Dabie Mountains are located at the junction of Anhui,Henan and Hubei provinces in the East of China.With its varied altitude,climate,and soil texture,Dabie Mountains are extremely rich in wild plant resources.The 12th...Dabie Mountains are located at the junction of Anhui,Henan and Hubei provinces in the East of China.With its varied altitude,climate,and soil texture,Dabie Mountains are extremely rich in wild plant resources.The 12th Traditional Chinese Medicine(TCM)Resources Scientific Expedition Team of Shenyang Pharmaceutical University conducted a study on wild vascular plants resources,especially medicinal vascular plants,through field investigation,literature review and specimen identification.There were 472 species of vascular plants belonging to 347 genera and 125 families collected during July 2018 in this area,of which 424 species were medicinal vascular plants,accounting for 89.83%of the total.From the perspective of medicinal parts,most of the medicinal plants there have values in their roots and rhizomes,as well as the whole plants.The efficacy and characteristics of these pharmaceutical dimensions were also summarized and analyzed in detail.Besides,among the wild vascular plants collected,the most dominant families with the biggest numbers of species are Compositae,Lamiaceae,Liliaceae,Rosaceae,Leguminosae,Ranunculaceae,Saxifragaceae and Polygonaceae,and the dominant genus are Viola and Sedum.In terms of life form,perennial herbs are dominant,accounting for 55.72%of the total species,followed by some annual(or biennial)herbs,shrubs and lianas.Finally,recommendations are put forward for strengthening the protection and utilization of wild medicinal plant resources in Dabie Mountains.展开更多
Mountain ecosystems play an essential role in supporting regional sustainable development and improving local ecological environments. However, economic development in mountainous areas has long been lagging, and mult...Mountain ecosystems play an essential role in supporting regional sustainable development and improving local ecological environments. However, economic development in mountainous areas has long been lagging, and multiple conflicts related to resource assurance, ecological protection, and economic development have emerged. An accurate grasp of the current status and evolutionary trends of mountain ecosystems is essential to enhance the overall benefits of ecosystem services and maintain regional ecological security. Based on the In VEST(Integrated Valuation of Ecosystem Services and Trade-offs) model, this study analyzed the spatiotemporal evolution patterns and the trade-offs and synergies among ecosystem services(ES) in the Dabie Mountains Area(DMA) of eastern China. The Markov-PLUS(Patch-generating Land Use Simulation) model was used to conduct a multi-scenario simulation of the area's future development. Water yield(WY) and soil conservation(SC) had overall increasing trends during 2000-2020, carbon storage(CS)decreased overall but slowed with time, and habitat quality(HQ) increased and then decreased. The ecological protection scenario is the best scenario for improving ES in the DMA by 2030;compared to 2020, the total WY would decrease by 3.77 × 10^(8) m^(3), SC would increase by 0.65 × 10^(6) t, CS would increase by 1.33 × 10^(6) t, and HQ would increase by 0.06%. The comprehensive development scenario is the second-most effective scenario for ecological improvement, while the natural development scenario did not have a significant effect. However, as the comprehensive development scenario considers both environmental protection and economic development, which are both vital for the sustainable development of the mountainous areas, this scenario is considered the most suitable path for future development. There are trade-offs between WY, CS, and HQ, while there are synergies between SC, CS, and HQ. Spatially, the DMA's central core district is the main strong synergistic area, the marginal zone is the weak synergistic area, and trade-offs are mainly distributed in the transition zone.展开更多
1.Objective Unlike the North China Plate where Archean and Paleoproterozoic crustal rocks are widely distributed,Early Precambrian basement rocks in the Yangtze Block of South China are locally exposed(Fig.1a),such as...1.Objective Unlike the North China Plate where Archean and Paleoproterozoic crustal rocks are widely distributed,Early Precambrian basement rocks in the Yangtze Block of South China are locally exposed(Fig.1a),such as in the Kongling Complex,the Zhongxiang Complex,and the Douling Complex(Zhao GC and Cawood PA,2012).The Dabie Orogen is the eastward extension of the Qinling Orogen.展开更多
1.Objectives Precambrian microcontinents(terranes)or continental fragments are generally essential components in the evolution and architecture of Phanerozoic orogenic belts.Formation of the Qinling-Dabie Orogenic Bel...1.Objectives Precambrian microcontinents(terranes)or continental fragments are generally essential components in the evolution and architecture of Phanerozoic orogenic belts.Formation of the Qinling-Dabie Orogenic Belt,a typical Paleozoic to Triassic collisional zone between the South China Block(including the Yangtze Block and the Cathaysia Block)and the North China Block(inset map in Fig.1a),is characterized by the occurrence of several Precambrian complexes or microcontinents.展开更多
The regional extent and spatial distribution of ultrahigh pressure metamorphic(UHPM) and high pressure metamorphic (HPM) rocks, and the geometrical relationships of various petrotectonic units in the Dabie-Sulu region...The regional extent and spatial distribution of ultrahigh pressure metamorphic(UHPM) and high pressure metamorphic (HPM) rocks, and the geometrical relationships of various petrotectonic units in the Dabie-Sulu region indicate that the Triassic collisional suture line between the Sino-Korean and Yangtze cratons is situated at the northern margin of the Dabie massif, that is,along the Balifan-Mozitan-Xiaotian fault in the Dabie region, and possibly is linked to the Wulian-Yantai fault in the Sulu region to tbe east. The suture line has been strongly modified duriug and subsequent to UHPM aud HPM events.展开更多
Large-scale magmatism affected the Tongbai-Dabie orogenic belt during post-collisional lateral tectonic extension in the Cretaceous, which was suggested to account for the widespread deformation and migmatization in t...Large-scale magmatism affected the Tongbai-Dabie orogenic belt during post-collisional lateral tectonic extension in the Cretaceous, which was suggested to account for the widespread deformation and migmatization in the Tongbai-Dabie complexes. However, it cannot explain the most deformations in the shear zones. The northwest-southeast shear zones are developed around or wrapped the Tongbai-Dabie complexes. They play an important role for the interpretation of the tectonic evolution of the Tongbai-Dabie orogenic belt. By a systematically observation and description of the geometry and kinematics of these shear zones, we found that the shear zones to the north dip NE and have a uniform sinistral shear sense, the shear zone to the south dips SW and has a uniform dextral shear sense, and the shear zones at the core are sub-horizontal and have a uniform top-to-NW sense of shear. Combining with the comparison of previous and our geochronological studies, we interpret these associations as indicating that these shear zones were originally a single, more flat-lying and sub- horizontal shear zone with a uniform top-to-NW shear sense before the folding-doming of the Tongbai- Dabie complexes and suggest that the Tongbai-Dabie orogenic belt experienced a uniform top-to-NW orogen-paraUel extension in the ductile lithosphere before the widespread magmatism in the Cretaceous.展开更多
The present-day observed crustal-scale tectonic style of ultrahigh-pressure metamorphic (UH-PM) and high-pressure metamorphic (HPM ) belts in the Dabie-Sulu region was dominantly formedby extensional processes, postda...The present-day observed crustal-scale tectonic style of ultrahigh-pressure metamorphic (UH-PM) and high-pressure metamorphic (HPM ) belts in the Dabie-Sulu region was dominantly formedby extensional processes, postdating the Triassic collision between the Sino-Korean and Yangtze cratons. The extensional structures overprinting the previous structures related to contraction that produced the thickened continental crust of the UHPM and HPM belts, in particular display the typical features of a Cordilleran-type metamorphic core complex, in which at least four regionalscale, low-angle ductile shear zones that constitute a detachment system, are recognized in the Dabie region. In the Sulu region, the extensionaI structures show in the form of small-scale domes or a regional-scale SE-dipping pseudo-monocline. The geometry and the kinematics of tbe detachment zones are briefly described and their significance for the exhumation of UHPM and HPM rocks is discussed. It is iniliated that the subhorizontal crustal-scale extensional flow in the middle-lower crust, under amphibolite- to greenschist-facies conditions, was an important tectonothermal process at 200- 170 Ma and the exhumation or the UHPM and HPM rocks was achieved at least in part along multi-layered detachment zones. The regional detachment system has been the main factor enabling UHPM and HPM rocks to be brought from middle-lower crustal levels to middle-upper crustal levels.展开更多
Taking Huanggang city as an example, the requirements of basic indexes for the regional ecological agricultural construction in Dabie Mountains were ana- lyzed and the measures that must be taken in implementing the i...Taking Huanggang city as an example, the requirements of basic indexes for the regional ecological agricultural construction in Dabie Mountains were ana- lyzed and the measures that must be taken in implementing the in the Dabie Mountains were proposed.展开更多
The Qinling-Dabie-Sulu high-pressure and ultra-high pressure metamorphic belt wasformed by subduction and collision between the North China and Yangtze plates. The study ofthe eclogite belt is very important in unders...The Qinling-Dabie-Sulu high-pressure and ultra-high pressure metamorphic belt wasformed by subduction and collision between the North China and Yangtze plates. The study ofthe eclogite belt is very important in understanding the evolution of the Qinling Dabie orogen. Inthe present paper the geology, petrology, minerology and chronology of the eclogites in the Dabieand Sulu areas are described. The principal conclusions of this work are as follows: (1) Based up-on the field occurrence and the P-T conditions of the eclogites, two types of eclogite can be dis-tinguished: Type 1—the low-temperature and high-pressure eclogite in the mid-late Proterozoicmetamorphic series, and Type 2—the ultra-high pressure eclogite in the late Archaean to earlyProterozoic metamorphic complex. In the Dabie area, the ultra-high-pressure eclogite,high-pressure eclogite and epidote-blueschist units are nearly parallel to each other and stretchintermittently from north to south. (2) The P-T conditions of the high-pressure eclogites and ul-tra-high pressure eclogites have been estimated. The former are formed at 450-550℃ and1.4-1.6 GPa; while the latter at 650-870℃ and >2.7-2.9 GPa in the Dabie area and at820-1000℃ and >2.8-3.1 GPa in the Sulu area. The metamorphic temperatures of the eclogitesincrease progressively from west to east. (3) The ultra-high pressure eclogites were subjected to 5stages of metamorphism: pre-eclogite epidote amphibolite facies, peak coesite eclogite facies,post-eclogite amphibolite facies, epidote-blueschist facies or epidote amphibolite facies andgreenschist facies. The general features of the PTt path of the ultra-high pressure eclogite are:clockwise pattern, progressive metamorphism being a process of slow increasing temperature andrapid increasing pressure, and the retrogressive section with nearly isothermal decompression atthe early stage, isobaric cooling at the middle stage and nearly isothermal decompression at thelate stage. (4) At least two stages of high-pressure metamorphism occurred in the orogenic belt:the high-pressure eclogite and ultra-high pressure eclogite were formed by the subduction of theoceanic crust northward beneath the North China plate or the Dabie block during theCaledonian; while the epidote-blueschist belt came into being by subdution and collision be-tween the two continental plates during the Indosinian. (5) Due to the continuous sequentialsubduction of the cold plate, the ultra high-presssure metamorphic rocks were uplifted to thecrust by the underplating processes. They can be preserved just because of the 'frozen effect' re-sulting from the continuous subduction of the cold plate. (6) The carbonates, such as magnesite,breunnerite, aragonite and dolomite, and the H_2O-bearing minerals, such as phengite, epidoteand zoisite, were stable during the high-pressure and/or ultra-high pressure metamorphism.展开更多
The diurnal variation of precipitation over the Dabie Mountains(DBM) in eastern China during the 2013 mei-yu season is investigated with forecasts of a regional convection-permitting model. Simulated precipitation is ...The diurnal variation of precipitation over the Dabie Mountains(DBM) in eastern China during the 2013 mei-yu season is investigated with forecasts of a regional convection-permitting model. Simulated precipitation is verified against surface rain-gauge observations. The observed morning precipitation peak on the windward(relative to the prevailing synoptic-scale wind) side of the DBM is reproduced with good spatial and temporal accuracy. The interaction between the DBM and a nocturnal boundary layer low-level jet(BLJ) due to the inertial oscillation mechanism is shown to be responsible for this precipitation peak. The BLJ is aligned with the lower-level southwesterly synoptic-scale flow that carries abundant moisture.The BLJ core is established at around 0200 LST upwind of the mountains. It moves towards the DBM and reaches maximum intensity at about 70 km ahead of the mountains. When the BLJ impinges upon the windward side of the DBM in the early morning, mechanical lifting of moist air leads to condensation and subsequent precipitation.展开更多
The Huangtuling hypersthene-garnet-biotite gneiss at Luotian County, Hubei Provine, is a typicalgranulite-facies rock of the Dabie Group Complex in the Dabie orogenic belt. Investigations on the morphology andoccurren...The Huangtuling hypersthene-garnet-biotite gneiss at Luotian County, Hubei Provine, is a typicalgranulite-facies rock of the Dabie Group Complex in the Dabie orogenic belt. Investigations on the morphology andoccurrence of zircons and their internal structures shown in the thin sections lead to the recognition of three types ofzircons, which are in good agreement with the types identified on the basis of morphology, colour and external fea-tures from the related zircon concentrates. The observation of zircons in the rock reveals that part of type 1 zirconsshow signs of a double-layered structure. The interval part existed in the protolith prior to the granulite-facies meta-morphism. Type 2, the prismatic zircons which mainly occur in garnet and hypersthene are metamorphic minerals ofthe granulite-facies metamorphism. Type 3, the round multifaceted zircons in felsic minerals and biotite, are proba-bly attributed to a later geological event related to migmatization. The ^(207)Pb/^(206)Pb zircon dating by direct evaporationon (thermal evaporation ion mass spectrometer) yields ages ranging from 2814 Ma to 1992 Ma. The age discrepancyamong these different zircon types is conspicuous. The yellow-brown(type 1) zircons give ages of 2814±29 Ma to2527±6 Ma, the prismatic euhedral zircons (type 2), 2456±7 Ma to 2254±4 Ma, and the round multifaceted zircons(type 3), 1992±10 Ma. The results are geologically interpreted in consideration of the complicated behaviours of zir-cons during Precambrian geological evolution of the Dabie area. (1) If the protolith of the gneiss is a sedimentaryrock, then type 1 zircons are clastic ones and the ages 2814±29 Ma and 2811±27 Ma may reflect the minimum age ofthe rocks of its source region. also the first geological event in the area. Sedimentation of the protolith occurred be-tween 2814 Ma and 2527 Ma, probably close to 2814 Ma. If the protolith is a volcanic rock, then the formation age ofthe supracrustal rocks of the Dabie Group Complex is around 2814 Ma. The age 2456±7 Ma reflects the time whenthe granulite-facies metamorphism took place. The later migmatization event is dated at aboat 1992±10 Ma, and isprobably the latest early Precambrian event in the area. The present work provides geochronological evidence for the existence of the Dabie Archaean craton, whichhad probably experienced 3 or 4 geological events during its early Precambrian evolution.展开更多
Five samples of muscovite from mylonites of the earlier Tanlu ductile shear zone on the eastern margin of the Dabie Mountains yield 40Ar/39Ar ages ranging from 178 Ma to 196 Ma. Three of them have reliable plateau age...Five samples of muscovite from mylonites of the earlier Tanlu ductile shear zone on the eastern margin of the Dabie Mountains yield 40Ar/39Ar ages ranging from 178 Ma to 196 Ma. Three of them have reliable plateau ages of 188.7±0.7 Ma, 189.7±0.6 Ma and 192.5±0.7 Ma respectively, which indicates a syn-orogenic, sinistral strike-slip thermal event. This displacement movement derived from the continent-continent collision of the North and South China blocks took place in the Early Jurassic and after uplifting of high-pressure to ultrahigh-pressure slabs to the mid-crust. It is suggested that during the collision the Tanlu fault zone was an intracontinental transform fault caused by differential subduction speeds. The 40Ar/39Ar ages of mylonite whole-rock and muscovite from the later Tanlu ductile shear zone suggest another sinistral strike-slip cooling event at 128 Ma. During this strike-slip faulting, large-scale intrusion and doming uplift occurred in the eastern part of the Dabie orogenic belt. Data of K-feldspar 40Ar/39Ar MDD and apatite fission-track analysis from metamorphic rocks indicate two high-speed cooling events experienced by the Tanlu fault zone, which took place at 90 Ma and 45-58 Ma respectively. They correspond respectively to two phases of extensional activities in the Late Cretaceous and Eogene as well as development of the Qianshan fault-controlled basin to the east of the Tanlu fault zone. The cooling times recorded by K-feldspar and apatite show that the uplifting in the Dabie orogenic belt occured earlier than that on the eastern margin occupied by the Tanlu fault zone. The above phenomena suggest that the uplifting of the Dabie orogenic belt during the Late Cretaceous to Eogene was not controlled by the Tanlu normal faulting, but as a result of the lithospheric delamination.展开更多
The granitic gneisses from the ultrahigh-pressure (UHP) metamorphic terrain of the southeastern Dabie Mountains encompass two types: monzonitic granitic gneiss and alkali-feldspar granitic gneiss, which are characteri...The granitic gneisses from the ultrahigh-pressure (UHP) metamorphic terrain of the southeastern Dabie Mountains encompass two types: monzonitic granitic gneiss and alkali-feldspar granitic gneiss, which are characterized by rich alkalis, poor CaO, high FeO/MgO, particularly high Ba, Rb, Th, Ta, REE (except Eu), Ga, Nb and Zn, and low Sr, Eu, Cr, Co and Ni. The gneisses, particularly the alkali-feldspar granitic gneiss, have typical chemical characteristics of A-type granites. They resulted from partial melting of crustal materials existing in the rift zone along the northern margin of the South China block during the Neoproterozoic. These gneisses might not have undergone UHP metamorphism during the late Triassic, but were involved into UHP rocks by the tectonic mixing process and kept the exhumation message of the UHP rocks from the middle and upper crust.展开更多
A new species of the genus Tylototriton is described,from Yuexi county,Anhui province,in the south of the Dabie Mountains.It is based on morphological and molecular analysis.The new species is identified as belonging ...A new species of the genus Tylototriton is described,from Yuexi county,Anhui province,in the south of the Dabie Mountains.It is based on morphological and molecular analysis.The new species is identified as belonging to the Tylototriton asperrimus group and shares a number of similarities with T.wenxianensis,T.broadoridgus and T.dabienicus.The diagnostic characteristics of the new species are as follows： the head length is greater than the width of the head; bony ridges on the head are prominent and necked-in; the distal digit ends,ventral digits,peripheral area of the cloaca and the tail＇s lower edge are orange.The result from the molecular analysis of the genus Tylototriton（including the type specimen of the new species） based on three mitochondrial genes（ND1,ND2 and CYTB） indicated that the new species was close to T.wenxianensis,T.dabienicus,and T.broadoridgus,but formed an independent clade.This result was consistent with the morphological analysis above,which supports the theory that the population distributed in the south of the Dabie Mountains,namely in from Yuexi county,Anhui province,represented a distinct species,Tylototriton anhuiensis sp.nov.展开更多
The initiation of convective cells in the late morning of 24 June 2010 along the eastward extending ridge of the Dabie Mountains in the Anhui region, China, is studied through numerical simulations that include local ...The initiation of convective cells in the late morning of 24 June 2010 along the eastward extending ridge of the Dabie Mountains in the Anhui region, China, is studied through numerical simulations that include local data assimilation. A primary convergence line is found over the ridge of the Dabie Mountains, and along the ridge line several locally enhanced convergence centers preferentially initiate convection. Three processes responsible for creating the overall convergence pattern are identified. First, thermally-driven upslope winds induce convergence zones over the main mountain peaks along the ridge, which are shifted slightly downwind in location by the moderate low-level easterly flow found on the north side of a Mei-yu front. Second, flows around the main mountain peaks along the ridge create further convergence on the lee side of the peaks. Third, upslope winds develop along the roughly north-south oriented valleys on both sides of the ridge due to thermal and dynamic channeling effects, and create additional convergence between the peaks along the ridge. The superposition of the above convergence features creates the primary convergence line along the ridge line of the Dabie Mountains. Locally enhanced convergence centers on the primary line cause the initiation of the first convection cells along the ridge. These conclusions are supported by two sensitivity experiments in which the environmental wind （dynamic forcing） or radiative and land surface thermal forcing are removed, respectively. Overall, the thermal forcing effects are stronger than dynamic forcing given the relatively weak environmental flow.展开更多
The high-pressure （HP） eclogite in the western Dabie Mountain encloses numerous hornblendes, mostly barroisite. Opinions on the peak metamorphic P-T condition, PT path and mineral paragenesis of it are still in disp...The high-pressure （HP） eclogite in the western Dabie Mountain encloses numerous hornblendes, mostly barroisite. Opinions on the peak metamorphic P-T condition, PT path and mineral paragenesis of it are still in dispute. Generally, HP eclogite involves garnet, omphacite, hornblendes and quartz, with or without glaucophane, zoisite and phengite. The garnet has compositional zoning with XMg increase, XCa and XMn decrease from core to rim, which indicates a progressive metamorphism. The phase equilibria of the HP eclogite modeled by the P-T pseudosection method developed recently showed the following： （1） the growth zonation of garnet records a progressive metamorphic PT path from pre-peak condition of 1.9-2.1 GPa at 508~C-514~C to a peak one of 2.3-2.5 GPa at 528~C-531~C for the HP eclogite; （2） the peak mineral assemblage is garnet＋omphacite＋glaucophane＋quartz_＋phengite, likely paragenetic with lawsonite; （3） the extensive hornblendes derive mainly from glaucophane, partial omphacite and even a little garnet due to the decompression with some heating during the post-peak stage, mostly representing the conditions of about 1.4-1.6 GPa and 580~C-640~C, and their growth is favored by the dehydration of lawsonite into zoisite or epidote, but most of the garnet, omphacite or phengite in the HP eclogite still preserve their compositions at peak condition, and they are not obviously equilibrious with the hornblendes.展开更多
The geometry of the Dabie Mountains is manifested in terms of the distribution of petro-tectonic units in three dimensions. It is identified into three segments from east to west, four horizons in vertical profiles an...The geometry of the Dabie Mountains is manifested in terms of the distribution of petro-tectonic units in three dimensions. It is identified into three segments from east to west, four horizons in vertical profiles and eight petro- tectonic units from north to south. Three segments are the east, middle and west segments. Four horizons, from top to bottom, are two different meta-tectonic mélange in the uppermost part, underthrust basement and cover below them, and mantle at the bottom of the profiles. Eight petro-tectonic units from north to south are: (1) the hinterland basin, (2) the meta -flysch, (3) the ultramafic rock belt (UM) + Sujiahe eclogite belt (SH), (4) eclogite belt 2 (Ec2) with most eclogites of continental affinity, (5) eclogite belt 1 (Ecl1) with some eclogite of oceanic affinity, (6) the Dabie complex or underthrust basement of the Yangtze continent, (7) the Susong and Zhangbaling Groups or underthrust cover of the Yangtze continent and (8) the foreland belt. The (3), (4) and (5) units belong to meta-tectonic mélange. Some ultrahigh pressure metamorphic minerals such as coesite and micro-diamonds have been found in (3) and (4) units; a possible ultrahigh pressure mineral, clinozoisite aggregate pseudomorph after lawsonite, was found in unit (5). The three tectonic units are speculated to be coherent initially; the UM and SH units are suggested to be the root belt in the east, middle and west segments respectively. The kinematics of the Dabie orogen is divided into three stages: top-to-south thrusting during the eclogite-granulite facies metamorphism, top-to-north extension during the amphibolite metamorphic stage, and faults or shear bands of brittle deformation and greenschist facies metamorphism were formed in the post-orogenic stage since the Late Jurassic and the movement pictures of these faults is different from each other.展开更多
A new species of rhacophorid of the genus Rhacophorus is described from the Dabie Mountains of west Anhui, east China. The new species, Rhacophorus zhoukaiyae sp. nov. is distinguished from its congeners by a combinat...A new species of rhacophorid of the genus Rhacophorus is described from the Dabie Mountains of west Anhui, east China. The new species, Rhacophorus zhoukaiyae sp. nov. is distinguished from its congeners by a combination of the following characters： 1） the ventral surface and front-and-rear of the femur is paler yellowish and decorated with irregular grayish blotching, and without obvious spots on the dorsum of the hand and foot webbing; 2） the outer metatarsal tubercle is small; 3） outer fingers are half-webbed and outer toes two third webbed; 4） the skin on the dorsum is smooth and without compressed warts; 5） the throat, chest and belly are pure paler yellowish; 6） the dorsal part of the fingers and toes are grayish-white; 7） the iris is golden-yellow. In addition, the phylogenetic tree showed that all the individuals of R. zhoukaiyae sp. nov. clustered into one distinct clade which suggested the validity of this species. This results could also be used to the support of species delimitation. Currently, this species is known only from mid-elevation montane evergreen forest in the Dabie Mountains of west Anhui, China.展开更多
Omphacite grains from UHP eclogite of the Dabie Mountains in eastern China are elongated and show strong lattice preferred orientations (LPOs). Observations by the transmission electron microscopy (TEM) identified not...Omphacite grains from UHP eclogite of the Dabie Mountains in eastern China are elongated and show strong lattice preferred orientations (LPOs). Observations by the transmission electron microscopy (TEM) identified not only structures of plastic deformation occurring as free dislocation, dislocation loops and dislocation walls, but also bubbles of water present in the deformed omphacite. The bubbles attach to the dislocation loops which are often connected to one another via a common bubble. Using infrared spectroscopy (IR), two types of hydrous components are identified as hydroxyl and free-water in the omphacite. An analysis of deformation mechanism of microstructure in omphacite suggests that the mineral deformed plastically under UHP metamorphic conditions by dislocation creep through hydrolitic weakening.展开更多
To the north of the Qinling-Dabie orogen there exists a Mesozoic (K1) granite-syenite belt called the Beihuaiyang granite-syenite belt, in which the Xianghongdian alkaline complex outcrops in the Devonian Foziling sch...To the north of the Qinling-Dabie orogen there exists a Mesozoic (K1) granite-syenite belt called the Beihuaiyang granite-syenite belt, in which the Xianghongdian alkaline complex outcrops in the Devonian Foziling schist and also intruded into the slightly earlier volcanic rocks. This alkaline complex is composed of syenite, alkaline syenite and nepheline syenite, but the nepheline syenite occurs inside the alkaline syenite in the pod-like, irregular, lenticular or layered shape. Researches on the petrogenesis of the alkaline complex and the relationship between the alkaline syenite and the nepheline syenite must rely on precise isotopic ages. Previous researches have reported isotopic dating results merely by the 40Ar/39Ar method on hornblende and biotite separated from the alkaline syenite and nepheline syenite. In view of this, the authors have made fairly detailed isotopic geochronological studies of the alkaline syenite and nepheline syenite by using Rb-Sr isochron for the whole rock and minerals, U-Pb for single zircon separate and the 40Ar/39Ar method for hornblende and potash feldspar. The results of this research are completely different from those of previous researches and show that the nepheline syenite was formed far earlier than the alkaline syenite.展开更多
文摘Dabie Mountains are located at the junction of Anhui,Henan and Hubei provinces in the East of China.With its varied altitude,climate,and soil texture,Dabie Mountains are extremely rich in wild plant resources.The 12th Traditional Chinese Medicine(TCM)Resources Scientific Expedition Team of Shenyang Pharmaceutical University conducted a study on wild vascular plants resources,especially medicinal vascular plants,through field investigation,literature review and specimen identification.There were 472 species of vascular plants belonging to 347 genera and 125 families collected during July 2018 in this area,of which 424 species were medicinal vascular plants,accounting for 89.83%of the total.From the perspective of medicinal parts,most of the medicinal plants there have values in their roots and rhizomes,as well as the whole plants.The efficacy and characteristics of these pharmaceutical dimensions were also summarized and analyzed in detail.Besides,among the wild vascular plants collected,the most dominant families with the biggest numbers of species are Compositae,Lamiaceae,Liliaceae,Rosaceae,Leguminosae,Ranunculaceae,Saxifragaceae and Polygonaceae,and the dominant genus are Viola and Sedum.In terms of life form,perennial herbs are dominant,accounting for 55.72%of the total species,followed by some annual(or biennial)herbs,shrubs and lianas.Finally,recommendations are put forward for strengthening the protection and utilization of wild medicinal plant resources in Dabie Mountains.
基金Under the auspices of National Natural Science Foundation of China (No. U2102209)。
文摘Mountain ecosystems play an essential role in supporting regional sustainable development and improving local ecological environments. However, economic development in mountainous areas has long been lagging, and multiple conflicts related to resource assurance, ecological protection, and economic development have emerged. An accurate grasp of the current status and evolutionary trends of mountain ecosystems is essential to enhance the overall benefits of ecosystem services and maintain regional ecological security. Based on the In VEST(Integrated Valuation of Ecosystem Services and Trade-offs) model, this study analyzed the spatiotemporal evolution patterns and the trade-offs and synergies among ecosystem services(ES) in the Dabie Mountains Area(DMA) of eastern China. The Markov-PLUS(Patch-generating Land Use Simulation) model was used to conduct a multi-scenario simulation of the area's future development. Water yield(WY) and soil conservation(SC) had overall increasing trends during 2000-2020, carbon storage(CS)decreased overall but slowed with time, and habitat quality(HQ) increased and then decreased. The ecological protection scenario is the best scenario for improving ES in the DMA by 2030;compared to 2020, the total WY would decrease by 3.77 × 10^(8) m^(3), SC would increase by 0.65 × 10^(6) t, CS would increase by 1.33 × 10^(6) t, and HQ would increase by 0.06%. The comprehensive development scenario is the second-most effective scenario for ecological improvement, while the natural development scenario did not have a significant effect. However, as the comprehensive development scenario considers both environmental protection and economic development, which are both vital for the sustainable development of the mountainous areas, this scenario is considered the most suitable path for future development. There are trade-offs between WY, CS, and HQ, while there are synergies between SC, CS, and HQ. Spatially, the DMA's central core district is the main strong synergistic area, the marginal zone is the weak synergistic area, and trade-offs are mainly distributed in the transition zone.
基金financially supported by the Open Fund of the Research Center for Petrogenesis and Mineralization of Granitoid Rocks(PMGR202014)the project of the China Geological Survey(DD20190050)。
文摘1.Objective Unlike the North China Plate where Archean and Paleoproterozoic crustal rocks are widely distributed,Early Precambrian basement rocks in the Yangtze Block of South China are locally exposed(Fig.1a),such as in the Kongling Complex,the Zhongxiang Complex,and the Douling Complex(Zhao GC and Cawood PA,2012).The Dabie Orogen is the eastward extension of the Qinling Orogen.
基金Supported by the National Natural Science Foundation of China(42002246,42002244,and 41725011)the Fundamental Research Funds of the Chinese Academy of Geological Sciences(DZLXJK202202)+1 种基金China Postdoctoral Scientific Foundation(2019M660740 and 2021T140628)project of the China Geological Survey(DD20221644).
文摘1.Objectives Precambrian microcontinents(terranes)or continental fragments are generally essential components in the evolution and architecture of Phanerozoic orogenic belts.Formation of the Qinling-Dabie Orogenic Belt,a typical Paleozoic to Triassic collisional zone between the South China Block(including the Yangtze Block and the Cathaysia Block)and the North China Block(inset map in Fig.1a),is characterized by the occurrence of several Precambrian complexes or microcontinents.
文摘The regional extent and spatial distribution of ultrahigh pressure metamorphic(UHPM) and high pressure metamorphic (HPM) rocks, and the geometrical relationships of various petrotectonic units in the Dabie-Sulu region indicate that the Triassic collisional suture line between the Sino-Korean and Yangtze cratons is situated at the northern margin of the Dabie massif, that is,along the Balifan-Mozitan-Xiaotian fault in the Dabie region, and possibly is linked to the Wulian-Yantai fault in the Sulu region to tbe east. The suture line has been strongly modified duriug and subsequent to UHPM aud HPM events.
基金funded by the National Natural Science Foundation of China(Grants.41272222 to C.Z.Song and 41472166 to S.Lin)China Geological Survey(Grants.1212011121116 to S.Lin)a China Scholarship Council scholarship to H.Liu
文摘Large-scale magmatism affected the Tongbai-Dabie orogenic belt during post-collisional lateral tectonic extension in the Cretaceous, which was suggested to account for the widespread deformation and migmatization in the Tongbai-Dabie complexes. However, it cannot explain the most deformations in the shear zones. The northwest-southeast shear zones are developed around or wrapped the Tongbai-Dabie complexes. They play an important role for the interpretation of the tectonic evolution of the Tongbai-Dabie orogenic belt. By a systematically observation and description of the geometry and kinematics of these shear zones, we found that the shear zones to the north dip NE and have a uniform sinistral shear sense, the shear zone to the south dips SW and has a uniform dextral shear sense, and the shear zones at the core are sub-horizontal and have a uniform top-to-NW sense of shear. Combining with the comparison of previous and our geochronological studies, we interpret these associations as indicating that these shear zones were originally a single, more flat-lying and sub- horizontal shear zone with a uniform top-to-NW shear sense before the folding-doming of the Tongbai- Dabie complexes and suggest that the Tongbai-Dabie orogenic belt experienced a uniform top-to-NW orogen-paraUel extension in the ductile lithosphere before the widespread magmatism in the Cretaceous.
文摘The present-day observed crustal-scale tectonic style of ultrahigh-pressure metamorphic (UH-PM) and high-pressure metamorphic (HPM ) belts in the Dabie-Sulu region was dominantly formedby extensional processes, postdating the Triassic collision between the Sino-Korean and Yangtze cratons. The extensional structures overprinting the previous structures related to contraction that produced the thickened continental crust of the UHPM and HPM belts, in particular display the typical features of a Cordilleran-type metamorphic core complex, in which at least four regionalscale, low-angle ductile shear zones that constitute a detachment system, are recognized in the Dabie region. In the Sulu region, the extensionaI structures show in the form of small-scale domes or a regional-scale SE-dipping pseudo-monocline. The geometry and the kinematics of tbe detachment zones are briefly described and their significance for the exhumation of UHPM and HPM rocks is discussed. It is iniliated that the subhorizontal crustal-scale extensional flow in the middle-lower crust, under amphibolite- to greenschist-facies conditions, was an important tectonothermal process at 200- 170 Ma and the exhumation or the UHPM and HPM rocks was achieved at least in part along multi-layered detachment zones. The regional detachment system has been the main factor enabling UHPM and HPM rocks to be brought from middle-lower crustal levels to middle-upper crustal levels.
基金Supported by Soft Science Research Program of Science and Technology Department of Hubei Province(2013BDF081)~~
文摘Taking Huanggang city as an example, the requirements of basic indexes for the regional ecological agricultural construction in Dabie Mountains were ana- lyzed and the measures that must be taken in implementing the in the Dabie Mountains were proposed.
文摘The Qinling-Dabie-Sulu high-pressure and ultra-high pressure metamorphic belt wasformed by subduction and collision between the North China and Yangtze plates. The study ofthe eclogite belt is very important in understanding the evolution of the Qinling Dabie orogen. Inthe present paper the geology, petrology, minerology and chronology of the eclogites in the Dabieand Sulu areas are described. The principal conclusions of this work are as follows: (1) Based up-on the field occurrence and the P-T conditions of the eclogites, two types of eclogite can be dis-tinguished: Type 1—the low-temperature and high-pressure eclogite in the mid-late Proterozoicmetamorphic series, and Type 2—the ultra-high pressure eclogite in the late Archaean to earlyProterozoic metamorphic complex. In the Dabie area, the ultra-high-pressure eclogite,high-pressure eclogite and epidote-blueschist units are nearly parallel to each other and stretchintermittently from north to south. (2) The P-T conditions of the high-pressure eclogites and ul-tra-high pressure eclogites have been estimated. The former are formed at 450-550℃ and1.4-1.6 GPa; while the latter at 650-870℃ and >2.7-2.9 GPa in the Dabie area and at820-1000℃ and >2.8-3.1 GPa in the Sulu area. The metamorphic temperatures of the eclogitesincrease progressively from west to east. (3) The ultra-high pressure eclogites were subjected to 5stages of metamorphism: pre-eclogite epidote amphibolite facies, peak coesite eclogite facies,post-eclogite amphibolite facies, epidote-blueschist facies or epidote amphibolite facies andgreenschist facies. The general features of the PTt path of the ultra-high pressure eclogite are:clockwise pattern, progressive metamorphism being a process of slow increasing temperature andrapid increasing pressure, and the retrogressive section with nearly isothermal decompression atthe early stage, isobaric cooling at the middle stage and nearly isothermal decompression at thelate stage. (4) At least two stages of high-pressure metamorphism occurred in the orogenic belt:the high-pressure eclogite and ultra-high pressure eclogite were formed by the subduction of theoceanic crust northward beneath the North China plate or the Dabie block during theCaledonian; while the epidote-blueschist belt came into being by subdution and collision be-tween the two continental plates during the Indosinian. (5) Due to the continuous sequentialsubduction of the cold plate, the ultra high-presssure metamorphic rocks were uplifted to thecrust by the underplating processes. They can be preserved just because of the 'frozen effect' re-sulting from the continuous subduction of the cold plate. (6) The carbonates, such as magnesite,breunnerite, aragonite and dolomite, and the H_2O-bearing minerals, such as phengite, epidoteand zoisite, were stable during the high-pressure and/or ultra-high pressure metamorphism.
基金supported by the Special Foundation of the China Meteorological Administration (Grant No.GYHY201506006)supported by the National Science Foundation of China (Grant Nos.41405100,41322032 and 41275031)
文摘The diurnal variation of precipitation over the Dabie Mountains(DBM) in eastern China during the 2013 mei-yu season is investigated with forecasts of a regional convection-permitting model. Simulated precipitation is verified against surface rain-gauge observations. The observed morning precipitation peak on the windward(relative to the prevailing synoptic-scale wind) side of the DBM is reproduced with good spatial and temporal accuracy. The interaction between the DBM and a nocturnal boundary layer low-level jet(BLJ) due to the inertial oscillation mechanism is shown to be responsible for this precipitation peak. The BLJ is aligned with the lower-level southwesterly synoptic-scale flow that carries abundant moisture.The BLJ core is established at around 0200 LST upwind of the mountains. It moves towards the DBM and reaches maximum intensity at about 70 km ahead of the mountains. When the BLJ impinges upon the windward side of the DBM in the early morning, mechanical lifting of moist air leads to condensation and subsequent precipitation.
文摘The Huangtuling hypersthene-garnet-biotite gneiss at Luotian County, Hubei Provine, is a typicalgranulite-facies rock of the Dabie Group Complex in the Dabie orogenic belt. Investigations on the morphology andoccurrence of zircons and their internal structures shown in the thin sections lead to the recognition of three types ofzircons, which are in good agreement with the types identified on the basis of morphology, colour and external fea-tures from the related zircon concentrates. The observation of zircons in the rock reveals that part of type 1 zirconsshow signs of a double-layered structure. The interval part existed in the protolith prior to the granulite-facies meta-morphism. Type 2, the prismatic zircons which mainly occur in garnet and hypersthene are metamorphic minerals ofthe granulite-facies metamorphism. Type 3, the round multifaceted zircons in felsic minerals and biotite, are proba-bly attributed to a later geological event related to migmatization. The ^(207)Pb/^(206)Pb zircon dating by direct evaporationon (thermal evaporation ion mass spectrometer) yields ages ranging from 2814 Ma to 1992 Ma. The age discrepancyamong these different zircon types is conspicuous. The yellow-brown(type 1) zircons give ages of 2814±29 Ma to2527±6 Ma, the prismatic euhedral zircons (type 2), 2456±7 Ma to 2254±4 Ma, and the round multifaceted zircons(type 3), 1992±10 Ma. The results are geologically interpreted in consideration of the complicated behaviours of zir-cons during Precambrian geological evolution of the Dabie area. (1) If the protolith of the gneiss is a sedimentaryrock, then type 1 zircons are clastic ones and the ages 2814±29 Ma and 2811±27 Ma may reflect the minimum age ofthe rocks of its source region. also the first geological event in the area. Sedimentation of the protolith occurred be-tween 2814 Ma and 2527 Ma, probably close to 2814 Ma. If the protolith is a volcanic rock, then the formation age ofthe supracrustal rocks of the Dabie Group Complex is around 2814 Ma. The age 2456±7 Ma reflects the time whenthe granulite-facies metamorphism took place. The later migmatization event is dated at aboat 1992±10 Ma, and isprobably the latest early Precambrian event in the area. The present work provides geochronological evidence for the existence of the Dabie Archaean craton, whichhad probably experienced 3 or 4 geological events during its early Precambrian evolution.
基金The research was supported by the National Natural Science Foundation of China(Grant 40272094).
文摘Five samples of muscovite from mylonites of the earlier Tanlu ductile shear zone on the eastern margin of the Dabie Mountains yield 40Ar/39Ar ages ranging from 178 Ma to 196 Ma. Three of them have reliable plateau ages of 188.7±0.7 Ma, 189.7±0.6 Ma and 192.5±0.7 Ma respectively, which indicates a syn-orogenic, sinistral strike-slip thermal event. This displacement movement derived from the continent-continent collision of the North and South China blocks took place in the Early Jurassic and after uplifting of high-pressure to ultrahigh-pressure slabs to the mid-crust. It is suggested that during the collision the Tanlu fault zone was an intracontinental transform fault caused by differential subduction speeds. The 40Ar/39Ar ages of mylonite whole-rock and muscovite from the later Tanlu ductile shear zone suggest another sinistral strike-slip cooling event at 128 Ma. During this strike-slip faulting, large-scale intrusion and doming uplift occurred in the eastern part of the Dabie orogenic belt. Data of K-feldspar 40Ar/39Ar MDD and apatite fission-track analysis from metamorphic rocks indicate two high-speed cooling events experienced by the Tanlu fault zone, which took place at 90 Ma and 45-58 Ma respectively. They correspond respectively to two phases of extensional activities in the Late Cretaceous and Eogene as well as development of the Qianshan fault-controlled basin to the east of the Tanlu fault zone. The cooling times recorded by K-feldspar and apatite show that the uplifting in the Dabie orogenic belt occured earlier than that on the eastern margin occupied by the Tanlu fault zone. The above phenomena suggest that the uplifting of the Dabie orogenic belt during the Late Cretaceous to Eogene was not controlled by the Tanlu normal faulting, but as a result of the lithospheric delamination.
文摘The granitic gneisses from the ultrahigh-pressure (UHP) metamorphic terrain of the southeastern Dabie Mountains encompass two types: monzonitic granitic gneiss and alkali-feldspar granitic gneiss, which are characterized by rich alkalis, poor CaO, high FeO/MgO, particularly high Ba, Rb, Th, Ta, REE (except Eu), Ga, Nb and Zn, and low Sr, Eu, Cr, Co and Ni. The gneisses, particularly the alkali-feldspar granitic gneiss, have typical chemical characteristics of A-type granites. They resulted from partial melting of crustal materials existing in the rift zone along the northern margin of the South China block during the Neoproterozoic. These gneisses might not have undergone UHP metamorphism during the late Triassic, but were involved into UHP rocks by the tectonic mixing process and kept the exhumation message of the UHP rocks from the middle and upper crust.
基金partly supported by the Graduate Student Academic Innovation Research Project of Anhui University(yqh100101)the National Key Research and Development Programme(2016YFC1200700)
文摘A new species of the genus Tylototriton is described,from Yuexi county,Anhui province,in the south of the Dabie Mountains.It is based on morphological and molecular analysis.The new species is identified as belonging to the Tylototriton asperrimus group and shares a number of similarities with T.wenxianensis,T.broadoridgus and T.dabienicus.The diagnostic characteristics of the new species are as follows： the head length is greater than the width of the head; bony ridges on the head are prominent and necked-in; the distal digit ends,ventral digits,peripheral area of the cloaca and the tail＇s lower edge are orange.The result from the molecular analysis of the genus Tylototriton（including the type specimen of the new species） based on three mitochondrial genes（ND1,ND2 and CYTB） indicated that the new species was close to T.wenxianensis,T.dabienicus,and T.broadoridgus,but formed an independent clade.This result was consistent with the morphological analysis above,which supports the theory that the population distributed in the south of the Dabie Mountains,namely in from Yuexi county,Anhui province,represented a distinct species,Tylototriton anhuiensis sp.nov.
基金primarily supported by the National Natural Science Foundation of China(Grant Nos.41375061,41130964 and 41461164008)the National Program on Key Basic Research project(973)(Grant Nos.2013CB430103 and 2012CB417200)the Special Public Sector Research of China(Grant No.GYHY201006004)
文摘The initiation of convective cells in the late morning of 24 June 2010 along the eastward extending ridge of the Dabie Mountains in the Anhui region, China, is studied through numerical simulations that include local data assimilation. A primary convergence line is found over the ridge of the Dabie Mountains, and along the ridge line several locally enhanced convergence centers preferentially initiate convection. Three processes responsible for creating the overall convergence pattern are identified. First, thermally-driven upslope winds induce convergence zones over the main mountain peaks along the ridge, which are shifted slightly downwind in location by the moderate low-level easterly flow found on the north side of a Mei-yu front. Second, flows around the main mountain peaks along the ridge create further convergence on the lee side of the peaks. Third, upslope winds develop along the roughly north-south oriented valleys on both sides of the ridge due to thermal and dynamic channeling effects, and create additional convergence between the peaks along the ridge. The superposition of the above convergence features creates the primary convergence line along the ridge line of the Dabie Mountains. Locally enhanced convergence centers on the primary line cause the initiation of the first convection cells along the ridge. These conclusions are supported by two sensitivity experiments in which the environmental wind （dynamic forcing） or radiative and land surface thermal forcing are removed, respectively. Overall, the thermal forcing effects are stronger than dynamic forcing given the relatively weak environmental flow.
基金funded by the National Natural Science Foundation of China (No.40525006 and 40372032).
文摘The high-pressure （HP） eclogite in the western Dabie Mountain encloses numerous hornblendes, mostly barroisite. Opinions on the peak metamorphic P-T condition, PT path and mineral paragenesis of it are still in dispute. Generally, HP eclogite involves garnet, omphacite, hornblendes and quartz, with or without glaucophane, zoisite and phengite. The garnet has compositional zoning with XMg increase, XCa and XMn decrease from core to rim, which indicates a progressive metamorphism. The phase equilibria of the HP eclogite modeled by the P-T pseudosection method developed recently showed the following： （1） the growth zonation of garnet records a progressive metamorphic PT path from pre-peak condition of 1.9-2.1 GPa at 508~C-514~C to a peak one of 2.3-2.5 GPa at 528~C-531~C for the HP eclogite; （2） the peak mineral assemblage is garnet＋omphacite＋glaucophane＋quartz_＋phengite, likely paragenetic with lawsonite; （3） the extensive hornblendes derive mainly from glaucophane, partial omphacite and even a little garnet due to the decompression with some heating during the post-peak stage, mostly representing the conditions of about 1.4-1.6 GPa and 580~C-640~C, and their growth is favored by the dehydration of lawsonite into zoisite or epidote, but most of the garnet, omphacite or phengite in the HP eclogite still preserve their compositions at peak condition, and they are not obviously equilibrious with the hornblendes.
基金financed by 973 Chinese National Key Project for Basic Research(2003CB716500)the Scientific Investigation of Chinese Continental Scientific Drilling Project(2001 CCB00900)National Natural Science Foundation of China(Grant No.40172079),Anhui Bureau of Geology and Mineral Resources
文摘The geometry of the Dabie Mountains is manifested in terms of the distribution of petro-tectonic units in three dimensions. It is identified into three segments from east to west, four horizons in vertical profiles and eight petro- tectonic units from north to south. Three segments are the east, middle and west segments. Four horizons, from top to bottom, are two different meta-tectonic mélange in the uppermost part, underthrust basement and cover below them, and mantle at the bottom of the profiles. Eight petro-tectonic units from north to south are: (1) the hinterland basin, (2) the meta -flysch, (3) the ultramafic rock belt (UM) + Sujiahe eclogite belt (SH), (4) eclogite belt 2 (Ec2) with most eclogites of continental affinity, (5) eclogite belt 1 (Ecl1) with some eclogite of oceanic affinity, (6) the Dabie complex or underthrust basement of the Yangtze continent, (7) the Susong and Zhangbaling Groups or underthrust cover of the Yangtze continent and (8) the foreland belt. The (3), (4) and (5) units belong to meta-tectonic mélange. Some ultrahigh pressure metamorphic minerals such as coesite and micro-diamonds have been found in (3) and (4) units; a possible ultrahigh pressure mineral, clinozoisite aggregate pseudomorph after lawsonite, was found in unit (5). The three tectonic units are speculated to be coherent initially; the UM and SH units are suggested to be the root belt in the east, middle and west segments respectively. The kinematics of the Dabie orogen is divided into three stages: top-to-south thrusting during the eclogite-granulite facies metamorphism, top-to-north extension during the amphibolite metamorphic stage, and faults or shear bands of brittle deformation and greenschist facies metamorphism were formed in the post-orogenic stage since the Late Jurassic and the movement pictures of these faults is different from each other.
基金supported by the National Natural Science Foundation of China (Grant Nos. 31272332, 31071894, 30911120031, 30670243)Anhui Province Higher Education Revitalization Plan+2 种基金2014 Colleges and Universities Outstanding Youth Talent Support ProgramFoundation for Graduate Student Academic Innovation Research Project of Anhui University (yqh100081)the Foundation for College Student Innovation & Venture Project of Anhui University(201610357026)
文摘A new species of rhacophorid of the genus Rhacophorus is described from the Dabie Mountains of west Anhui, east China. The new species, Rhacophorus zhoukaiyae sp. nov. is distinguished from its congeners by a combination of the following characters： 1） the ventral surface and front-and-rear of the femur is paler yellowish and decorated with irregular grayish blotching, and without obvious spots on the dorsum of the hand and foot webbing; 2） the outer metatarsal tubercle is small; 3） outer fingers are half-webbed and outer toes two third webbed; 4） the skin on the dorsum is smooth and without compressed warts; 5） the throat, chest and belly are pure paler yellowish; 6） the dorsal part of the fingers and toes are grayish-white; 7） the iris is golden-yellow. In addition, the phylogenetic tree showed that all the individuals of R. zhoukaiyae sp. nov. clustered into one distinct clade which suggested the validity of this species. This results could also be used to the support of species delimitation. Currently, this species is known only from mid-elevation montane evergreen forest in the Dabie Mountains of west Anhui, China.
基金funded by the Ministry of Science and Technology of China(No.G19990755-01)the National Natural Science Foundation of China,Postdoctoral Science Foundation of China,the Chinese Academy of Sciences Wong K.C.Post-doctoral Research Award Fund and the State Key Laboratory of Mineral Deposits,Nanjing University
文摘Omphacite grains from UHP eclogite of the Dabie Mountains in eastern China are elongated and show strong lattice preferred orientations (LPOs). Observations by the transmission electron microscopy (TEM) identified not only structures of plastic deformation occurring as free dislocation, dislocation loops and dislocation walls, but also bubbles of water present in the deformed omphacite. The bubbles attach to the dislocation loops which are often connected to one another via a common bubble. Using infrared spectroscopy (IR), two types of hydrous components are identified as hydroxyl and free-water in the omphacite. An analysis of deformation mechanism of microstructure in omphacite suggests that the mineral deformed plastically under UHP metamorphic conditions by dislocation creep through hydrolitic weakening.
文摘To the north of the Qinling-Dabie orogen there exists a Mesozoic (K1) granite-syenite belt called the Beihuaiyang granite-syenite belt, in which the Xianghongdian alkaline complex outcrops in the Devonian Foziling schist and also intruded into the slightly earlier volcanic rocks. This alkaline complex is composed of syenite, alkaline syenite and nepheline syenite, but the nepheline syenite occurs inside the alkaline syenite in the pod-like, irregular, lenticular or layered shape. Researches on the petrogenesis of the alkaline complex and the relationship between the alkaline syenite and the nepheline syenite must rely on precise isotopic ages. Previous researches have reported isotopic dating results merely by the 40Ar/39Ar method on hornblende and biotite separated from the alkaline syenite and nepheline syenite. In view of this, the authors have made fairly detailed isotopic geochronological studies of the alkaline syenite and nepheline syenite by using Rb-Sr isochron for the whole rock and minerals, U-Pb for single zircon separate and the 40Ar/39Ar method for hornblende and potash feldspar. The results of this research are completely different from those of previous researches and show that the nepheline syenite was formed far earlier than the alkaline syenite.
