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The Neoproterozoic sedimentary strata in the central Jiangnan Orogen of South China are separated into the Lengjiaxi and Banxi groups by a mid-Neoproterozoic angular unconformity. This unconformity, previously interpreted as the evidence of continental collision between the Yangtze and Cathaysia blocks, is crucial for understanding the Neoproterozoic tectonic regime in the South China Craton. Here we report U-Pb ages and in situ Lu-Hf isotopes of detrital zircon grains from the sedimentary rocks near this unconformity. Zircon grains in meta-sandstone samples collected from the top part of Lengjiaxi Group yield maximum depositional ages of ∼827 Ma, ∼828 Ma and 836 Ma, and combined with other available age data, we suggest that the upper limit of the sedimentation for Lengjiaxi Group is at ca. 825 Ma. Zircon U-Pb analysis for two sandstone samples collected from the bottom of Banxi Group and Nanhuan strata yields two youngest ages of 797 Ma and 719 Ma, marking the initial depositional ages for these strata. All the samples contain abundant Neoproterozoic euhedral zircon grains, suggesting their near-source provenance. The Hf isotopic model ages of detrital zircons with positive εHf(t) values reveal two periods of juvenile crustal growth at 1.5–0.9 Ga and 2.8–1.6 Ga in the Yangtze Block. Several grains display core-rim structure with ages of rim part ranging from 864 to 851 Ma. We correlate these metamorphic ages with the amalgamation of Yangtze and Cathaysia blocks in the central segments. Our data in combination with those from other studies suggest that a back-arc basin existed in the central Jiangnan belt during ca. 860 Ma to ca. 825 Ma. We propose a four-phase crustal evolution model for the central Jiangnan belt. [ABSTRACT FROM AUTHOR]

Debate on whether the Early Paleozoic tectono-magmatic event in South China is related to a subduction–collision or an intracontinental orogen has been lasted for decades within the geoscience community. This study deals with LA-ICP-MS zircon U–Pb ages, whole-rock chemistry, rare earth elements, trace elements and Hf isotopes from granitoid samples collected in the Yunkai domain in order to better constrain the Early Paleozoic tectonic evolution of the South China Block. The weighted mean 206 Pb/ 238 U ages for eight samples range from 426 Ma to 443 Ma, representing the crystallization ages of the magma. Fourteen samples were analyzed for geochemistry, all of which are characterized by a peraluminous signature with A/CNK values greater than 1.0. The REE geochemistry reveals enrichment in light rare earth element. LREE/HREE values range from 2.81 to 30.36 and (La/Yb) N vary from 1.23 to 55.14 (mean of 14 analyses is 14.69). All the samples exhibit distinct negative Ba, Sr and Nb anomalies and enrichment in Rb, Th, U and Pb. Hf isotopic analyses indicate negative εHf (t) values mainly ranging from − 3 to − 12, corresponding to two model age distributing from 1637 Ma to 2208 Ma. The geochemical analyses indicate that the Silurian granitic magmas in the Yunkai domain were derived from partial melting of crustal materials with little or no input of mantle source. These new data support the intracontinental subduction model already proposed to account for the Early Paleozoic tectonic, metamorphic and magmatic event of South China. [ABSTRACT FROM AUTHOR]

The link between two tectono-magmatic events during Early and Late Mesozoic periods in the Nanling Belt of South China remains debated. Here we present zircon U–Pb geochronology, Hf isotopes and whole-rock geochemistry of granitic intrusions from Zhuguangshan in the Nanling Belt. The zircon data exhibit two magmatic episodes with 206 Pb/ 238 U ages of ca. 230 Ma and 150 Ma, representing the Indosinian (Early–Middle Triassic period) and Early Yanshanian (Jurassic–Cretaceous period) events, respectively. The Indosinian granites are characterized by strongly peraluminous nature with high A/CNK values (> 1.1), whereas the Early Yanshanian granites are weakly peraluminous (average A/CNK value of 1.06). Although the Early Yanshanian granites bear higher HREE contents and lower LREE/HREE ratios, the two-phase granites show enrichment in LREE, Rb, Th, U and Pb, depletion in Eu and negative Ba, Sr, Nb and Ti anomalies. All samples show variably negative ε Hf (t) values (− 5 to − 16) with two-stage Hf model ages clustered around 1.8–2.1 Ga. Our data indicate that the two-phase granitic magmas were generated from the partial melting of early Paleoproterozoic basement rocks with no input of mantle material. Combined with other geological evidence, we infer that the Indosinian tectono-magmatic event was closely related to intracontinental orogeny triggered by collisions along the boundaries of South China Craton, in relation to processes associated with the E–W trending Tethys tectonic domain. We envisage that the Early Yanshanian event might be a response to the back-arc extension of NW-directed paleo-Pacific plate subduction. The Nanling Belt is a critical zone that records the transformation from Tethys to paleo-Pacific tectonic regimes. [ABSTRACT FROM AUTHOR]

The late Early Paleozoic and Early Mesozoic tectonic events in South China have been central to the debate over plate subduction versus intracontinental orogeny. Here we present zircon U–Pb geochronology, Hf isotopes and whole-rock geochemistry of six representative granitic plutons from South China. The zircon data show two groups with 206 Pb/ 238 U ages of ca. 430 Ma and 225 Ma, representing the crystallization ages of magma. The six plutons investigated in this study are characterized by peraluminous nature with high A/CNK values (> 1.1) and the presence of aluminous minerals like muscovite. They exhibit enrichment in LREE, depletion in Eu, negative Ba, Sr, Nb and Ti anomalies and enrichment in Rb, Th, U and Pb. All samples show variably negative ε Hf (t) values (− 2 to − 16) with two-stage Hf model ages clustered around 1.5–1.8 Ga. These data indicate that both the Early Paleozoic and Early Mesozoic granitic magmas were generated by the partial melting of early-middle Paleoproterozoic basement rocks without significant input of mantle material. The distribution of all the plutons with ages around 430 Ma and 225 Ma are unrelated to subduction tectonic regime. Combining with other geological evidence, our study suggests that the tectono-magmatic events during late Early Paleozoic and Early Mesozoic were largely related to intracontinental orogeny triggered by interactions between the Yangtze and Cathaysia continental blocks. The far-field stress propagation derived from the South China plate boundary might have played a crucial role as the primary cause of the stress field within the continental interior of the South China Craton. [ABSTRACT FROM AUTHOR]

The Central Asian Orogenic Belt is an accretionary orogen with many distinct terranes including the Chinese Central Tianshan, whose Precambrian tectonic affinity is not yet clearly known. We present Precambrian age spectra of inherited/xenocrystic zircons from magmatic rocks in the Chinese Central Tianshan, collected from published papers. The age patterns are dominated by zircons with ages ranging from 3261 to 541 Ma. These spectra provide robust clues regarding the Precambrian affinity of the Chinese Central Tianshan. The age spectra record two major tectonothermal events, represented by salient age peaks of c. 950 and 900 Ma within the ‘Grenville Orogeny’ period, and age peaks at c. 750 and 630 Ma, synchronous with magmatic events corresponding to Rodinia break-up. These results are consistent with the hypothesis that the Chinese Central Tianshan was part of the Tarim craton during Precambrian time as well as documenting its incorporation into, and separation from the Rodinia landmass. [ABSTRACT FROM AUTHOR]

Abstract: The Jiangnan Orogen, the eastern part of which comprises the oceanic Huaiyu terrane to the northeast and the continental Jiuling terrane to the southwest, marks the collision zone of the Yangtze and the Cathaysia Blocks in South China. Here, zircon U–Pb geochronological and Lu–Hf isotopic results from typical basement and cover meta-sedimentary/sedimentary rock units in the eastern Jiangnan Orogen are presented. The basement sequences in southwestern Huaiyu terrane are mainly composed of marine volcaniclastic turbidite, ophiolite suite and tuffaceous phyllite, whereas those in the northeastern Huaiyu consist of littoral face pebbly feldspathic sandstones and greywacke interbedded with intermediate-basic volcanic rocks. Combined with previous studies, the present data show that the basement sequences exhibit arc affinities. Zircons from the basement phyllite in the southwestern margin of the Huaiyu terrane, representing a Neoproterozoic back-arc basin, yield a single age population of 800–900Ma. The basement greywacke from northeastern Huaiyu terrane, representing fore-arc basin, is also characterized by zircons that preserve a single tectono-thermal event during 800–940Ma. However, the late Neoproterozoic cover sequence preserves zircons from multiple sources with age populations of 750–890Ma, 1670–2070Ma and 2385–2550Ma. Moreover, Hf isotopic data further reveal that most detrital zircons from the basement sequences yield positive εHf(t) values and late Mesoproterozoic model ages, while those of the cover sequence mostly show negative εHf(t) values. The Hf isotopic data therefore suggest that the basement sequences are soured from a Neoproterozoic arc produced by reworking of subducted late Mesoproterozoic materials. The geochronological and Hf isotopic data presented in this study suggest ca. 800Ma for the assembly of the Huaiyu and Jiuling terranes, implying that the amalgamation of the Yangtze and Cathaysia Blocks in the eastern part occurred at ca. 800Ma. [Copyright &y& Elsevier]

The bimodal association of basalts and rhyolites in the Hongshankou area of the East Tianshan area (NW China) provides an important suite to investigate magma petrogenesis and tectonics evolution in a convergent margin setting. In this study we present petrological, geochemical and zircon U–Pb geochronological data from the basalts and rhyolites. Zircons from the basalts yield crystallization ages of 347.1±3.9Ma whereas those from the rhyolites are dated as 344.4±1.9 and 345.0±2.5Ma. The major and trace element signatures of basalts suggest high alumina basalt (HAB) as the source magma which was generated from metasomatised asthenosphere mantle. Both the mafic and felsic rocks are enriched in light rare earth elements (LREE) and large ion lithophile elements (LILE), and are depleted in high field strength elements (HFSE). Broadly homogenous Rb–Sr and Sm–Nd isotopic compositions of mafic and felsic rocks are also characteristic. The basalts display a distinct enrichment in incompatible elements and positive εNd(345Ma) (from +5.87 to +8.25). We envisage a subduction-related origin to account for the LILE enrichment with arc-like melts (enriched in Th and LREE and depleted in Nb, with εNd(345Ma)>+6) produced through the partial melting of a depleted-mantle source, and the involvement of minor crustal component. The rhyolites also display high εNd(345Ma) (from +6.35 to +8.53). Consequently, we suggest a mixing process between a source similar to mid-ocean ridge basalt (depleted end-member mantle) and arc-like magmas for the petrogenesis of the mafic rocks, whereas the rhyolites are best interpreted to have formed by fractional crystallization from the parental magma of the basalts. Several lines of evidence from elemental and isotopic geochemistry suggest a close genetic relationship between the mafic and felsic rocks in the Hongshankou bimodal suites. We propose that the essentially bimodal character of this complex reflects the features of back-arc extensional magmatism, induced by the subduction of the Junggar plate during the Late Paleozoic. [ABSTRACT FROM AUTHOR]

Abstract: The Central Tianshan, which is proposed to be part of the Tarim Block during Precambrian time, holds a pivotal role in the evolution of the Central Asian Orogenic Belt. In this study we employ detrital zircon age spectra to probe the Precambrian history of the region and to evaluate the link with the Proterozoic supercontinents. Detailed U–Pb zircon age data are reported for detrital zircons from Neoproterozoic metasedimentary rocks in the Baluntai region, the heartland of Central Tianshan. The metasediments here are dominated by zircons with major age populations of 2544–2394Ma, 1900–1500Ma, 1070–752Ma, ca. 560Ma and ca. 445Ma. The 2544–2394Ma ages correlate with the generation of continental nuclei in Tarim. The tectonothermal events during the periods of 1900–1500Ma and 1070–752Ma correspond to the assembly and breakup of the Columbia and Rodinia supercontinents. The magmatic ages represented by the age peak at ca. 560Ma correlate with those reported from the Late Neoproterozoic–Cambrian orogens in different fragments of the Gondwana supercontinent. The youngest age peak of ca. 445Ma is interpreted to represent the Caledonian orogenic event in Central Tianshan that is linked to the history of the Central Asian Orogenic Belt. Recyling of ancient crustal materials dominated, with minor input of juvenile materials during the above time intervals, with exception at ca. 2460Ma when significant addition of juvenile material occurred. A combination of U–Pb dating and Hf-isotope data in our study reveals that Central Tianshan was a part of the Tarim Block. [Copyright &y& Elsevier]

Abstract: The Late Carboniferous to Permian marks an important phase of terrane amalgamation through accretion–collision in the Central Asian Orogenic Belt (CAOB). The Tianshan Belt forms part of this sequence, where the post-collisional event generated an E–W trending bimodal volcanic zone that extends for ca. 500km from the southern Bogda Mt. to the easternmost Tianshan Belt. Here we report the petrology, geochemistry and geochronology of the bimodal volcanic rocks to characterize the post-collisional tectonic evolution in Late Paleozoic. The major element chemistry of the basalt and rhyolite samples indicates a bimodal high-K calc-alkaline affinity. The basalts are characterized by high abundance in TiO2, Th, U and Pb and depletion in Nb, Ta and P, together with slight enrichment in LREE contents and low HFSE/LREE ratios. The rhyolites show a close affinity to aluminous A-type granites, with enrichment in K+Na, Zr, Ce, Y, and depletion in P, Nb, Ta and Ti. They also exhibit fractionated REE patterns with prominent negative Eu anomalies. The petrographic and geochemical data suggest that this bimodal rock series was generated in a post-collisional setting. The mafic rocks are likely derived from a metasomatized lithospheric mantle. Assimilation of different crustal components played a minor role in the genesis of these basaltic rocks. The LA-ICP-MS analysis on zircons from four rhyolites and two basalts yielded similar ages ranging from 295.8±2.8 to 293.3±1.7Ma, suggesting an Early Permian event. Zircons from the basalts show a wide εHf(t) range from −0.49 to +13, whereas those from the rhyolites show two groups of εHf(t) values: from −5 to 3 and from 6 to 12, suggesting a mixing of crust–mantle material. The magmatic zircons from the bimodal volcanic rocks yielded two peaks of TDM2 between 600–820Ma and 1160–1360Ma, probably representing two significant episodes of continental crust growth. The bimodal volcanic rocks are correlated with the early stage of post-collision. Our results suggest that vertical crustal growth through mantle-derived magmas in post-collisional setting also played a major role in the construction of the CAOB. [Copyright &y& Elsevier]

This paper describes an olistostrome formation and accompanied bimodal volcanic rocks occurring in the Baiyanggou area, south of Bogda Shan. The main lithotectonic units consist of olistostrome, volcanic rocks and turbidite. The olistostrome is tectonically underlain by Upper Carboniferous limestone and sandstone along a NEE-trending detachment fault. Paleo-growth fault is locally observed. The olistostrome unit includes plenty of blocks of limestone, sandstone, rhyolite and volcaniclastic rocks, and a matrix of graywacke. Limestone blocks are dated as Pennsylvanian-Bashkirian in age by the coral and brachiopod fossils that are extensively recognized in the Upper Carboniferous strata. The volcanic unit consists of pillowed and massive basalt and rhyolite, the latter occur as an 8- to 10-meter-thick layer above the olistostrome unit. The turbidite unit is mainly composed of chert, siliceous mudstone and sandstone, within which the Bouma sequence can be locally recognized. Meter-wide gabbro and diabase dykes intrude these three units. Geochemically, rhyolites are characterized by high ACNK value of >1.1, depletion of Ba, Nb and Sm, and enrichment in Rb, Th and Zr. Basaltic rocks are rich in KO, they show a LREE-enriched pattern and depletion in Ba, Nb and Zr, and enrichment in Ti, Ce and Hf, similar to continental rift-type tholeiite series. A gabbro porphyrite intruding the olistostrome was dated at 288 ± 3 Ma by a sensitive high-resolution ion microprobe (SHRIMP) zircon U-Pb method, and a rhyolite at 297 ± 2 Ma by a laser ablation inductively coupled plasma mass spectrometer (LA-ICPMS) zircon U-Pb method. The Baiyanggou olistostrome and accompanying bimodal volcanic series are linked to an extensional setting that developed in the south of the Bogda Shan. Several lines of evidence, e.g. occurrence of large-scale strike-slip shear zones, large number of mantle-derived magmatic rocks and available geochronological data, demonstrate a significant geodynamic change from convergence to extension in the Chinese Tianshan belt, even in the whole Central Asian Orogenic Belt. The extension in the Chinese Tianshan belt is initiated at ca. 300 Ma, i.e. around Carboniferous-Permian boundary times, and the peak period of intra-plate magmatism occurred in the interval of 300-250 Ma. [ABSTRACT FROM AUTHOR]

Abstract: This paper reports some new results from U–Pb geochronological, Hf isotopic and REE geochemical studies of detrital zircons in the Ordovician sandstones from South Jiangxi within Cathaysia. 426 groups of U–Pb age determinations define five major age populations: 2560–2380Ma (a peak of 2460Ma), 1930–1520Ma (a peak of 1700Ma), 1300–900Ma (a major peak at 970Ma and two subordinate peaks at 1250Ma and 1130Ma), 850–730Ma (a prominent peak of 780Ma) and 670–530Ma (a major peak at 540Ma and a subordinate peak at 650Ma). We also report zircon U–Pb concordia age of 3.96Ga, which is the oldest age so far obtained from Cathaysia. The age peak at 2460Ma correlates with similar ages reported for Neoarchean global continental growth. The 1930–1520Ma population broadly overlaps with the time of amalgamation and disruption of the Columbia supercontinent. The major age peak at 970Ma and two secondary peaks at 1250Ma and 1130Ma reflect multiple tectonothermal events associated with the assembly of Rodinia. Similar ages are widely reported from the South China Craton (SCC). Our study reveals that the 850–730Ma population is consistent with the breakup period of Rodinia, suggesting that the SCC within Rodinia began to break up since 850Ma. Geologically, the evidence for this breakup event is widespread and presented by Neoproterozoic granites, bimodal igneous rocks, basic dyke swarms and formation of continental rift type basins. Our study also reveals a 670–530Ma population that correlates well with the assembly of Gondwana during end Neoproterozoic. However, direct geological evidence for this event has not yet been found within the studied area. Furthermore, the Hf isotopic model age data suggest two major stages of crustal evolution within Cathaysia. The first is the event dated at 1.6–2.8Ga and the second one at 3.5–3.9Ga. The zircons show a large range of εHf(t) values from +8.64 to −30.54, suggesting that they have different origins with a similar age of crystallization. The fact that most detrital zircons show negative εHf(t) values suggests the ancient provenances of Cathaysia were dominated by reworked crustal materials. [Copyright &y& Elsevier]

Five volcanic rock samples and two granite samples taken from the volcanic basins in western Fujian and southern Jiangxi were dated by using the zircon laser albation-inductively coupled plasma mass spectrometry U-Pb method. Together with previously dated ages, the dates obtained provide important constraints on the timing of late Mesozoic tectonic events in SE China. The volcanic rock samples yield ages of 183.1±3.5 Ma, ca. 141 Ma to 135.8±1.1 Ma, 100.4±1.5 to 97.6±1.1 Ma, confirming three episodes of late Mesozoic volcanic activities, which peaked at 180±5 Ma, 140±5 Ma and 100±5 Ma, respectively, along the Wuyishan belt. Moreover, based on field investigations of these volcano-sedimentary basins, we have recognized two compressional tectonic events along this belt The early one was characterized by Upper Triassic to Middle Jurassic NNE-trending folds that were intruded by late Jurassic granites; and the late one caused the Lower Cretaceous volcano-sedimentary layer to be tilted. The dated age 152.9±1.4 Ma of the granitic samples from the Hetian granitic pluton in the Changting Basin and that from the Baishiding granitic pluton, 100.2±1.8 Ma, in the Jianning Basin, give the upper boundaries of these two tectonic events respectively. Hence, the late Mesozoic tectonic evolution of SE China was alternated between extension and compression. [ABSTRACT FROM AUTHOR]

• Magnetic fabrics of the two plutons can be divided into primary magmatic and secondary post-solidus ones. • The magma probably intruded into the weak zone within the Sibao group, then laterally and upward accreted to construct dome shaped plutons. • S-type granitic magma emplacement probably marked the latest stage of the Jiangnan Orogeny. The Neoproterozoic S-type granitic plutons, distributed along the suture zone of the Yangtze and Cathaysia blocks, play an important role in the tectonic evolution of the Jiangnan Orogeny. However, few studies had focused on the scientific issues on the physical construction process of these plutons, therefore, we carried out multidisciplinary approaches on the Sanfang and Yuanbaoshan plutons in the western Jiangan Orogenic Belt to figure out the construction mechanism of these plutons. Zircon Hf and U-Pb dating indicates that the magma, originated from the crustal partial melting, was crystallized at ca. 830 Ma. Field investigation shows that the plutons are dome shaped, and the inclinations of bedding/foliation of the country rocks, the Sibao group, gradually decreases away from the contact zone with pluton boundaries. A top-to-the–E kinematic sense was observed in the eastern margin of the Yuanbaoshan pluton. Both the textural analysis and AMS measurement reveal primary magmatic and secondary general top-to-the-W/NW post-solidus fabrics. The Bouguer gravity modeling reveals that the feeder zone probably locates in the southern part of each pluton and these two plutons are connected at depth. According to the primary magmatic fabric patterns, deep geometric shape as well as structural features of the country rocks, we propose that crustal partial melting magma probably initially intruded into the pre-existing mechanically weak (fold/fault) zone of the Sibao group, and meanwhile laterally and upward accreted to progressively construct the dome-shape plutons. The intrusion of ca. 850–820 Ma S-type granites in the Jiangnan region possibly marked the latest stage of the Jiangnan Orogeny. However, the timing and mechanism of the post-solidus deformation are not well constrained, the proposed interpretations remain hypothetical yet. [ABSTRACT FROM AUTHOR]

Abstract: The Kuruktag uplift is located to the north of the Tarim Block, NW China. At the western end of the Kuruktag uplift, mafic dykes crop out in the Korla area, which were rarely subjected to deformation and metamorphism in contrast to their metamorphic wall-rocks that were strongly deformed and metamorphosed to amphibolite facies. A SHRIMP U–Pb zircon age of 634Ma was obtained for a spessartite dyke, documenting the youngest known igneous activity associated with rifting in the Tarim Block during the Neoproterozoic. Most samples of the Korla mafic dykes show clear enrichments in Th, La, and variable depletions in Nb, Ta and Ti, except for samples 08T-14 and 08T-19 that display incompatible element distribution patterns similar to those of OIB without obvious depletions in Nb, Ta and Ti. The geochemical signatures suggest that the Korla mafic dykes were formed in an intra-plate setting and their primary magama was possibly produced by partial melting of a sub-continental lithospheric mantle that has been metasomatized by previous subduction processes, and then heated by a rising mantle plume. In combination with previous geochronological data of Neoproterozoic igneous rocks throughout the Tarim Block, at least three pulses of magmatic activity, from ca. 830 to 800Ma, from ca. 790 to 740Ma and from ca. 650 to 615Ma, are recognized, which reveal that multiple episodes of rifting occurred within the Tarim Block, implying that the breakup of the Rodinia supercontinent in the Tarim Block may have been a long-lasting process. [Copyright &y& Elsevier]

Abstract: U–Pb geochronology and Lu–Hf isotopic studies on detrital zircons from late Neoproterozoic sediments of the Cathaysia block, South China, show abundant Grenville-age (∼1.0Ga) and Neoarchaean populations, and minor Eoarchaean (∼3.8Ga), Paleo- to Mesoarchaean (3.3–3.0Ga), Mesoproterozoic (1.7–1.4Ga) and Pan-African (0.70–0.54Ga) populations. This is the first report of ∼3.8Ga material in the crust of the Cathaysia block. The presence of euhedral ∼1.0Ga zircons indicates that a Grenville orogenic belt was within or very close to the southern Cathaysia block. However, the provenance containing the ∼3.8Ga, 3.3–3.0Ga, ∼2.5Ga, ∼1.0Ga and 0.70–0.54Ga zircon populations cannot be found in the South China Block; the combination of zircon age distributions and the rounded, strongly abraded shapes of the Archean zircons suggesting long transport is consistent with derivation from other continental terranes previously linked with the southern part of the South China Block. Comparison with the tectono-magmatic history and compositions of rocks in western Laurentia – eastern Australia and eastern India – East Antarctica – western Australia, we suggest that these late Neoproterozoic sediments may have originated mainly from Eastern India-East Antarctica. This indicates that the South China Block was linked with the Eastern India - East Antarctica continents in the late Neoproterozoic rather than being located between the western Laurentia and eastern Australia continental blocks. U–Pb and Hf-isotope studies on detrital zircons provide an important independent constraint on the palaeogeography of the South China Block in the context of the breakup of Rodinia and the subsequent assembly of Gondwana in late Neoproterozoic time, and insights into the relationship between the Cathaysia and Yangtze blocks. [Copyright &y& Elsevier]