The Kangdian terrane in the western South China block,having witnessed the Cenozoic continental oblique collision,is one of the few regions globally where orogenic gold and porphyry gold-polymetallic deposits are clos...The Kangdian terrane in the western South China block,having witnessed the Cenozoic continental oblique collision,is one of the few regions globally where orogenic gold and porphyry gold-polymetallic deposits are closely spatially-temporally associated.The control of regional lithospheric evolution on mineralization remains unclear.This study reveals that inherited zircons from the 30.0-24.6 Ma intrusions along the terrane's western boundary,which intruded the Proterozoic igneous rocks,exhibit abundant Proterozoic to Cenozoic ages.This indicates the eastward wedging of the Paleozoic and Mesozoic rocks beneath the Ailaoshan Proterozoic granites,which potentially drove the early Paleogene shearing along the boundary and crustal rotating within the terrane.Orogenic gold deposits derived from metasomatized lithospheric mantle were controlled by largescale shear zones along terrane boundaries.Hydrothermal monazite U-Pb dating and published mineralization ages of orogenic gold deposits demonstrate two mineralization episodes at 52-45 Ma and 30-25 Ma,corresponding to crustal compression and shearing phases during continental collision,respectively.Porphyry gold-polymetallic deposits,coeval with volcanic extensional basins and lamprophyre swarms,formed at ca.35 Ma during the transition from compression to shearing.Paleomagnetic and petrochemical data suggest their formation under crustal rotation within thickened crust.It was revealed that the Cenozoic mafic and felsic rocks in the terrane share similar Nd isotopic compositions,indicating their analogue mantle source from which felsic magma leading to porphyry mineralization was derived.This study demonstrates that mantle devolatilization and shearing along terrane boundaries generated orogenic gold mineralization during stress relaxation,while the evolution of mantle-derived magmatic systems associated with crustal rotation within the terrane governed porphyry gold-polymetallic mineralization during the tectonic transition.展开更多
The compositions of the whole rocks and trace elements of minerals in peridotites can reflect the characteristics of the lithospheric mantle. The nature and evolution of the Cenozoic lithospheric mantle beneath Hannuo...The compositions of the whole rocks and trace elements of minerals in peridotites can reflect the characteristics of the lithospheric mantle. The nature and evolution of the Cenozoic lithospheric mantle beneath Hannuoba （汉诺坝）, located on the north edge of the intra-North China orogenic belt, are discussed based on the in-situ LAM-ICPMS detected trace element compositions of clinopyroxenes in the Hannuoba peridotitic xenoliths combined with detailed petrography and geochemistry studies. The Hannuoba lithospheric mantle was formed by different partial meltings of the primitive mantle. Most of the samples reflect the partial melting degree of lower than 5% with a few samples of 15%-20%. Major element compositions of the whole rocks and geochemical compositions of clinopyroxenes reveal the coexistence of both fertile and depleted mantle underneath the Hannuoba region during the Cenozoic. This was probably caused by the asthenospheric mantle replacing the aged craton mantle through erosion, intermingling and modification. Our conclusion is further supported by the existence of both carbonatitic magmatic material and silicate melt/ fluid metasomatism as magnified by the trace elements of the clinopyroxencs from the Hannuoba lithospherJc mantle.展开更多
The experimental results of the reactions between an alkaline basaltic melt and mantle orthopyroxenes under high-temperature and high-pressure conditions of 1300–1400℃ and 2.0–3.0 GPa using a six-anvil apparatus ar...The experimental results of the reactions between an alkaline basaltic melt and mantle orthopyroxenes under high-temperature and high-pressure conditions of 1300–1400℃ and 2.0–3.0 GPa using a six-anvil apparatus are reported in this paper.The reactions are proposed to simulate the interactions between melts from the asthenospheric mantle and the lithospheric mantle.The starting melt in the experiments was made from the alkaline basalt occurring in Fuxin,Liaoning Province,and the orthopyroxenes were separated from the mantle xenoliths in Damaping,Hebei Province.The results show that clinopyroxenes were formed in all the reactions between the alkaline basaltic melt and orthopyroxenes under the studied P–T conditions.The formation of clinopyroxene in the reaction zone is mainly controlled by dissolution–crystallization,and the chemical compositions of the reacted melt are primarily infl uenced by the diff usion eff ect.Temperature is the most important parameter controlling the reactions between the melt and orthopyroxenes,which has a direct impact on the melting of orthopyroxenes and the diff usion of chemical components in the melt.Temperature also directly controls the chemical compositions of the newly formed clinopyroxenes in the reaction zone and the reacted melt.The formation of clinopyroxenes from the reactions between the alkaline basaltic melt and orthopyroxenes can result in an increase of CaO and Al_(2)O_(3) contents in the rocks containing this mineral.Therefore,the reactions between the alkaline basaltic melt from the asthenospheric mantle and orthopyroxenes from the lithospheric mantle can lead to the evolution of lithospheric mantle in the North China Craton from refractory to fertile with relatively high CaO and Al 2 O 3 contents.In addition,the reacted melts in some runs were transformed from the starting alkaline basaltic into tholeiitic after reactions,indicating that tholeiitic magma could be generated from alkaline basaltic one via reactions between the latter and orthopyroxene.展开更多
Objective The North China Craton （NCC） is a large Archean craton with a long geological history, yet very few studies have been carried out on the evolution of the redox conditions of its underlying mantle. Oxidati...Objective The North China Craton （NCC） is a large Archean craton with a long geological history, yet very few studies have been carried out on the evolution of the redox conditions of its underlying mantle. Oxidation state of the mantle is critical in controlling the formation of metallic mineral deposits because metals can be readily released from the mantle to partial melt under oxidized conditions. In contrast, highly reduced and stable conditions are essential for the crystallization of diamond. The subcontinental lithospheric mantle （SCLM） beneath major cratons in the world has been stable since their formation and highly reduced in its oxidation state, but the SCLM below the NCC is different.展开更多
The ophiolites that crop out discontinuously along the;000 km Yarlung Zangbo Suture zone（YZSZ）between the Nanga Parbat and Namche Barwa syntaxes in southern Tibet represent the remnants of Neotethyan oceanic lithosp...The ophiolites that crop out discontinuously along the;000 km Yarlung Zangbo Suture zone（YZSZ）between the Nanga Parbat and Namche Barwa syntaxes in southern Tibet represent the remnants of Neotethyan oceanic lithosphere（Fig.1a）.We have investigated the internal structure and the geochemical makeup of mafic-ultramafic rock assemblages that are exposed in the westernmost segment of the YZSZ where the suture zone architecture displays two distinct sub-belts of ophiolitic and mélange units separated by a continental Zhongba terrane（Fig.1b）.These two sub-belts include the Daba–Xiugugabu in the south（Southern sub-belt,SSB）and the Dajiweng–Saga in the north（Northern sub-belt,NSB）.We present new structural,geochemical,geochronological data from upper mantle peridotites and mafic dike intrusions occurring in these two sub-belts and discuss their tectonomagmatic origin.In-situ analysis of zircon grains obtained from mafic dikes within the Baer,Cuobuzha and Jianabeng massifs in the NSB,and within the Dongbo,Purang,Xiugugabu,Zhaga and Zhongba in the SSB have yielded crystallization ages ranging between130 and 122 Ma.Dike rocks in both sub-belts show N-MORB REE patterns and negative Nb,Ta and Ti anomalies,reminiscent of those documented from SSZ ophiolites.*Harzburgitic host rocks of the mafic dike intrusionsmainly display geochemical compositions of abyssal peridotites（Fig.2）,with the exception of the Dajiweng harzburgites,which show the geochemical signatures of forearc peridotites（Lian et al.,2016）.Extrusive rocks that are spatially associated with these peridotite massifs in both sub-belts also have varying compositional and geochemical features.Tithonian to Valanginian（150–135 Ma）basaltic rocks in the Dongbo massif have OIB-like geochemistry and 138 Ma basaltic lavas in the Purang massif have EMORB-like geochemistry（Liu et al.,2015）.Tuffaceous rocks in the Dajiweng massif are140 Ma in age and show OIB-like geochemistry.We interpret these age and geochemical data to reflect a rifted continental margin origin of the extrusive rock units in both sub-belts.These data and structural observations show that the western Yarluang Zangbo ophiolites represent fragments of an Ocean-Continent Transition（OCT）peridotites altered by fluids in an initial supersubduction setting.We infer that mafic-ultramafic rock assemblages exposed in the SSB and NSB initially formed in an ocean–continent transition zone（OCTZ）during the late Jurassic,and that they were subsequently emplaced in the forearc setting of an intraoceanic subduction zone within a Neotethyan seaway during 130 to 122 Ma.The NSB and SSB are hence part of a single,S-directed nappe sheet derived from a Neotethyan seaway located north of the Zhongba terrane.展开更多
The boundary between lithosphere and asthenosphere essentially represents a thermal boundary (the solidus). Temperature variation across this boundary can lead to the change of lithosphere thickness. In the case of el...The boundary between lithosphere and asthenosphere essentially represents a thermal boundary (the solidus). Temperature variation across this boundary can lead to the change of lithosphere thickness. In the case of elevated temperatures in a lithospheric layer above 1 200℃, partial melting will begin and the result of that is a thinned lithosphere. The other mechanism that can also thin lithosphere is extension. Stretching during an extension event can result in a thinner and longer lithosphere. The two mechanisms above are the reason why we can alserve large variations in lithosphere thickness spatially across various continents and temporally throughout the geological history.展开更多
Recent seismic studies reveal a sharp velocity drop mostly at^70–100 km depth within the thick mantle keel beneath cratons, termed the mid-lithosphere discontinuity(MLD). The common presence of the MLD in cratonic re...Recent seismic studies reveal a sharp velocity drop mostly at^70–100 km depth within the thick mantle keel beneath cratons, termed the mid-lithosphere discontinuity(MLD). The common presence of the MLD in cratonic regions indicates structural and property layering of the subcontinental lithospheric mantle(SCLM). The nature and origin of the MLD, and many issues associated with the layering of the SCLM are essential to understand the formation and evolution of continents, and have become frontier subjects in the Earth sciences.展开更多
Most giant porphyry-skarn Cu-Au ore systems are associated with either the metasomatic mantle wedge,formed by the dehydration of subducting oceanic crust,or the melting of Cu-rich juvenile lower crust.The ore-forming ...Most giant porphyry-skarn Cu-Au ore systems are associated with either the metasomatic mantle wedge,formed by the dehydration of subducting oceanic crust,or the melting of Cu-rich juvenile lower crust.The ore-forming parent rocks are typically depleted adakites.In contrast,parent rocks in intracontinental Cu-Au ore systems exhibit enriched isotopic compositions,yet their formation mechanisms and deep processes remain unclear.To address this,our study focuses on the central Yangtze River ore belt(CYROB)and adjacent areas.By compiling regional petrological and chronological data,we conducted multi-isotope tracing and Hf isotope mapping,integrated with regional seismic velocity tomography and magnetotelluric detection results,to reconstruct the lithospheric architecture and its evolutionary processes.Our findings indicate that the CYROB underwent significant crustal accretion during the Meso-and Neo-proterozoic,forming a juvenile crust.In the Late Mesozoic,the crust experienced polygenetic reworking,through two distinct periods(156–136 Ma and 136–120 Ma).During the transition from the Late Jurassic to the Early Cretaceous(156–140 Ma),in the area near and north of the Gaotan fault,lithospheric delamination in an extensional setting facilitated mantle convection and partial melting of enriched lithospheric mantle.This process modified the pre-existing juvenile lower crust,leading to the formation of adakites with slightly negativeεHf values(-5 to 0)and associated porphyry-skarn Cu-Au deposits.Concurrently,ascent of adakitic magma occasionally incorporated W-rich middle-to-upper crustal materials,enriching the melts in W and forming localized small-to medium-sized skarn W deposits.During 140–136 Ma,with the continued relaxation of lithospheric stress,a more intense modification of the lower crust by enriched mantle occurred west of Anqing and north of Qingyang.This led to the formation of adakic magmas with strongly negativeεHfvalues(-24 to-8)and related skarn Cu-Fe deposits.To the south of the Jiangnan fault,where the crust was deeper,mantle convection induced the remelting of Proterozoic reworked crust,releasing W and Mo into crust-derived melts,ultimately forming a series of large-and medium-sized porphyry-skarn W-Mo deposits.During the late period(136–120 Ma),progressive lithospheric extension triggered large-scale lithospheric delamination and oblique asthenospheric upwelling from the southeast to the northwest,further modifying the lower crust.The remelting of reworked crust with input from depleted mantle materials,led to the formation of extensive alkali-rich granitic batholiths.This study demonstrates that,under the extensional regime of the Late Mesozoic,the polygenic reworking of juvenile crust and the remelting of previously reworked crust—driven by ongoing lithosphere-scale delamination and asthenospheric upwelling—played a key role in controlling the temporal and spatial distribution of metal ore systems in the CYROB and adjacent areas.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.42125203)the 111 Project of China(Grant No.BP0719021)。
文摘The Kangdian terrane in the western South China block,having witnessed the Cenozoic continental oblique collision,is one of the few regions globally where orogenic gold and porphyry gold-polymetallic deposits are closely spatially-temporally associated.The control of regional lithospheric evolution on mineralization remains unclear.This study reveals that inherited zircons from the 30.0-24.6 Ma intrusions along the terrane's western boundary,which intruded the Proterozoic igneous rocks,exhibit abundant Proterozoic to Cenozoic ages.This indicates the eastward wedging of the Paleozoic and Mesozoic rocks beneath the Ailaoshan Proterozoic granites,which potentially drove the early Paleogene shearing along the boundary and crustal rotating within the terrane.Orogenic gold deposits derived from metasomatized lithospheric mantle were controlled by largescale shear zones along terrane boundaries.Hydrothermal monazite U-Pb dating and published mineralization ages of orogenic gold deposits demonstrate two mineralization episodes at 52-45 Ma and 30-25 Ma,corresponding to crustal compression and shearing phases during continental collision,respectively.Porphyry gold-polymetallic deposits,coeval with volcanic extensional basins and lamprophyre swarms,formed at ca.35 Ma during the transition from compression to shearing.Paleomagnetic and petrochemical data suggest their formation under crustal rotation within thickened crust.It was revealed that the Cenozoic mafic and felsic rocks in the terrane share similar Nd isotopic compositions,indicating their analogue mantle source from which felsic magma leading to porphyry mineralization was derived.This study demonstrates that mantle devolatilization and shearing along terrane boundaries generated orogenic gold mineralization during stress relaxation,while the evolution of mantle-derived magmatic systems associated with crustal rotation within the terrane governed porphyry gold-polymetallic mineralization during the tectonic transition.
基金This paper is supported by the Research Foundation for OutstandingYoung Teachers , China University of Geosciences ( Wuhan )(CUGQNL0510)the National Natural Science Foundation of China(No .40425002) .
文摘The compositions of the whole rocks and trace elements of minerals in peridotites can reflect the characteristics of the lithospheric mantle. The nature and evolution of the Cenozoic lithospheric mantle beneath Hannuoba （汉诺坝）, located on the north edge of the intra-North China orogenic belt, are discussed based on the in-situ LAM-ICPMS detected trace element compositions of clinopyroxenes in the Hannuoba peridotitic xenoliths combined with detailed petrography and geochemistry studies. The Hannuoba lithospheric mantle was formed by different partial meltings of the primitive mantle. Most of the samples reflect the partial melting degree of lower than 5% with a few samples of 15%-20%. Major element compositions of the whole rocks and geochemical compositions of clinopyroxenes reveal the coexistence of both fertile and depleted mantle underneath the Hannuoba region during the Cenozoic. This was probably caused by the asthenospheric mantle replacing the aged craton mantle through erosion, intermingling and modification. Our conclusion is further supported by the existence of both carbonatitic magmatic material and silicate melt/ fluid metasomatism as magnified by the trace elements of the clinopyroxencs from the Hannuoba lithospherJc mantle.
基金supported by the National Natural Science Foundation of China(Nos.41472065 and 42073059).
文摘The experimental results of the reactions between an alkaline basaltic melt and mantle orthopyroxenes under high-temperature and high-pressure conditions of 1300–1400℃ and 2.0–3.0 GPa using a six-anvil apparatus are reported in this paper.The reactions are proposed to simulate the interactions between melts from the asthenospheric mantle and the lithospheric mantle.The starting melt in the experiments was made from the alkaline basalt occurring in Fuxin,Liaoning Province,and the orthopyroxenes were separated from the mantle xenoliths in Damaping,Hebei Province.The results show that clinopyroxenes were formed in all the reactions between the alkaline basaltic melt and orthopyroxenes under the studied P–T conditions.The formation of clinopyroxene in the reaction zone is mainly controlled by dissolution–crystallization,and the chemical compositions of the reacted melt are primarily infl uenced by the diff usion eff ect.Temperature is the most important parameter controlling the reactions between the melt and orthopyroxenes,which has a direct impact on the melting of orthopyroxenes and the diff usion of chemical components in the melt.Temperature also directly controls the chemical compositions of the newly formed clinopyroxenes in the reaction zone and the reacted melt.The formation of clinopyroxenes from the reactions between the alkaline basaltic melt and orthopyroxenes can result in an increase of CaO and Al_(2)O_(3) contents in the rocks containing this mineral.Therefore,the reactions between the alkaline basaltic melt from the asthenospheric mantle and orthopyroxenes from the lithospheric mantle can lead to the evolution of lithospheric mantle in the North China Craton from refractory to fertile with relatively high CaO and Al 2 O 3 contents.In addition,the reacted melts in some runs were transformed from the starting alkaline basaltic into tholeiitic after reactions,indicating that tholeiitic magma could be generated from alkaline basaltic one via reactions between the latter and orthopyroxene.
基金granted by the National Natural Science Foundation of China(grants no.41173034 and 41472051)
文摘Objective The North China Craton （NCC） is a large Archean craton with a long geological history, yet very few studies have been carried out on the evolution of the redox conditions of its underlying mantle. Oxidation state of the mantle is critical in controlling the formation of metallic mineral deposits because metals can be readily released from the mantle to partial melt under oxidized conditions. In contrast, highly reduced and stable conditions are essential for the crystallization of diamond. The subcontinental lithospheric mantle （SCLM） beneath major cratons in the world has been stable since their formation and highly reduced in its oxidation state, but the SCLM below the NCC is different.
文摘The ophiolites that crop out discontinuously along the;000 km Yarlung Zangbo Suture zone（YZSZ）between the Nanga Parbat and Namche Barwa syntaxes in southern Tibet represent the remnants of Neotethyan oceanic lithosphere（Fig.1a）.We have investigated the internal structure and the geochemical makeup of mafic-ultramafic rock assemblages that are exposed in the westernmost segment of the YZSZ where the suture zone architecture displays two distinct sub-belts of ophiolitic and mélange units separated by a continental Zhongba terrane（Fig.1b）.These two sub-belts include the Daba–Xiugugabu in the south（Southern sub-belt,SSB）and the Dajiweng–Saga in the north（Northern sub-belt,NSB）.We present new structural,geochemical,geochronological data from upper mantle peridotites and mafic dike intrusions occurring in these two sub-belts and discuss their tectonomagmatic origin.In-situ analysis of zircon grains obtained from mafic dikes within the Baer,Cuobuzha and Jianabeng massifs in the NSB,and within the Dongbo,Purang,Xiugugabu,Zhaga and Zhongba in the SSB have yielded crystallization ages ranging between130 and 122 Ma.Dike rocks in both sub-belts show N-MORB REE patterns and negative Nb,Ta and Ti anomalies,reminiscent of those documented from SSZ ophiolites.*Harzburgitic host rocks of the mafic dike intrusionsmainly display geochemical compositions of abyssal peridotites（Fig.2）,with the exception of the Dajiweng harzburgites,which show the geochemical signatures of forearc peridotites（Lian et al.,2016）.Extrusive rocks that are spatially associated with these peridotite massifs in both sub-belts also have varying compositional and geochemical features.Tithonian to Valanginian（150–135 Ma）basaltic rocks in the Dongbo massif have OIB-like geochemistry and 138 Ma basaltic lavas in the Purang massif have EMORB-like geochemistry（Liu et al.,2015）.Tuffaceous rocks in the Dajiweng massif are140 Ma in age and show OIB-like geochemistry.We interpret these age and geochemical data to reflect a rifted continental margin origin of the extrusive rock units in both sub-belts.These data and structural observations show that the western Yarluang Zangbo ophiolites represent fragments of an Ocean-Continent Transition（OCT）peridotites altered by fluids in an initial supersubduction setting.We infer that mafic-ultramafic rock assemblages exposed in the SSB and NSB initially formed in an ocean–continent transition zone（OCTZ）during the late Jurassic,and that they were subsequently emplaced in the forearc setting of an intraoceanic subduction zone within a Neotethyan seaway during 130 to 122 Ma.The NSB and SSB are hence part of a single,S-directed nappe sheet derived from a Neotethyan seaway located north of the Zhongba terrane.
文摘The boundary between lithosphere and asthenosphere essentially represents a thermal boundary (the solidus). Temperature variation across this boundary can lead to the change of lithosphere thickness. In the case of elevated temperatures in a lithospheric layer above 1 200℃, partial melting will begin and the result of that is a thinned lithosphere. The other mechanism that can also thin lithosphere is extension. Stretching during an extension event can result in a thinner and longer lithosphere. The two mechanisms above are the reason why we can alserve large variations in lithosphere thickness spatially across various continents and temporally throughout the geological history.
基金supported by the National Natural Science Foundation of China (41225016, 41688103, 91414301)Chinese Academy of Sciences
文摘Recent seismic studies reveal a sharp velocity drop mostly at^70–100 km depth within the thick mantle keel beneath cratons, termed the mid-lithosphere discontinuity(MLD). The common presence of the MLD in cratonic regions indicates structural and property layering of the subcontinental lithospheric mantle(SCLM). The nature and origin of the MLD, and many issues associated with the layering of the SCLM are essential to understand the formation and evolution of continents, and have become frontier subjects in the Earth sciences.
基金jointly funded by the National Key Technologies Research and Development Program(Grant Nos.2019YFA0708603,2023YFF0804203)the China Geological Survey(Grant No.DD20243510)+2 种基金the Scientific Research Fund Project of BGRIMM Technology Group(Grant No.JTKY202427822)the National Natural Science Foundation of China(Grant No.42073042)the Basic Scientific Research Fund of the Institute of Geology,Chinese Academy of Geological Sciences(Grant No.J2402)。
文摘Most giant porphyry-skarn Cu-Au ore systems are associated with either the metasomatic mantle wedge,formed by the dehydration of subducting oceanic crust,or the melting of Cu-rich juvenile lower crust.The ore-forming parent rocks are typically depleted adakites.In contrast,parent rocks in intracontinental Cu-Au ore systems exhibit enriched isotopic compositions,yet their formation mechanisms and deep processes remain unclear.To address this,our study focuses on the central Yangtze River ore belt(CYROB)and adjacent areas.By compiling regional petrological and chronological data,we conducted multi-isotope tracing and Hf isotope mapping,integrated with regional seismic velocity tomography and magnetotelluric detection results,to reconstruct the lithospheric architecture and its evolutionary processes.Our findings indicate that the CYROB underwent significant crustal accretion during the Meso-and Neo-proterozoic,forming a juvenile crust.In the Late Mesozoic,the crust experienced polygenetic reworking,through two distinct periods(156–136 Ma and 136–120 Ma).During the transition from the Late Jurassic to the Early Cretaceous(156–140 Ma),in the area near and north of the Gaotan fault,lithospheric delamination in an extensional setting facilitated mantle convection and partial melting of enriched lithospheric mantle.This process modified the pre-existing juvenile lower crust,leading to the formation of adakites with slightly negativeεHf values(-5 to 0)and associated porphyry-skarn Cu-Au deposits.Concurrently,ascent of adakitic magma occasionally incorporated W-rich middle-to-upper crustal materials,enriching the melts in W and forming localized small-to medium-sized skarn W deposits.During 140–136 Ma,with the continued relaxation of lithospheric stress,a more intense modification of the lower crust by enriched mantle occurred west of Anqing and north of Qingyang.This led to the formation of adakic magmas with strongly negativeεHfvalues(-24 to-8)and related skarn Cu-Fe deposits.To the south of the Jiangnan fault,where the crust was deeper,mantle convection induced the remelting of Proterozoic reworked crust,releasing W and Mo into crust-derived melts,ultimately forming a series of large-and medium-sized porphyry-skarn W-Mo deposits.During the late period(136–120 Ma),progressive lithospheric extension triggered large-scale lithospheric delamination and oblique asthenospheric upwelling from the southeast to the northwest,further modifying the lower crust.The remelting of reworked crust with input from depleted mantle materials,led to the formation of extensive alkali-rich granitic batholiths.This study demonstrates that,under the extensional regime of the Late Mesozoic,the polygenic reworking of juvenile crust and the remelting of previously reworked crust—driven by ongoing lithosphere-scale delamination and asthenospheric upwelling—played a key role in controlling the temporal and spatial distribution of metal ore systems in the CYROB and adjacent areas.
