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A review of current understanding of structures in shear zones reveals that correlating the orientation of stretching lineations with movement direction, once a common practice based on the simple shear model, is not generally applicable to transpressional zones. It is difficult to determine the movement direction of a transpressional zone based on internal structures. We show that the movement direction can be better defined by considering the variation in strain geometry and kinematics of differently oriented and kinematically related shear zones or different segments of a curved shear zone. Application of this method to a shear zone in the northwestern Superior Province of Manitoba shows that the movement direction there is approximately north-south, in contrast to a commonly held view for similarly oriented shear zones in the Superior Province that the movement direction is approximately east-west. Keywords: transpression, shear zone, strain geometry, kinematics, movement direction, Superior Province.

U–Pb ages and Hf isotope compositions of zircons from the Chencai complex in Zhejiang Province have been determined to provide constraints on mechanisms of migmatization and tectonic evolution related to the early Palaeozoic orogeny in the Cathaysia Block, South China. Zircons from leucosome samples of migmatites are characterized by nebulous overgrowths enclosing inherited cores or occur as newly formed grains with weak zoning. Five samples gave weighted mean ages ranging from 438±3 Ma to 432±4 Ma, which are interpreted as recording the time of anatexis of a regional tectono-thermal event. Their ε Hf(t) values range from −21.4 to −4.8 (with peak at −11), with corresponding T DM2 ages of 1.73–2.77 Ga (with peak at c. 1.9–2.3 Ga), suggesting that the protoliths formed by reworking of ancient crust evolved from Late Palaeoproterozoic – early Archaean crust–mantle differentiation. The migmatization was spatially and temporally associated with reported 460–435 Ma metamorphism with a clockwise pressure–temperature (P – T) path and was most likely controlled by crustal thickening driven by the early Palaeozoic orogenesis. The T DM2 ages of the Chencai complex are consistent with those of the Wuyi–Yunkai structural belt in the Cathaysia Block, but distinct from those (with peak at 2.7–3.0 Ga) of the Badu complex which lacks early Palaeozoic tectono-thermal records. The data support the suggestion that a postulated geological entity, instead of the east domain (the Badu complex being its main part) of the Cathaysia Block, was probably involved in the early Palaeozoic orogeny. [ABSTRACT FROM AUTHOR]

The detrital zircon geochronological record of Permian-Triassic clastic rocks of the Beishan region in the southern Central Asian orogenic belt indicates a pattern of cyclical, successive Paleozoic accretion events. Comparison of zircon age spectra derived from two individual arc terranes reveals similar age patterns offset by 30-40 m.y. Detrital samples with a provenance interpreted as the southern arc terrane indicate magmatic peaks at 275, 370, and 430 Ma with a 50 m.y. hiatus from 350 to 300 Ma. Samples with a provenance interpreted as the northern arc terrane exhibit a similar pattern yet with consistently earlier component peaks at 310, 400, and 445 Ma with a 40 m.y. hiatus from 380 to 340 Ma. This is interpreted to reflect that subduction developed successively between terranes and progressed until Silurian-Devonian sequential docking of the arcs along separate suture zones. Detrital geochronology of accreted sediments (single peak at 445 Ma) within the northern suture, with coincident tuff and pillow basalt U-Pb zircon ages of 409 ± 2.9 and 416.6 ± 15.0 Ma, respectively, may redefine a principal phase of amalgamation as Devonian, over previously interpreted ages in the Carboniferous-Permian. Initiation and cessation of arc magmatism are shown to correlate with regional phases of ophiolite generation and emplacement, respectively. This supports regional models that ophiolite belts in the Central Asian orogenic belt correlate with suture zones developed from multiple contemporaneous subduction systems between arcs. We explore whether a pericratonic archipelago of crustal slivers around the Tarim craton may have initiated successive arc formation. [ABSTRACT FROM AUTHOR]

The Tongbai orogenic belt has an overall antiformal geometry and the hinge of the antiform is sub-horizontal and trends NW–SE. The Tongbai complex (TBC) in the core of the antiform is bounded by the S-dipping Yindian–Malong shear zone in the south, the sub-horizontal Taibaiding shear zone at the top and the N-dipping Hongyihe–Tongbai shear zone in the north. The three shear zones have dextral, top-to-NW and sinistral movement, respectively. They are parts of a single shear zone, termed the Tongbai shear zone, that has a uniform top-to-NW sense of shear. Three samples of deformed granitoid (mylonite or protomylonite) from the shear zone have U–Pb zircon ages of 145 ± 6 Ma, 142 ± 2 Ma and 131 ± 6 Ma, respectively. An L-tectonite in the TBC yielded a metamorphic age of 137 ± 8 Ma and a migmatite an age of 137 ± 1 Ma. The Tongbai shear zone is intruded by undeformed Early Cretaceous granite and dykes and deformation in the shear zone is constrained to ca. 140–135 Ma, synchronous with metamorphism and migmatization in the TBC. Early Cretaceous magma emplacement and the associated uplift modified the TBC into a gentle antiform and the uplift may have continued to ca. 102–85 Ma. Similar geometry and kinematics have been documented in the Dabie orogenic belt to the east, which suggests that the Central Orogenic Belt in China probably experienced a uniform orogen-parallel extension and top-to-NW shearing in the ductile lithosphere in the Early Cretaceous. [ABSTRACT FROM PUBLISHER]

Zheng-Xiang Li suggests that the upper crust of the South China block was separated from the lower crust and thrown over into the North China block when the South and North China blocks collided. This phenomenon occurred east of the Tanlu fault. He also claims that the sinistral offset of the Qinling suture is only 110-120 kms. deep. However, Li does not elaborate on why the South China block separated east of the Tanlu fault and not to the west. Nor is there any explanation given for the sinistral offset of the Qinling suture.

The basis for understanding continental tectonics to a large degree relies on terrane recognition. However, discrepant identifications and interpretations of the same terrane as well as its boundary are still commonly seen in South China. For years, the central debate has been revolving around the Yangtze-Cathaysia boundary and West-East Cathaysia boundary. Here we characterized the geochemical patterns (or differences) of the proposed terranes and located their boundaries by using a big geochemical dataset of South China, which consists of compositions of 75 elements in 5231 sediment samples. To extract valuable information from this big geochemical dataset, we applied multiple data mining techniques, including principal component analysis, sequential binary partition, Sobel operator, and support vector machine. Our results show that the geochemical patterns vary distinctly at regional scale across both the subblocks (i.e., Yangtze and Cathaysia) and terranes (i.e., Jiuling, Huaiyu, and Youjiang). Accordingly, we conclude that 1) the Northeast Jiangxi fault marks not only the Jiuling-Huaiyu boundary but also the north-eastern Yangtze-Cathaysia boundary; 2) the Yangtze-Cathaysia boundary extends westward along the Jiangshan-Pingxiang-Chaling fault; and 3) a fault zone comprising the Northwest Fujian fault and Zhenghe-Dapu fault possibly demarcates the West and East Cathaysia. The boundaries defined by the contrasting geochemical patterns in this study are also supported by geophysical, Nd isotopic, and geological evidence. Our observations will allow better explanation of where the proposed terranes originated and how South China was assembled. Our work demonstrates that data mining techniques are effective in deriving and integrating information for solving geoscience problems. • We characterized geochemical patterns of multiple terranes of South China. • Big geochemical dataset containing 75 element compositions in 5231 sediments were used. • We located terrane boundaries in South China by applying multiple data mining methods. • Geophysical, isotopic, and geological studies support the boundaries defined herein. [ABSTRACT FROM AUTHOR]

• The ca. 1885 Ma I- and S-type granites are different in their source rocks. • The adakitic granites suggest thickened crust in the JLJB syn-orogenic process. • The granitoids reflect a heterogeneity of the JLJB in the Late Paleoproterozoic. A suite of Paleoproterozoic syn-orogenic magmatism with distinctive natures in the Jiao-Liao-Ji Belt (JLJB) of North China Craton is studied, including I-type monzogranite, related quartz gabbro, S-type granites, and adakitic granites. The Caiyuan monzogranite and quartz gabbro intrusions yield zircon U-Pb ages of 1881 ± 31 Ma and 1889 ± 19 Ma, respectively. They exhibit light rare earth element enriched patterns, and are rich in Rb, Ba, and K, but depleted in Nb, Ta, and Ti. These granites have relatively low (87Sr/86Sr) i ratios of 0.701985–0.706703, εNd(t) values of −13.0 to −0.3 and dominantly negative zircon εHf(t) values. Two Siping porphyritic granite samples give U-Pb ages of 1877 ± 11 Ma and 1881 ± 11 Ma respectively. They display enriched REE patterns, characterized by high Al 2 O 3 and A/CNK ratio (>1.1), similar to S-type granites, with high (87Sr/86Sr) i ratios up to 0.711142 and negative εNd(t) values of −8.0 to −2.2. The Wafang and Xujiapu granites intrusions yield zircon U-Pb age of 1887 ± 11.0 Ma and 1885 ± 9.7 Ma and have high Sr/Y, (La/Yb) N and strikingly positive Eu anomalies, likely belonging to adakite. The association of quartz gabbro, I-type, and S-type granites in the Caiyuan region indicate that they were derived from mafic parental magma triggered by slab subduction. Crustal materials mixed in further AFC processes of the magma, before the monzogranite and porphyritic granite crystallized. The Wafang adakitic granite was probably related to the partial melting of a thickened crust. A complex syn-orogenic evolution model is thus proposed in the Late Paleoproterozoic of the JLJB, as slab subduction and partial melting of thickened crust simultaneously occurred at ~1885 Ma. [ABSTRACT FROM AUTHOR]

• SJC experienced multiple magmatism of ~2.78, ~2.69 and ~2.55 Ga. • Neoarchean magma derived from episodic juvenile crust growth and crustal reworking. • Recycling of sediments was not intense or extensive in SJC during Neoarchean. • A bottom-up tectonic regime related to plume activity is favored for NCC in Neoarchean. Recent advances in high-precision in-situ analysis of zircon U-Pb-Hf-O isotopes have significantly improved our approach to studying the origin and evolution of Archean crust. This study presents high-precision in-situ zircon U-Pb-Hf-O isotopes for the Southern Jilin Complex (SJC) on the northeastern margin of the North China Craton (NCC) and explores the potential of such an integrated approach in understanding the Archean crust evolution and its tectonic implications. The SJC consists mainly of Archean granitoid gneisses hosting minor supracrustal rock xenoliths. Zircon U-Pb data from representative lithologies reveal three episodes of magmatism at ~2.78, ~2.69 and ~2.55 Ga, respectively. The former two granitoid magmatic events are recognized for the first time in NE NCC, while the latest one is widespread over the NCC. All metamorphic zircon domains document similar metamorphic ages of 2.51–2.48 Ga, consistent with the widespread metamorphism of ~2.50 Ga in the NCC. Most concordant magmatic zircons preserve "mantle-like" O isotopic signatures, indicating the magma sources were not contaminated by large amounts of high δ18O supracrustal sediments. Hf depleted mantle model ages of magmatic zircons display one predominant peak at 2.9–2.8 Ga and two subordinate peaks at 3.3–3.2 Ga and 2.7–2.6 Ga, indicating possible episodic crust-mantle differentiation in Southern Jilin. Integrated zircon U-Pb-O-Hf data from the SJC suggest that magma sources were mainly derived from multiple episodes of reworking of juvenile or ancient crust with mantle component addition, while recycling of sediments was trivial during the Neoarchean in this region. The spatial–temporal relations of magmatism, lack of supracrustal addition to magma sources, and other geological evidence from the NCC are in favor of a bottom-up geodynamic regime possibly related to plume activities, arguing against a widespread top-down mechanism involving modern-style subduction in the NCC during the Neoarchean. [ABSTRACT FROM AUTHOR]

Opinion. Comments on Gregory Lynch's article `Tectonic Burial, Thrust Emplacement, and Extensional Exhumation of the Cabot Nappe in the Appalachian Hinterland of Cape Breton Island, Canada,' published in a 1996 issue of `Tectonics.' Evidence in the Eastern Cape Breton Highlands for a folded highlands shear zone.

• The volcanic rocks formed in an arc setting at 756-740 Ma. • The late Tonian arc in the Wuyi domain was part of a major arc system in the West Cathaysia terrane. • The Wuyi arc system was different from the arc system along the western margin of the Yangtze Block at the late Tonian. • The West Cathaysia terrane was distinct from the southeastern margin of the Yangtze Block and they were not amalgamated until after the late Tonian. The late Tonian tectonic setting of the West Cathaysia terrane in South China is highly controversial and is key to better understanding the timing of amalgamation between the Yangtze Block and the West Cathaysia terrane and the positions of these two terranes in Rodinia and Gondwana. A detailed field-based study was conducted on the petrology, zircon U-Pb geochronology and Lu-Hf isotopes, and whole-rock geochemistry of a series of Neoproterozoic meta-volcanic and meta-sedimentary rocks in the Wuyi domain in the northeastern West Cathaysia terrane. The results indicate that the meta-volcanic rocks formed in an arc setting at 756-740 Ma, and the meta-sedimentary rocks were developed in an arc-related basin with single zircon age peaks of 765-728 Ma. We propose that the late Tonian arc in the Wuyi domain was part of a major arc system in the West Cathaysia terrane. An arc setting for the West Cathaysia terrane is distinct from the continental rift setting for the southeastern margin of the Yangtze Block at the time, supporting an interpretation that the two terranes were not amalgamated until after the late Tonian and occupied separate positions in Rodinia. [ABSTRACT FROM AUTHOR]

A Neoproterozoic subduction-accretion complex have been identified along the Zhenghe-Dapu fault (ZDF) zone in the inner Cathaysia Block, South China. The serpentinites are characterized by low 187Os/188Os ratios of 0.11621 to 0.12008 and very low 187Re/188Os values of 0.031-0.129, which are similar to those from highly refractory mantle residues, indicating that they are tectonic rather than igneous origin. The meta-ultramafic rocks, including pyroxene hornblende schist and hornblende schist, are characterized by high Ni, Cr and low K2O content. Their convex upward REE partterns, along with lower concentrations of highly incompatible elements indicate that their protolith were cumulate origin. Low initial 87Sr/86Sr and high 143Nd/144Nd ratios suggest that they were derived from partial melting of an depleted mantle source. Low Nb/Yb, Th/Yb and Ti/V imply they have IAT-like geochemical features which occurred in oceanic island arc setting. The associated metasedimentary rocks have low chemical index of alteration (CIA) values (34.7-58.2) and relatively high index of compositional variability (ICV) values (0.98-3.22) suggested weak chemical weathering and an immature source. Low K2O/Al2O3 (0.01-0.03), low zirconδ18O values (4.4 to 5.3‰) and high zircon ɛHf (t) values (+13.5 to +16) of the metasedimentary rocks point to mantle-derived material supply for their protolith. TDM1 (616-719 Ma) of the zircons reflect the source material was derived from a mantle source with Neoproterozoic model ages. Low La/Sc and Th/Sc values infer that their source material were derived from an ocean island arc setting. These rocks have experienced strong mylonitization. Shear-sense indicators show that the mylonitized rocks experienced sinistral strike-slip motion parallel to the ZDF zone. Metamorphic zircons from the mylonitized rocks yield SIMS U-Pb age of ca.522-520 Ma, suggesting that the subduction-accretion complex experienced intensive Pan-African metamorphic event. All these features prefer that there was a Pan-African accretionary orogeny in the South China Block. The ZDF zone probably marks the collisional belt between the west Cathaysia Block and the west Australia, corresponding to the assembly of the Gondwanaland. [ABSTRACT FROM AUTHOR]

• ∼785 Ma mafic-ultramafic cumulates in West Cathaysia formed from hydrous basaltic magmas. • Their geochemical data are consistent with arc-related cumulate petrogenesis. • They were probably formed at a crustal depth in a subduction setting. • Yangtze and West Cathaysia were not amalgamated in the Tonian, but more likely in the early Paleozoic. The Neoproterozoic tectonic setting of the West Cathaysia terrane and its relationship with the Yangtze Block are critical to understanding the formation and tectonic evolution of South China. A detailed study of late Tonian mafic-ultramafic cumulate slivers embedded in the Shenshan tectonic mélange along the northwest margin of West Cathaysia is presented here with the aim of elucidating its Neoproterozoic tectonic history. These partly-altered mafic-ultramafic rocks include olivine-bearing cumulates (olivine pyroxene hornblendite or olivine hornblende pyroxenite), pyroxene hornblendite, and gabbroic cumulates. The early crystallization of clinopyroxene and the abundance of hornblende indicate that they formed from hydrous magmas. The rocks have similar geochemical distribution patterns and show variable initial 87Sr/86Sr ratios of 0.702679 to 0.709742 and positive εNd(t) values of +2.10 to +4.52. The mineral compositions of the clinopyroxene and hornblende and their whole-rock extended normalized trace element patterns show features (e.g., negative Nb anomalies, LILE enrichment) typical of rocks with an arc affinity. The high calculated Mg# values (58–77, average 71) of the equilibrium magmas are close to those of primary mantle-derived basalts. We conclude that these mafic and ultramafic cumulates were derived from a subduction-related, hydrous, magnesian basalt in a subduction setting. The estimated crystallization temperature and pressure, based on the composition of the amphiboles, suggest that the minerals accumulated in magma chambers at middle to lower crustal depths. LA-ICP-MS U-Pb dating of zircon from the gabbroic cumulate indicates crystallization at ca. 785 Ma. A previous interpretation for West Cathaysia at this time involved a continental rift basin (the Nanhua basin) that straddled the southeastern margin of the Yangtze Block and the northwestern margin of West Cathaysia. In contrast, our results suggest that West Cathaysia was an arc at ca. 785 Ma, which supports the interpretation that the amalgamation between Yangtze and West Cathaysia did not occur in the Tonian, but more likely in the early Paleozoic. [ABSTRACT FROM AUTHOR]

To better reveal the early Neoproterozoic tectonic process of South China with respect to the assembly of the Rodinia supercontinent, an integrated dataset of geochronology, whole-rock geochemistry, and Sr-Nd-Hf isotopic compositions for diabases that intruded the Kunyang Group in the southwestern Yangtze Block is herein presented. Zircon U-Pb dating gives four weighted mean 206Pb/238U ages of 946 ± 4 Ma, 948 ± 6 Ma, 939 ± 4 Ma, and 918 ± 7 Ma, suggesting mafic magmatism in the earliest Neoproterozoic. The diabases possess Nb = 12.3–30.5 ppm, Nb/U = 19.99–37.06, Nb/La = 0.78–1.05, (Nb/Th) PM = 0.44–0.80, and (Nb/La) PM = 0.75–1.02, geochemically resembling those of typical Nb-enriched basalts. They are tholeiitic in composition with low SiO 2 (49.49–51.95 wt%), high TiO 2 (2.03–4.65 wt%), MgO (2.50–6.14 wt%), and Fe 2 O 3 T (15.38–18.84 wt%) contents. They are enriched in light rare earth elements (LREEs) with weak negative Eu anomalies (Eu/Eu* = 0.75–0.96) and show E-MORB-like characteristics with slight to moderate Nb-Ta depletion. The samples show zircon ε Hf (t) values ranging from + 5.8 to + 10.3 and whole-rock ε Nd (t) values from + 0.5 to + 0.9. These elemental and isotopic characteristics suggest that the 0.95–0.92 Ga diabases may have derived from an E-MORB-like magma source with the injection of metasomatized slab melts. Integrating previous studies with our results, we propose that the southwestern Yangtze Block evolved from an intracontinental rift to a passive continental margin in the late Mesoproterozoic, followed by the development of an earliest Neoproterozoic continental arc-back-arc basin system analogous to the Northern Okinawa Trough. The distinct tectonic processes between the southern and northern parts of the Yangtze Block at ca. 1.0–0.9 Ga favour the hypothesis that the final cratonization of the present-day Yangtze Block occurred slightly later than ∼ 0.9 Ga in response to the Rodinia supercontinent assembly. [ABSTRACT FROM AUTHOR]

Zhang et al. present new data on the geology, geochronology, fluid inclusions, and S-He-Ar-H-O isotopes of the Huangtan Au-Cu-Zn deposit in the East Tianshan of the Central Asian Orogenic Belt. Accretionary orogenesis plays an important role in continent growth and generates considerable mineral deposits. Li et al. recognize three stages of ore-forming processes in the Doranasai gold deposit of the Irtysh gold belt, including albite-quartz-pyrite stage, quartz-polymetallic sulfide stage and barren quartz-carbonate stage. [Extracted from the article]

The Jiangnan Orogenic Belt in South China formed as a result of the amalgamation between the Yangtze Block and the Cathaysian Block and records the geological information of collision. However, the timing of the amalgamation of two blocks remains controversial. Here, structural deformation and zircon U-Pb geochronological results from Precambrian metamorphosed sedimentary-volcanic rock units at the eastern domain of the Jiangnan orogenic belt in southern Anhui Province are presented. The pre-Nanhua rocks in the study area were widely involved in the metamorphism and deformation to with NW or SE-dipping foliation, tight folds and local development of strike-slip ductile shear zones, which is induced by collision of Yangtze Block and the Cathaysia Block. In this study, a mylonitic granodiorite sample intruding in the Xikou Group, a mylonitic dacite sample from Jingtan Formation and two deformed quartz veins samples in the Shexian region were dated by LA-ICP-MS zircon U-Pb dating method. Zircons from the mylonitic granodiorite and dacite yield the weighted mean ages of 811.2 ± 7.5 Ma (MSWD = 0.51, n = 30) and 779 ± 7.4 Ma (MSWD = 0.42, n = 29), respectively, interpreted as the crystallization ages of the original rocks, whereas the zircons from deformed quartz veins yield the weighted mean ages of 779 ± 14 Ma (MSWD = 2.6, n = 22) and 769 ± 16 Ma (MSWD = 2.4, n = 16), respectively, representing the crystallization age of the quartz veins. Combined with previous data, our results show that the metamorphosis and deformation of Pre-Nanhua rocks took place during the period of 820–770 Ma. Therefore, we consider that the Yangtze Block and the Cathaysian Block the eastern Jiangnan Orogenic Belt don't amalgamate until 770 Ma. [ABSTRACT FROM AUTHOR]

[Display omitted] • Arc-related mafic magmatism occurred at the latest Mesoproterozoic (1.03–1.01 Ga); • An arc–back-arc system may have developed in the southwestern Yangtze Block; • Amalgamation of the Yangtze Block at 0.9 Ga linked to the Rodinia assembly. Although the latest Mesoproterozoic tectonics of the southwestern Yangtze Block have been the focus of many recent studies, the paleogeographic configuration and related processes that controlled the South China Block with respect to the Rodinia assembly are still poorly understood. Here, an integrated dataset of zircon U–Pb geochronology, whole–rock geochemistry, and Sr–Nd–Hf isotopes of mafic intrusions from the Yonglang and Luji areas in the southwestern Yangtze Block is presented. Zircon U–Pb dating reveals that the mafic intrusions were emplaced at 1.03–1.01 Ga. These samples are divided into three groups based on mineralogical and geochemical characteristics. Group 1 meta -diabase samples exhibits calc-alkaline features and have obvious negative Nb-Ta-Ti anomalies and low zircon ε Hf (t) and whole-rock ε Nd (t) values. They may have been derived from an enriched lithospheric mantle source in an arc-related setting. Group 2 amphibolites are characterized by higher Nb contents (8.3–12.8 ppm), Nb/U, (Nb/Th) N , and (Nb/La) N ratios, resembling those of Nb-enriched basalt derived from a metasomatized mantle wedge. Group 3 meta -diabase samples have higher TiO 2 (1.7–2.8 wt%), MgO (5.4–6.5 wt%), and Fe 2 O 3 t (13.1–17.4 wt%), with obvious negative Nb-Ta anomalies and high positive zircon ε Hf (t) values, indicative of derivation from a depleted mantle affected by subducted components. Integrating previous studies with our new results, an arc–back-arc system, with northward subduction (current coordinates), is suggested to have been developed in the southwestern Yangtze Block during the latest Mesoproterozoic. Furthermore, we suggest that the amalgamation of the current united Yangtze Block may occur at ca. 0.9 Ga, which is more likely linked to the assembly of the Rodinia supercontinent. [ABSTRACT FROM AUTHOR]

• Three episodes of magmatism are firstly recognized in the Qianlishan Complex. • Initiation subduction contributed to the formation of the Ordos arc at 2.3–2.0 Ga. • HP metamorphism and syn -collisional magmatism occurred at 1.97–1.95 Ga. • The post-collisional extension caused UHT metamorphism and magmatism at 1.93–1.91 Ga. This study presents detailed petrology, major and trace element chemistry, Sr-Nd isotope, and in-situ zircon U-Pb dating and Hf-O isotopes on granites from the Qianlishan Complex of the Khondalite Belt in North China. Zircon SIMS U-Pb data indicate three episodes of Paleoproterozoic magmatism at ca. 2.06 Ga, 1.95 Ga and 1.92 Ga. Of those, the ca. 2.06 Ga hornblende monzogranites and fine-grained potassic granites display typical features of A-type granite, represented by metaluminous affinity, high FeOT/MgO ratios (3.29–5.63), and high Ga/Al and Zr + Nb + Ce + Y values with high zircon saturation temperatures (916–1000 °C). Moreover, they have positive zircon εHf values of +0.29 to +5.01 and homogenous δ18O values of 5.11–5.87 ‰, probably derived from the partial melting of calc-alkaline granitoids without addition of supracrustal rocks. The ca. 1.95 Ga garnet-bearing granites contain peraluminous minerals of garnet and muscovite and have high ASI index (>1.1) and δ18O values (7.14–9.18 ‰), indicating S-type granite. Their negative whole-rock εNd(t) values (−2.87 to −2.81) and zircon εHf(t) values (−4.06 to +1.29) suggest a source of ancient supracrustal rocks. The ca. 1.92 Ga coarse-grained potassic granites present metaluminous and magnesian signatures of I-type granite, including low A/CNK and FeOT/MgO ratios. Their negative εHf(t) values (−5.00 to −1.64) and homogenous δ18O values (5.20–6.00%) suggest that the original magma was derived primarily from enriched lower crust. The results, combined with regional geology and previous studies, establish a prolonged magmatic-metamorphic evolution of the Khondalite Belt from subduction to collision, involving ca. 2.3–2.0 Ga subduction-related arc magmatism, ca. 1.95 Ga syn -collisional high-pressure high-temperature crustal anatexis, and ca. 1.92 Ga post-collisional magmatism and synchronous ultrahigh temperature metamorphism. [ABSTRACT FROM AUTHOR]