Genesis of S-type Granites in the Pengshan Sn-polymetallic Ore Field, Northern Jiangxi Province and its Implications

The Pengshan Sn-polymetallic ore field is located in the southeastern part of the Yangtze block,spanning the southeast edge of the MLYDZ and the northern edge of the mid-segment of the Jiangnan Uplift,and on one side of the MLYDZ.The studies of LA-ICP-MS zircon U-Pb chronology and petrogeochemistry for Early Cretaceous acid granites from the Pengshan ore field were carried out in this paper.We report zircon U-Pb geochronology and whole-rock geochemistry for acid granites in the Pengshan ore field.The zircon U-Pb ages of the muscovite-granite,biotite adamellite and granite-porphyry are 127.6±1.7 Ma,126.9±1.6 Ma and 126.6±2.0 Ma,respectively.The granites in Pengshan are characterized by a high silicon content and are rich in alkali.They belong to high-potassium,calc-alkaline,peraluminous granite.The rocks have a relatively high Rb/Ba ratio,and the data points for muscovite-granite and biotite adamellite all fall within the clay-rich sources region,near the pelite-derived end-member,showing that the Pengshan muscovite-granite and biotite adamellite mainly originated from the partial melting of metapelites with high maturity.The transformation of the compressional and extensional tectonics in this region approximately 128 Ma obviously lags behind that in the mid-segment of the Jiangnan Uplift(135 Ma),but occurred earlier than the MLYDZ(126 Ma).The Pengshan ore field extends from the mid-segment of the Jiangnan Uplift to the MLYDZ.Although the tectonic stress field is constrained by the combination of the two secondary tectonic units,the time of tectonic system transformation is closer to the MLYDZ because the spatial orientation of the area is enclosed in the MLYDZ.Relevant geophysical and drilling data confirm the rationality of Pengshan-Ao'xia as a multi-center vertical zoning ore field,and show the scientificity of the prospecting idea of abutting joint between the north-west of Pengshan area and the south-east of Ao'xia area.

Chronology and Genesis of S-type Granites in Hetai District, Guangdong Province: Constraints from LA-ICP-MS Zircon U-Pb Dating and Tourmaline Boron Isotope In-situ Analyses

1 Introduction Hetai district,which is a mountainous area,situated on Guangning and Zhaoqing city,west Guangdong Province.Hetai district is generally located on southwest of South China Caledonian fold belt,east margin of Yunkai post-Caledonian uplift.Multiple type granites are widely distributed in Hetai district,including Caledonian,Indosinian and Yanshanian granites.Based on different

Determination of the Neoproterozoic Shicaogou Syn-collisional Granite in the Eastern Qinling Mountains and Its Geological Implications

The Shicaogou granite has been identified as a magnesian (Fe-number=0.71-0.76), calcic to calc-alkalic (MALI=3.84-5.76) and peraluminous (ASI=1.06-1.13) granite of the syn-collisional S-type, with high SiO2(>71%), A12O3 (>13%) and Na2O+K2O (6.28%-7.33%, equal for NaO2 and K2O). Trace element and REE analyses show that the granite is rich in LILE such as of Rb, Sr, Ba and Th, and poor in HFSE like Yb, Y, Zr and Hf. Its Rb/Sr ratio is greater than 1; the contents of Nb and Ta, and the ratio of Nb/Ta as well as the REE geochemical features (e.g. REE abundance, visible fractionation of LREE and HREE and medium to pronounced negative Eu anomalies) are all similar to those of crust-origin, continent-continent syn-collisional granite. Moreover, the granite exhibits almost the same pattern as that of the typical continent-continent syn-collisional granite on the spider diagram and all samples fall within the syn-collisional granite field.The cathodoluminescence (CL) investigations have revealed that the zircon from the Shicaogou granite represents a typical magmatic product characterized by its colorless, transparent and euhedral crystals, and distinct zoning of oscillatory bands. Residual cores of irregular zircon can be found in a few enhedral grains. Trace element studies of the zircon grains, with high contents of P, Y, Hf, Th, U and REE and high ratios of Th/U, obviously positive Ce anomalies and HREE enrichment compared to LREE, also result in the same conclusion.The LA-ICP-MS U-Pb isotopic data from 24 spots of 21 zircon grains demonstrate that 20 spots in the oscillatory zone yield an average weighted 206Pb/238U age of 925±11 Ma, indicating that the Shicaogou granite was formed in the Neoproterozoic. Combined with other Neoproterozoic syn-collisional granites found in the study area, the present geochronological determination can further reveal that collision-amalgamation events could have occurred among some continental blocks in the Qinling orogenic belt during the Neoproterozoic. This in turn provides an accurate chronological constraint on the Neoproterozoic break-up and convergence in the belt.

Two Types of Granites in the Western Yangtze Block and Their Implications for Regional Tectonic Evolution： Constraints from Geochemistry and Isotopic Data

In the western Yangtze Block, widespread Mesoproterozoic to Neoproterozoic rocks are the key to understanding the Precambrian tectonic-magmatic evolution of the region. However, their petrogenesis and tectonic setting are still controversial. In this paper, zircon U-Pb ages, Sm-Nd isotopic and whole-rock geochemical data are reported from selected fresh samples in the southern Dechang county, southwestern China, in order to constrain their emplacement age and magma source, as well as their petrogenesis and tectonic setting. They are mainly composed of biotite monzogranite, monzonitic granite, biotite granodiorites, and quartz diorite. Two ages of 1055 ± 43 Ma and 837.6 ± 3.8 Ma were obtained through zircon U-Pb dating by LA-ICP-MS and LA-MC-ICP-MS, respectively. According to their major element compositions, the Grenville-age granites are peraluminous calc-alkaline series calcic S-type granite. In contrast, the mid-Neoproterozoic granites are metaluminous calc-aikaline series alkalic I-type granite. Furthermore, the S-type granites are enriched in LREEs relative to HREEs with （La/Yb）N ratios of 3.85-18.56 and underwent major fractionation with strongly negative Eu anomalies （Eu/Eu＊ = 0.38-0.66）. In the MORB-normalized trace element variation diagram, all the samples are enriched in Ce and large ion lithophile elements such as Rb, Th, and K, and depleted in high field strength elements such as Nb, and Ti, with negative Sr and Ti anomalies. The I-type granites are enriched in LREEs with slight negative Eu anomalies （Eu/Eu＊= 0.83-0.93）. They are characterized by the enrichment of highly incompatible elements （such as K, Rb, Ba, Th） and LREEs, relative to MORB. Neodymium isotopic data show that the S-type granites display 143Nd/144Nd values of 0.51241-0.51256, and have eNa （t = 1055 Ma） values of （-3.29） to （-3.81）. Calculated tDM ages yield values from 1.87 to 1.91 Ga with the tDM.2stg ages of 1.86 to 1.9 Ga. The I-type granites have 143Nd/144Nd ratios between 0.51192 and 0.51195, corresponding to initial eNd （t = 837 Ma） values of 1.22 to 5.63. Calculated tDM ages yield values from 1.0 to 1.38 Ga and the tDM.2stg ages yield values from 0.99 to 1.06 Ga. The S-type granites are distinguished as syn-collision granite, whereas the I-type granites were formed as arc magmas according to the Rb-（Yb＋Ta） and R1-R2 tectonic discrimination diagrams. To conclude, there are two types of spatially associated granite, the Mesoproterozoic S-type granite which were derived from re- melting of upper crustal mudstone and/or clastics and resulted from the convergence of two continental plates, and the mid-Neoproterozoic I-type granite which formed in continental arc and resulted from mantle-derived magma mixed crust material, in the western Yangtze Block. Furthermore, we suggest that collision between the Yangtze and Cathaysia blocks occurred at about 1055 Ma, and caused the S- type granite. The I-type granite related to the subduction of oceanic lithosphere eastward underneath the Yangtze Block in the mid-Neoproterozoic.

Geochemical Characteristics and Tectonic Significance of Triassic Granite from Taer Region, the Northern Margin of West Kunlun

Late Hercynian-early Indosinian （Triassic） granite is widely distributed around the Taer region of the northern margin of West Kunlun. The rock mass is mainly composed of calc-alkaline porphyroid biotite adamellite and characterized by SiO2-rich, high-Ca, moderate-alkaline, and strongly peraluminous attributes, and relatively low ~REE with LREE enrichment and a moderate Eu anomaly. As shown in the trace element spider web diagram, distinct peaks appear for Th, La, Nd, and Zr and clearly low values appear for Ba, Nb, Sr, P, and Ti. Further, compared with the primitive mantle, Rb/Sr and Rb/Ba are considerably higher and Nd/Th and Nb/Ta are relative low, all falling into the scope of the crust-origin rocks, indicating the characteristics of the crust-origin S-type granite. The rock mass＇s zircon U-Pb isotopic age is determined to be 235.7 -~ 3.9 Ma. On the basis of the age data, spatio-temporal location, lithology, and geochemistry of the rock mass, we conclude that the formation of the rock mass is closely related to the strong compressional orogenic movement （240 Ma） of the Tianshuihai terrane and the South Kunlun terrane. The rock mass is the product of the collision orogenic movement. However, distinct differences are observed between the studied rock mass and the synorogenic Bulunkou rock mass, which may be caused by the different collision strength and different positions with respect to the collision zone.

Origin of Early Creceouscalc-alkaline granite, Taxkorgan: Implications for evolution of Tethys evolution in central Pamir

The Pamir plateau may have been a westward continuation of Tibet plateau.Meanwhile,the Rushan-Pshart suture is correlative to the Bangong-Nujiang suture of Tibet,and the Central Pamir is the lateral equivalent of the Qiangtang Block.We present the first detailed LA-ICPMS zircon U-Pb chronology,major and trace element,and Lu-Hf isotope geochemistry of Taxkorgan two-mica monzogranite to illuminate the Tethys evolution in central Pamir.LA-ICPMS zircon U-Pb dating shows that two-mica monzogranite is emplaced in the Cretaceous(118 Ma).Its geochemical features are similar to S-type granite,with enrichment in LREEs and negative Ba,Sr,Zr and Ti anomalies.All the samples show negative zirconεHf(t)values ranging from 17.0 to 12.5(mean 14.5),corresponding to crustal Hf model(TDM2)ages of 1906 to 2169 Ma.It is inferred that these granitoids are derived from partial melting of peliticmetasedimentary rocks analogous to the Paleoproterozoic Bulunkuole Group,predominantly with muscovite schists component.Based on the petrological and geochemical data presented above,together with the regional geology,this work provides new insights that Bangong Nujiang Ocean closed in Early Cretaceous(120114 Ma).

Early Paleozoic Granite in the Talate Mining District, Chinese Altay, and its Geological Significance for the Altay Orogenic Belt

Zircon dating,geochemical and Nd-Sr isotopic analyses have been determined for samples from two granitic intrusions in the Talate mining district,Chinese Altay.Our data suggest that these intrusions were emplaced from 462.5 Ma to 457.8 Ma.These rocks have strong affinity to peralumious S-type granite and are characterized by prominent negative Eu anomalies(δEu=0.20–0.35),strong depletion in Ba,Sr,P,Ti,Nb,Ta and positive anomalies in Rb,Th,U,K,La,Nd,Zr,Hf.Nd-Sr isotopic compositions of the whole rock show negativeεNd(t)values(-1.21 to-0.08)and Mesoproterozoic Nd model ages(T2 DM=1.20–1.30 Ga).Their precursor magmas were likely derived from the partial dehydration melting of Mesoproterozoic mica-rich pelitic sources and mixed with minor mantle-derived components,under relatively low P(≤1 kbar)and high T(746–796℃)conditions.A ridge subduction model may account for the early Paleozoic geodynamic process with mantle-derived magmas caused by Ordovician ridge subduction and the opening of a slab window underplated and/or intraplated in the middle–upper crust,which triggered extensive partial melting of the shallow crust to generate diverse igneous rocks,and provided the heat for the crustal melting and juvenile materials for crustal growth.

Age and geochemistry of the granitoid from the Lunte area,Northeastern Zambia:Implications for magmatism of the Columbia supercontinent

The Paleoproterozoic tectonic evolution of the Bangweulu Block has long been controversial.Paleoproterozoic granites consisting of the basement complex of the Bangweulu Block are widely exposed in northeastern Zambia,and they are the critical media for studying the tectonic evolution of the Bangweulu Block.This study systematically investigated the petrography,zircon U-Pb chronology,and petrogeochemistry of the granitoid extensively exposed in the Lunte area,northeastern Zambia.The results show that the granitoid in the area formed during 2051±13-2009±20 Ma as a result of Paleoproterozoic magmatic events.Geochemical data show that the granites in the area mainly include syenogranites and monzogranites of high-K calc-alkaline series and are characterized by high SiO2 content(72.68%‒73.78%)and K_(2)O/Na_(2)O ratio(1.82‒2.29).The presence of garnets,the high aluminum saturation index(A/CNK is 1.13‒1.21),and the 1.27%‒1.95%of corundum molecules jointly indicate that granites in the Lunte area are S-type granites.Rare earth elements in all samples show a rightward inclination and noticeably negative Eu-anomalies(δEu=0.16‒0.40)and are relatively rich in light rare earth elements.Furthermore,the granites are rich in large ion lithophile elements such as Rb,Th,U,and K and are depleted in Ba,Sr,and high field strength elements such as Ta and Nb.In addition,they bear low contents of Cr(6.31×10^(−6)‒10.8×10^(−6)),Ni(2.87×10^(−6)‒4.76×10^(−6)),and Co(2.62×10^(−6)‒3.96×10^(−6)).These data lead to the conclusion that the source rocks are meta-sedimentary rocks.Combining the above results and the study of regional tectonic evolution,the authors suggest that granitoid in the Lunte area were formed in a tectonic environment corresponding to the collision between the Tanzania Craton and the Bangweulu Block.The magmatic activities in this period may be related to the assembly of the Columbia supercontinent.

Mantle contributions to granitoids associated with Sn mineralization:Geochemical and isotopic evidence from the giant Dachang deposit,South China

Major Sn deposits are commonly linked to crust-derived and highly evolved granites,with magma generation aided by mantle heating.However,whether and how the mantle components contribute to Sn polymetallic mineralization remains unclear.In this study,in combination with a compilation of equivalent data in the region,we provide new constraints on this issue based on detailed investigations on the petrogenesis and metallogenic significance of granitoids including the causative batholith and later granodiorite porphyry dike in the giant Dachang Sn deposit from South China.The former has zircon U-Pb ages of 93-91 Ma and belongs to highly evolved S-type biotite granite,which experienced fractionation of massive feldspar.The latter shows zircon U-Pb ages of 90 Ma and displays I-type granite features.The batholith was mainly derived from the dehydration melting of biotite in the metasedimentary sources,as revealed by the relatively low whole-rock Pb contents(<30 ppm)and high Ba/Pb ratios(2.71-17.1)and initial T(ti-zr)of 790℃.Compared with the adjacent crust-derived S-type granites(-24.8--5.1)and I-type granites(-11.0 to-5.2),the Dachang S-type biotite granites present higher zirconεHf(t)values(-9.1 to-2.1).Furthermore,the low magmatic zirconδ18O values(6.2‰)and higher apatite LREE(3277-4114 ppm)and Sr(1137-1357 ppm)contents than of arc-type basic rocks were discerned.These characteristics jointly hint the contributions of mantle components.The higher initial T(ti-zr)(>850℃),whole-rock Mg#(52 to 58),apatiteεNd(t)(-9.2 to-6.5)and zirconεHf(t)(-7.6 to 2.5)values but lower zirconδ18O values(6.33 to 8.30‰)of the later granodiorite porphyry dike than those of the batholith also suggest that mantle material was involved in the generation of the dikes,which is evident by the variational features of zircon and apatite trace elements.In addition,at the zircon Hf<12000 ppm and Eu/Eu*>0.05,the higher zirconΔFMQ values(mostly from-1.8 to 2.0)and H2O contents(100-1100 ppm)of the Dachang granitoids than the pure crust-derived S-type granites(ΔFMQ=mostly from-3.7 to-1.5;H2O<100 ppm)imply that mantle materials involved are relatively rich in water and oxidized.These suggest that the addition of mantle components is conducive to the extraction of Sn from metasedimentary sources,and moderately facilitates the increase of oxygen fugacity which still maintains the incompatibility of Sn in magmas withΔFMQ<2.Also,the involvement of mantle components upgrades the H2O contents in S-type magmas,favoring the migration of ore-forming elements from magmas to hydrothermal fluids.The sediment-derived causative granites displayed higherεHf(t)andεNd(t)values with greater Sn tonnages of their associated world-class Sn polymetallic deposits,supporting the opinion that the contributions of mantle components play an important role in the generation of giant Sn deposits.

Ga-(Nb+Ta)-(Nb/Ta)(Zr/Hf) Ternary Diagram: An Excellent Tool for Discriminating Barren and Ta-Hosting Granite-Pegmatite Systems

Discriminating barren and fertile intrusions is one of the main challenges in the search for rare-element pegmatites.Diagrams comprising more than one element can make discrimination of productive and barren samples more valid.These diagrams distinguish samples by simultaneous means of positive and/or negative correlations between variables.A ternary diagram for S-type peraluminous granites has been obtained in this study.Firstly,a database composed of Ta-bearing and barren granitic systems was created,then geochemical behavior of trace elements was studied,and statistical investigations were done using GCDkit software,which resulted in the Ga-(Nb+Ta)-(Nb/Ta)(Zr/Hf)ternary diagram which can distinguish the non-mineralized granites from productive ones.The Ta-bearing samples,which are situated in the fertile field in the diagram,are those which have high Nb and Ta contents,elevated Ga content and the lowest Nb/Ta and Zr/Hf values.

The giant tin polymetallic mineralization in southwest China:Integrated geochemical and isotopic constraints and implications for Cretaceous tectonomagmatic event

The Gejiu-Bozushan-Laojunshan W-Sn polymetallic metallogenic belt(GBLB)in southeast Yunnan Province is an important part of the southwestern Yangtze Block in South China.Tin polymetallic mineralization in this belt includes the Niusipo,Malage,Songshujiao,Laochang and Kafang ore fields in the Gejiu area which are spatially and temporally associated with the Kafang-Laochang and Songshujiao granite plutons.These granites are characterized by variable A/CNK values(mostly>1.1,except for two samples with 1.09),high contents of SiO2(74.38-76.84 wt.%)and Al2 O3(12.46-14.05 wt.%)and variable CaO/Na2 O ratios(0.2-0.65)as well as high zirconδ18O values(7.74‰-9.86‰),indicative of S-type affinities.These rocks are depleted in Rb,Th,U,Ti,LREE[(La/Yb)N=1.4-20.51],Ba,Nb,Sr,and Ti and display strong negative Eu and Ba anomalies.The rocks possess high Rb/Sr and Rb/Ba ratios,relatively low initial 87Sr/86Sr ratios(0.6917-0.7101),and less radiogenicεNd(t)values(-8.0 to-9.1).The zircon grains from these rocks show negativeεHf(t)values in the range of-3.7 to-9.9 with mean TDM2(Nd)and TDM2(Hf)values of 1.57 Ga and 1.55 Ga.They show initial 207Pb/204Pb ranging from15.69 to 15.71 and 206Pb/204Pb from 18.36 to 18.70.Monazite from Songshujiao granites exhibits higher U and lower Th/U ratios,lowerδ18O values and higherεHf(t)values than those of the zircon grains in the KafangLaochang granites.The geochemical and isotopic features indicate that the Laochang-Kafang granites originated by partial melting of Mesoproterozoic crustal components including biotite-rich metapelite and metagraywacke,whereas the Songshujiao granites were derived from Mesoproterozoic muscovite-rich metapelite crustal source.Most zircon grains from the Songshujiao,Laochang and Kafang granites have high-U concentrations and their SIMS U-Pb ages show age scatter from 81.6 Ma to 88.6 Ma,80.7 Ma to 86.1 Ma and 82.3 Ma to 87.0 Ma,suggesting formation earlier than the monazite and cassiterite.Monazite SIMS U-Pb ages and Th-Pb ages of three same granite samples are consistent and show yielded 206 Pb/238U ages of 83.7±0.6 Ma,83.7±0.6 Ma,and 83.4±0.6 Ma,and 208Pb/232Th ages of 83.2±0.5 Ma,83.8±0.4 Ma,and 83.5±0.9 Ma,which are within the range of the SIMS zircon U-Pb ages from these rocks.The data constrain the crystallization of the granites at ca.83 Ma.In situ U-Pb dating of two cassiterite samples from the cassiterite-sulfide ore in the Songshujiao ore field and Kafang ore field,and two from the cassiterite-oxide+cassiterite bearing dolomite in the Laochang ore field yielded weighted mean 206 Pb/238U ages of 83.5±0.4 Ma(MSWD=0.6),83.5±0.4 Ma(MSWD=0.5),83.6±0.4 Ma(MSWD=0.6)and 83.2±0.7 Ma(MSWD=0.6),respectively.Combined with geological characteristics,the new geochronological data indicate that the formation of the granites and Sn polymetallic deposits are coeval.We correlate the magmatic and metallogenic event with lithospheric thinning and asthenosphere upwelling in continental extension setting in relation to the eastward subduction of the Neo-Tethys beneath the Sanjiang tectonic domain during Late Cretaceous.

Petrogenesis of Jurassic Granitoids on Liaodong Peninsula,Northeast China:Constraints on the Evolution of the Mongol-Okhotsk and Pacific Tectonic Regimes

The tectonic setting of Jurassic magmatism in the Northeast China(NE China)is unclear.Here,we present new petrological,whole-rock geochemical,zircon U-Pb geochronological,and zircon Lu-Hf isotope data for Jurassic granitoids of the Wulong region,Liaodong Peninsula,NE China.Laser ablation-inductively coupled plasma-mass spectrometry(LA-ICP-MS)zircon U-Pb data indicate that these granitoids were emplaced at 165-156 Ma.The biotite monzogranite,two-mica monzogranite,monzogranite,granodiorite,biotite granodiorite,and syenogranite are strongly peraluminous(A/CNK=1.09-1.29),contain peraluminous minerals such as muscovite,have high normative corundum abundances(1.26 wt.%-3.28 wt.%),and have high K2_(O)/Na2O ratios(0.76-1.48),all of which indicate an S-type granite affinity.However,the biotite granodiorite and syenogranite have high Sr(391 ppm-570 ppm)and low Y(3.06 ppm-5.94 ppm)contents,with high Sr/Y(65.8-185.9)ratios,and the two-mica monzogranite,monzogranite,and granodiorite have relatively high Sr(138 ppm-379 ppm)and low Y(3.38 ppm-8.71 ppm)contents,with high Sr/Y ratios(19.1-77.9).All of the analyzed samples have negative zircon eHf(t)values(-41.4 to-20.6)with old two-stage Hf model ages(TDM2(Hf)=2.50-3.76 Ga).Therefore,we infer that the biotite monzogranite is the typical feature of S-type granite that was derived by partial melting of metagraywacke.The monzogranite,two-mica monzogranite,granodiorite,biotite granodiorite,and syenogranite exhibit geochemical characteristics of S-type granite with K-rich adakitic features,and were possibly derived by mixing of melts from clastic crustal materials and ada-kitic magmas.There are voluminous Jurassic igneous rocks in the NE China.By combining our study with the previous researches,this paper infers that the Jurassic magmatism within the Erguna-Xing'an Massif was related to the southward subduction and closure of the Mongol-Okhotsk Ocean;the Early Jurassic magmatism to the east of the Songliao Basin and in the northern North China Cra-ton(NCC)was related to the subduction of the Pacific Plate;however,the Middle-Late Jurassic igne-ous rocks to the west of the Songliao Basin were related to the closure of the Mongol-Okhotsk Ocean and,in the northern NCC,were related to closure of the Mongol-Okhotsk Ocean with an influence from flat-slab subduction of the Pacific Plate.

The magnetic properties of different genetic granitoids in Guangdong Province and its geological meaning

Granitoids constituted a major part of the continental crust and are closely related to many kinds of metallic mineral resources. The petrology, mineralogy and geochemistry of granitoids have long been studied, but the study of physical properties of different genetic granitoids and their geological meaning has not been done at all. The authors have made the study of magnetic properties of two genetic granitoids of Guangdong Province.

Late Paleozoic magmatism in South China:Oceanic subduction or intracontinental orogeny?

A gneissic granite with an U-Pb age of 313±4 Ma was found in northeastern Fujian Province,South China.It is an S-type granite characterized by high K2O,Al2O3 and low SiO2,Na2O contents with high A/CNK ratio of 1.22 for the whole rock.Zircons with stubby morphology from the gneissic granite yield 206 Pb/238 U ages ranging from 326 to 301 Ma with a weighted average age of 313±4 Ma,and negative εHf(t) values from -8.35 to -1.74 with Hf model ages (TCDM) of 1.43 to 1.84 Ga.This S-type granite probably originated from late Paleoproterozoic crust in intracontinental orogeny.Integrated with previous results on paleogeographic reconstruction of South China,the nature of Paleozoic basins,Early Permian volcanism and U-Pb-Hf isotope of detrital zircons from the late Paleozoic to early Mesozoic sedimentary rocks,we suggest the occurrence of a late Paleozoic orogeny in the eastern Cathaysia Block,South China.This orogenic cycle includes Late Carboniferous (340-310 Ma) orogeny (compression) episode and Early Permian (287-270 Ma) post-orogenic or intraplate extension episode.Therefore,the late Paleozoic magmatism in the southeastern South China probably occurred during the intraplate orogeny rather than the arc-related process.