Western Hunan Province Research Articles

The Sustainability Analysis of Land Use and Social Economy in Mountain Areas, Western Hunan Province, China

Western Hunan is the core and key area of ecological restoration and protection in the mountain areas of southern China and the middle and upper reaches of the Yangtze River. How to make a good trade-off in land-using between ecological conservation and economic development is the primary issue for the regional sustainable development. We analyzed the spatial-temporal changes of land use and socio-economic development in this area. The results showed that: 1) The change of cropland, woodland and urban construction land from 1980 to 2018 was significant, and cropland was evolving towards the hollowing pattern, while the urban construction was expanding from the center to the periphery; 2) With the high speed of socio-economic development in recent years, rural population and the production industry proportion of each county deceased, while urban population, the manufacturing industry proportion and the service industry proportion were increasing; 3) There was a strong correlation between the area proportion of cropland, woodland and the proportion of rural population and the production industry, and the correlation decreased first and then increased with the annual economic development, while the urban construction land had a certain correlation with urban population and the manufacturing industry and the service industry, especially with the service industries. On the basis of further analysis, it was concluded that the social and economic development were the important driving factors to land use change, the capacity of ecosystem services reduced in recent years. The results could be used as the basis for the local government to make decision on the effective land protection. It was also a reference information for researchers to carry out in-depth optimization and integrated management on land resources, so as to achieve the good synergistic effect for both socio-economic development and land protection and promote the sustainable development of human society and economy.

Contribution to the knowledge of subterranean ground beetles from eastern Wuling Mountains, China (Coleoptera: Carabidae: Trechinae)

Two new genera and three new species of troglobitic trechine beetles are described and illustrated from the eastern part of Wuling Mountains: Xiangxius jiangi n. gen., n. sp. and Guizhaphaenopsodes solidior n. gen., n. sp. from the limestone cave Tangle Dong (Jishou, western Hunan Province); Sinotroglodytes hefengensis n. sp. from the limestone cave Qizimei Dong (Hefeng, southwestern Hubei Province). Xiangxius jiangi is a highly modified cave-adapted beetle with elongate body and appendages, recognized by its peculiar elytral shape and remarkable dorsal and marginal umbilicate pores of elytra. Guizhaphaenopsodes solidior is peculiar for its stout body, robust antennae and pigmented forebody, antennae and legs though it shares several generic important characteristics with the genus Guizhaphaenops Vigna Taglianti, 1997. Sinotroglodytes hefengensis has an elongated and parallel-sided head.

Genesis of the carbonate-hosted Pb–Zn deposits in western Hunan, South China: Constraint from Pb isotopic signature

Lead-zinc ore deposits hosted by carbonatic strata are the most important ore type of Pb–Zn resources in South China and have long been studied. Although their metallogenic timing has been well constrained recently to the Caledonian, our understanding of the metal sources and mineralization mechanism remains controversial. This study aims to provide new insights to these contexts via a new Pb isotope tracing of the Xiangshuidong deposit in the western Hunan Province. The Xiangshuidong deposit is one of the typical deposits in the Huayuan-Tongren Pb–Zn ore-concentrated area in South China. Both ore-forming sulfides and carbonates of the host strata were analyzed by in situ analysis using MC-LA-ICPMS. Along with compiled data of other typical deposits of the same type in South China, it is revealed that: the ore-forming sulfides were distinctively different from the carbonates of the host strata in Pb isotopic signatures; the ore-forming metals were sourced mainly by regional high-grade crystalline basements, rather than host rocks or adjacent strata; the ores display metallogenic characteristics typical of Mississippi Valley Type (MVT) Pb–Zn deposits, rather than reworked sedimentary deposits. A metallogenic model for the Caledonian Pb–Zn ores is accordingly proposed and a new guidance on further ore exploration is suggested.

Phytochemical profiling of antioxidative polyphenols and anthocyanins in the wild plant Campanumoea lancifolia (Roxb.) Merr

ABSTRACT The wild plant Campanumoea lancifolia (Roxb.) Merr (also called Hong Guo ginseng, HGG), is naturally distributed in a Hmong minority area in western Hunan Province, China. The objective of this study was to identify, quantify, and elucidate the polyphenols and anthocyanins, and their antioxidant activities (via 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical and 2,2ʹ-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cation scavenging abilities) tested in vitro in the whole fruit, fruit skin, fruit pulp, and leaves of the plant. Results showed that Total polyphenol content (TPC) was highest in leaves (97.76 mg/g), followed by whole fruit (18.18 mg/g), fruit skin (26.16 mg/g), and fruit pulp (8.99 mg/g). Total anthocyanin content (TAC) in fruit skin was the highest at 27.44 mg/g, compared with leaves (20.18 mg/g), whole fruit (12.94 mg/g), and fruit pulp (4.36 mg/g). DPPH scavenging ability and ABTS scavenging ability test followed a decreasing order with the highest ability in leaves, fruit skin, whole fruit, and fruit pulp. Main phenolic compounds (chlorogenic acid, rutin, luteolin-7-O-glucoside, and apigenin) were also highest in leaves. Phenolic compounds and anthocyanins in whole fruit and leaves were further identified using UPLC-QTOF-MS, resulting in the identification of six phenolic acids and their derivatives, seventeen flavonoids and their derivatives, and two anthocyanins observed. These results thus provide the phytochemical evidence to explain and understand the medical and health benefits of HGG.

Effects of Forest Canopy Structure on Forest Aboveground Biomass Estimation Using Landsat Imagery

Accurate remote sensing-based forest aboveground biomass (AGB) estimation is important for accurate understanding of carbon accounting and climate change at a large scale. However, over- and underestimation are common in the process, resulting in inaccurate AGB estimations. Here, the AGB was estimated and mapped by combining Landsat 8 images and forest inventory data in western Hunan Province, China. We used forest canopy density (FCD) mapper to quantify the forest canopy structure. The linear model (LR) and piecewise model with FCD gradients (classified by k-means clustering; sparse, medium, and dense) were developed to estimate AGB for each forest type (coniferous, broadleaf, mixed, and total forests). The piecewise model considered the following scenarios: piecewise model using the variables of LR model (PM), and piecewise model using the variables selected for different FCD gradients (PMV). The PM (R2:0.45–0.56) and PMV (R2:0.63–0.75) models showed better agreement between observed and predicted AGB than the LR (R2:0.18–0.27) models, and the PMV model was the most accurate for each forest type. The PM and PMV models performed better than LR models at different FCD gradients. The PM and PMV models can better alleviate the over- and underestimations of the LR models. At different FCD gradients, the PMV models had different variables, indicating that the correlation between the AGB and spectral variables was different. Overall, FCD is an important forest parameter that influences AGB estimation, and the piecewise model has potential to improve remote sensing-based AGB estimation.

Origin of the carbonate-hosted Danaopo Zn-Pb deposit in western Hunan Province, China: Geology and in-situ mineral S-Pb isotope constraints

The western Hunan-eastern Guizhou (WHEG) Pb-Zn metallogenic belt hosts around 300 carbonate-hosted Pb-Zn deposits (total Pb-Zn metal reserve: >20 Mt), accounting for a major proportion of Pb-Zn resource in China. The origin and ore-forming process of these Pb-Zn deposits are still under debate. The newly-discovered Danaopo Zn-Pb deposit (~150 Mt ore @ 2.58% Zn and 0.48% Pb), which was formed during the Early Devonian orogenic event (~410 Ma), is one of the largest Zn-Pb deposits in the region. In this study, LA-MC-ICP-MS S-Pb isotope analyses were performed on sulfides (pyrite, sphalerite, and galena) and sulfate (barite) from the Danaopo Zn-Pb deposit. δ34SVCDT values of the diagenetic and late hydrothermal barites are of +36.5 to +36.9‰ and +27.1 to +28.1‰, respectively. The sulfides δ34SVCDT values (+23.5 to +35.5‰) imply a thermochemical sulfate reduction (TSR) origin from coeval seawater sulfates, as supported also by the dissolution cavities of diagenetic barite and the nodular and stripe-textured calcite. Furthermore, in-situ sulfide Pb isotopic ratios of different ore-forming stages and altitudes are highly similar: 206Pb/204Pb = 18.144–18.254, 207Pb/204Pb = 15.718–15.797, and 208Pb/204Pb = 38.378–38.605. Such narrow Pb isotopic ranges suggest well-mixing of multiple Pb sources, which likely include the Lower Cambrian Niutitang Fm. (LCNF) black shale, Proterozoic Banxi Group metamorphic basement rocks, and the Lower Cambrian Qingxudong Fm. (LCQF) reef limestone. Considering the deposit geological and S-Pb isotopic features, we suggest that the hydrothermal fluids may have circulated and extracted metals from various sequences in the basin. The fluids then ascended along the Huayuan-Zhangjiajie fault zone and mixed with reduced sulfur-bearing fluids from ore-bearing strata and precipitated the sulfide ores. Mineralization at the Danaopo deposit is thus best classified as Mississippi Valley Type (MVT), which is controlled by the ore-hosting reef limestone and various fault structures.

Spatiotemporal Dynamics of Cultivated Land and Its Influences on Grain Production Potential in Hunan Province, China

Understanding the impact of changes in cultivated land in terms of structure, distribution, and quantity on grain production potential (GPP) is essential for a sustainable land utilization strategy and food security. Cultivated land balance (CLB), as a critical policy aiming at protecting farmland in China, has greatly restricted the loss of cultivated land. However, changes in cultivated land were largely generated due to the land-use activities led by the CLB policy. To clarify how the spatiotemporal dynamics of cultivated land led by the CLB policy affects the GPP, this work discusses the impact mechanism of cultivated land changes on GPP and provides an empirical analysis in Hunan Province, China. This study shows that the activities that merely aim at restricting the loss of cultivated land under CLB cannot stop the decline in GPP in China, since it requires the government to reclaim a certain amount of cultivated land that is equal to that occupied for non-cultivated land use. Furthermore, the distribution of cultivated land changed after the implementation of CLB and, as a result, contributed to the decrease in the quality of cultivated land and GPP. Quantity, productivity, and other elements that may potentially facilitate cultivated land protection are greatly advocated to be considered to enrich the connotation of the CLB policy in China. It also found that less developed regions located in central and western Hunan Province, among other areas, observed a higher sensitivity of GPP to cultivated land change. More attention should be paid to protecting cultivated land in these regions and addressing issues such as the abandonment of high-quality cultivated land.

STUDY ON THE CHARACTERISTICS OF HMONG MINORITY'S VERNACULAR DWELLINGS AT HUAYUAN COUNTY IN XIANGXI AREA (CHINA)

Abstract. Hmong vernacular dwellings are an indispensable and essential branch of traditional Chinese architecture, which bears the profound history of the integration of minority culture and Han culture for thousands of years. As a typical representative of the Hmong settlement in China, the Hmong Village in Huayuan County, western Hunan Province, has the distinct characteristics of respecting nature and making good use of terrain in the construction of vernacular dwellings, which embodies the unique regional, historical, cultural and national character. Firstly, the article analyzes the influence of terrain, landform, climatic environment, historical culture, and social structure on the layout, shape, and materials of the rural homes of the Hmong people in Huayuan County. Secondly, by analyzing the elements of the courtyard space, the layout characteristics of the courtyard, and the organization mode of the courtyard group, the overall spatial characteristics of the residential courtyard are analyzed. At the same time, from the perspective of a single residential house, to sort out the characteristics of its type as well as the floor plan, building structure, material colour, and detailed decoration. Finally, it emphasizes that the Hmong vernacular dwellings in Huayuan County, embody the distinctive cultural connotation of the Hmong nationality, and show the unique aesthetic and romantic sentiment of the Hmong vernacular architecture to the world.

A Horodyskia-Nenoxites-dominated fossil assemblage from the Ediacaran-Cambrian transition (Liuchapo Formation, Hunan Province): Its paleontological implications and stratigraphic potential

Because of the scarcity of fossil data, life evolution in deep-water settings through the Ediacaran-Cambrian transitional interval is still poorly understood. This study describes a Horodyskia-Nenoxites-dominated fossil assemblage from the chert of the Liuchapo Formation in Liujiata Village, western Hunan Province, which was deposited in a slope to basinal setting at the terminal Ediacaran and earliest Cambrian. In this assemblage, Horodyskia covers the longest range, possibly from the upper part of the Lower Ediacaran to the base of the Cambrian. Other members, including three types of Nenoxites, ?Helanoichnus, ?Shaanxilithes, and two affinity-undetermined forms, appear in the upper part of the Liuchapo Formation. The whole assemblage exhibits an upward increasing complexity and fossil abundance, which reaches its acme at a few meters below the Cambrian Xiaoyanxi Formation. Regardless of the lithology of the host rock, these fossils are exclusively preserved with clay minerals and devoid of any detectable concentration of carbon. Such a preservation mode is dominant among the known records of these fossils worldwide and possibly related to an unknown biological commonality of these organisms. Microscope observations support a body-fossil origin of Nenoxites and contradict the trace-fossil interpretation. Meanwhile, some large Horodyskia show features implying a close relation to testate amoebae. However, despite some resemblances, the differences between these fossils and any suggested relatives are considerable. Taking all the information together, we tentatively interpret this fossil assemblage as a diverse and complex deep-water community of protist-grade organisms. The worldwide occurrence of some members in this assemblage endows them with a biostratigraphic potential. Nevertheless, to establish such a tool, more quality data of fossil occurrences and referential radiometric ages, and a better understanding of the interplay between these organisms and sedimentary environments are required.

Pore-structure characterisation of tectonically deformed shales: a case study of Wufeng-Longmaxi Formation in western Hunan Province, southern China

The impacts of tectonic deformation on pore structure of the Wufeng-Longmaxi shales in southern China were studied on tectonically deformed shales. Core description, thin-section observation, total organic carbon, X-ray diffraction, low-pressure gas (N2 and CO2) adsorption, mercury intrusion capillary pressure and field emission-scanning electron microscopy experiments were performed. The undeformed shale (UDS), brittle deformed shale (BDS) and ductile deformed shale (DDS) can be sorted based on the variability of original texture, fabric and structure properties of the shale samples. In addition, shale samples with different deformation mechanisms have various pore-structure characteristics. Organic matter pores and interparticle pores in clay minerals are the dominant pore types in the selected shale samples. The BDS sample has a greater proportion of macropores (or micro-fractures), indicating brittle tectonic deformation has a significant effect on the development of macropores in shales. In contrast, the DDS sample has more micropores than the UDS and BDS samples, suggesting ductile tectonic deformation may damage larger pores owing to the compression by complex tectonic stress.

An Estimation and Analysis of CO2 Emission of Tourism Industry in Western Hunan Province, China

An Estimation and Analysis of CO2 Emission of Tourism Industry in Western Hunan Province, China

Heavy metal concentrations in Chinese folk medicines for treating epilepsy in children in rural China, and their prescription by village doctors: a cross-sectional survey

BackgroundIn areas of rural China inhabited by minority groups, local village doctors often use traditional Chinese folk medicines to treat primary epilepsy in children. However, such folk medicines have been implicated in heavy metal poisoning in children. This study determined the heavy metal concentrations of samples of folk medicines, and examined the attitudes of local doctors regarding their use. MethodsInductively coupled plasma-optical emission spectrometry (ICP-OES) was used to identify toxic heavy metals from 33 samples of folk medicines (28 mixtures and five monomers) from eight counties in western Hunan Province, China, from March 1, 2018 to March 30, 2018. Village doctors in western Hunan Province, China, participated in face-to-face interviews based on a questionnaire focused on knowledge about the heavy metal toxicity of folk medicines. FindingsFour toxic heavy metals—cadmium (Cd), lead (Pb), mercury (Hg), and arsenic (As)—were identified in the samples. The mean (SD) concentrations of Cd, Pb, Hg, and As, were 0·513 (0·237), 5·145 (2·404), 0·298 (0·179), and 0·321 (0·106) mg/kg, respectively. Furthermore, Cd was found in 76%, Pb in 68%, Hg in 38%, and As in 24% of the samples. These levels exceeded the Chinese legal limits of 0·3, 5·0, and 0·2 mg/kg, respectively. The highest concentration of lead found in a sample was 65·42 mg/kg. The questionnaire was completed by 112 village doctors, of whom 68% considered folk medicine to be safe for treating epilepsy and 77% believed that some heavy metals, especially lead, were efficacious for treating epilepsy. InterpretationSome folk medicines contain heavy metal concentrations exceeding safe limits. The use of folk medicines by rural village doctors to treat epilepsy might lead to increased heavy metal exposure in children in these rural areas. It is important to focus on this issue given the potential harmful effects on children's health. There is a clear need for multifaceted interventions that target village doctors to improve their knowledge of heavy metal poisoning in children. FundingThis study was supported by the Yale-China Association.

Protocol of Miao medical LIU's infant tuina genre "Tui Wu Jing" in western Hunan province for prevention of asthma recurrence

The Miao medical LIU's (LIU Kaiyun) infant tuina genre in western Hunan Province is one of the most famous infant tuina genres in China. Based on physiological and pathological characteristics of infants, generation-inhibition theory of five-elements and Miao medical's promotion-inhibition theory of five-meridians, the tuina protocol of "Tui Wu Jing" was flexibly adjusted; according to different constitution types, including lung-deficiency type, spleen-deficiency type, kidney-deficiency type, qi-deficiency type, yin-deficiency type, yang-deficiency type, phlegm-wet type, phlegm-heat type, different protocols were adopted to prevent or reduce the asthma recurrence and reach the aim of regulating constitution and disease prevention.

Intraspecific variation of trunk segmentation in the oryctocephalid trilobiteDuyunaspis duyunensisfrom the Cambrian (Stage 4, Series 2) of South China

A detailed exploration of growth and trunk segmentation of the oryctocephalid trilobite, Duyunaspis duyunensis Chang & Chien in Zhou et al. 1977, from the lower Cambrian (Stage 4, Series 2) Balang Formation in western Hunan Province, South China, is presented. Because of the excellent preservation, the complete post-protaspid ontogenetic series from merapsid degree 0 to the holaspid phase is described. The ontogenetic series reveals new information on morphological changes such as the migration of the posterior branch of the facial sutures (from proparian to opisthoparian) and contraction of the posteromedial notch in the pygidium. The abundance of articulated specimens available from a narrow stratigraphical interval makes this material singularly useful for studying the morphogenesis and post-embryonic growth of D. duyunensis in comparison with other oryctocephalids. Strong evidence that multiple numbers of pygidial segment are recognized in each meraspid degree as well as in the holaspid period showed unusual intraspecific variability in the rate of trunk segmentation, providing insights into how Cambrian subisopygous trilobites controlled their body patterning, including size, shape and trunk segment number in both thorax and caudal plate during growth.

Geochronological constraints on stratigraphic correlation and oceanic oxygenation in Ediacaran-Cambrian transition in South China

The continuous late Ediacaran - early Cambrian deep-water successions of South China archive the complete evolution of seawater chemical conditions in the deep ocean during this critical time interval. However, the geochemical data from these poorly fossiliferous and condensed successions lack high-resolution stratigraphic constraints, hampering their interpretation for the spatio-temporal evolution of the sweater chemistry in this time interval. In this study, we report a new SIMS and CA-ID-TIMS zircon U-Pb age 545.76±0.66Ma (total uncertainty) for an ash bed at the lower Liuchapo Formation in the deep-water Longbizui section in western Hunan Province. The new age suggests that the lower and the middle-upper parts of the Liuchapo Formation in the deep water facies can be correlated with the lower Dengying Formation and the upper Dengying - lower Zhujiaqing formations in the shallow water facies, respectively. This correlation implies that the correlative horizon of the Ediacaran-Cambrian boundary in the deep water facies in South China is likely located near the base of a widespread negative δ13Corg excursion at the upper Liuchapo Formation. Based on our new geochronological framework, the compilations of Fe-speciation, Mo, and U data indicate that the deep ocean was characterized by widespread anoxic, ferruginous water, with intermittent euxinic water impinged on the middle-lower slope in Ediacaran-Cambrian transition, and significant oxygenation events occurred in 533–520Ma. The compilations do not support any significant oceanic oxygenation events in 551–535Ma.

A new species of the Southeast Asian genus Opisthotropis (Serpentes: Colubridae: Natricinae) from western Hunan, China.

A new species of natricine snake of the Southeast Asian genus Opisthotropis Günther, 1872 is described from western Hunan Province of China based on both mitochondrial DNA and morphological data. The new species is morphologically most similar and genetically most closely related to O. cheni Zhao, 1999 and O. latouchii (Boulenger, 1899), but possesses considerable genetic divergence (p-distance 5.1%-16.7%) and can be differentiated from all other congeners by a combination of the following morphological characters: (1) body size large (total length 514-586 mm) and strongly built; (2) dorsal scale rows 17 throughout, feebly keeled anteriorly and moderately keeled posteriorly; (3) ventral scales 147-152, subcaudal scales 54-62; (4) preocular absent, loreal elongated and touching orbit; (5) supralabials 8-9, fifth and sixth entering obit; (6) anterior temporals short, length 1.74-2.04 times longer than width; (7) maxillary teeth subequal, 28-30; (8) dorsal surface of head with distinct irregular yellow stripes and markings edged with ochre; (9) body with clear black and yellow longitudinal streaks, partly fused to several lighter patches or thicker stripes anteriorly; and (10) venter pale yellow, with asymmetric blackish speckles along outer margin. We present an updated diagnostic key to all members of the genus Opisthotropis, and recommendations on the ecological study for the group are provided.

Ontogenetic characterization of sporangium and spore of Huperzia serrata: an anti-aging disease fern

Background Huperzia serrata is a medicinal plant used in Traditional Chinese Medicine, which has been used to prevent against aging diseases. It is mainly propagated by spores and grows extremely slowly. Due to severe harvest, it is a highly endangered species. In this report, we characterize ontogenesis of sporangia and spores that are associated with propagation. A wild population of H. serrata plants is localized in western Hunan province, China and protected by Chinese Government to study its development (e.g. sporangia and spores) and ecology. Both field and microscopic observations were conducted for a few of years.ResultsThe development of sporangia from their initiation to maturation took nearly 1 year. Microscopic observations showed that the sporangial walls were developed from epidermal cells via initiation, cell division, and maturation. The structure of the mature sporangial wall is composed of one layer of epidermis, two middle layers of cells, and one layer of tapetum. Therefore, the sporangium is the eusporangium type. Spore development is characterized into six stages, initiation from epidermal cell and formation of sporogenous cells, primary sporogenous cell, secondary sporogenous cell, spore mother cell, tetrad, and maturation.ConclusionThe sporangial development of H. serrata belongs to the eusporangium type. The development takes approximately 1 year period from the initiation to the maturation. These data are useful for improving propagation of this medicinal plant in the future.

Ore‐Forming Material Sources of the Shizishan Pb‐Zn Deposit in Western Hunan Province, China

Ore‐Forming Material Sources of the Shizishan Pb‐Zn Deposit in Western Hunan Province, China

Influence of different ecosystems on the soil moisture and karst effect in Luota, West Hunan Province of China

In this paper, we study the soil CO2 concentration, soil respiration rate, dissolution rate and soil water content of different ecosystems in Luota, western Hunan Province, China, using the CO2 gas monitoring tube method, alkali absorption method, standard specimen method and drying method. The results show the following: the soil CO2 concentrations of the different depths have the same change trends in the forest and bush ecosystems. In spring, autumn and winter, the trends increase as the soil layer deepens, while in summer they first reduce and then increase as the soil layer deepens. However, the seasonal change dynamics differ slightly, and the soil CO2 concentrations of the forest ecosystem at the different depths and in the different seasons are greater than those of the bush ecosystem. From the perspective of comparing the full-year soil CO2 concentration, the full-year soil CO2 concentrations of the forest ecosystem at the depths of 10, 20 and 40 cm are, respectively, 1.66, 1.59 and 1.90 times those of the bush ecosystem. From the perspective of the soil respiration rates of the different seasons, the seasonal change trends of the forest and bush ecosystems are the same, both being summer > autumn > spring. The soil respiration rates of the forest ecosystem in the different seasons are higher than those of the bush ecosystem, and in spring, summer and autumn the respective soil respiration rates of the forest ecosystem are 2.09, 3.46 and 3.06 times those of the bush ecosystem. At the different depths, the dissolution rates have the same change trends in the forest and bush ecosystems, and the dissolution rates at the depth of 15 cm are both greater than those on the ground. At the same depth, the dissolution rate of the forest ecosystem is greater than that of the bush ecosystem, and the dissolution rates on the ground and at the depth of 15 cm are, respectively, 1.11 and 2.57 times those of the bush ecosystem. The soil water content of the forest ecosystem is 1.07 times of that of the bush ecosystem, and the soil water content stability of the forest ecosystem is higher, indicating that the forest ecosystem has a better karst effect.

New SIMS U–Pb zircon age and its constraint on the beginning of the Nantuo glaciation

A new SIMS U–Pb zircon age of 654.2 ± 2.7Ma was reported from the middle Datangpo Formation in Changyang County of Hubei Province, China. The age is identical with that of 654 ± 3.8Ma from the top Datangpo Formation in western Hunan Province, revealing that the volcanic activities (~654Ma) may have occurred widely in South China. The occurrence of the tuff beds (~654Ma) at different intervals of the Datangpo Formation indicates that the erosion process after the Datangpo deposition varied significantly in different areas. It is thus consequently suggested that the rift in South China was active until the Nantuo glaciation. In addition, the new age confirms that the Nantuo glaciation started much later than 654Ma.