New Early Triassic paleomagnetic data from Huangben section, Guangdong and its tectonic implications

Continent China is composed of several blocks of variable sizes during different geological times, inwhich South China Block is composed of three tectonic units: Yangtze Block, Jiangnan Fold Belt and Southeast China Coastal Fold Belt (Fig. 1(a)), the last…     

华南地块中三叠统巴东组红层磁倾角浅化效应

对华南地块中三叠统巴东组红层样品进行系统的岩石磁学和古地磁学研究, 采用高场等温剩磁各向异性(hf-AIR)方法, 识别出巴东组红层的磁倾角浅化因子f = 0.63。岩石磁学研究结果显示, 巴东组红层的主要载磁矿物为赤铁矿和少量磁铁矿; 磁化率和高场等温剩磁各向异性组构均指示其具有典型沉积组构特征, 表明未遭受后期构造应力改造。高温特征剩磁分量为碎屑赤铁矿所携带, 具有单一负极性, 并在95%置信水平上通过褶皱检验, 与前人在同一剖面不同位置获得的以正极性为主的古地磁方向一致。该特征剩磁方向在地层校正后的平均方向为D_s = 222.1°, I_s = ?27.2° (α₉₅ = 8.7°), 对应古地磁极为48.1°N, 215.5°E (A₉₅ = 8.4°)。对包括本文数据在内的华南中三叠世红层高质量古地磁极数据(Q≥5)用f = 0.63 进行统一校正后, 获得平均古地磁极为48.5°N, 207.6°E (A₉₅ = 10.7°)。对比华北地块同样经hf-AIR方法浅化校正后的早三叠世古地磁极, 两者在其东部参考点上的古纬度完全一致, 验证了前人提出的华南华北中生代剪刀式旋转拼合模型。     

Cretaceous synfolding remagnetization components revealing tectonic rotation of the middle Yangtze fold belt

To reveal the deformation process of the middle Yangtze fold belt, we conducted a paleomagnetic study on Middle Triassic limestones and Middle to Late Jurassic sandstones from Wanzhou, Chongqing. Stepwise thermal and alternating field demagnetization were used to isolate the multi-component re-manent magnetizations. The Jurassic samples were overprinted by recent geomagnetic field, while three magnetization components were isolated from the Middle Triassic samples. A low temperature component (LTC) was isolated at temperatures below 200℃, an intermediate temperature component (ITC) at 200―360℃ and a high temperature component (HTC) at 400―460℃. The LTC is distributed around the present-day Earth magnetic field, probably a viscous component. Stepwise unfolding indi-cates that the maximum precision parameters of ITC and HTC components are achieved at 33±8% and 50±27% (with 95% confidence) unfolding, respectively. The best-clustered ITC mean direction, Dec = 11.2°, Inc = 45.2° (α₉₅ = 4.5°, N = 34), corresponding to a paleopole at 79.3°N, 219.5°E (d_p = 3.6°, d_m = 5.7°), is consistent with the Cretaceous reference direction of the South China Block (SCB). The best-clustered HTC mean direction (taking 70% unfolding), Dec = 24.2°, Inc =49.0° (α₉₅ = 3.6°, N = 23), corresponding to a paleopole at 69.2°N, 195.5°E (d_p =3.1°, d_m = 4.8°), suggests a clockwise rotation of 12.8°±3.5°. These synfolding remagnetization components clearly reveal that a clockwise rotation happened at the middle stage of folding, thus supporting that at least part of the variation in fold axis strikes is due to orocline rotation. Combined with published data, our analysis indicates that the Wan-zhou-Xiangxi segment of the middle Yangtze fold belt experienced oroclinal bending. Furthermore, a published post-folding component isolated from the Middle Triassic Puqi Formation suggests a 27.5°±5.8° clockwise rotation, confirming that at least 50% of the observed clockwise rotations in the eastern middle Yangtze fold belt can be attributed to oroclinal bending. The remagnetization data and geological evidence observed in the middle Yangtze fold belt suggest that collision between SCB and North China Block (NCB) probably lasted till the early period of Early Cretaceous.     

华北地块沁水盆地下三叠统刘家沟组古地磁倾角浅化研究

对华北地块沁水盆地下三叠统刘家沟组红层样品进行系统的岩石磁学、磁组构和古地磁学研究, 并用E/I (elongation/inclination)方法对其进行磁倾角浅化的识别与校正, 获得刘家沟组红层磁倾角浅化因子f = 0.6。岩石磁学结果显示, 刘家沟组红层的主要载磁矿物是赤铁矿及磁铁矿, 其磁组构具有典型的静水沉积特征。经地层校正后, 15个采样点特征剩磁分量的平均方向为D_s=318.8°, I_s=30.9°(α₉₅= 6.9°), 对应的古地磁极为49.3°N, 5.5°E (A₉₅=6.7°), 磁倾角浅化校正后的古地磁极为53.5°N, 18.0°E。对包括本文数据在内的高质量的华北早三叠世古地磁极数据(Q≥4)进行平均, 得到校正前的古地磁极为55.3°N, 357.1°E (A₉₅=5.5°), 校正后的古地磁极为60.8°N, 13.4°E (A₉₅=5.8°)。经过古地磁倾角浅化校正, 华北地块早三叠世的古纬度有约10°的明显提高, 指示其东部早三叠世时与华南地块之间可能存在一定的纬度差, 但是该纬度差很可能并不代表华北地块东部早三叠世时与华南地块尚未对接, 而是指示华南地块下三叠统灰岩同样存在显著的磁倾角浅化现象。     

ISEA reversed event in the Cretaceous Normal Super-chron （CNS）： ^40Ar／^39Ar dating and paleomagnetic results

ThegeomagneticfieldwasfoundtobeofnormalpolarityforalongtimeduringtheCretaceousbyHelsleyandSteiner[1]andthiswaslaternamedasCretaceousNormalSuperchron(CNS)[2].TheCNSlastedalmost37Ma(120—83Ma).Severalabnormalgeologicalevents,suchasanoceanicanoxicevent,alargenumberofvol-canismandglobalclimaticwarmingduringtheCNShavebeenreported[3—11].Thishasledtomanyquestionsbeingraised.IsittruethattheEarthsmagneticfielddidnotreverseatallintheCNS?Ifitdidreverse,howmanytimesandwhendidthishappen?Istherea…     

Discussion on the Neoproterozoic glaciations in the South China Block and their related paleolatitudes

The Kaigas, Sturtian, Marinoan, and Gaskiers glaciations are widely recognized in Neoproterozoic. However, in the South China Block only the Jiangkou （Sturtian） and Nantuo （Marinoan） are symbolized by sedimentary records. The Kaigas, recorded by isotopic and chemical proxies, exhibited likely the nature of cold paleoclimate with local mountain glaciation. The correlation of the Doushantuo Formation with the Gaskiers is indicated by the carbon isotope excursion and the dated age from the interval, however the South China Block was then under non-glacial weather. With no paleomagnetic data, the position of the South China Block during the Sturtian glaciation cannot be determined. The paleolatitudes of the South China Block during the Kaigas and Nantuo glaciations are intermediate, even though the Nantuo was once rendered erratically deduced equatorial. In fact, the paleolatitudes of the South China Block during the Neoproterozoic glaciations are all likely at about 30°-40°.     

New paleomagnetic results from the Yangzhuang Formation of the Jixian System,North China,and tectonic implications

A paleomagnetic study was carried out on the Yangzhuang Formation （-1350 Ma） of the Jixian System in the North China Block （NCB）. Detailed stepwise thermal demagnetization isolated two components. The soft component （component A） was interpreted as a remagnetization in the recent geomagnetic field. The hard component （component B） with higher unblocking-temperatures was carried by hematite. Its site-mean direction is D/I = 77.6°/-24.3°κ= 5.4, α 95 = 18.3°, N = 15 sites） before, and D/I = 72.2°/11.5° （ κ=24.6, α95 = 7.9°） after tilt correction. It passes a fold test（Mesozoic folding） at 99% confidence level and reversal test at 95% confidence level. The corresponding pole locates at 17.3°N, 214.5°E （dp = 4.1°, dm= 8.0°）. A best fit of paleomagnetic poles from the NCB, Baltica, Siberia and the apparent polar wander path for Laurentia suggests a long-lived connection between these paleo-continents between -1800and 1350 Ma.     

SHRIMP zircon U-Pb geochronology of Indosinian granites in Hunan Province and its petrogenetic implications

The structure, magmatism and sedimentation within the South China Block (SCB) related to the Indosinian Orogeny had attracted considerable attention since De-prat[1] and Fromagat[2] proposed the “Indosinian move-ment” based on two unconformities between Pre-Norian and Pre-Rhaetian during Triassic in Vietnam. However, Indosinian tectonic evolution of the SCB has been long debated[3―6]. Some researchers believed that the compli-cated structure-magmatism-sedimentation within the SCB w…     

西秦岭中生代花岗岩锆石U-Pb-Lu-Hf同位素特征及地质意义

对西秦岭地区中川岩体、柏家庄岩体和教场坝花岗岩体进行LA-ICP-MS锆石U-Pb同位素年代学分析, 获得其岩浆侵位年龄分别为220±1, 216±6和222±3 Ma, 表明3个岩体均形成于中?晚三叠世。样品的全岩地球化学分析结果表明, 3个岩体具有相似的稀土及微量元素特征, 均表现为显著亏损高场强元素Nb, Ti和P等, 具有明显的右倾式球粒陨石标准化稀土元素配分模式。锆石Lu-Hf同位素分析结果表明, 3个岩体锆石测年样品的ε_Hf(t)值介于?3.31~+1.68之间, 二阶段模式年龄介于1151~1456 Ma之间。岩石成因分析表明, 这些印支期花岗岩体的母岩浆主要来源于新元古代地壳物质的部分熔融。结合岩体形成时代、岩石成因和区域岩浆作用, 认为这些岩体形成于南秦岭与华南板块沿勉略缝合带相碰撞的造山动力学背景, 可能与华南板块的俯冲板片断离有关。     

Zircon SHRIMP U-Pb dating for olivine gabbro at Wangmuguan in the Beihuaiyang zone and its geological significance

In the Neoproterozoic, a large-scale magmatic activ- ity took place in the northern margin of the South China Block, with ages in a range of 700―800 Ma[1―4]). A systematic zircon U-Pb dating for bimodal metaigneous rocks in the Dabie-Sulu orogen yields ages of 758 ± 15 Ma[5], typifying rift magmatism along the northern margin of the South China Block during the middle Neoproterozoic. In addition, there is a widespread oc- currence of volcanic tuff interlayers around 635 Ma with the se…     

中国南方大地构造演化及其对油气的控制

按照板块构造理论及活动论、阶段论的思想，大致以中晚三叠世为界，将中国南方自震旦纪以来大地构造演化历史划分成海相盆地演化阶段（Z－T2）及陆相盆地演化阶级（T3－Q）两大阶段；又可进一步细分为扬子克拉通及其周缘裂谷盆地（Z－1q)、裂谷－克拉通－被动大陆边缘盆地（1c-O1）、被动陆缘－克拉通－前陆盆地（O2－S）、加里东运动（S末）、裂谷－克拉通盆地（D－T1）、克拉通残留海盆－弧后（浊积）盆地（T2）、印支运动（T2－T3）、华北－华南板块焊合、古特提斯封闭与前陆盆地的形成（T3－J2）、压扭背景下的改造作用及拉分盆地的形成（J3－K1）、伸展－裂陷盆地的形成（K2－E）、喜马拉雅运动（E末－N初）及披盖性构造层的形成（N－Q）12个阶段。特别是对南方自中晚三叠世以来的大地构造演化及其对现存油气的控制作用进行了系统研究，提出了晚侏罗世－早白垩世燕山运动对南方中生界、古生界原生油气藏的保存与破坏起到了决定性作用及燕山、喜马拉雅运动控制了现今南方原生、次生及再生烃（二次生烃）油气藏分布的新观点。     

Indosinian isotope ages of plutons and deposits in southwestern Miaoershan-Yuechengling,northeastern Guangxi and implications on Indosinian mineralization in South China

The Miaoershan-Yuechengling complex pluton is the largest granitoid complex in the western Nanling metallogenic belt with a surface exposure of >3000 km2.The complex pluton is composed of an early stage granitoid batholith and late stage small intrusions.The early stage batholith contains mainly medium-grained porphyritic mica granite and porphyritic monzonite granite,whereas the late stage intrusions are composed of muscovite granite porphyry and muscovite monzonitic granite.There are many W-Sn-Mo-Pb-Zn-Cu ores in the contact zone between the batholith and strata,forming an ore-rich belt around the batholith.Based on zircon LA-ICP-MS U-Pb ages,the southwestern part of the early stage batholith formed at 228.7 ± 4.1 Ma(MSWD = 2.49),with slightly earlier magmatic activity at 243.0 ± 5.8 Ma(MSWD = 2.62).The Yuntoujie muscovite granite was associated with W-Mo mineralization and has a zircon LA-ICP-MS U-Pb age of 216.8 ± 4.9 Ma(MSWD = 1.44).The Re-Os isochron age of molybdenite from the Yuntoujie W-Mo ore was 216.8 ± 7.5 Ma(MSWD = 11.3).Our new isotope data suggest that the late stage intrusive stocks from the southwestern Miaoershan-Yuechengling batholith were closely associated with W-Mo mineralization from the Indosinian period.These new results together with previous isotope data,suggest that South China underwent not only the well-known Yanshanian mineralization event,but also a widespread Indosinian metallogenic event during the Mesozoic period.Therefore,South China has a greater potential for Indosinian mineralization than previously thought such that more attention should be given to the Indosinian ore prospecting in South China.     

Zircon U-Pb ages of granites at Changba and Huangzhuguan in western Qinling and implications for source nature

Mesozoic granitoids are widespread in the Qinling-Dabie-Sulu orogenic belt. Precise U-Pb dating on these granitoids can reveal the evolution of the continental collision orogen and thus provide information on the nature of magma sources. This study presents zircon LA-ICP-MS U-Pb dating and whole-rock geochemical analyses for two intrusions at Changba and Huangzhuguan in western Qinling. Zircon U-Pb ages for central and marginal phases of the Huangzhuguang intrusion are 214±1 Ma and 213±3 Ma, respectively. Zircons from the Changba intrusion yield a dominant cluster with an U-Pb age of 213±2 Ma. Collectively, these ages are younger than ages of 220 to 240 Ma for ultrahigh-pressure metamorphism due to the continental collision between the South China Block and the North China Block, corresponding to syn-exhumation magmatism. Some inherited zircons occur in the Changba intrusion, yielding a weighted mean of ²⁰⁶Pb/²³⁸U ages at 757±14 Ma. This indicates that the Changba intrusion has the crustal source of mid-Neoproterozoic ages and a tectonic affinity to the South China Block. Geochemically, the two intrusuons are both rich in LILE and LREE but depleted in HFSE and HREE, similar to arc-type igneous rocks. The Huangzhuguang intrusion exhibits linear correlations between SiO₂ and the other major oxides, implying chemical evolution from a cognate magma source. It contains mafic enclaves, suggesting possible mixing of felsic-mafic magmas. The Changba granite is rich in Si and K but poor in Fe and Mg as well as has a high value of Fe*, suggesting strong differentiation of granitic magma. Therefore, the two intrusions were derived from the Late Triassic anatexis of the continental crust of different compositions in the northern margin of South China Block. This process may be coupled with exhumation of the subducted continental crust in the stage of late collision.     

Position of South China in configuration of Neoproterozoic supercontinent

ConfigurationandevolutionofNeoproterozoicsu-percontinentandthepositionofSouthChinawithinithavebeenveryimportanttargetsinearthsciencesconcerningmanyforefronttopicsofgeneralinterest.InthecommonreconstructionofthesupercontinentRodinia,SouthChinawaslocatedbetweenAustraliaandLaurentia,andthusliesinthecenterofthesupercontinentandsoutheastofAus-tralia[1].Accordingtothenewpaleomagneticandgeo-chronologicaldataforthe~800MaXiaofengdykeinYi-changaswellasexistingdata,Lietal.[2]suggestthatRodiniawouldp…     

Zircon U-Pb age of the Shacun gabbro body, Yuexi, Dabie orogen and its geological implications

The single grain zircon U-Pb age of the Shacun mafic-ultramafic intrusion, Yuexi, North Dabie is (128.1±2.0) Ma. This date indicates that the intrusion was implaced at Yanshanian when most Mesozoic granitoids were intruded. It was not the syn-collisional intrusion related to the subduction of the Yangtze Block and ultrahigh-pressure metamorphism at Indosinian.     

South China''s Gondwana connection in the Paleozoic: Paleomagnetic evidence

The reconstruction in which the South China Block (SCB) lies along the Great India-Australia region of Gondwana margin is tested by using existing Paleozoic paleomagnetic data.Under the proposed reconstruction, all six high quality paleopoles from the SCB between the Early Cambrian and late Early Devonian (～400 Ma) are in good agreement with coeval paleopoles from Gondwana.Thereafter, the apparent polar wander paths for the SCB and Gondwana diverge markedly.This indicates that the SCB had been part of Gondwana and the connection was intact from at least Early Cambrian until late Early Devonian, but they began to separate by late Middle Devonian (～375 Ma).     

Sm-Nd isotopic compositions of Cambrian-Ordovician strata at the Jinggangshan area in Jiangxi Province: Tectonic implications

Whole-rock Sm-Nd isotopes were investigated for Cambrian-Ordovician strata from the Jinggangshan area between the Yangtze Block and Cathysia Block in South China. These strata were deposited as a greatly thick unit of muddy-sandy laminas with intercalated carbonate and organic carbon-bearing layers. They have low εNd（t） values of -13.9 to -7.9 and old Nd model ages of 1842 to 2375 Ma. In tDM-tStr diagram, they are far away from the concordant line but fall within the evolution zone of the Proterozoic crust of South China. This indicates that the Cambrian-Ordovician strata are mainly composed of matters eroded from ancient Paleoproterozoic crust that may mainly consist of continental-derived detrital sediments with high maturity in the Cathysia Block. However, the Ordovician Jueshangou Formation and Dui＇ershi Formation have εNd（t） values of -10.5 and -7.9 at the higher end of the above range and Nd model ages of 1842 to 2059 Ma at the lower end of the above range. This suggests involvement of more detritus that were eroded from the relatively juvenile crust from Late Paleoproterozoic to the Early Neoproterozoic. All the Nd model ages for the Cambrian-Ordovician sedimentary rocks in the Cathysia Block and the southeastern margin of the Yangtze Block are older than 1800 Ma, suggesting that no material from the Early Paleozoic depleted mantle-derived magmas was involved in these regions.     

SHRIMP U-Pb geochronology of the zircons from the Precambrian basement of the Qilian Block and its geological significances

Origin and tectonic evolution of the Qilian Precambrian basement on NW China were investigated using zircon U-Pb ages with collaborating stratigraphic and paleontological evidence. Zircon grains were separated from two schists, two granitic gneisses and one mylonized gneiss and dated with SHRIMP. Seventy percent of sixty-one detrital zircon ages from two schists ranges from 0.88 Ga to 3.09 Ga, mostly within 1.0 Ga to 1.8 Ga with a peak at 1.6 Ga to 1.8 Ga, and twenty percent varies from 2.0 Ga to 2.5 Ga. A few falls in the Archean and Neoproterozoic periods. The two granitic gneisses were dated 930±8 Ma and 918±14 Ma, whereas the mylonized granitic gneiss was dated 790±12 Ma. These ages represent two periods of magmatisms, which can be correlated with the early and late stages of magmatisms associated with the Jinningian movement on the Yangtze Blocks. The results from this and previous studies indicate that the ages of the Precambrian detrital zircons from the Qilian Block are widely distributed in the Proterozoic era, distinct from the North China Block which was stable in the Neo-Mesoproterozoic era. By contrast, the age histograms of the detrital zircons from the Qilian Block is similar to those from Precambrian basement of the Yangtze Craton. Therefore, it is suggested that the Qilian Block had a strong affinity toward the Yangtze Craton and might belong to the supercontinent Gondwana in the Neoproterozoic time. This inference is supported by Nd model age (TDM), stratigraphic, and paleontological evidence. It is further considered that the Qilian Block was rifted from the supercontinent Gondwana during late Sinian to form an isolated continent in the Proto-Tethyan Ocean, moving towards the Alaxa Block in the North China Craton. The part of Proto-Tethyan Ocean between the Qilian and Alaxa Blocks should correspond to the so-called Paleo-Qilian Ocean. Following the closure of the Paleo-Qilian Ocean in the early Paleozoic, the Qilian Block collided with the Alaxa Block to form the North Qilian Orogenic Belt. Based on this tectonic explanation, the North Qilian ophiolites should represent parts of lithosphere from the Proto-Tethyan Ocean. Lithological and geochronological evidence also indicates that the Qilian Block underwent continental reactivation possibly induced by the deep northward subduction of the North Qaidam Block in early Paleozoic time.     

Ore-forming event and geodynamic setting of molybdenum deposit at Wenquan in Gansu Province, Western Qinling

The Wenquan molybdenum deposit is associated with a Triassic granite in this area. The Wenquan granite is enriched in LILE and LREE, poor in HFSE, and has significantly higher contents of alkali （K2O＋Na2O） and Sr, Ba than those of the island arc volcanic rocks. These geochemical characteristics are similar to post-collisional granites in high K calc-alkaline series. Studies of major elements, trace elements, REEs and chronology of the Wenquan pluton show that, in the geodynamic transition stage of continent-continent convergence to extension, the partial melting of the enriched lithospheric mantle generated the basaltic magma and triggered the partial melting of the thickened lower crust which produceded the acidic magma, and the Wenquan pluton was formed by mixing of the two magmas. Molybdenite Re-Os isotopic dating gave Os model ages of 212.7±2.6 Ma to 215.1±2.6 Ma with a weighted mean of 214.1±1.1 Ma, and an Re-Os isochron age of 214.4±7.1 Ma. These ages are close to K-Ar ages （223 to 226 Ma） and a SHRIMP zircon U-Pb age （223±7 Ma） for the Wenquan granite within the error range, but relatively younger. This implies that the Mo mineralization occurred in a late stage of the magmatic intrusion, and the metallogenesis took place in the transition stage from syn-collision to post-collision in the tectonic setting of the Qinling Orogenic Belt （QOB） after continental collision between the North China Block （NCB） and the South China Block （SCB）. This process is also corresponding to the geological events of metamorphism and deformation in South Qinling, closure of the Mian-Lue oceanic basin, and exhumation of the Dabie-Sulu ultrahigh-pressure metamorphic rocks. The large-scale continent-continent collision between NCB and SCB in the middle Triassic triggered significant crustal thickening and exhumation of subducted slab. In the late Triassic, the tectonic setting was transformed to the transition stage from collision to extension. Materials from the asthenospheric mantle would ascend into the root of the lower crust, which could induce partial melting of the lower crust and generate Mo-enriched granitic magma. The ore-forming elements enriched in the fluid derived from the condensation and fraction of the magma resulted in the Mo mineralization. The Mo deposits in the QOB are mainly formed in two episodes, namely 220± Ma and 140± Ma. The two episodes of metallogenesis were developed in the tectonic transition settings from compression to extension, but they were in the different stages of the tectonic evolution. The occurrence of the Wenquan Mo-bearing pluton indicates that the Triassic tectonic-magmatic belt of Western Qinling is another favorable region for Mo mineralization in the QOB. Therefore, it is significant to pay more attention to evaluation of the ore-forming potentiality in the Triassic granites in Western Qinling.     

A detailed Lower Triassic conodont biostratigraphy and its implications for the GSSP candidate of the Induan–Olenekian boundary in Chaohu, Anhui Province

Chaohu is located in a deep part of carbonate ramp on the Lower Yangtze Block, which belonged to the low-latitude eastern Tethyan archipelago during the Early Triassic. Fossils were very rich in the Lower Triassic of Chaohu. Bivalves, ammonoids, conodonts were very common throughout the Lower Triassic, while fish fossils were generally rich in some beds of the upper part. It is one of the most typical sections for the Early Triassic chronostratigraphy in the world. Although various fossils had been studied in the 1980s and 1990s, recent studies based upon new and more detailed collections from the Lower Triassic of Chaohu showed that the conodont zonation needs revision. We collected Lower Triassic conodont fossils from continuous sections of the West Pingdingshan, North Pingdingshan and South Majiashan, Chaohu, Anhui Province, and updated zonations were made for each section. Eight conodont zones have been distinguished. They are, in ascending order, Hindeodus typicalis zone, Neogondolella krystyni zone, Neospathodus kummeli zone, Neospathodus dieneri zone, Neospathodus waageni zone, Neospathodus pingdingshanensis zone, Neospathodus homeri zone, and Neospathodus anhuinensis zone. The first occurrence of Neospathodus waageni eowaageni of the N. w. eowaageni subzone （i.e. the base of the N. waageni zone） is suggested as the marker to define the Induan-Olenekian boundary.