.g. Sandeman and Ryan, 2008);\n(4) partial melting of the lithospheric mantle that had been modified by subduction\nprocesses during major crust-formation events in the region (Zhao and McCulloch,\n1993);\n(5) contamination during passage through the SCLM of magmas derived from\nsublithospheric plume or MORB sources, or mixing between sublithospheric and\nlithospheric mantle melts (e.g. Marsh and Eales, 1984; Arndt and Christensen, 1992;\nRiley et al., 2005; Jourdan et al., 2007a; Heinonen and Luttinen, 2010);\n(6) assimilation of sediments (Elburg and Goldberg, 2000);\n(7) polybaric fractional crystallization (Marsh and Eales, 1984);\n(8) contamination by sedimentary country rocks combined with fractional crystallization\nin addition to processes at depth (e.g. Riley et al., 2005, 2006; Jourdan et al., 2007a);\n(9) contamination of mantle melts by crustal material in deep–mid-level crustal “staging\nchambers” (e.g. Nelson et al., 1990; Ihlenfeld and Keays, 2011; Ciborowski et al., 2013;\nJowitt and Ernst, 2013);\n(10) crustal contribution derived from within an ancient region of the mantle lithosphere,\ni.e. from recycled sediment rather than from the overlying continental crust (Lightfoot et\nal., 1993b); or\n(11) sudden reactivation of dormant arc or backarc sources trapped under continental-\nplate sutures (Puffer, 2001).\nLine 209–: Results are written in past tense (yielded) but these analyses still yield.\nHence, this should be in present tense (yield).\nOk, changed all yielded to yield in the results section.\nLine 231: Add these ratios as columns in supplementary table to easily check. A mean\nTh/U of 1 is very high.\nAfter a careful examination of Th/U ratios in zircon, the compilation of Kirkland et al.\n(2015; http://dx.doi.org/10.1016/j.lithos.2014.11.021) indicates that igneous zircon has\na mean Th/U of 0.77 (N = 10,693). For specific rock types, mean values are 0.85 in\nalkali granite (N = 280), 1.03 in diorite (N = 249), 0.84 in granite (N = 1963), and 0.98 in\nquartz monzonite (N = 102). Thus, a mean Th/U close to 1 is not anomalously high; it is\nslightly above the average for granitic compositions but well within the expected range\nfor diorite and quartz monzonite. Nevertheless, as requested, we have included the\nratios as a column in the supplementary table.\nAlso, the word “ratios” is redundant as the Th/U and Yb/Sm are ratios. Hence, this\nreads “ratio ratio”.\nOk, rewritten.\nLines 291–295: Statement requires references.\nOk, now properly cited.\nLine 300: What DM was used? What CHUR values were used?\nWe added a sentence in the beginning of this section citing “Reference values for the\nchondritic uniform reservoir (CHUR) are from Bouvier et al. (2008) whereas those for\nfor the depleted mantle (DM) are from Andersen et al. (2009).”\nLines 303-304: “Primary sub-populations for Cycle 1, identified in KDE plots, occur at -\n5.4 and +2.7.” 1. What does this mean? 2. Occur?\nReplaced by “Primary sub-populations for Cycle 1, identified in KDE plots, display\npeaks at -5.4 and +2.7”\nLine 305: clustering at -0.89 is very specific, please rephrase.\nReplaced -0.89 by -0.9.\nLine 306: haspredominantly (missing space)\nOk, fixed.\nLine 311: Figure 3? Should be figure 4, right?\nYes, fixed.\nLine 315: What is clustering here at the specific value of +0.68? All data? Some of the\ndata? It doesn’t look like a tight cluster. If this is a mean value I assume the MSWD is\nrather high if all data is included. If all data is not included, then this needs to be stated.\nOh, now I saw the curve in the figure. So this is a peak, not a cluster… Please explain\nthis more carefully.\nReplaced ‘clustering’ by ‘with a peak at’.\nFig. 4: What DM was used in the model age calculations for Nd data?\nThis is explained in the figure caption: ‘Unfilled squares are data from rocks that do not\nbelong to the igneous cycles. DM curve according to [52].’\n[52] DePaolo, D.J., 1981. Neodymium isotopes in the Colorado Front Range and\ncrust–mantle evolution in the Proterozoic. Nature 291, 193–196.\nhttps://doi.org/10.1038/291193a0\nLine 444: These are not only zircon U-Pb dates. Baddeleyite have been used to date at\nleast a few of these, which is apparent even from the titles of the references.\nYes, corrected: ‘Cycles 1, 2, and 3 have U-Pb zircon and baddeleyite ages of’\nLine 446: Well. The time difference between the direct ages of the dykes are 100–110\nMyrs. The difference between the zircon peaks, which I assume have an uncertainty\nthat overlaps the baddeleyite/zircon ages of the dykes might be ca. 95 Myrs. But these\nare peaks, not direct ages. I think the authors needs to be more up front about this. Ca\nargument if based on the direct dates presenting the “actual” age gaps. However, the\nage interval presented and forwarded in the cited reference [58] is NOT 94 Myrs but 90\nMyrs. So, now the difference is going from 95–94 to from 100 (or 110) Myrs to 90,\nwhich is not as strong of a match.\nThe suggestion to be clearer regarding these ages is fundamental. Direct ages of\nbasaltic dyke swarms yield intervals of ~100 Myr and ~90 Myr, whereas KDE peaks of\nzircon crystallization ages from associated silicic rocks suggest intervals of ~93 Myr\n(1886–1979 Ma) and ~98 Myr (1788–1886 Ma). This paragraph has now been\nrewritten as follows:\n‘The intraplate magmatism in the Amazon Craton occurred at consistent, regular\nintervals. Basaltic dyke swarms associated with Cycles 1, 2, and 3 have U-Pb zircon\nand baddeleyite ages of 1980 Ma15, 1880 Ma31, and 1790 Ma20, respectively, pointing\nto 100 Myr and 90 Myr intervals, that potentially represent episodes of mantle partial\nmelting. Contemporaneous silicic rocks yield zircon-age peaks at 1979 Ma, 1886 Ma,\nand 1788 Ma, as shown in KDE plots (Fig. 7a), corresponding to 93 Myr and 98 Myr\nintervals, representing peaks of zircon production by partial crustal melting.’\nThe offset between basaltic and silicic ages could be discussed throughout the paper\nbut may not add much for the reader. In general, ages of basaltic dykes are more\nprecise (typically dated by TIMS, SHRIMP, or ID-TIMS) and may better record mantle\nmelting episodes. Silicic units, in contrast, are more numerous but commonly dated by\nmethods with larger uncertainties (e.g., LA-ICPMS), producing broader peaks that\nreflect widespread crustal melting during LIP activity.\nRegarding mantle cycle periodicity, Condie & Puetz (2019) used time-series analysis\nand reported that ~50% of age peaks coincide with a predicted ~94 Myr cycle (a\nsimplification of the original 93.5 Myr value). Later, Condie et al. (2021) incorporated\n~400 additional samples and concluded that, from 2300 Ma onwards, spectral analysis\nof LIPs and zircon ages reveals ~24 repetitions of a 90–93 Myr cycle, which they\nsummarized as a “90 Myr cycle” driven by bottom-up mantle processes.\nThus, two sources of uncertainty exist: (i) which reference value to use (94, 93.5, 93, or\nages defining ~100–90 Myr intervals, or KDE-derived silicic peaks yielding ~98–95 Myr\nintervals?). Although the correspondence is not exact (but is also not a large\ndiscrepancy, like 80 Myr or 120 Myr intervals), the observed ~100–90 Myr recurrence\naligns reasonably with proposed mantle-related cycles.\nLine 452: This is not ref [58] but rather the work of: S.J. Puetz, K.C. Condie\nTime series analysis of mantle cycles Part I: The geologic record in zircons, large\nigneous provinces and mantle lithosphere Geosci. Front., 10 (2019), pp. 1305-1326,\n10.1016/j.gsf.2019.04.002\nThese authors claim mantel cyclicity of ca 93 and 187 Myrs.\nYes, now corrected.\nLine 466: You present data, not evidence. Evidence is a very strong word choice. I\nwould suggest rephrasing.\nAgree. Replaced ‘evidence’ by ‘data’.\nLines 480–488: Recent studies have shown, using several different basis of evidence\nthat there is a lot of water in the mantle. Hence, I would strongly argue that subduction\nis NOT a prerequisite for the generation of silicic magma.\nSee for example papers below.\n1. Schmandt, B., & Jacobsen, S. D. (2014). Dehydration melting at the top of the lower\nmantle. Science, 344(6189), 1259-1262.\n2. Pearson, D. G., Brenker, F. E., Nestola, F., McNeill, J., Nasdala, L., Hutchison, B. J.,\n... & Stachel, T. (2014). Hydrous mantle transition zone indicated by ringwoodite from\nBrazilian diamond. Nature, 507(7491), 221-224.\n3. Wang, W., Schmandt, B., & Hu, J. (2025, forthcoming or recent). Water Stored in the\nMantle for Millions of Years May Be Linked to Continental Volcanism.\n4. Bolfan-Casanova, N. (2018). Water in the Earth's mantle. Mineralogical Magazine,\n69(3), 229-257.\nIn summary, the scientific consensus over the last decade has solidified the\nunderstanding that the Earth's mantle, particularly the transition zone, is a vast\nreservoir of water, likely holding several times the volume of our surface oceans. This\nunderstanding is built on a multidisciplinary approach combining seismology, high-\npressure mineral physics, and geochemistry.\nWe also agree that subduction is not a prerequisite for the generation of silicic\nmagmas. However, the upper mantle must first be hydrothermalized in order to\nproduce basalts with arc-like geochemical signatures (e.g., Ernst, 2014; Pearce et al.,\n2021), such as negative Nb–Ta anomalies. This observation is an excellent contribution\nand further strengthens our interpretation; accordingly, we have rephrased the\nsentence as shown below.\n‘Nonetheless, the mantle transition zone is a major H₂O reservoir (Schmandt et al.,\n2014), and hydrous upwellings from this region may generate intraplate volcanism\n(Wang et al., 2025). Large volumes of silicic magmas, however, can only be produced\npredominantly through partial melting of fertile, hydrous lower-crustal material\npreviously generated by subduction (Bryan, 2007). Such processes not only facilitate\nthe generation of extensive silicic magmatism but also account for mantle-normalized\nnegative Nb and Ta anomalies, together with elevated Pb concentrations.’\nFigure. 1A. The colour difference between the eclogite and ophiolites are too small. I\nwould recommend changing these (or one of these) colours.\nOk, changed.\nFigure. 2. I cannot find dyke swarm C2 in the figure.\nWe changed a little bit the red tone and added labels for the dyke swarms into the map\nin Fig 2A.\nFigure 3C. Are the error bars 1 or 2 sigma?\n1 sigma, now informed in the figure caption.\nFigure 4. The authors mention second stage TDM ages. These are: 1. Not defined by\n176Lu/177Hf for the second stage. 2. They are not presented anywhere.\nThese are second stage Nd TDM ages compiled from Motta et al. (2022) and Puetz\nand Condie (2021) present in the Supplementary Table 1.\nFigure 5. Why are charnokites and 2.11–2.08 granitic magmatism denoted using\nmagma blobs instead of squares like other magmatic events/intrusions, like for\nexample the 2.0–1.93 Grnaulite, charnokite, high T/P gneisses?\nOk, blobs replaced by squares to match with the other events.\nFigure 6. The evolution of the figures from A–Dare not discussed. Please expand the\nfigure caption to guide the reader what is happening in the transition between these\nstages.\nOk, now the capture is extended so A, B, C and D are properly explained.\nFigure 7. The colour difference between the greenstone belts and cycle 1 is too small in\n(B).\nOk, changed to a lighter green color and enlarged the contour of Cycle 1 line a little bit.\nIntroduction\nLines 27-30: “The period from the Late-Rhyacian to the 27 Statherian includes anachronic events\nof rift-drift, accretionary and collisional orogenies in most Paleoproterozoic belts, with episodes\nof silicic additions to the continental crust. An exception to these belts is the Late-Rhyacian to\nStatherian record of the Amazon Craton in South America.”\nWhy is the Amazon Craton record an exception? As you mention further down, in the geological\ncontext, the evolution of the Amazon Craton has long been interpreted as the result of\nsouthwestward continental growth, characterized by the continuous migration of tectonic and\nmagmatic processes from an ancient Archean core in the east. This process is thought to have\noccurred through successive magmatic arcs accreted along the southwestern margin of the\ncraton or the development of a long-lived accretionary belt (e.g., Tassinari and Macambira,\n1999; Santos et al., 2000; Cordani and Teixeira, 2007; Scandolara et al., 2017; Trevisan et al.,\n2021; Motta et al., 2022), in line with the broader concept of the Great Proterozoic Accretionary\nOrogen (Condie, 2013).\nLines 31-33: This is a key area to investigate mechanisms of crustal growth and a potential\nrelationship with subduction since no plate tectonic indicators have been identified. Instead,\nthe period from 2.0 Ga Ma to 1.74 Ga Ma in this crustal segment is marked by the emplacement\nof large igneous provinces with an extensive bimodal igneous association.\nThis sentence likely needs rephrasing, as many will disagree with its current wording. What do\nthe authors consider to be “plate tectonic indicators”? Arc-related geochemical signatures in\nPaleo- to Mesoproterozoic magmatic rocks, along with increasingly positive εNd and εHf values\nwith decreasing U-Pb crystallization ages away from the craton are typical characteristics of\naccretionary orogens. Additionally, “instead” may not be the most appropriate transition. A\nmore suitable alternative would be: \"Between 2.0 and 1.74 Ga, the Amazon Craton also records\nthe emplacement of large igneous provinces with extensive bimodal magmatism.\"\nI will return to this point later, but I believe a key aspect of the manuscript should focus on\nwhether the presence of LIPs/SLIPs necessarily contradicts the widely accepted accretionary\norogeny model for the evolution of the Amazon Craton. Alternatively, could these processes be\nreconciled? If so, craton growth could be understood as the result of both mechanisms—\nhorizontal growth through accretionary processes and vertical growth associated with the\nemplacement of LIPs/SLIPs away from the craton margin (subduction zone). As noted by Teixeira\net al. (2019), LIPs/SLIPs “appear to accompany the stepwise accretionary crustal growth of\nAmazonia,” and several other authors have linked them to slab retreat events.\nGeological context of the Amazon Craton\nGeneral comment:\nThis section would greatly benefit from a simplified geological map of the Amazon Craton. It is\nextremely difficult to follow the text without a figure (and I am rather familiar with the Amazon\nCraton).\nThe figure should display: i) the main tectonic provinces of the Amazon Craton, with their ages\nindicated in the legend; the superposition of the studied SLIPs; iii) the locations of the analysed\nsamples. Additionally, since the \"SAMBA\" model is referenced, it would be useful to include it\nas an inset within the geological map.\nFurthermore, given that you have a detailed map of the Guiana Shield (current Fig. 4), it would\nbe appropriate to provide a similar one for the Central Brazil Shield, as the majority of the\nstudied samples come from this area.\nLines 59-53: “The distribution of Archean crust is evidenced as an isotopic provinciality that\ndivides the Amazon Craton into an eastern segment, characterized by Archean Nd depleted\nmantle model (TDM) ages and the most negative εNd(t) values, and a western segment, where\nRhyacian to Orosirian Nd TDM ages and slightly negative to slightly positive εNd(t) values\npredominate (Fig. 1a, b).”\nThis figure does not seem to be the most appropriate choice for this section. A Nd TDM age map\nis not necessary to highlight the Archean crust and the Paleo- to Mesoproterozoic provinces; a\ngeological map is much more effective. To enhance clarity, as mentioned earlier, the SLIPs and\nsample locations should be plotted on a geological map, rather than on an Nd TDM age or εNd(t)\nmap.\nComments about Fig. 1:\n“The database for contour construction is sourced from 27 and 21.”\ni) Reference '27', Condie et al., 2021, does not include any Nd isotopic data. Similarly, '21', Motta\net al., 2022, only provides Nd data for the Central-Brazil Shield. Could the authors clarify the\nsource of the remaining data?\nii) If the data is from different sources, did the authors confirm that the TDM ages were all\ncalculated using the same Depleted Mantle model? If not, they should consider recalculating\nthem for consistency.\niii) The Nd data used should be provided as supplementary material (figures must be\nreproducible by the reviewers and future readers). The figure should also include the sample\npositions so that the reader can assess the sample density and distribution.\niv) The software used and the interpolation method applied for generating the data in the figure\nshould be specified.\nLines 75-79: “Nevertheless, the record of plate tectonic indicators in the Amazon Craton\ncomprise a 1460-1440 Ma ophiolite in the Sunsás Belt, that post-dates Paleoproterozoic belts\nand pre-dates the late Mesoproterozoic events (1.2 – 0.95 Ga). These events are correlated with\nthe Grenville-type orogens related to the collision of Amazonia and Laurentia”.\nI’m not sure why the authors included this or what they intend to convey with this text.\nLines 79-82: Further, the proposition of Orosirian-Statherian orogenic belts in the Amazon\nCraton does not match with some important surface geological relationships, including two\nOrosirian and one Statherian igneous belts exhibiting N-S and E-W, NW-SE and E-W trends that\nconflict with the parallel NW-SE orogenic provinces.”\nI don’t fully understand the sentence. From the regional geological maps provided by other\nauthors (since this manuscript does not include one), it is very clear that the provinces are\ngenerally oriented in a NW-SE direction. This orientation is well-documented and widely\naccepted in the published literature. If the authors are suggesting a different orientation, they\nshould provide evidence to support this claim.\nOrosirian and Statherian igneous belts:\nIt is essential to provide at least a brief description of the geology of each of the igneous belts.\nAre there notable differences between them, or are they very similar? As it currently stands,\nwithout referring to the literature, all I know is that there are three Paleoproterozoic SLIPs in the\nAmazon Craton and their respective ages, nothing more. The lithologies they encompass, their\nrelationships with one another, etc, remain unclear.\nYou analysed 15 volcanic rocks, mostly ignimbrites, from three SLIPs. While the supplementary\nmaterial lists the geological unit of each sample, there is no context provided. The reader is left\nuncertain about the nature of these formations, whether they are associated with sedimentary\nrocks, how they relate to the calc-alkaline I-type to A-type plutonic rocks, and so on. There is a\nsignificant lack of geological context. In addition, there is an absence of field and petrographic\nphotos of the samples. While the field constraints might be well-established, and I don’t doubt\nthat, this information is not conveyed in the manuscript.\nResults\nAge of volcanic rocks\nPlease refer to the comments in the separate Word file regarding the U-Pb data. Additionally, I\nbelieve this section would benefit from a figure comparing your data with previously published\ndata from the literature.\nZircon composition, crystallization conditions and source-depth\nThe calculated Ti-in-zircon crystallization temperatures (which are not presented as a figure in\nthe manuscript or as a supplementary figure) and ΔQFM values should be provided in the\nsupplementary data table. Additionally, is there any correlation between these values and the\nU-Pb ages and εHf(i) values of the analysed zircons? Additional insights may be gained from this.\nLines 175-178: “To estimate crustal thickness for each studied magmatic cycle we applied the\nchemical mohometry model, by using a large dataset of geochemical data available from the\nliterature. Data was filtered to exclude major and mobile trace elements sensitive to\nhydrothermal alteration processes.”\nData should be presented as supplementary material as it must be available to the reviewers to\nensure the calculations are correct.\nLines 180-184: KDE plots of the depth estimate proxy using the ¹⁷⁶Lu/¹⁷⁷Hf ratio are not\npresented as a figure in the manuscript or as a supplementary figure. Results could/should be\npresented in the supplementary data table.\nComment on Figures 2b and 2c: if I am not mistaken, the fields were created by the users. If this\nis the case, I believe the data compiled from the literature to construct the fields should be\nprovided as supplementary data to allow the reviewers to verify the data and ensure the\naccuracy of the figures.\nHf isotopic signatures from Paleoarchean to 201 Tonian in the Amazon Craton\nLines 201-204: “In addition to previously published datasets including detrital and igneous zircon\nage and Hf 203 isotopes, we present 172 coupled zircon U-Pb and Lu-Hf analyses from 15\nvolcanic rock samples representing the three Paleoproterozoic igneous cycles.”\nReference 27, Condie et al. 2021, does not include any Hf isotopic data. Compiled Hf data should\nbe provided as supplementary material and references indicated.\nLines 216-244: This part of the text focus on interpretation and implications rather than the\npresentation of the results, therefore, it would be more appropriate to move this content to the\ndiscussion section.\nComments of figure 3:\ni) Detrital and igneous zircon Hf data from the literature are currently presented as grey circles.\nThey should be represented with different symbols for clarity. Igneous zircon should be\nsymbolized according to their geological unit or, alternatively, tectonic province to provide more\ncontext and facilitate interpretation.\nii) What exactly do the literature data for Cycle 1, Cycle 2, and Cycle 3 represent? Why are they\nseparated from the general \"detrital and igneous (literature)\" data? Given that you only\nanalysed volcanic rocks, mainly ignimbrites from each of the SLIPs, how do these volcanic rocks'\nHf compositions compare to the plutonic rocks of each SLIP? Are there any notable differences\nor similarities between them that could provide additional insights into the geochemical\ncharacteristics or tectonic settings of these regions?\nFor example, zircon from the three analysed volcanic samples of the Uatamã SLIP (Cycle 2) show\na relatively restricted range of εHf(i) values, from -6.7 to +1.7, with an average value of -2.0.\nHowever, the \"Cycle 2 literature\" data shows a major cluster at -15.0. What lithologies does this\ncluster represent? Are they the same as the more radiogenic cluster or are they different? Why\ndo the Uatamã SLIP rocks reach much more enriched (more negative) εHf(i) values, approaching\nthe evolution trend of the Archean crust as defined by the \"detrital and igneous (literature)\"\nzircon? (By the way, what exactly do these Archean \"detrital and igneous (literature)\" represent?\nIgneous rocks from Carajás? Archean detrital zircon from younger sequences?)\nOn another note, how do the Hf isotopic data from this study and the literature compilation\ncompare with the Nd data from the literature? You compiled Nd data for the Amazon Craton, as\nshown in Fig. 1. Why not compare the two datasets? Do they show similar or divergent trends?\nThis could provide further insights into the evolution of the Amazon Craton.\niii) It is unclear what the starting point ages are for the C-F2, TTG, and KREEP, and why those\nparticular ages were chosen. Please specify the rationale behind these age selections.\niv) The references for the 'previously published zircon ages' used to construct the KDE diagram\nmust be provided. Additionally, the compilation of age data, coordinates, and other relevant\ninformation should be included as supplementary material to ensure transparency and allow for\nreproducibility.\nDiscussion\nChanges in structure and composition of the Amazon Craton crust\nThe discussion of the Hf data should be moved to this section, and should be discussed along\nwith the Nd isotopic data.\nLines 292-293: “The isotope composition of silicic igneous rocks reveals that the proportion of\nreworked crust during magmatism was highly dependent on the availability of pre-existing\ncrustal material.”\nWhile this statement might be valid for Cycle 3 rocks, as you explain in lines 296 to 299, it does\nnot explain the differences observed between Cycle 2 and Cycle 1. Although there is no available\nprojection of the Hf-analysed samples on a geological map, the existing projection on the Nd\nTDM age map suggests that both Cycle 1 and Cycle 2 rocks are spatially associated with Archean\ncrust, whereas Cycle 3 rocks, further west, overlie a region characterized by predominantly\nPaleoproterozoic Nd TDM ages. If Cycle 1 and Cycle 2 broadly overlap spatially, their availability\nof pre-existing crustal material and its characteristics should be comparable. However, the\nisotopic results indicate that Cycle 2 rocks have incorporated significantly more evolved crustal\nmaterial than Cycle 1.\nCycle 3 rocks exhibit an εHf(i) range identical to that of Cycle 1. Identical εHf(i) values for two\nmagmatic events of distinct ages suggest either an increase in the juvenile component and/or a\nreduction in the influence of the Archean crust in the younger cycle. Given the apparent overall\ncorrespondence between the Nd and Hf isotopic data (as seen in both Fig. 1 of this study and\nFig. 8 of Motta et al., 2022), and also that Cycle 3 rocks are located west of the Cycle 1 and 2\nrocks (i.e., further away from the Archean core), the data strongly suggest that Cycle 3 rocks\nwere emplaced in a distinct crustal “structure” (either younger crust or thinned Archean\nbasement) compared to Cycles 1 and 2.\nComments on Figure 5: i) There are no KDEs shown on the right side of the figure. ii) The\nabbreviations MU, MC, UC, and SM are not indicated in the figure.\nRepeated Cycles of Mantle-Derived Magmatism at ~95 Myr Intervals\nComments on Figure 6: i) Fig. 6A and B are exchanged. ii) Sources of data from the literature\nmust be indicated in the figure caption. Compiled data should be made available as\nsupplementary material.\nCrustal growth by intraplate igneous events during the Paleoproterozoic\nLines 411-416: \"Prior to this, from the Orosirian to the Statherian, no clear evidence of\nsubduction events exists within the Amazon Craton following the Rhyacian Transamazonian-\nEburnean-Birimian orogenies. Instead, crustal growth during this interval was primarily driven\nby large igneous province (LIP) events. A potential exception is the proposed Statherian arc\nmagmatism in the Rio Negro Province; however, this interpretation remains unsupported by\ndefinitive plate tectonic indicators.\"\nThis is a classic case where the phrase \"absence of evidence is not evidence of absence\" applies.\nThe absence of “definitive plate tectonic indicators” could be due to a true lack of subduction or\nsimply because of an incomplete record (ophiolite sequences and high-pressure rocks are not\nvery common in the Paleoproterozoic).\nThe assertion that crustal growth during the Orosirian-Statherian was \"primarily driven by LIP\nevents\" is a strong claim that requires robust evidence. While the authors correctly highlight the\nimportance of LIPs in crustal growth, they do not sufficiently address the geochemical and\nisotopic trends that are commonly associated with accretionary orogens, such as the\nsouthwestward decrease in crystallization ages and TDM model ages observed in the magmatic\nrocks of the Paleoproterozoic Ventuari-Tapajós and Rio Negro-Juruena belts, which in addition\nexhibit arc-related geochemical signatures . This pattern is a hallmark of long-lived accretionary\norogens from the Proterozoic to the Phanerozoic (e.g., Bahlburg et al., 2023 and references\ntherein) and should not be dismissed without a compelling alternative explanation.\nInstead of positioning LIP magmatism in opposition to accretionary tectonics, the authors should\nexplore how these processes may have interacted. Could the emplacement of LIPs have played\na role in modifying an accretionary orogen? Is there geochemical evidence suggesting interplay\nbetween plume-derived and arc-related magmatism? These are the types of questions that\ncould provide a more nuanced and comprehensive interpretation of the Amazon Craton's\nevolution. A more balanced discussion would acknowledge the role of LIPs while evaluating\nwhether they necessarily contradict an accretionary orogenic model. Rather than dismissing one\nprocess in favour of the other, the manuscript could explore how both may have contributed to\ncrustal growth of the Amazon Craton.\nComments on the data and figures presented in the supplementary table:\n1) When reviewing a manuscript with geochronology data, my first step is always to check the\nreference materials and to attempt reproducing the figures and age calculations. Results from\nthe reference materials are in excellent agreement with the accepted values.\nUsing Isoplot-R and following the same conditions outlined in the Methods section, I tested the\ndata reported in the supplementary table for the studied samples. While the calculated ages\nagree within uncertainty, I cannot reproduce the age results and diagrams presented by the\nauthors: the plots differ. Below, I provide an example for sample VR05, though this issue applies\nto all samples. As shown, the calculated ages are consistent within uncertainty, but the plots\nthemselves are different.\nWhile this discrepancy does not affect the overall results of the manuscript, because the\ncalculated ages usually overlap within uncertainty, it is important that any reader should be able\nto reproduce the figures presented by the authors. This is an issue and should be addressed.\nI am not sure about the cause of these differences. One possibility is that the authors may have\nplotted the diagrams using the 207/235 and 206/238 ratios, rather than the 238/206 and\n207/206 ratios reported in the table, meaning that the results calculated by Iolite are producing\nslightly inconsistent isotopic ratios (this is a known issue of Iolite). However, this is just a guess,\nas the 207/235 ratio is not included in the data table, and I cannot confirm this. Depending on\nhow the 207/235 ratio was calculated (mean of ratios versus ratio of means), this could explain\nthe discrepancies observed.\nAuthors should report the U-Pb isotopic data as follows:\n206Pb/204Pb (or % of common Pb), 207Pb/235U, 206Pb/238U, rho, 207Pb/206Pb, 238U/206Pb, rho,\n232Th/238U.\nPlot for sample VR05 reported in supplementary table:\nPlot for the same sample VR05 with data from columns B to F:\n(Note that in the plot above, I did not reject the youngest and oldest analyses. To obtain an\nacceptable MSWD I would have had to reject more than 2.)\n2) Furthermore:\n Please indicate the type of concordance used (e.g., % difference between the ²⁰⁶Pb/²³⁸U\nand ²⁰⁷Pb/²³⁶Pb ages, concordia distance, etc.). The authors appear to have used\nconcordia distance (or a similar approach), but this should be explicitly stated.\n When examining the data for each individual sample, many of the rejected analyses\ncould be interpreted as either significantly older and discordant grains (xenocrysts or\ninherited cores) or grains affected by common Pb. However, common Pb estimation is\nnot provided in the data table, nor are CL images that could clarify whether these\nanalyses correspond to inherited cores. CL images of representative zircons of each\nsample should be provided.\n Building on the above, when plotting the data for all samples, the common Pb\nhypothesis seems unlikely, as most data align along discordia lines toward geologically\nmeaningful ages (those younger than 2.2 Ga). In contrast, analyses older than 2.2 Ga are\nmore scattered and usually highly discordant (except for PB07A_8: 2852 Ma), making\ntheir ²⁰⁷Pb/²⁰⁶Pb ages questionable.\n3) A potential approach for the treatment of U-Pb data could be considered. As noted by\nVermeesch (2021, Geoscience Frontiers 12, 843–850), “volcanic rocks often exhibit positively\nskewed age distributions with a short tail of syn-eruptive U–Pb ages and a long tail of pre-\neruptive or xenocrystic ages.”. In such cases, the maximum likelihood age model (minimum age\non radialplot of Isoplot-R) might be a good alternative for determining the crystallization age, as\nit statistically rejects possible xenocrystic ages. This automated method is likely more accurate\nfor identifying inherited grains than manually removing analyses by visual inspection. This is\nparticularly relevant for Paleoproterozoic rocks, where a conservative 1% uncertainty\ncorresponds to approximately ± 20 Ma, leading to inevitable overlap between crystallization\nages and slightly older xenocrysts (e.g., see comments on sample GLR-35 below).\nSome comments on the data of a few samples:\nSample LA-01:\n Grains LA01_17 and 18 overlap with the main group and, therefore, should not be\nconsidered as inherited. They should be included in the weighted mean 207Pb/206Pb\nand concordia age calculations. Based on the rejection criteria indicated in the\nsupplementary table (concordance > 0.95), grain LA01_10 could also be included in the\nweighted mean 207Pb/206Pb age calculation.\n Grain LA01_19 (2064 ± 19 Ma) should be considered as an inherited grain as it aligns\nwith LA01_3 (2061 ± 23 Ma) and 13 (2061 ± 22 Ma).\n Grains LA01_20, 24 and 25 seem affected by common Pb.\nSample PA-34:\nThe reported MSWD of 3.4 the weighted mean concordia age (2002.3 ± 3.2/6.3 Ma) exceeds the\nrange of acceptable MSWD values for n = 19 at 2 sigma level. The weighted mean 207/206 age\nshould be the preferred age (1996 ± 4 Ma, MSWD = 0.87).\nSample TM43:\nUsing the 15 analyses selected by the authors to calculate the weighted mean ²⁰⁷Pb/²⁰⁶Pb age,\nI obtain a lower MSWD value of 1.3, compared to the reported 2.5 in the data table. This suggests\nthat the weighted mean ²⁰⁷Pb/²⁰⁶Pb age should be preferred over the weighted mean concordia\nage.\nSample MA-02:\nSimilarly to the sample above, using the 22 analyses selected by the authors to calculate the\nweighted mean ²⁰⁷Pb/²⁰⁶Pb age, I obtain a lower MSWD value of 0.56, compared to the reported\n1.6 in the data table. In any case, both of these MSWD values are statistically more reliable than\nthe MSWD of 4 reported for the weighted mean Concordia age, which was chosen as the\npreferred age by the authors. Given this, the weighted mean ²⁰⁷Pb/²⁰⁶Pb age should be preferred\nover the weighted mean Concordia age.\nSample GLR-35:\n The statistical parameters of the three “age” types provided clearly indicated that the\ncalculated dates are not statistically sound:\no concordia age (n = 23): MSWD = 6.8 and p = 0 (for concordance and\nequivalence);\no weighted mean 207/206 age (n = 23): MSWD = 4.8, p = 0);\no weighted mean concordia age (n = 20): MSWD = 3, p = 0).\nThe three analyses, considered inherited by the authors, are represented in grey. However, both\nthe MSWD values and visual inspection of the diagram clearly indicate the presence of more\nthan one population of analyses within the green group.\n Considering that the 23 analyses are all nearly concordant, we can use the radial plot\nfunction of Isoplot-R to assess the presence of more than one age component. The\nalgorithm indicates the presence of two distinct age components within the 23\nanalyses, one at 1795 ± 6 Ma and an older one at 1830.6 ± 8.9 Ma. From the plot, it is\nclear that analyses older than 1820 Ma belong to the older component.\n Considering analyses older than 1820 Ma as inherited (GLR35_8, GLR35_16, GLR35_19,\nGLR35_22, GLR35_24, in addition to the 3 selected by the authors), we can calculate a\nweighted mean 207/206 age of 1795.2 ± 5.6 Ma (MSWD = 0.82, p = 0.66) for the younger\ngroup.\n Using the MLA algorithm, we obtain an identical age of 1794 ± 7 Ma.\nRadial plot (finite mixtures = auto)\nRadial plot (finite mixtures = minimum)\nSample PGR27:\n The authors consider only the existence of one inherited grain (PGR27_25). However,\ninspection of the Concordia diagram clearly indicates the presence of more inherited\ngrains. Excluding analyses PGR27_8 and PGR27_9, which have very large uncertainties,\nit is clear that there are at least four analyses that are older than the main group.\n This is clearly depicted in the radial plot, which shows a younger population with a\nweighted mean 207/206 age of 1791 ± 5 Ma and an older one at 1840.4 ± 9.9 Ma.\nSample SS-39:\nRejecting analyses SS39A_23 and SS39A_25 results in a statistically more robust concordia age\n(considering MSWD and p for concordance and equivalence).\nSample PB07A:\n Analyses PB07A_18 and PB07A_24 are not represented in the diagrams and were not\nused in the calculations; however, this is not indicated in the data table.\n From the inspection of the Concordia diagram, it is clear that, apart from grain PB07A_8\n(2852 ± 17 Ma), there are other xenocrysts. This is also evident from the statistical\nparameters reported by the authors for the Concordia age, where MSWD = 5.1 and p =\n0 (for concordance and equivalence) clearly point to excess scatter. Indeed, the radial\nplot indicates the presence of an older group comprising 4 analyses with a weighted\nmean 7/6 age of 1814 ± 12 Ma, and a younger group, the main one, at 1762.2 ± 5.4 Ma.\nCalculating a Concordia age for the latter group yields an excellent age of 1761.3 ± 3.9\nMa (MSWD = 1.1, p = 0.28, for concordance and equivalence).\nSample PB09A:\n This is a sample where the differences between the plots constructed for the same\nanalyses with the data reported in the supplementary table (left) and the plot presented\nby the authors (right) differ significantly (see figures below). From the inspection of the\ndiagram and the 7/6 ages (1810 ± 21 Ma and 1796 ± 22 Ma), it is clear that the two\nanalyses in red on the left diagram are older than the main group (ages around 1760\nMa). This difference is not depicted in the diagram presented by the authors (right),\nwhich raises questions regarding the validity of the plots.\n As I mentioned before, while this does not have major implications for the calculation\nof the crystallization ages of the studied samples, since the final age differences overlap\nwithin uncertainty and therefore do not affect the conclusions of the study, it does\nindicate that something is wrong. While I can't be 100% sure that this is the cause of the\nissue, my guess is that it has to do with the fact that users plotted the diagrams using\nthe 207/235 (not reported in the data table) and 206/238 ratios, meaning that the\nresults calculated by Iolite are producing slightly inconsistent isotopic ratios (this is a\nknown issue of Iolite).\n Considering the data presented in the data table, which is the one I have access to,\nthis sample as an inherited component with a WM 7/6 age of 1803 ± 16 Ma and a\ncrystallization age of 1758.6 ± 5.4 Ma (WM 7/6 age of the youngest group); the latter\noverlap with the Concordia age of 1758 ± 4 Ma (MSWD = 1.4, p = 0.07; excluding the\nmost discordant analysis PB09_21).\nOk, we recalculated the ages and presented it in a revised table with the diagrams\n(Supplementary Table 3).\nconcordia_age::: 175 8 ± 4 Ma (n:::17)\nMSWIJ. 0 .0041'11-.-4'1-1-.-4.'-P=l-x-\"I-•'-0.-9-5'-1 -0.-0-5-8-1-0-.0-7-2\no\nie\n170-0\no\n\"o'\n21\nie\n16 50\ng)\no\n4 . 0 4. 2 4 . 4 4. 6 4 . 8 5. 0\n2 07p b/ 2 J SU"}, {"round": 3, "reviewer_comments": {"reviewer_3": "I am happy with the new, updated data table and how the data treatment has been updated.\nAs all my major issues have been dealt with I am now happy with this manuscript proceeding to publication."}, "author_response": ""}]

Decision letter