Hua Xiang

Chinese Academy of Geological Sciences | CAGS · Institute of Geology

The generation and modification of silicic magma systems are essential processes in resolving the differentiation of continental crust. This understanding motivated the geochronological and geochemical study of the early Permian Hongliujing granite complex, consisting of quartz monzonite, granite, and leucogranite in the Central Tianshan microconti...

Appinite-granite suites commonly occur in the final stage of collisional orogenic processes, providing a unique opportunity to reveal the properties of continental lithospheric mantle and crust-mantle geodynamics. In this paper, we present a systematic study of the petrology, mineral chemistry, whole-rock geochemistry and geochronology of the Xiong...

The Kongur-Muztaghata-Maeryang terrane in NE Pamir is considered to be the western extension of the Songpan-Ganze terrane located in the northern Tibetan Plateau. The Kongur-Muztaghata gneiss dome (KMGD) is situated in the north while the Maeryang gneiss dome (MYGD) is in the south. The KMGD comprises Triassic granites and granitic gneiss in the co...

The Qilian orogen marks the northern boundary of the Proto-Tethys Ocean and consists of the North Qilian belt, the Central Qilian block and the South Qilian belt. The metamorphic P-T-t path of the Central Qilian block and the tectonothermal processes that affected it are crucial to understanding the closure of the ocean. This paper presents a syste...

The tectonic mechanism responsible for the Neoproterozoic magma generation at the northern margin of the Yangtze craton is crucial to understanding the assembly and breakup of the Rodinia supercontinent. Here, we present a systematic study of the petrology, whole-rock geochemistry and geochronology of mafic and felsic volcanic rocks from the Yaolin...

Zircon is a common accessory mineral in various rocks, especially in the crustal ones. It is the best mineral for U-Pb dating. Meanwhile, trace elements and isotopes of the mineral can also provide much information concerning the formation and evolution of rocks. There are a growing number of reports of zircon existing in mantle peridotite. However...

The Meso-Neoproterozoic Rodinia supercontinent formed a coherent large landmass, which was later dispersed over all current major continents and a number of microcontinents. The Qinling block is a Precambrian continental mass, located in the Qinling orogenic belt, which marks the junction of the North China and South China cratons. In this paper, w...

The Proto-Tethys Ocean existed from the Neoproterozoic through early Paleozoic during the breakup of Rodinia and was closed with the subduction and accretion of numerous East Asian blocks. The North Qinling Orogenic Belt is thought to have formed upon the closure of the Kuanping Ocean between the North China Craton and the Qinling Block. However, t...

锆石是各种岩石中常见的副矿物，不仅是最佳的定年矿物，且其微量元素、同位素还记录岩石形成演化过程的大量信息。锆石在地幔橄榄岩等超基性岩中的报道越来越多，但通常认为超基性岩SiO2不饱和，不太可能结晶锆石，导致其成因和来源常受质疑。本文通过热力学相平衡模拟，计算不同条件下岩石的SiO2活度与锆石/斜锆石转变线，以探讨SiO2活度的受控因素、锆石/斜锆石在超基性-基性岩特别是地幔橄榄岩中的稳定性，为解释地幔岩中出现的锆石成因和意义提供热力学依据。SiO2活度主要受控于稳定矿物组合及温压条件。在橄榄岩中，由于斜方辉石+橄榄石组合的缓冲作用使岩石具有较高的SiO2活度并维持在较小的变化范围内，且锆石稳定温度可达1500oC以上。橄榄岩在低温蛇纹石化过程中，蛇纹石取代橄榄石和辉石，SiO2活度会明显降低...

The availability of thermodynamic data for geologically relevant phases has made practical the calculation of stable phase relations throughout the mantle and crust of terrestrial planets. GeoPS (http://www.geops.org) is a program designed for this purpose in which both input and output are done through an intuitive graphical user interface. GeoPS...

The early Mesozoic evolution of the Lhasa terrane, which represents a major component of the Himalayan-Tibetan orogen, remains highly controversial. In particular, geological units and events documented either side of the eastern Himalayan syntaxis (EHS) are poorly correlated. Here, we report new petrological, geochemical and geochronological data...

Zircon double dating technique for U-Pb and fission track (FT) ages is used to reassess the cooling conditions for the Pingtan-Dongshan Metamorphic Belt (PDMB). Three Cretaceous gneissic bodies from the Chinmen area and two dioritic plutons from the Zhangzhou Igneous Complex (ZIC) in two sides of the Changle-Nanao fault are studied. U-Pb dating res...

Gonghe basin, located at the junction of Qinling, Qilian and Kunlun orogenic belts, records complex tectonic, magmatic, metamorphic and sedimentary events, and is a key area to study the tectonic and magmatic evolution of the northern Tibetan Plateau. In recent years, the discovery of high-temperature hot dry rocks (HDR) in Gonghe basin makes this...

The Qinling arc terrane (QAT) at the southern margin of the North Qinling Early Paleozoic orogen, Central China, is composed of gneiss domes overridden by cold allochthon nappes. The gneiss domes are characterized by migmatitic and plutonic cores of granite or gabbro and overlying upper amphibolite to granulite facies metamorphic sequences with per...

Early Paleoproterozoic rocks occur sporadically in the Sulu ultrahigh‐pressure (UHP) belt. The tectonic affinity and evolution of these rocks are still disputed. Two magmatic events (Early Paleoproterozoic and Neoproterozoic) and two metamorphic events (Late Paleoproterozoic and Triassic) were revealed by the zircon U–Pb ages and trace elements fro...

Middle- to high-grade metamorphic rocks exposed in the eastern Gangdese magmatic arc, southern Tibet, represent the middle and lower crust of the arc. These rocks are ideal carriers for studying the deep component and evolution of the magma arc. This paper presents a combined study of petrology, phase equilibrium modeling and geochronology of the p...

Although zircon U-Pb geochronometer has been widely used for dating metamorphism in moderate- to high-grade metamorphic rocks, it is still difficult to link the zircon U-Pb age to pressure and temperature (P-T) conditions. In this study, zircon trace elements and Hf isotopes and REE partitioning between zircon and garnet are adopted to track the fo...

Wuyishan is one of the most important terrains exposing the Precambrian basement of the Cathaysia Block, South China. Conventionally, Paleoproterozoic and Neoproterozoic sequences have been proposed in this terrain, however, the thermal histories affecting each unit within these sequences remain unclear. We report here spot analysis of 448 LA-ICPMS...

The Greater Himalayan Sequence and leucogranite forming the core of the Himalayan orogen provide an excellent natural laboratory in which to study processes related to crustal melting, granitoid formation, and the tectonic evolution of mountain belts. In contrast to most previous studies, which considered the Himalaya-aged granitoids as leucogranit...

The core of the Himalayan orogen consists of high-grade metamorphic rocks and leucogranites, and is a natural laboratory for studying collisional orogeny and plate-tectonics. This paper reviews recent research progress and controversies about metamorphism and partial melting of the orogenic core. The main contents are as follows: (1) the metamorphi...

Geohistory of the Yunkai massif in South China Block is important in understanding the geodynamics for the build-up of this block during the Phanerozoic orogenies. To investigate this massif, we conduct EMP monazite and U-Pb zircon geochronological determinations on mineral inclusions and separate for seventeen samples in four groups, representing...

Metamorphic P–T–t–D paths have been determined in the Yardoi gneiss dome of the eastern Himalaya that place new constraints on the genesis of the North Himalayan Gneiss Dome and tectonic evolution of the Himalayan orogen. Our study shows that the schists from the Yardoi dome underwent at least three stages of metamorphism and deformation. The first...

The leucogranites in the Higher Himalayan Sequence (HHS) provide a probe to elucidate the crustal melting of continental collisional orogen. An integrated geochemical and geochronological study of the Yadong leucogranites, southern Himalaya, shows that these rocks have relatively high SiO2 contents of 69.77 to 75.32 wt.% and alumina saturation inde...

Despite several decades of investigations, the nature and timing of the India-Asia collision remain debated. In the western Himalaya, the leading edge of the Indian continent was deeply subducted to mantle depths and experienced ultrahigh-pressure metamorphism in the Eocene at c. 50 Ma. In this paper, however, we demonstrate that the North Himalaya...

The Chinese Tianshan in the southwestern part of the Central Asian Orogenic Belt (CAOB) is characterized by a variety of high-grade metamorphic rocks, which provide critical constraints for understanding the geodynamic evolution of the CAOB. In this paper, we present detailed petrological and zircon U-Pb geochronological studies of the Weiya low-pr...

The Higher Himalayan Crystalline Sequences in the core of the Himalayan orogenic belt was produced by the Cenozoic collision of Indian and Asian plates, and record the history of formation and evolution of the orogenic belt. Here we present a detailed petrological and zircon U-Pb geochronological study of the pelitic granulitesfrom the Yadong area,...

Mesozoic magmatic rocks are ubiquitous in the Lhasa terrane, and understanding the petrogenesis and geodynamic implications of the magmatism may provide important constraints on the pre-Cenozoic geohistory of the Tibetan Plateau. In this paper, we report late Early Cretaceous mafic-felsic volcanics from the Lhasa terrane. Petrographic and whole-roc...

The Higher Himalayan Crystalline Sequence (HHCS) provides an excellent natural laboratory to study continental subduction, crustal melting and tectonic evolution of orogenic belt generated through the collision of India with Eurasia. Our petrological study and phase equilibrium modeling reveal that the pelitic migmatites in the HHCS of Yadong regio...

The Namche Barwa Complex exposed in the Eastern Himalayan Syntaxis, south Tibet, underwent the high-pressure (HP) and high-temperature (HT) granulite-facies metamorphism and associated anatexis. The HP pelitic granulites contain garnet, kyanite, sillimanite, cordierite, biotite, quartz, plagioclase, K-feldspar, spinel, ilmenite and graphite. These...

The Qinling orogenic belt experienced multiple phases of orogenesis during the Palaeozoic. Unraveling the timing and P–T conditions of these events is the key to understanding the convergence processes between the South China and the North China Blocks. The Songshugou Complex, located in the southern part of the North Qinling orogenic belt, has reg...

The Gangdese magmatic arc, southeastern Tibet, was built by mantle-derived magma accretion and juvenile crustal growth during the Mesozoic to Early Cenozoic northward subduction of the Neo-Tethyan oceanic slab beneath the Eurasian continent. The petrological and geochronological data reveal that the lower crust of the southeastern Gangdese arc expe...

We report here for the first time the occurrence of sapphirine-bearing granulites within the Qinling Group of the Qinling-Tongbai orogen and provide robust evidence for extreme crustal metamorphism at ultrahigh-temperature (UHT) conditions. We document the UHT indicator of sapphirine and spinel in a mafic granulite consisting of orthopyroxene, biot...

The Jadeite rocks, which usually produced by the interaction between subduction-related fluids and ultramafic rocks (peridotite), are generally occurs in serpentinized ultramafic rocks in oceanic subduction zones. The Myanmar jadeitite is the largest and most important jadeitite deposits in the world, which occurs in a distinctive tectonic unit of...

The Dunhuang block, which constitutes the northeastern segment of the Tarim Craton, is located between the Central Asian Orogenic Belt (CAOB) to the north and the Altyn─Qilian Orogenic Belt to the south. The present study reveals that the early Paleozoic HP mafic granulites from the Dunhuang block underwent four stages of metamorphism: prograde amp...

The Chinese Tianshan occupies the southernmost part of the Central Asian Orogenic Belt (CAOB). High-grade metamorphic rocks are widely distributed in its central uplift zones, composing the crustal basement of the Central Tianshan Block of the Chinese Tianshan. However, the origin of the crustal basement and whether the high-grade metamorphism was...

The Gangdese batholith of the southern Tibet is regarded as a principal component of the pre-Himalayan collision, Andean-type continental margin. However, the Gangdese arc root remains poorly understood because most of previous studies concentrated on granitoids from the middle and upper crust of the arc. In this paper, we report new petrochemical...

In this paper, we report the Paleoproterozoic ultrahigh-temperature pelitic granulites from the northern segment of Sulu ultrahigh-pressure metamorphic belt. The pelitic granulites occur as interlayer within other metamorphic supracrustal rocks, such as marble, calc-silicate rock and gneiss. In turn, these rocks together occur as larger lens within...

The Jadeite rocks, which usually produced by the interaction between subduction-related fluids and ultramafic rocks (peridotite), are generally occurs in serpentinized ultramafic rocks in oceanic subduction zones. The Myanmar jadeitite is the largest and most important jadeitite deposits in the world, which occurs in a distinctive tectonic unit of...

High-grade metamorphic rocks in North Qinling orogen, traditionally regarded as the Qinling Group, consist of eclogites, high pressure granulites, medium-low P/T granulite-amphibolite facies metamorphic rocks and experienced intensive migmatization. This paper presents a combined study of CL image, LA-ICP-MS U-Pb age, and trace element of zircon in...

The Beishan orogenic collage represents a major part of the southern Central Asian Orogenic Belt (CAOB), which is a tectonically significant region between the Tianshan orogen and the Solonker Suture Zone. It would provide important clues for examining the accretionary orogenic processes of the CAOB and the final closure event of the Paleo-Asian Oc...

The metamorphic belt in the Basongco area, the eastern segment of Lhasa terrane, south Tibet, occurs as the tectonic blocks in Paleozoic sedimentary rocks. The Basongco metamorphic rocks are mainly composed of paragneiss and schist, with minor marble and orthogneiss, and considered previously to be the Precambrian basement of the Lhasa terrane. Thi...

The Nyingchi complex, forming the eastern segment of the Gangdese magmatic arc, occurs within the southern Lhasa terrane in south Tibet, and is composed dominantly of plutons and their metamorphosed equivalents. Together with some metasedimentary units these rocks record multiple Mesozoic and Cenozoic magmatic and metamorphic events during northwar...

The Namche Barwa complex ( NBC) in Eastern Himalayan Syntaxis, is generally interpreted as a part of the Higher Himalayan CrystaUine Series. The Namche Barwa complex experienced high pressure ( HP) metamorphism during the deep subduction of the Indian continent beneath Eurasian continent. In this paper, based on petrology and mineral chemistry, pha...

The Lhasa terrane in southern Tibet has long been accepted as the last crustal block accreted with Eurasia prior to its collision with the northward drifting of Indian continent in the Cenozoic. Thus, the Lhasa terrane is the key to studying the origin and evolution of the Tibetan Plateau. The Lhasa terrane experienced multistage metamorphism, whic...

The Himalayan orogen formed in response to ongoing continental convergence between the India and Asia that began as ca. 55Ma, and is the largest active orogen in existence and provides a nature laboratory for studying plate tectonics. High-pressure (HP) and ultrahigh-pressure (IMP) metamorphic rocks occur in the core segment of Himalayan orogen. Th...

The jadeitite that occurs in Myanmar is one of the largest and most important jadeite deposits in the world. However, the formation age of the Myanmar jadeitite remains poorly constrained. Here, we conduct an integrated study using petrology and 40Ar/39Ar geochronology to analyze the Myanmar jadeitite. Petrological observations show that the studie...

The in-situ EMP (electron microprobe) monazite age dating performed directly in the polished sections, in addition to the conventional U-Pb zircon and EMP monazite age dating on grains from heavy mineral concentrates, has been applied to the granulite, charnockite and gneiss in the Gaozhou Complex of the Yunkai massif in South China. While the conv...

Recognition of multiple metamorphic events can provide essential evidences to constrain the evolution history of a polycyclic orogen. The basic rocks in the Songshugou area have recorded two metamorphic events in Eopaleozoic, which is an important "fingerprint" to study the evolution of North Qinling. The field work and petrology research show that...

Mafic and semi-pelitic granulites from the Qinling-Tongbai orogen in central China preserve petrological evidence and mineral paragenesis suggesting four distinct stages of metamorphic evolution. The prograde history (M1) is recorded by the occurrence of cordierite, orthopyroxene and biotite inclusions in garnet porphyroblasts of the peak-metamorph...

The fluid rock interactions and fluid circulations in subduction zone have been a focus for geologists. As a kind of high grade gem material, the genesis of jadeite rocks attracts an increasing concern. The jadeite rocks generally occur in the serpentinized ultramafic rocks in subduction zones and its formation is related to the interaction between...

U–Pb ages, trace elements, and Hf isotope compositions of zircons from the Mayuan migmatite complex in NW Fujian province have been determined to provide constraints on the source and genesis of anatexis and tectonothermal evolution related to the Caledonian orogeny in South China. The migmatites investigated consist of various amounts of mesosome,...

The recently discovered large Nanpu Oilfield is located in the NW part of the Bohai Bay Basin, eastern China. Extensive drilling and geophysical research have revealed widespread occurrence of Eocene to Miocene mafic volcanic rocks. On the basis of stratigraphic constraints, three cycles of volcanism have been recognised. Petrological and geochemic...

Foliated (garnet-bearing) (FGB) granites are associated closely with and are usually the major wall rocks of the high-pressure (HP) and ultrahigh-pressure (UHP) metamorphic rocks in the Tongbai-Dabie region, the mid segment of the Qinling-Dabie-Sulu orogenic belt in central China. These granites appear either as small plutons or as veins, which com...

LA-ICP-MS U-Pb dating of metamorphic zircons from mafic granulites in northern Tongbai area yielded weighted mean 206Pb/238U concordia age of 418.7±3.2Ma. Detailed studies on petrology and mineralogy of the mafic granulites indicate that the peak metamorphic condition was at 880~900 °C and ca. 1.1GPa. According to the Zr saturation model, Zr was no...

Detailed studies on zircons from the Jianfengling granite in the Baolun gold deposit indicate that the zircons can be divided into magmatic and hydrothermal zircons. The magmatic zircons are colorless, transparent, prismatic, euhedral crystal with few inclusions, and have moderate U, Th contents (mostly less than 1000 μg/g). LA-ICP-MS U-Pb analyses...

Abstract U–Pb age, trace element and Hf isotope compositions of zircon were analysed for a metasedimentary rock and two amphibolites from the Kongling terrane in the northern part of the Yangtze Craton. The zircon shows distinct morphological and chemical characteristics. Most zircon in an amphibolite shows oscillatory zoning, high Th/U and 176Lu/1...

Mineralogical characteristics of gold in the Baolun gold deposit were investigated by u- sing optical microscopy, X-ray diffraction (XRD) and electron probe microanalysis (EPMA) methods. The results showed that metal minerals in the ore were mainly pyrite and pyrrhotite, with minor amounts of chalcopyrite, sphalerite, arsenopyrite and galenite, whi...

A combined study of zircon LA-ICP-MS U-Pb dating, trace elements and Hf isotope was carried out for gneissic granite from the Sanzhishu area in Jingning, SW Zhejiang Province. Nearly all the zircons separated from the granite exhibited oscillatory zoning and high Th/U ratios (>0.1). The REE profile showed a pronounced positive Ce anomaly, negative...

LA-ICP-MS U-Pb dating of metamorphic zircons from mafic granulite in northern Tongbai area yielded weighted mean 206PbZ238U concordia age of 418. 7 ±3. 2Ma. Detailed studies on petrology and mineralogy of the mafic granulites indicate that the peak metamorphic condition was at ca. 845°C and ca. 0. 85GPa. According to the Zr saturation model, Zr was...

LA-ICP-MS U-Pb dating of metamorphic zircons from mafic granulite in northern Tongbai area yielded weighted mean 206PbZ238U concordia age of 418. 7 ±3. 2Ma. Detailed studies on petrology and mineralogy of the mafic granulites indicate that the peak metamorphic condition was at ca. 845°C and ca. 0. 85GPa. According to the Zr saturation model, Zr was...

The upper basement of the Cathaysia block in Zhejiang and Fujian provinces consists mainly of the Neoproterozoic Longquan Group, Mamianshan Group, and Wanquan Group. These three groups exhibit similarity in rock assemblage as well as major and trace elements geochemistry. They are the main components of the uniform upper basement of the Cathaysia b...

A combined study using LA-ICP-MS U-Pb dating, Hf isotopes, trace elements and the Ti-in-zircon geothermometer was carried out on zircons from the metamorphosed basic-ultrabasic rocks in the metamorphic basement of the Cathaysia Block, southwestern Zhejiang Province. The formation and metamorphic ages of the rocks from the metamorphic basement of th...

A suite of migmatiles and related granites from northwestern Fujian Province ( South China) were studied in order to explore their linkage in formation. Detailed studies Of lithology and geochemistry including zircon U-Pb geochronology suggest that the migmatites were derived from the syn-deformational crustal anatexis. The Original granitic melts...

A combined study of zircon U-Pb dating, Hf isotopes and trace elements has been carried out for granodioritic neosomes of migmatites from the Tianjingping area in northwestern Fujian Province. Zircons are characterized by zoning, higher Th/U ratios (mostly ⩾0.1), HREE enrichment, and positive Ce and negative Eu anomalies, and show features similar...

The upper Precambrian basement of the Cathaysia block in southwestern Zhejiang and northwestern Fujian Provinces was mainly composed of Longquan Group, Mamianshan Group and Wanquan Groups. The contrastive study suggested that the assemblage, geochemical characteristics and formation age of the three groups were similar, and therefore, they can be c...

Proterozoic magmatism along the margin of the Yangtze Block is extensive and provides important evidence in the plate tectonic reconstructions for the Proterozoic. The Bikou Terrane on the northwestern margin of the Yangtze Block consists of complex Archean to Paleozoic metamorphosed sedimentary and volcanic sequences, intruded by several mafic-int...