Eastern Guangxi Research Articles

Analysis on the Growth and Convergence of Agricultural Green Total Factor Productivity in Guangxi

This paper uses DEA-SBM super-efficiency model and GML index to calculate the agricultural green total factor productivity (AGTFP) of Guangxi from 2014 to 2020, and analyzes the convergence of AGTFP and its influencing factors. The study finds that: First, Guangxi's AGTFP increased by 5.42% annually, mainly driven by the agricultural green technology progress; Second, the growth of AGTFP in different regions exists heterogeneous, and the growth rate of western Guangxi ranks first in Guangxi; Third, the AGTFP in Guangxi shows a state of first σ converges and then σ diverges, there is absolute β convergence in AGTFP in Guangxi, this phenomenon exist in northern Guangxi, central Guangxi, southern Guangxi and eastern Guangxi, but there is no absolute β Convergence in western Guangxi ; Fourth, agricultural structure inhibits AGTFP, while the level of fiscal support for agriculture promotes AGTFP.

Potentially suitable habitat prediction of Pinus massoniana Lamb. in China under climate change using Maxent model

BackgroundPinus massoniana is an important timber species with high ecological and economic value in southern China and a pioneer species for the reforestation of barren mountains. The structure and function of the existing Masson pine ecosystem have been seriously affected by worsening habitats under current climate change. Its suitable habitat is likely to change greatly in the near future.MethodsTo estimate the potential geographic distribution of P. massoniana and its response to climate change, the Maxent model was selected to simulate the potentially suitable habitat and corresponding changes in the distribution pattern of P. massoniana under current and future climate scenarios (SSP1-2.6, SSP2-4.5, and SSP5-8.5) with two periods (2050s and 2090s).ResultsUnder current climate conditions, the total suitable habitat area of P. massoniana was 2.08 × 106 km2, including 0.76 × 106 km2 of highly suitable habitat, concentrated mainly in Jiangxi and Zhejiang, central and southeastern Hunan, northern Fujian, central and western Chongqing, southern Anhui, central and surrounding areas of Guangdong, central and eastern Guangxi, and northern Taiwan. The areas of moderately suitable habitat and poorly suitable habitat were 0.87 × 106 km2 and 0.45 × 106 km2, respectively. Temperature and precipitation appear to be the most important predictors: precipitation of the driest month (14.7–215.6 mm), minimum temperature of the coldest month (−3.5–13.8°C), annual temperature range (8.1–32.9°C), and mean temperature of the warmest quarter (23.6–34.7°C). P. massoniana are predicted to expand their potential distribution under future climate change: by the end of this century, their total suitable habitat area increased 0.26 × 106 km2 (10.61%) and 0.45 × 106 km2 (17.05%) under the most moderate (SSP1-2.6) and severe (SSP5-8.5) warming scenarios, respectively, by mainly extending northward.ConclusionUnder the different future climate scenarios, the total suitable habitat area of P. massoniana increased by mainly extending northward. Overall, our study clarifies the potential habitat distribution of P. massoniana and provides a critical empirical reference for future P. massoniana conservation and planting practices.

Landslide Susceptibility Assessment Based on Different MaChine Learning Methods in Zhaoping County of Eastern Guangxi

Regarding the ever increasing and frequent occurrence of serious landslide disaster in eastern Guangxi, the current study was implemented to adopt support vector machines (SVM), particle swarm optimization support vector machines (PSO-SVM), random forest (RF), and particle swarm optimization random forest (PSO-RF) methods to assess landslide susceptibility in Zhaoping County. To this end, 10 landslide disaster-related variables including digital elevation model (DEM)-derived, meteorology-derived, Landsat8-derived, geology-derived, and human activities factors were provided. Of 345 landslide disaster locations found, 70% were used to train the models, and the rest of them were performed for model verification. The aforementioned four models were run, and landslide susceptibility evaluation maps were produced. Then, receiver operating characteristics (ROC) curves, statistical analysis, and field investigation were performed to test and verify the efficiency of these models. Analysis and comparison of the results denoted that all four landslide models performed well for the landslide susceptibility evaluation as indicated by the area under curve (AUC) values of ROC curves from 0.863 to 0.934. Among them, it has been shown that the PSO-RF model has the highest accuracy in comparison to other landslide models, followed by the PSO-SVM model, the RF model, and the SVM model. Moreover, the results also showed that the PSO algorithm has a good effect on SVM and RF models. Furthermore, the landslide models devolved in the present study are promising methods that could be transferred to other regions for landslide susceptibility evaluation. In addition, the evaluation results can provide suggestions for disaster reduction and prevention in Zhaoping County of eastern Guangxi.

Linking ocean subduction with early Paleozoic intracontinental orogeny in South China: Insights from the Xiaying complex in eastern Guangxi Province

The tectonic setting of the early Paleozoic orogeny in the South China Block (SCB) has been hotly controversial. Although most studies have ascribed it to an intracontinental orogeny, there are various views on the geodynamic drivers of the intracontinental orogeny. This study reports on the Ordovician Xiaying igneous complex in the eastern part of Guangxi province, southern South China. This complex is composed of granodiorite, monzogranite and micro-granular diorite enclosed by granodiorite. The zircon U–Pb dating suggests that these three types of rocks emplaced synchronously at around 464–442 Ma, significantly older than those S- and I-type granites (450–400 Ma) distributed in the interior of the SCB. One monzogranite collected in the border of the complex has an older age (480 Ma). The Xiaying hornblende–bearing granodiorites have low SiO2 (61.8–68.7 wt%), P2O5 (0.07–0.10 wt%), Rb/Sr (0.52–1.30) and Rb/Ba (0.13–0.34) and high Fe2O3t (3.84–5.57 wt%), MgO (1.48–2.35 wt%), CaO (2.28–4.54 wt%) and Na2O/K2O (0.90–1.91), with metaluminous to weakly peraluminous features (most A/CNK = 0.87–1.07), showing typical I-type granitoid characteristics. The Nd–Hf isotopic model ages (ca 1.6–1.8 Ga) indicate that the Xiaying granodiorites were probably formed by partial melting of a late Paleoproterozoic basement in the deep crust. The micro–granular dioritic enclaves (MMEs) have similar formation ages and Nd–Hf isotopic compositions to the host granodiorites, and show geochemical evolution relation with granodiorites, suggesting that they resulted from the mixing of mafic and granodioritic magmas, which derived from a depleted mantle and a Paleoproterozoic crust, respectively. Based on their similar formation ages and zircon Hf-isotope compositions and the assimilation and fractional crystallization (AFC) modelling, it is suggested that major monzogranites were generated from the granodioritic magma through the AFC process. The rock associations and arc-related geochemical characteristics of the granodiorites and dioritic MMEs suggest that they probably formed in a subduction-related tectonic setting. Combined with the spatial distribution of the rock types and formation ages of these early Ordovician to early Devonian magmatic rocks in the SCB from southeast to northwest, it is inferred that there was an Ordovician northwestward subduction of the proto–South China Ocean occurring to the south of the SCB, which may connect with the Tam Ky–Phuoc Son Suture Zone in the eastern Indochina Block. It was the subduction of the proto–South China Ocean and subsequent collision between the southern SCB and an unknown continent that triggered early Ordovician to early Devonian intracontinental orogeny in the interior of the SCB.

桂东大瑶山地区六安金矿床金的赋存状态研究

桂东大瑶山地区六安金矿床金的赋存状态研究

Newly identified Caledonian gabbro (450 Ma) in the eastern Guangxi, South China: Production of intraplate orogenic process

Newly identified Caledonian gabbro (450 Ma) in the eastern Guangxi, South China: Production of intraplate orogenic process

Deinostigma fasciculatum, a new species of Gesneriaceae in Yunnan, China.

A new species of Deinostigma (Gesneriaceae) from Yunnan, China, Deinostigma fasciculatum W.H.Chen & Y.M.Shui, sp. nov., has been discovered and described. In the genus, the new species is similar to D. cicatricosum (W.T. Wang) D.J. Middleton & Mich. Möller and D. cyrtocarpum (D. Fang & L. Zeng) Mich. Möller & H.J. Atkins in dark purple flowers and falcate fruit, but differs from them mainly in the inflorescences with fasciculate flowers, calyx lobes (reflexed, narrowly lanceolate and 1.2–1.3 cm long), corolla tubes (sharply contracted below middle and white outside and below throat). The above three species grow nearby non-limestone wet cliffs and geographically isolated with different distributions (the new species in Southeast Yunnan, D. cicatricosum in Eastern Guangxi and D. cyrtocarpum in Southern Guangxi and Guangdong, China).

New Discovery and Zircon Hf Isotopic Composition of the Early Yanshannian Monzogranite in the Yingyangguan Group of Eastern Guangxi, China

New Discovery and Zircon Hf Isotopic Composition of the Early Yanshannian Monzogranite in the Yingyangguan Group of Eastern Guangxi, China

A further study of Zosterophyllum sinense Li and Cai (Zosterophyllopsida) based on the type and the new specimens from the Lower Devonian of Guangxi, southwestern China

Zosterophyllum sinense Li and Cai was reported in 1977 from the Lower Devonian Cangwu Formation, eastern Guangxi of China but was rarely acknowledged by authors for its obscure original description. Based on the re-observations to the type specimens and newly-collected specimens of Z. sinense, its detailed morphological information is revealed. Zosterophyllum sinense consists of tufted rooting system and axes, sporangia with long and straight stalks and two unequal valves, are helically and loosely arranged forming the terminal spikes. By far Z. sinense is only reported from the Lower Devonian of Guangxi, palaeogeographically belonging to the Cathaysia Block, a sub-region of the whole South China Block. An Early Devonian floristic distinction is suggested by the plant components between the Yangtze and Cathaysia blocks.

Detrital zircon U-Pb Geochronology of Sinian-Cambrian strata in the Eastern Guangxi area, China

The Eastern Guangxi area locates in the southwestern part of the transition zone between Yangtze and Cathaysia blocks, which is an important region because the boundary between two blocks probablycrosses there. We determined LA-ICPMS U-Pb ages for detrital zircons extracted from three sandstone samples in the Sinian-Cambrian strata in this region. The resulting ages are in the range of the Archeozoic and Neoproterozoic, with three notable concentrates at 991 Ma, 974 Ma, and 964 Ma, all of which are coeval to the Grenvillian magmatic activity. The new age distribution is similar to the data reported in the Precambrian strata of the adjacent southwestern Cathaysia Block, suggesting that most of our detrital zircons are likely derived from the Cathaysia Block. Combined with others' research, we are more inclined to accept the opinion that there was not an ocean basin between the two blocks during the Sinian-Cambrian period in Eastern Guangxi area if the timing of collision is the Early Neopro-terzoic. But if the timing of collision is the Early Paleozoic, we conclude that Luzhai uplift (i.e., the uplift between Guilin-Yongfu faultand Lipu fault) beyond the west of Dayaoshan regoin might be one part of southwestern sedimentation boundary of Cathaysia Block and Yangtze Block. We also get a few of detrital zircons with ages of ~590 Ma which probably sourced from northeastern Gondwana and 13 detrital zircons with over 3 000 Ma U-Pb ages which record the early formation of the earth.

Anisotropic patterns of liver cancer prevalence in Guangxi in Southwest China: is local climate a contributing factor?

Geographic information system (GIS) technology has useful applications for epidemiology, enabling the detection of spatial patterns of disease dispersion and locating geographic areas at increased risk. In this study, we applied GIS technology to characterize the spatial pattern of mortality due to liver cancer in the autonomous region of Guangxi Zhuang in southwest China. A database with liver cancer mortality data for 1971-1973, 1990-1992, and 2004-2005, including geographic locations and climate conditions, was constructed, and the appropriate associations were investigated. It was found that the regions with the highest mortality rates were central Guangxi with Guigang City at the center, and southwest Guangxi centered in Fusui County. Regions with the lowest mortality rates were eastern Guangxi with Pingnan County at the center, and northern Guangxi centered in Sanjiang and Rongshui counties. Regarding climate conditions, in the 1990s the mortality rate of liver cancer positively correlated with average temperature and average minimum temperature, and negatively correlated with average precipitation. In 2004 through 2005, mortality due to liver cancer positively correlated with the average minimum temperature. Regions of high mortality had lower average humidity and higher average barometric pressure than did regions of low mortality. Our results provide information to benefit development of a regional liver cancer prevention program in Guangxi, and provide important information and a reference for exploring causes of liver cancer.

Chronology of the Tungsten Deposits in Southern Jiangxi Province, and Episodes and Zonation of the Regional W‐Sn Mineralization – Evidence from High‐precision Zircon U‐Pb, Molybdenite Re‐Os and Muscovite Ar‐Ar Ages

Abstract:Previous studies have obtained some petrogenetic and metallogenic chronological data with SHRIMP (sensitive high‐resolution ion microprobe) zircon U‐Pb, zircon LA‐ICPMS (laser‐ablation–inductively coupled plasma mass spectroscopy) U‐Pb, molybdenite Re‐Os isochron and muscovite Ar‐Ar methods in southern Jiangxi Province and its adjacent areas. Based on these, the purpose of this paper is to study the petrogenetic and metallogenic ages and their time gap for different genetic types of W‐Sn deposits, and thus to research their numerous episodes, zonal arrangement and their geodynamic background. The result shows that the large‐scale W‐Sn mineralization in southern Jiangxi Province occurred in the middle to late Jurassic (170–150 Ma), the skarn W‐Sn‐polymetallic deposits formed much earlier (170–161 Ma), and all of the wolframite – quartz vein type, greisen type, altered granite type and fractured zone type tungsten deposits formed in the late Jurassic (160–150 Ma). In one ore field or ore district, greisen type tungsten deposits formed earlier than quartz vein type ones hosted in the endo‐ or exo‐contact zone; and quartz vein type hosted in the endocontact zone formed earlier than that of exocontact zone. There is no significant time difference between tungsten‐tin mineralization and its intimately associated parent granite emplacement (1–6 Ma). They all formed in the same rock‐forming and ore‐forming system and under the same geodynamic setting. Regionally, rock‐forming and ore‐forming processes of the W‐Sn deposits in the Nanling region (include southern Jiangxi Province, southern Hunan Province, northern Guangdong Province and eastern Guangxi Zhuang Autonomous Region) exhibit numerous episodes. The mineralization in the Nanling region mainly occurred at (240–210) Ma, (170–150) Ma and (130–90) Ma. The tungsten‐tin deposits in this region are centered by the largest scale in southern Jiangxi Province and southern Hunan Province, and become small in the east, west, south and north directions. This displays a zonal arrangement and temporal and spatial distribution regularity. Integrated with the latest research results, it is concluded that the W‐Sn mineralization in southern Jiangxi Province and its adjacent areas corresponds to the second large‐scale mineralization in South China. The Indosinian W‐Sn mineralization formed under the extensional tectonic regime between collisional compressional stages, while the Yanshanian large‐scale petrogenetic and metallogenic processes occurred in the Jurassic intraplate extensional geodynamic setting of lithosphere extension.

Sinification of Zhuang place names in Guangxi, China: a GIS‐based spatial analysis approach

Zhuang, the largest minority language in China, is the label given to a variety of Tai languages and dialects spoken mostly in Guangxi. As a result of the process known as Sinification or Sinicisation stemming from the influx of Han soldiers and settlers moving in from many directions, but primarily the north, many Zhuang place names (toponyms) were changed to Han or pronounced with a Han accent or spelled in Chinese in such a way as to obscure the original Zhuang form. The objectives of this paper are to (1) construct a GIS database of toponyms in Guangxi at the township, county and prefecture levels from a comprehensive toponymical dictionary series of China; (2) analyse the spatial distribution of Zhuang vs non‐Zhuang toponyms and its association with environmental factors; and (3) examine the historical evolution of toponyms to better understand the process of Sinification. Results show that Zhuang toponyms have the highest concentrations in the southwest Twin‐Rivers Basin and the western mountainous area, and decline gradually towards the east. Zhuang toponyms are better preserved in areas that are more remote from major transport routes and major cities, and at higher ground level and with a somewhat steeper slope. Analysis of the limited number of toponyms with time stamps reveals that the Zhuang toponyms on contemporary maps are older in the west but more recent in the east. We speculate that in eastern Guangxi, with larger Han settlements for a longer period, older Zhuang toponyms were likely to be obliterated. The centroids of Zhuang and non‐Zhuang toponyms converge towards the centre of Guangxi over time, reflecting the impact of increasingly integrated Sino‐Zhuang settlement patterns.

Inversion of stress field in Guangdong and its adjacent area

We determine the stress field of Guangdong and its adjacent area by using focal mechanism solutions of 137 earthquakes and obtain tectonic stress tensors in 12 zones. The result shows that the azimuth of maximum principal stress σ1 is approximately WNW in southwestern Fujian, southern Jiangxi, Guangdong’s Heyuan and the Pearl River Delta, NW in Guangdong’s Yangjiang, and nearly NNW in the two zones of eastern Guangxi and Beibuwan Gulf (the Northern Gulf), varying clockwise in WNW-NW-NNW from east to west. The azimuth of minimum principal stress σ3 varies from NNE to ENE. The relative magnitude of medium principal stress σ2 (R value), is the smallest in Beibuwan and largest in Longyan of Fujian. Strike-slip faulting is dominated in the study area.

Pb, Cu botanogeochemical anomalies and toxic effects on plant cells in Pb-Zn (Sn) ore fields, Northeast Guangxi Autonomous Region, China

In the Lingchuan-Daoping and Xinglu Pb-Zn ore fields in northern and eastern Guangxi Autonomous Region, Pb, Cu botanogeochemical anomalies may be ascribed to the excessive amounts of Pb and Cu taken up by the root system of plants, such as China fir (Cunninghamia lanceolata Lamb. Hook), mason pine (Pinus massoniana Lamb.) and bracken fern (Pteridium aquilinum var. latiusculum). Under transmission electron microscope (TEM), the excess Pb, Cu in the leaf cells of the plants are present as high electron-density substances, which were precipitated in the leaf cells, causing phytotoxic effects by deforming and injuring cellular tissues. The sorts of toxic elements accumulating in the leaf cells are consistent with those of the botanogeochemically anomalous elements in the polluted soil where the plants grow. In addition, the plants may also be capable of resisting the invasion of excess Cu (and Pb).

Jurassic intraplate magmatism in southern Hunan-eastern Guangxi: 40 Ar/ 39 Ar dating, geochemistry, Sr-Nd isotopes and implications for the tectonic evolution of SE China

Abstract The Mesozoic geology of SE China is characterized by intensive and widespread magmatism. However, the tectonic regime that accounted for the Mesozoic magmatism has been an issue with little consensus. A comprehensive study of 40 Ar- 39 Ar dating, geochemistry and Sr-Nd isotopes has been conducted on basalts from southern Hunan and syenite intrusions from eastern Guangxi. Three episodes of Jurassic magmatism, i.e. alkaline basalts of c. 175 Ma in age, syenitic intrusions of c. 160 Ma and high-Mg basalts of c. 150 Ma, are identified. The older, c. 175 Ma alkaline basalts are characterized by low Sr ( I Sr = 0.7035–0.7040) and high Nd ( ε Nd ( T ) = 5 to 6) isotopic compositions and OIB-like trace-element patterns (e.g. Nb/La > 1). In contrast, the younger, c. 150 Ma high-Mg basalts have high Sr ( I Sr c. 0.7054) and low Nd ( ε Nd ( T ) c. -2) isotopic compositions and incompatible trace-element patterns of arc affinity. The c. 160 Ma syenitic intrusions display a relatively large range of Sr and Nd isotopic compositions ( I Sr = 0.7032–0.7082, ε Nd ( T ) = 5.5 to −4.1), with the Qinghu syenites having the lowest I Sr , highest ε Nd ( T ) and OIB-type incompatible trace-element patterns analogous to the c. 175 Ma alkaline basalts. Such a secular variation in rock types and geochemical and isotopic characteristics reveals changes in melt segregation depth and mantle sources, which are inferred to have resulted from the post-Indosinian orogenic lithosphere extension and thinning. The c. 175 Ma alkaline basalts are suggested to have formed by small degrees of decompression melting of the asthenosphere or an enriched lithospheric mantle source accreted by asthenosphere-derived melts during the initial extension. The c. 160 Ma syenitic and c. 150 Ma high-Mg basaltic rocks mainly originated from the enriched lithospheric mantle that melted owing to a raised geotherm caused by lithosphere thinning. This interpretation is at odds with the active continental margin related to the subduction of palaeo-Pacific plate, but consistent with continental rifting and extension for the Mesozoic of SE China.

Evidence for the Paleo-Tethyan Tectonic Belt in Western Guangdong and Eastern Guangxi, China

Evidence for the Paleo-Tethyan Tectonic Belt in Western Guangdong and Eastern Guangxi, China

Deep tectonic processes and superaccumulations of metals in Mesozoic intracontinental orogenic belt of Nanling metallogenic province,China

The Nanling region is an important nonferrous and rare metal metallogenetic province in South of China. It covers southern Hunan, southern Jiangxi, eastern Guangxi, Guangdong (without Hainan island) and Fujian provinces, with a total area about 550,000 km (Zhang, Pei, et al., 1987). This metallogenetic province is rich in tungsten and tin and is well known in the world. In the past forty years, a vast amount of geological surveying and great achievements in prospecting for minerals have been done and obtained in the province. This paper focuses on the deep tectonic processes of intracontinental orogeny in the Mesozoic. These processes also play an important role in the superaccumulation of metals.