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Journal articles on the topic 'Neoarchean'

Author: Grafiati

Published: 4 June 2021

Last updated: 9 February 2022

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1

Lubnina, N. V., and A. I. Slabunov. "Karelian сrаtоn in the struсturе of the Nео-Аrсhаеаn supercontinent Kеnоrlаnd: nеw paleomagnetic and isotopic-geochronological data on granulites of the Onega complex." Moscow University Bulletin. Series 4. Geology, no. 5 (October 28, 2017): 3–15. http://dx.doi.org/10.33623/0579-9406-2017-5-3-15.

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New paleomagnetic and isotopic-geochronological data obtained for Neoarchean Onega granulite complex, were used to reconstruct the position of the Karelian craton in the Neoarchean supercontinent Kenorland. Geological correlations were made for the Karelian, Kaapvaal, Pilbara, Superior, and Slave cratons. Comparison of independent geological and paleomagnetic data allowed us to propose a new configuration of the Neoarchean supercontinent Kenorland. The position of the ancient core of the Karelian craton (the Vodlozero terrane), located in the North-Western margin of the supercontinent structure, reconstructed based on the previously paleomagnetic data for the Neoarchean Panozero sanukitoid massif and new one for granulite of Onega complex.

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2

Li, Dapeng, Yuelong Chen, Guoliang Xue, Huan Kang, Yang Yu, Jianzhen Geng, Yulong Zhang, and Ting Li. "Initiation of modern-style subduction in the Neoarchean: From plume to subduction with frequent slab break-off." GSA Bulletin 132, no. 9-10 (March 9, 2020): 2119–34. http://dx.doi.org/10.1130/b35522.1.

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Abstract Fundamental geodynamic changes from vertical tectonics to lateral subduction occurred during the Neoarchean, yet detailed processes related to this transition and initiation of modern-style subduction remain enigmatic. Successive Neoarchean magmatic rocks including both plume-derived komatiites and subduction-related supracrustal and intrusive rocks appeared and preserved key information on the late Archean geodynamic changes in the Western Shandong Province granite-greenstone belt (WSP), North China Craton. In this study, whole-rock geochemical and Sm-Nd isotopic data and zircon U-Pb and Lu-Hf isotopes are reported for early Neoarchean supracrustal and intrusive rocks for the WSP. Temporally, the early Neoarchean magmatic movements in the WSP can be subdivided into two stages, including the early stage (2.77–2.69 Ga) and the late stage (2.69–2.60 Ga). Spatially, from southwest to northeast, intrusive rocks with similar ages define three belts (A, B, and C). Early stage tholeiitic and enriched meta-basalts were plume-related, representing oceanic crust opening from a pre-early Neoarchean continent. Slab subduction at least initiated at ca. 2.74 Ga and generated various Neoarchean tonalite-trondhjemite-granodiorites, quartz diorites, and arc-related volcanic rocks and mafic intrusions. Episodic emergence of meta-basaltic rocks and/or mafic intrusions with depleted εHf(t) values and low (La/Yb)N ratios indicates frequent slab break-offs during ca. 2.70–2.68 Ga, 2.66–2.64 Ga, and 2.62–2.60 Ga due to a relatively hotter mantle and regional heating by mantle plume. Secular geochemical changes of mafic and felsic rocks in this study outline roles of slab subduction in contributions of cooling the mantle, secular mantle refertilization, and crustal growth.

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3

Hinchey, Alana M., William J. Davis, James J. Ryan, and Léopold Nadeau. "Neoarchean high-potassium granites of the Boothia mainland area, Rae domain, Churchill Province: U–Pb zircon and Sm–Nd whole rock isotopic constraintsThis article is one of a series of papers published in this Special Issue on the theme of Geochronology in honour of Tom Krogh." Canadian Journal of Earth Sciences 48, no. 2 (February 2011): 247–79. http://dx.doi.org/10.1139/e10-071.

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The Boothia mainland region of the north-central Rae domain is underlain by remnants of a Neoarchean volcano sedimentary sequence dismembered by two regionally extensive Neoarchean high-potassium granitoid suites with rare occurrences of a structurally interleaved, Paleoproterozoic sedimentary cover sequence. The granitoids and their gneissic equivalents are dominated by variably deformed and metamorphosed I-type, metaluminous, polyphase, commonly porphyritic to augen, biotite ± hornblende monzogranite, and subordinate granodiorite, with rare tonalite. New geochronological results, the first for this area, demonstrate that the widespread Neoarchean granitoid plutonism is dominantly 2.61–2.59 Ga, with a less prominent 2.66 Ga plutonic event. The age of zircon recrystallization suggests that ca. 2.60 Ga Archean metamorphism and fabric development (S1) affected the 2.66 Ga plutons prior to or contemporaneously with intrusion of the voluminous ca. 2.6 Ga suite. εNd(t) for the ca. 2.61–2.59 Ga suite range from 1.4 to –1.9, overlapping with the ca. 2.66 Ga suite that range from 1.4 to 1.5. The Nd isotopic data, coupled with the presence of inherited ca. 2.65, 2.70, and 2.85–2.90 Ga zircon, suggests recycling of older, Neoarchean to Mesoarchean crust in the formation of these suites. Metaplutonic rocks preserve Paleoproterozoic deformation (F4 and F5) and amphibolite-facies metamorphism, sporadically recorded in zircon rims that formed at 1.81 Ga. This event strongly reoriented the Neoarchean fabrics in metaplutonic rocks, generally without the development of a new coaxial Paleoproterozoic fabric, and we attribute this strain and metamorphism to the Hudsonian orogeny.

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Ludden, John, and Andrew Hynes. "The Lithoprobe Abitibi-Grenville transect: two billion years of crust formation and recycling in the Precambrian Shield of Canada." Canadian Journal of Earth Sciences 37, no. 2-3 (April 2, 2000): 459–76. http://dx.doi.org/10.1139/e99-120.

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We summarize the results of Lithoprobe studies in the Neoarchean southeastern Superior Province and the Mesoproterozoic Grenville Province, in the southeastern Precambrian Shield of Canada, through two composite cross-sections based on seismic reflection data, which define dramatically different styles of crust formation and tectonic accretion in the Neoarchean and Mesoproterozoic. In the Neoarchean, the structures at the surface are steep, with discontinuous and flatter structures at depth, much of the crust appears to be juvenile, and the predominant process of crustal growth is inferred to have been subduction-accretion of primitive crust in a prograding arc system. In the Mesoproterozoic, surface structures are shallow and the seismic character of the crust is continuous over the entire cross-section. Archean parautochthonous rocks and reworked Archean crust comprise a very significant proportion of the preserved crust in the Mesoproterozoic and provided the backstop to the Grenvillian orogeny, resulting in the exhumation of crustal rocks formed at high pressures. Preservation of Neoarchean crust, including a thickened lithosphere in the Superior Province, in contrast to its general destruction in younger orogens, may well relate to a unique thermal regime at this time on Earth.

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5

Kazmierczak, J. "Neoarchean Biomineralization by Benthic Cyanobacteria." Science 298, no. 5602 (December 20, 2002): 2351. http://dx.doi.org/10.1126/science.1075933.

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6

Flannery, David T., Abigail C. Allwood, Robert Hodyss, Roger Everett Summons, Michael Tuite, Malcolm R. Walter, and Kenneth H. Williford. "Microbially influenced formation of Neoarchean ooids." Geobiology 17, no. 2 (November 18, 2018): 151–60. http://dx.doi.org/10.1111/gbi.12321.

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7

Grace, Rashmi LB, Kevin R. Chamberlain, B. Ronald Frost, and Carol D. Frost. "Tectonic histories of the Paleo- to Mesoarchean Sacawee block and Neoarchean Oregon Trail structural belt of the south-central Wyoming Province." Canadian Journal of Earth Sciences 43, no. 10 (October 1, 2006): 1445–66. http://dx.doi.org/10.1139/e06-083.

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The Sacawee block is a narrow belt of Paleo- to Mesoarchean crust that extends for ~70 km across the northern Granite Mountains. It is composed of the ~3.3 Ga Sacawee orthogneiss, additional calc-alkalic and tonalitic orthogneisses, and the ~2.86 Ga Barlow Gap Group. The Sacawee block basement is characterized by negative εNd values and Paleoarchean Nd crustal residence model ages. A broad east–west-trending zone of Neoarchean high strain, which is part of the Oregon Trail structural belt, transects the Sacawee block and was studied at two locations, the Beulah Belle Lake area and West Sage Hen Rocks. U–Pb analyses of magmatic zircon from a sheared amphibolite within the high-strain zone of the Beulah Belle Lake area constrain the age of the Neoarchean deformation to be later than 2688 ± 5 Ma. At West Sage Hen Rocks, metamorphic zircons in a sheared amphibolite provide a direct date on the shear zone of 2649 ± 2.8 Ma. These data, combined with similar ages of deformation from two other shear zones, are interpreted to suggest that the Neoarchean Oregon Trail structural belt is a pervasive feature of the Sacawee block and may represent a deformation front related to accretion. Multiple east–west-trending shear zones within the Sacawee block are evidence for tectonic modification of the crust between ~2.65 and 2.63 Ga and horizontal convergence analogous to modern plate tectonics processes. The Sacawee block is either a rare exposure of ancient basement typical of that which originally underlay much of the Wyoming Province or it is an exotic block that was accreted to the core of the Wyoming Province in Neoarchean time.

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Singh, Vinod K., Sanjeet K. Verma, Pradip K. Singh, A. I. Slabunov, Sumit Mishra, and Neeraj Chaudhary. "Archean crustal evolution of the Bundelkhand Craton: evidence from granitoid magmatism." Geological Society, London, Special Publications 489, no. 1 (November 7, 2019): 235–59. http://dx.doi.org/10.1144/sp489-2018-72.

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AbstractThis study presents petrological and geochemical data on Neoarchean granitoids from the northern and central parts of the Bundelkhand Craton to discuss its crustal evolution and tectonic history. The study deals with two granitoid suites, i.e. tonalites–trondhjemites–granodiorites (TTG) and sanukitoids. TTGs are characterized by high SiO2, Na2O and mostly low to moderate Mg#. They display enrichment in light rare earth elements, low to moderately fractionated heavy rare earth elements (HREE) and low Sr/Y ratios, suggesting their high-HREE character or low-pressure origin from melting of a mafic protolith. The sanukitoid samples show relatively low SiO2, high K2O (2.1–4.6 wt%), Pb, Sr and Ba, and moderate to low Mg#, Cr, Ni. These granitoids probably generated from partial melting of hydrous mafic rocks followed by interaction with a mantle peridotite. Geochemical characteristics, tectonic discrimination using ratios like (Ce/Pb)PM, (La/Nb)PM and (Th/Nb)PM and regional rock association suggest that the Neoarchean TTGs and sanukitoids were emplaced in a subduction setting. Combining the existing knowledge base, a schematic model for generation and evolution of crust from Paleoarchean to Neoarchean has been proposed for the Bundelkhand Craton.

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Mohan, M. Ram, Ajay Dev Asokan, and Simon A. Wilde. "Crustal growth of the Eastern Dharwar Craton: a Neoarchean collisional orogeny?" Geological Society, London, Special Publications 489, no. 1 (December 11, 2019): 51–77. http://dx.doi.org/10.1144/sp489-2019-108.

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AbstractThe Eastern Dharwar Craton (EDC) is predominantly made of Neoarchean potassic granitoids with subordinate linear greenstone belts. Available geochemical and isotopic systematics of these granitoids suggest variations in the source and petrogenetic mechanisms. By compiling the available geochemical data, these granitoids can be classified into four groups, namely: TTGs (tonalite–trondhjemite–granodiorite); sanukitoids; biotite and two-mica granites; and hybrid granites. This classification scheme is in line with the global classification of Neoarchean granites, and enables the sources and petrogenetic mechanisms of these variants to be distinguished. Available geochemical, isotopic and geochronological datasets of these granitoids are integrated and the existing tectonic models for the Neoarchean EDC are reviewed. The variability of the EDC granitoids is ascribed to crustal reworking associated with the collision of two continental blocks. The tectonomagmatic evolution of the EDC is analogous to the development of the Himalayan Orogeny. Based on the evolutionary history of the Dharwar Craton, it can be concluded that convergent margin tectonics were operational in the Indian Shield from at least c. 3.3 Ga and continued into the Phanerozoic. However, the nature and style of plate tectonics could be different with time.

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Li, Yilong, Jianping Zheng, Wenjiao Xiao, Guoqing Wang, and Fraukje M. Brouwer. "Circa 2.5 Ga granitoids in the eastern North China craton: Melting from ca. 2.7 Ga accretionary crust." GSA Bulletin 132, no. 3-4 (August 29, 2019): 817–34. http://dx.doi.org/10.1130/b35091.1.

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Abstract The Neoarchean crust-mantle interaction and crustal evolution of the North China craton are controversial and are instructive of the processes of continental crust growth and cratonic evolution. We present here a systematic study of the petrology, geochemistry, and geochronology of Neoarchean granitoids from the eastern North China craton to elucidate their petrogenesis and tectonic setting. The rocks were collected from the Jielingkou, Anziling, and Qinhuangdao plutons, and an amphibole-monzoporphyry dike in the Qinhuangdao pluton. Samples from the Jielingkou pluton, consisting dominantly of monzodiorite and diorite with minor monzonite and granodiorite, contain 52.2–64.4 wt% SiO2, 2.46–4.52 wt% MgO (Mg# = 0.41–0.54), 3.76–5.77 wt% Na2O, and K2O/Na2O ratios of 0.29–0.71. The Anziling pluton samples, comprising syenite and monzonite, display slightly higher SiO2 (60.9–66.7 wt%) and K2O/Na2O ratios (0.70–1.11), but lower MgO (1.54–2.33 wt%) and Mg# (0.40–0.47) values, compared to the Jielingkou rocks. The Qinhuangdao pluton samples, consisting mainly of granite and minor syenite and granodiorite, with some diorite and monzoporphyry dikes, are characterized by the highest SiO2 values (75.7–76.9 wt%) and K2O/Na2O ratios (0.73–1.41) and lowest MgO content (0.14–0.32 wt%) among the studied samples. The amphibole-monzoporphyry dike has intermediate SiO2 (56.3 wt%), high MgO (3.79 wt%), Na2O (5.55 wt%), and Mg# (0.45), and low K2O/Na2O ratio (0.66). Zircon U-Pb laser-ablation–inductively coupled plasma–mass spectrometry dating showed that all plutons have a ca. 2.5 Ga crystallization age. Zircon crystals have mildly positive εHf(t) values (+0.24 to +5.45) and a depleted mantle model age (TDM1) of ca. 2.7 Ga. We interpret the granitoid rocks as sanukitoid-related, Closepet-type granites, potassium-rich adakites, and potassium-rich granitoid rocks that crystallized in the late Neoarchean (2.5 Ga) and were derived from partial melting of mantle peridotite that was metasomatized with the addition of slab melt, thickened alkali-rich juvenile lower crust and juvenile metamorphosed tonalitic rocks. Mantle plume activity ca. 2.7 Ga is thought to have been responsible for the early Neoarchean tectono-thermal event in the eastern North China craton. This activity resulted in a major crustal accretion period in the craton, with subordinate crustal reworking at its margins. A steep subduction regime between ca. 2.55 Ga and ca. 2.48 Ga led to the remelting of older crustal material, with subordinate crustal accretion by magma upwelling from a depleted mantle source resulting in late Neoarchean underplating. This crustal reworking and underplating resulted in the widespread ca. 2.5 Ga plutons in the eastern North China craton. Continental crust growth in the North China craton thus occurred in multiple stages, in response to mantle plume activity, as well as protracted subduction-related granitoid magmatism during the Neoarchean.

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Tschirhart, V., W. A. Morris, and C. W. Jefferson. "Framework geophysical modelling of granitoid versus supracrustal basement to the northeast Thelon Basin around the Kiggavik uranium camp, Nunavut." Canadian Journal of Earth Sciences 50, no. 6 (June 2013): 667–77. http://dx.doi.org/10.1139/cjes-2012-0149.

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The northeast Thelon Basin in the Kivalliq region of Nunavut is prospective for uranium deposits. Recently discovered basement-hosted, unconformity-associated prospects west of Kiggavik are restricted to deformed and metamorphosed Neoarchean psammitic enclaves of the Woodburn Lake group within 1.83 Ga Hudson granite and Martell syenite that together comprise the Shultz Lake intrusive complex (SLIC). The depth and geometry of the intrusive complex are relatively unknown as the geological constraints are poor; the drilling is sparse and of shallow depth extent as it was not targeting the basement but shallower multiply faulted and highly altered demagnetized zones. This study aims to constrain the geometry and context of the Shultz Lake intrusive complex with respect to the ore-hosting Neoarchean metasedimentary rocks and intersecting reactivated fault arrays through geophysical modelling of detailed aeromagnetic and gravity data integrated with new geological knowledge. By integrating detailed gravity, aeromagnetic, and structural geology observations measured along a series of transects with a petrophysical rock properties database, it is possible to derive constraints on the depth and thickness (200–300 m) of the SLIC. Quantitative comparison and integration of multiple hypothetical geometries favours a model wherein the SLIC, together with metasedimentary and older basement gneiss, has been structurally emplaced over the Neoarchean metasediments.

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Kalinin, Arkady, Oleg Kazanov, Vladimir Bezrukov, and Vsevolod Prokofiev. "Gold Prospects in the Western Segment of the Russian Arctic: Regional Metallogeny and Distribution of Mineralization." Minerals 9, no. 3 (February 26, 2019): 137. http://dx.doi.org/10.3390/min9030137.

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Location of the deposits and occurrences of gold mineralization in metamorphic complexes of the Kola region is controlled by tectonic zones at the regional scale at the boundaries of major segments of the Fennoscandian Shield. Three zones are the most important: (1) the system of Neoarchean greenstone belts Kolmozero–Voron’ya–Ura-guba along the southern boundary of the Murmansk craton; (2) the suture, delineating the core of the Lapland–Kola orogeny in the north; and (3) the series of overthrusts and faults at the eastern flank of the Salla–Kuolajarvi belt. Gold deposits and occurrences are located within greenstone belts of Neoarchean and Paleoproterozoic age, and hosted by rocks of different primary compositions (mafic metavolcanics, diorite porphyry, and metasedimentary terrigenous rocks). The grade of metamorphism varies from greenschist to upper amphibolite facies, but the mineralized rocks are mainly lower amphibolite metamorphosed, close to the transition from greenschist to amphibolite facies. Gold deposits and occurrences in the northeastern part of the Fennoscandian Shield formed during two periods: the Neoarchean 2.7–2.6 Ga and the Paleoproterozoic 1.9–1.7 Ga. According to paleo-geodynamic reconstructions, these were the periods of collisional and accretionary orogeny in the region. Those Archean greenstone belts, which were reworked in the Paleoproterozoic (e.g., Strel’na and Tiksheozero belts), can contain gold deposits of Paleoproterozoic age.

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13

Aspler, Lawrence B., and Jeffrey R. Chiarenzelli. "Two Neoarchean supercontinents? Evidence from the Paleoproterozoic." Sedimentary Geology 120, no. 1-4 (September 1998): 75–104. http://dx.doi.org/10.1016/s0037-0738(98)00028-1.

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Fakhraee, Mojtaba, Sean A. Crowe, and Sergei Katsev. "Sedimentary sulfur isotopes and Neoarchean ocean oxygenation." Science Advances 4, no. 1 (January 2018): e1701835. http://dx.doi.org/10.1126/sciadv.1701835.

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Sun, Si, Kurt O. Konhauser, Andreas Kappler, and Yi-Liang Li. "Primary hematite in Neoarchean to Paleoproterozoic oceans." Geological Society of America Bulletin 127, no. 5-6 (January 22, 2015): 850–61. http://dx.doi.org/10.1130/b31122.1.

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16

HUANG, Xiongnan. "Microscopic deformation of the Neoarchean oceanic lithospheric mantle; evidence from the zunhua Neoarchean ophiolitic melange, North china Craton." Progress in Natural Science 13, no. 8 (2003): 607. http://dx.doi.org/10.1360/03jz9108.

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Huang, Xiongnan, Jianghai Li, Xianglong Niu, and Jun Feng. "Microscopic deformation of the Neoarchean oceanic lithospheric mantle: evidence from the Zunhua Neoarchean ophiolitic mélange, North China Craton *." Progress in Natural Science 13, no. 8 (August 1, 2003): 607–14. http://dx.doi.org/10.1080/10020070312331344120.

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18

Heard, Andy W., Nicolas Dauphas, Romain Guilbaud, Olivier J. Rouxel, Ian B. Butler, Nicole X. Nie, and Andrey Bekker. "Triple iron isotope constraints on the role of ocean iron sinks in early atmospheric oxygenation." Science 370, no. 6515 (October 22, 2020): 446–49. http://dx.doi.org/10.1126/science.aaz8821.

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The role that iron played in the oxygenation of Earth’s surface is equivocal. Iron could have consumed molecular oxygen when Fe3+-oxyhydroxides formed in the oceans, or it could have promoted atmospheric oxidation by means of pyrite burial. Through high-precision iron isotopic measurements of Archean-Paleoproterozoic sediments and laboratory grown pyrites, we show that the triple iron isotopic composition of Neoarchean-Paleoproterozoic pyrites requires both extensive marine iron oxidation and sulfide-limited pyritization. Using an isotopic fractionation model informed by these data, we constrain the relative sizes of sedimentary Fe3+-oxyhydroxide and pyrite sinks for Neoarchean marine iron. We show that pyrite burial could have resulted in molecular oxygen export exceeding local Fe2+ oxidation sinks, thereby contributing to early episodes of transient oxygenation of Archean surface environments.

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Taylor, Richard J. M., Tim E. Johnson, Chris Clark, and Richard J. Harrison. "Persistence of melt-bearing Archean lower crust for >200 m.y.—An example from the Lewisian Complex, northwest Scotland." Geology 48, no. 3 (December 17, 2019): 221–25. http://dx.doi.org/10.1130/g46834.1.

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Abstract Geochronological data from zircon in Archean tonalite–trondhjemite–granodiorite (TTG) gneisses are commonly difficult to interpret. A notable example is the TTG gneisses from the Lewisian Gneiss Complex, northwest Scotland, which have metamorphic zircon ages that define a more-or-less continuous spread through the Neoarchean, with no clear relationship to zircon textures. These data are generally interpreted to record discrete high-grade events at ca. 2.7 Ga and ca. 2.5 Ga, with intermediate ages reflecting variable Pb loss. Although ancient diffusion of Pb is commonly invoked to explain such protracted age spreads, trace-element data in zircon may permit identification of otherwise cryptic magmatic and metamorphic episodes. Although zircons from the TTG gneiss analyzed here show a characteristic spread of Neoarchean ages, they exhibit subtle but key step changes in trace-element compositions that are difficult to ascribe to diffusive resetting, but that are consistent with emplacement of regionally extensive bodies of mafic magma. These data suggest suprasolidus metamorphic temperatures persisted for 200 m.y. or more during the Neoarchean. Such long-lived high-grade metamorphism is supported by data from zircon grains from a nearby monzogranite sheet. These preserve distinctive trace-element compositions consistent with derivation from a mafic source, and they define a well-constrained U-Pb zircon age of ca. 2.6 Ga that is intermediate between the two previously proposed discrete metamorphic episodes. The persistence of melt-bearing lower crust for hundreds of millions of years was probably the norm during the Archean.

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Heaman, L. M., Ch O. Böhm, N. Machado, T. E. Krogh, W. Weber, and M. T. Corkery. "The Pikwitonei Granulite Domain, Manitoba: a giant Neoarchean high-grade terrane in the northwest Superior ProvinceThis article is one of a series of papers published in this Special Issue on the theme of Geochronology in honour of Tom Krogh.N. Machado, T.E. Krogh, and W. Weber are deceased." Canadian Journal of Earth Sciences 48, no. 2 (February 2011): 205–45. http://dx.doi.org/10.1139/e10-058.

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The Pikwitonei Granulite Domain located at the northwestern margin of the Superior Province is one of the largest Neoarchean high-grade terranes in the world, with well-preserved granulite metamorphic assemblages preserved in a variety of lithologies, including enderbite, opdalite, charnockite, and mafic granulite. U–Pb geochronology has been attempted to unravel the protolith ages and metamorphic history of numerous lithologies at three main localities; Natawahunan Lake, Sipiwesk Lake, and Cauchon Lake. The U–Pb age results indicate that some of the layered enderbite gneisses are Mesoarchean (3.4–3.0 Ga) and the more massive enderbites are Neoarchean. The high-grade metamorphic history of the Pikwitonei Granulite Domain is complex and multistage with at least four episodes of metamorphic zircon growth identified: (1) 2716.1 ± 3.8 Ma, (2) 2694.6 ± 0.6 Ma, (3) 2679.6 ± 0.9 Ma, and (4) 2642.5 ± 0.9 Ma. Metamorphic zircon growth during episodes 2 and 3 are interpreted to be regional in extent, corresponding to M1 amphibolite- and M2 granulite-facies events, respectively, consistent with previous field observations. The youngest metamorphic episode at 2642.5 Ma is only recognized at southern Cauchon Lake, where it coincides with granite melt production and possible development of a major northeast-trending deformation zone. The timing and multistage metamorphic history recorded in the Pikwitonei Granulite Domain is similar to most Superior Province high-grade terranes and marks a fundamental break in Archean crustal evolution worldwide at the termination of prolific global Neoarchean greenstone belt formation.

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Zibra, I., Y. Lu, F. Clos, R. F. Weinberg, M. Peternell, M. T. D. Wingate, M. Prause, M. Schiller, and R. Tilhac. "Regional-scale polydiapirism predating the Neoarchean Yilgarn Orogeny." Tectonophysics 779 (March 2020): 228375. http://dx.doi.org/10.1016/j.tecto.2020.228375.

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22

de Kock, Michiel O., David A. D. Evans, and Nicolas J. Beukes. "Validating the existence of Vaalbara in the Neoarchean." Precambrian Research 174, no. 1-2 (October 2009): 145–54. http://dx.doi.org/10.1016/j.precamres.2009.07.002.

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Halla, Jaana, Jeroen van Hunen, Esa Heilimo, and Pentti Hölttä. "Geochemical and numerical constraints on Neoarchean plate tectonics." Precambrian Research 174, no. 1-2 (October 2009): 155–62. http://dx.doi.org/10.1016/j.precamres.2009.07.008.

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Fralick, Philip, and James E. Carter. "Neoarchean deep marine paleotemperature: Evidence from turbidite successions." Precambrian Research 191, no. 1-2 (November 2011): 78–84. http://dx.doi.org/10.1016/j.precamres.2011.09.004.

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25

Bédard, Jean H., and Lyal B. Harris. "Neoarchean disaggregation and reassembly of the Superior craton." Geology 42, no. 11 (November 2014): 951–54. http://dx.doi.org/10.1130/g35770.1.

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Paris, G., J. F. Adkins, A. L. Sessions, S. M. Webb, and W. W. Fischer. "Neoarchean carbonate-associated sulfate records positive 33S anomalies." Science 346, no. 6210 (November 6, 2014): 739–41. http://dx.doi.org/10.1126/science.1258211.

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Stüeken, E. E., R. Buick, R. E. Anderson, J. A. Baross, N. J. Planavsky, and T. W. Lyons. "Environmental niches and metabolic diversity in Neoarchean lakes." Geobiology 15, no. 6 (August 30, 2017): 767–83. http://dx.doi.org/10.1111/gbi.12251.

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Schneiderhan, E., U. Zimmermann, J. Gutzmer, K. Mezger, and R. Armstrong. "Sedimentary Provenance of the Neoarchean Ventersdorp Supergroup, Southern Africa: Shedding Light on the Evolution of the Kaapvaal Craton during the Neoarchean." Journal of Geology 119, no. 6 (November 2011): 575–96. http://dx.doi.org/10.1086/661988.

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Sandeman, H. A., B. L. Cousens, and C. J. Hemmingway. "Continental tholeiitic mafic rocks of the Paleoproterozoic Hurwitz Group, Central Hearne sub-domain, Nunavut: insight into the evolution of the Hearne sub-continental lithosphere." Canadian Journal of Earth Sciences 40, no. 9 (September 1, 2003): 1219–37. http://dx.doi.org/10.1139/e03-035.

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The Paleoproterozoic Hurwitz Group of the western Churchill Province is an erosional remnant of an areally extensive, predominantly shallow-water intracratonic basin comprised of four major sequences. Sequence 2, forming the central part of the stratigraphy, contains the Ameto Formation, a sequence of pillowed and massive basaltic rocks and associated gabbro sills termed the Happotiyik Member that are interlayered with subordinate deep-water mudstones, siltstones, and diamictites. Whole-rock geochemical data for the mafic rocks reveals a suite of homogeneous tholeiitic basalts with affinities to both continental and volcanic-arc tholeiites. Compatible trace elements and large-ion lithophile elements exhibit scattered behavior, whereas all high field strength elements show a systematic increase with Zr. The rocks are large-ion lithophile and light rare-earth element enriched, and have parallel primitive mantle normalized extended trace element patterns with prominent negative Nb, Ta, and Ti anomalies. εNd(t=2200 Ma) values for the rocks range from 0.0 to +0.8. The data indicate that the parental magmas were derived from a heterogeneous, predominantly depleted mantle source that included a minor metasomatically enriched component. Contamination by Neoarchean, juvenile silicic upper crust during ascent was minimal. We envisage that the rocks of the Happotiyik Member were generated from sub-continental lithospheric mantle that was stabilized immediately after formation of the ca. 2680 Ma, Neoarchean Central Hearne sub-domain. This enrichment occurred via metasomatic infiltration of subduction-derived fluids and melts into the overlying lithosphere. A wide range of Paleoproterozoic intra-continental mafic rocks in the western Churchill Province exhibit comparable geochemical and isotopic signatures that suggest an origin in the lithospheric mantle. These observations imply that the Hearne sub-continental lithospheric mantle has endured since the Neoarchean and likely persists today.

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Heaman, Larry M., and D. Graham Pearson. "Nature and evolution of the Slave Province subcontinental lithospheric mantleThis article is one of a series of papers published in this Special Issue on the theme Lithoprobe — parameters, processes, and the evolution of a continent." Canadian Journal of Earth Sciences 47, no. 4 (April 2010): 369–88. http://dx.doi.org/10.1139/e09-046.

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A review of the ages determined for mantle material (xenoliths and xenocrysts entrained in kimberlite) derived from the Slave Province continental lithospheric mantle (CLM) indicates that a portion of the central Slave lithosphere may be ancient (3.5–3.3 Ga) harzburgite, but the majority of this lithosphere is much younger (2.9–2.0 Ga). Relying on the most robust chronometers, the majority of Slave lithosphere peridotite formed in the Neoarchean (peak at 2.75 Ga), whereas the majority of eclogite formed in the Paleoproterozoic (2.2–2.0 Ga). The northern Slave lithosphere contains evidence of peridotite xenolith ages that young with depth. The Paleoproterozoic eclogites may have multiple origins including remnants of subducted oceanic crust and mafic–ultramafic magmas that crystallized at great depth (100–200 km). Re–Os studies of sulfide inclusions in diamond indicate that some diamonds currently mined are ancient (∼3.5 Ga), but many Slave diamonds could be considerably younger. Most eclogitic diamonds recovered from the Slave craton are interpreted to be related to the formation of Paleoproterozoic eclogite. There is abundant evidence for Mesoproterozoic modification of the Slave lithosphere (e.g., heating by magma emplacement at great depth and metasomatism) and possible new addition to the lithosphere at that time. The Canadian Slave and African Kaapvaal lithospheres have similar peaks in cratonic peridotite formation ages at about 2.8 Ga, indicating that a large portion of the CLM in these two cratons formed and stabilized in the Neoarchean. One difference is that the Slave peridotites are much less enriched in SiO2, possibly reflecting the more metasomatized nature of the Kaapvaal CLM. The dominance of Paleoproterozoic formation ages for Slave mantle eclogites contrasts with the dominance of Neoarchean formation ages for Kaapvaal mantle eclogites.

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Wang, Chao, Shuguang Song, Yaoling Niu, Chunjing Wei, and Li Su. "TTG and Potassic Granitoids in the Eastern North China Craton: Making Neoarchean Upper Continental Crust during Micro-continental Collision and Post-collisional Extension." Journal of Petrology 57, no. 9 (November 25, 2016): 1775–810. http://dx.doi.org/10.1093/petrology/egw060.

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As the major component, Archean granitoids provide us with an insight into the formation of the early continental crust. We report the study of a series of Neoarchean granitoids, including tonalite–trondhjemite–granodiorite (TTG) and potassic granitoids, in the Xingcheng region of the eastern North China Craton. Zircon U–Pb dating shows that the TTG granitoids were emplaced in the Neoarchean within a 75 Myr period (2595–2520 Ma), with coeval mafic magmatic enclaves, followed by intrusion of potassic granitoids. The geochemistry of the TTG granitoids is consistent with partial melting of Mesoarchean enriched mafic crustal sources at different depths (up to 10–12 kbar equivalent pressure) during a continental collision event. The potassic granitoids are derived from either low-degree melting of Mesoarchean enriched mafic crustal sources or remelting of Mesoarchean TTGs in response to post-collisional extension, and were hybridized with Neoarchean mantle-derived mafic melts to various degrees. The TTG and potassic granitoids in the Xingcheng region record the evolution from collision of micro-continental blocks to post-collisional extension, consistent with other studies, suggesting that the amalgamation of micro-continental blocks is what gave rise to the cratonization of the North China Craton at the end of the Archean. The rock assemblage of these granitoids resembles those of syn- and post-collisional magmatism in Phanerozoic orogenic belts, and the estimated average composition is similar to that of the present-day upper continental crust, suggesting that a prototype upper continental crust might have been developed at the end of the Archean from a mixture of TTG and potassic granitoids. Together with concurrent high-grade metamorphism in the North China Craton, we conclude that collisional orogenesis is responsible for continental cratonization at the end of the Archean in the North China Craton.

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Frost, Carol D., and Fabio A. Da Prat. "Petrogenetic and tectonic interpretation of strongly peraluminous granitic rocks and their significance in the Archean rock record." American Mineralogist 106, no. 8 (August 1, 2021): 1195–208. http://dx.doi.org/10.2138/am-2022-8001.

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Abstract Strongly peraluminous granitic rocks (SPG), defined by an aluminum saturation index ≥1.1, become abundant in the rock record in the Neoarchean. This study identifies three different varieties of Neoarchean SPG in the Archean Wyoming Province, U.S.A. These include calcic SPG, represented by the Webb Canyon Gneiss and Bitch Creek Gneiss of the Teton Range; calc-alkalic to alkali-calcic suites composed entirely of SPG, including the Rocky Ridge garnet granite gneiss of the northern Laramie Mountains and the Bear Mountain granite in the Black Hills; and calc-alkalic to alkali-calcic suites that include both weakly and strongly peraluminous granitic rocks, such as the Mount Owen batholith, Wyoming batholith, and Bears Ears granite. Although the petrogenesis of all the SPG suites involves partial melting of crustal sources, the composition of those sources, the melting conditions, and the tectonic settings vary. The calcic suites originate by dehydration melting or water excess melting of hornblende-plagioclase rocks at relatively high temperature. The suites composed entirely of SPG formed by partial melting of metasedimentary rocks by reactions involving muscovite at lower temperatures. Suites with both weakly and strongly peraluminous granite may form by partial melting of metasedimentary rocks by reactions involving biotite or by assimilation of aluminous melts of felsic crust by differentiated calc-alkalic magma. Most of the Wyoming SPG appear to have formed in collisional orogens, but SPG of the Wyoming batholith and Bears Ears granite are associated with continental arc magmatism. The appearance of SPG in the Neoarchean rock record marks the time when subduction enabled the formation of strong, thick, increasingly felsic continental crust, which in turn allowed the development of a mature, clastic sedimentary cover. Lateral movement of crustal blocks led to collisional orogeny, SPG magma genesis, and the formation of the first supercontinents.

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Zibra, Ivan. "Neoarchean structural evolution of the Murchison Domain (Yilgarn Craton)." Precambrian Research 343 (July 2020): 105719. http://dx.doi.org/10.1016/j.precamres.2020.105719.

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Zibra, I., F. Clos, R. F. Weinberg, and M. Peternell. "The ~2730 Ma onset of the Neoarchean Yilgarn Orogeny." Tectonics 36, no. 9 (September 2017): 1787–813. http://dx.doi.org/10.1002/2017tc004562.

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Vrevskii, A. B. "Non-subduction petrological mechanisms for the growth of the neoarcheam continental crust of the Kola–Norwegian terrane, Fennoscandian shield: geological and isotope-geochemical evidence." Петрология 27, no. 2 (April 2, 2019): 161–86. http://dx.doi.org/10.31857/s0869-59032161-186.

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The paper reports new data on the composition and age of the Neoarchean calc-alkaline volcanic rocks of the Uraguba–Kolmozero–Voron’ya greenstone belt (UKV GB). Petrological-geochemical modeling indicates a polygenetic origin of primary melts of the basalt–andesite–dacite association and non-subduction geodynamic mechanisms for the crustal growth in the largest greenstone belt of the Kola–Norwegian Block of the Fennoscandian shield.

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Kwelwa, S. D., I. V. Sanislav, P. H. G. M. Dirks, T. Blenkinsop, and S. L. Kolling. "The petrogenesis of the Neoarchean Kukuluma Intrusive Complex, NW Tanzania." Precambrian Research 305 (February 2018): 64–78. http://dx.doi.org/10.1016/j.precamres.2017.12.021.

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Li, Zhuang, Chunjing Wei, Shiwei Zhang, Chuan Yang, and Zhanzhan Duan. "Neoarchean granitoid gneisses in Eastern Hebei, North China Craton: Revisited." Precambrian Research 324 (May 2019): 62–85. http://dx.doi.org/10.1016/j.precamres.2019.01.020.

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Lubnina, Natalia, Richard Ernst, Martin Klausen, and Ulf Söderlund. "Paleomagnetic study of NeoArchean–Paleoproterozoic dykes in the Kaapvaal Craton." Precambrian Research 183, no. 3 (December 2010): 523–52. http://dx.doi.org/10.1016/j.precamres.2010.05.005.

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Zhelezinskaia, I., A. J. Kaufman, J. Farquhar, and J. Cliff. "Large sulfur isotope fractionations associated with Neoarchean microbial sulfate reduction." Science 346, no. 6210 (November 6, 2014): 742–44. http://dx.doi.org/10.1126/science.1256211.

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Rey, Patrice F., and Nicolas Coltice. "Neoarchean lithospheric strengthening and the coupling of Earth's geochemical reservoirs." Geology 36, no. 8 (2008): 635. http://dx.doi.org/10.1130/g25031a.1;.

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Paris, Guillaume, Woodward W. Fischer, Jena E. Johnson, Samuel M. Webb, Theodore M. Present, Alex L. Sessions, and Jess F. Adkins. "Deposition of sulfate aerosols with positive Δ33S in the Neoarchean." Geochimica et Cosmochimica Acta 285 (September 2020): 1–20. http://dx.doi.org/10.1016/j.gca.2020.06.028.

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Kanzaki, Yoshiki, and Takashi Murakami. "Estimates of atmospheric CO2 in the Neoarchean–Paleoproterozoic from paleosols." Geochimica et Cosmochimica Acta 159 (June 2015): 190–219. http://dx.doi.org/10.1016/j.gca.2015.03.011.

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Rego, Eric Siciliano, Vincent Busigny, Stefan V. Lalonde, Pascal Philippot, Amaury Bouyon, Camille Rossignol, Marly Babinski, and Adriana Cássia Zapparoli. "Anoxygenic photosynthesis linked to Neoarchean iron formations in Carajás (Brazil)." Geobiology 19, no. 4 (March 4, 2021): 326–41. http://dx.doi.org/10.1111/gbi.12438.

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Valério, Cristóvão da Silva, Moacir José Buenano Macambira, Valmir da Silva Souza, and Elton Luiz Dantas. "SiO2-saturated potassic alkaline magmatism in the central Amazonian Craton, southernmost Uatumã-Anauá Domain, NE Amazonas, Brazil." Brazilian Journal of Geology 47, no. 3 (September 2017): 441–46. http://dx.doi.org/10.1590/2317-4889201720170044.

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ABSTRACT: This paper approaches the record of SiO2-saturated potassic alkaline magmatism of Castanhal Quartz Monzonite, Mapuera Suite, and Ladeira da Vovó Quartz Syenite. These samples are located near the Northern border of the Amazon Basin. Such rocks show K2O + 2 > Na2O and K2O/Na2O < 2 values that confirm the potassic or shoshonitic character of these rocks. The Castanhal Quartz Monzonite contains less than 20% volume of quartz, which is also a characteristic of the shoshonitic or SiO2-satured potassic alkaline A-type magma signature observed on geochemical plots. Listric faults, representing the rifting phase of Amazon Basin formation, emplaced and reworked Ladeira da Vovó Quartz Syenite, which caused its granophyric texture, probably during the Tonian period. A group of 21 zircon crystals was extracted from a hornblende quartz monzonite and yields an average age of 1872 ± 6 Ma (MSWD = 2.4). However, an additional zircon crystal yielded a Trans-Amazonian age of 2062 ± 17 Ma. These potassic alkaline rocks of Orosirian (1872 Ma) age may correspond to a post-collisional setting. Dominantly negative εHft values and Hf TDM ages reveal a large contribution of a mafic crustal component from Mesoarchean to Neoarchean age (2.95 - 2.66 Ga), and a felsic crustal component from Neoarchean to later Siderian ages (2.51 - 2.34 Ga).

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GEUSEBROEK, P. A., and N. A. DUKE. "An Update on the Geology of the Lupin Gold Mine, Nunavut, Canada." Exploration and Mining Geology 13, no. 1-4 (January 1, 2004): 1–13. http://dx.doi.org/10.2113/gsemg.13.1-4.1.

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Abstract The Lupin mine, located in the central Slave province just east of the western boundary of Nunavut Territory, is a world-class example of a Neoarchean-aged banded iron formation (BIF)-hosted lode-gold deposit. At the minesite the gold-mineralized Lupin BIF, separating stratigraphically underlying psammitic wacke and overlying argillaceous turbidite sequences, delineates the Lupin dome, a hammerhead-shaped F2/F3 interference fold structure occurring at the greenschist to amphibolite facies metamorphic transition within the thermal aureole of the Contwoyto batholith. Detailed paragenetic relationships indicate that peak thermal metamorphism coincided with the switch from regional D2 compression to rapid D3 unroofing of the Neoarchean orogenic infrastructure. Gold initially precipitated with pyrrhotite, replacing amphibolitic BIF at the apex of the Lupin deformation zone, separating the east and west lobes of the Contwoyto batholith. Over the course of associated prograde/retrograde metasomatic overprints, gold was further remobilized during garnet and loellingite/arsenopyrite growth in chlorite-altered selvages of late-forming ladder quartz veins. A metamorphic model of ore genesis, with gold being scavenged and transported by metamorphic fluid that was shed and structurally trapped at the amphibolite recrystallization front, is favored over the previously proposed syngenetic and exogenic models of gold concentration that have tended to polarize genetic interpretations to date.

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Dey, Sukanta, and Jean-François Moyen. "Archean granitoids of India: windows into early Earth tectonics – an introduction." Geological Society, London, Special Publications 489, no. 1 (2020): 1–13. http://dx.doi.org/10.1144/sp489-2020-155.

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AbstractGranitoids form the dominant component of Archean cratons. They are generated by partial melting of diverse crustal and mantle sources and subsequent differentiation of the primary magmas, and are formed through a variety of geodynamic processes. Granitoids, therefore, are important archives for early Earth lithospheric evolution. Peninsular India comprises five cratonic blocks bordered by mobile belts. The cratons that stabilized during the Paleoarchean–Mesoarchean (Singhbhum and Western Dharwar) recorded mostly diapirism or sagduction tectonics. Conversely, cratons that stabilized during the late Neoarchean (Eastern Dharwar, Bundelkhand, Bastar and Aravalli) show evidence consistent with terrane accretion–collision in a convergent setting. Thus, the Indian cratons provide testimony to a transition from a dominantly pre-plate tectonic regime in the Paleoarchean–Mesoarchean to a plate-tectonic-like regime in the late Neoarchean. Despite this diversity, all five cratons had a similar petrological evolution with a long period (250–850 myr) of episodic tonalite–trondhjemite–granodiorite (TTG) magmatism followed by a shorter period (30–100 myr) of granitoid diversification (sanukitoid, K-rich anatectic granite and A-type granite) with signatures of input from both mantle and crust. The contributions of this Special Publication cover diverse granitoid-related themes, highlighting the potential of Indian cratons in addressing global issues of Archean crustal evolution.

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Ossa Ossa, Frantz, Axel Hofmann, Jorge E. Spangenberg, Simon W. Poulton, Eva E. Stüeken, Ronny Schoenberg, Benjamin Eickmann, Martin Wille, Mike Butler, and Andrey Bekker. "Limited oxygen production in the Mesoarchean ocean." Proceedings of the National Academy of Sciences 116, no. 14 (March 20, 2019): 6647–52. http://dx.doi.org/10.1073/pnas.1818762116.

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The Archean Eon was a time of predominantly anoxic Earth surface conditions, where anaerobic processes controlled bioessential element cycles. In contrast to “oxygen oases” well documented for the Neoarchean [2.8 to 2.5 billion years ago (Ga)], the magnitude, spatial extent, and underlying causes of possible Mesoarchean (3.2 to 2.8 Ga) surface-ocean oxygenation remain controversial. Here, we report δ15N and δ13C values coupled with local seawater redox data for Mesoarchean shales of the Mozaan Group (Pongola Supergroup, South Africa) that were deposited during an episode of enhanced Mn (oxyhydr)oxide precipitation between ∼2.95 and 2.85 Ga. Iron and Mn redox systematics are consistent with an oxygen oasis in the Mesoarchean anoxic ocean, but δ15N data indicate a Mo-based diazotrophic biosphere with no compelling evidence for a significant aerobic nitrogen cycle. We propose that in contrast to the Neoarchean, dissolved O2levels were either too low or too limited in extent to develop a large and stable nitrate reservoir in the Mesoarchean ocean. Since biological N2fixation was evidently active in this environment, the growth and proliferation of O2-producing organisms were likely suppressed by nutrients other than nitrogen (e.g., phosphorus), which would have limited the expansion of oxygenated conditions during the Mesoarchean.

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Bai, Wenqian, Chunyan Dong, Zhiyong Song, Allen P. Nutman, Hangqiang Xie, Shijin Wang, Shoujie Liu, et al. "Late Neoarchean granites in the Qixingtai region, western Shandong: Further evidence for the recycling of early Neoarchean juvenile crust in the North China Craton." Geological Journal 55, no. 9 (March 30, 2020): 6462–86. http://dx.doi.org/10.1002/gj.3824.

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Bergman, Stefan, and Pär Weihed. "Chapter 3 Archean (>2.6 Ga) and Paleoproterozoic (2.5–1.8 Ga), pre- and syn-orogenic magmatism, sedimentation and mineralization in the Norrbotten and Överkalix lithotectonic units, Svecokarelian orogen." Geological Society, London, Memoirs 50, no. 1 (2020): 27–81. http://dx.doi.org/10.1144/m50-2016-29.

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AbstractTwo lithotectonic units (the Norrbotten and Överkalix units) occur inside the Paleoproterozoic (2.0–1.8 Ga) Svecokarelian orogen in northernmost Sweden. Archean (2.8–2.6 Ga and possibly older) basement, affected by a relict Neoarchean tectonometamorphic event, and early Paleoproterozoic (2.5–2.0 Ga) cover rocks constitute the pre-orogenic components in the orogen that are unique in Sweden. Siliciclastic sedimentary rocks, predominantly felsic volcanic rocks, and both spatially and temporally linked intrusive rock suites, deposited and emplaced at 1.9–1.8 Ga, form the syn-orogenic component. These magmatic suites evolved from magnesian and calc-alkaline to alkali–calcic compositions to ferroan and alkali–calcic varieties in a subduction-related tectonic setting. Apatite–Fe oxide, including the world's two largest underground Fe ore mines (Kiruna and Malmberget), skarn-related Fe oxide, base metal sulphide, and epigenetic Cu–Au and Au deposits occur in the Norrbotten lithotectonic unit. Low- to medium-pressure and variable temperature metamorphic conditions and polyphase Svecokarelian ductile deformation prevailed. The general northwesterly or north-northeasterly structural grain is controlled by ductile shear zones. The Paleotectonic evolution after the Neoarchean involved three stages: (1) intracratonic rifting prior to 2.0 Ga; (2) tectonic juxtaposition of the lithotectonic units during crustal shortening prior to 1.89 Ga; and (3) accretionary tectonic evolution along an active continental margin at 1.9–1.8 Ga.

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Gordienko, I. V. "The role of island-arc oceanic, collisional and intraplate magmatism in the formation of continental crust in the Mongolia-Trasnbaikalia region: geostructural, geochronological and Sm-Nd isotope data." Geodynamics & Tectonophysics 12, no. 1 (March 21, 2021): 1–47. http://dx.doi.org/10.5800/gt-2021-12-1-0510.

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The formation of continental crust in the Mongolia-Transbaikalia region is researched to identify the mechanisms of interactions between the crust and the mantle in the development of the Neoarchean, Proterozoic and Paleozoic magmatic and sedimentary complexes in the study area. Using the results of his own studies conducted for many years and other published data on this vast region of Central Asia, the author have analysed compositions, ages and conditions for the formation of Karelian, Baikalian, Caledonian and Hercynian structure-formational complexes in a variety of geodynamic settings. Based on the geostructural, petrological, geochemical, geochronological and Sm-Nd isotope data, he determines the crustal and mantle sources of magmatism, conducts the identification and mapping of isotopic provinces, and reveals the role of island-arc oceanic, accretion-collision and intraplate magmatism in the formation of continental crust. Considering the formation of the bulk continental crust, three main stages are distinguished: (1) Neoarchean and Paleoproterozoic (Karelian) (almost 30% of the crust volume), (2) Meso-Neoproterozoic (Baikalian) (50%), and (3) Paleozoic (Caledonian and Hercynian) (over 20%). This sequence of the evolution stages shows the predominance of the ancient crustal material in igneous rocks sources at the early stage. During the subsequent stages, tectonic structures created earlier were repeatedly reworked, and mixed crustal-mantle and juvenile sources were widely involved in the formation of the bulk continental crust in the study area.

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