scholarly journals Mineralogy and Geochemistry of Late Permian Coals within the Tongzi Coalfield in Guizhou Province, Southwest China

Minerals ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 44 ◽  
Author(s):  
Baoqing Li ◽  
Xinguo Zhuang ◽  
Xavier Querol ◽  
Natalia Moreno ◽  
Linjian Yang ◽  
...  
Keyword(s):  
Southwest China ◽  
Guizhou Province ◽  
Late Permian ◽  
Quartz Content ◽  
Eu Anomaly ◽  
Marine Influence ◽  
Permian Coal ◽  
Western Guizhou ◽  
Fe Ions ◽  
Felsic Rocks

The lowermost Late Permian coal seam (C4 Coal) in the Tongzi Coalfield offers an opportunity to investigate the influence of terrigenous detrital materials from the Qianbei Upland on the mineralogical and geochemical patterns of the C4 Coal. The minerals are mainly dominated by pyrite and, to a lesser extent, tobelite, kaolinite, and calcite, along with traces of Al-oxyhydroxide minerals. The various degrees of marine influence may have resulted in the variation in the amount of Fe-sulfides (e.g., pyrite) and elements having Fe-sulfides affinity. Furthermore, the abundant Fe ions involved in the formation of Fe-sulfides were most likely derived from the claystone on the Qianbei Upland. The tobelite identified in the C4 Coal probably originated from the interaction between pre-existing kaolinite and NH4+ from NH3 released from the thermally affected organic matter at least shortly after the highly volatile bituminous stage under NH4+-rich and K+-poor conditions. The terrigenous detrital materials were derived from two possible sediment-region sources—the Qianbei Upland and Kangdian Upland—which is different from Late Permian coals in Western Guizhou Province. The claystone on the Qianbei Upland may have served as parent rock, as indicated by the presence of the Al-oxyhydroxide minerals as well as low SiO2/Al2O3 ratio (0.66 on average) and low quartz content. Meanwhile, the detrital materials from the Kangdian Upland most likely originated from the erosion of the felsic rocks at the uppermost part of the Kangdian Upland, as evidenced by the high Al2O3/TiO2 ratio (36.0 on average) and the strongly negative Eu anomaly (0.61 on average).

scholarly journals Origin of a Petrographic Coal Structure and Its Implication for Coalbed Methane Evaluation

Minerals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 543
Author(s):  
Wei Cheng ◽  
Ruidong Yang ◽  
Qin Zhang
Keyword(s):  
Coalbed Methane ◽  
Guizhou Province ◽  
Mineral Matter ◽  
Late Permian ◽  
Coal Structure ◽  
Sw China ◽  
Inorganic Matter ◽  
Western Border ◽  
Fractured Coal ◽  
Permian Coal

A petrographic coal structure of Late Permian coals from the Liupanshui coalfield, Western Guizhou, SW China, has been distinguished for its novel macro-lithological characteristics. Petrographic, mineralogical and geochemical studies have been conducted for a typical coal sample (No.3 coal, Songhe coalmine, Panzhou County, China) and its geological genesis and significance for coalbed methane (CBM) evaluation is accordingly discussed. It was found that coal is characterized by a banded structure with intensively fractured vitrain sublayers, where a great number of fractures were developed and filled with massive inorganic matter. The study of coal quality, coal petrography, mineralogy and lanthanides and yttrium (REY) geochemistry of the infilling mineral matter (IMM) indicates that this fractured coal structure resulted from the tissues of coal-forming plants or coal matrix shrinkage, as well as the precipitation of calcium rich groundwater and the addition of terrigenous materials. The coal depositional environment and coal-forming plant are considered to have played a role in inducing the special fractures. This provides a scientific reference for the study of CBM for coal with this fractured structure, such as the Late Permian coal from the western border of Guizhou Province, SW China.

Polystichum alluvium (subg. Haplopolystichum; Dryopteridaceae), a new cave species from Guizhou, China, with reference to new distribution records of P. leveillei

Phytotaxa ◽  
2017 ◽  
Vol 323 (1) ◽  
pp. 88
Author(s):  
NGAN THI LU ◽  
YI-FAN DUAN ◽  
LI-BING ZHANG
Keyword(s):  
Southwest China ◽  
Iucn Red List ◽  
Red List ◽  
Guizhou Province ◽  
Fern Species ◽  
Southern Central ◽  
Ca 50 ◽  
Iucn Red List Criteria ◽  
Western Guizhou ◽  
New Distribution

A new fern species, Polystichum alluvium, a member of P. subg. Haplopolystichum (Dryopteridaceae), is described from Guizhou Province in Southwest China. Polystichum alluvium is similar to P. lanceolatum in having small habit and subcoriaceous pinnae, but the former has oblanceolate laminae with basal pinnae strongly contracted toward lamina base, deltoid-ovate and sessile pinnae, and very short spinules on acroscopic pinna margins or no spinules, while the latter has lanceolate laminae with basal pinnae not contracted toward lamina base, oblong and petiolate pinnae, and long spinules on acroscopic pinna margins. Polystichum alluvium was found from the alluvial bottom of a karst cave at an elevation of 1410 m with humid and shady conditions and is currently known from one population with ca. 50 plants in western Guizhou. It is classified as Critically Endangered (CR) following IUCN Red List criteria. We also expanded the distribution of P. leveillei to southern-central Guizhou based on our new collections.

scholarly journals Geochemistry of elements associated with Late Permian coal in the Zhongliangshan mine, Chongqing, Southwest China

2018 ◽  
Vol 36 (6) ◽  
pp. 1655-1673
Author(s):  
Shenjun Qin ◽  
Qingfeng Lu ◽  
Kang Gao ◽  
Penghui Bo ◽  
Shihao Wu
Keyword(s):  
Trace Elements ◽  
Inductively Coupled Plasma ◽  
Southwest China ◽  
Major And Trace Elements ◽  
Chemical Extraction ◽  
Late Permian ◽  
Modes Of Occurrence ◽  
X Ray ◽  
Sequential Chemical Extraction ◽  
Permian Coal

The enrichment and geochemical significance of elements associated with Late Permian coals in Southwest China have always gained widespread interest in the field of coal geology. The present study focuses on the geochemical characterization of Late Permian coal in the Zhongliangshan mine. Twenty-three samples were collected from the K1a coal seam of the Zhongliangshan mine, and the major and trace elements in the coal were analyzed by using X-ray fluorescence spectroscopy (XRF) and inductively coupled plasma mass spectrometry. The composition of minerals in the Zhongliangshan coal, and the modes of occurrence of coal-associated elements, especially those with elevated contents, were studied through a combination of microscopic analyses, X-ray powder diffraction, and scanning electron microscope – energy dispersive X-ray spectrometer. The minerals in coal mainly consist of kaolinite, pyrite, calcite, and quartz, as well as small amount of gypsum and anatase. Compared with the average elemental concentrations in world coal, the Zhongliangshan coal is enriched in Cr, and slightly enriched in Li, U, Sr, V and Ag. Combining the correlation analysis and sequential chemical extraction experiments, it can be inferred that many trace elements in the Zhongliangshan coal have both inorganic and organic affinities. The elements Cr, Li, and V mainly occur in clay minerals, and also are related to organic matter in the coal. Uranium presents firstly in the organic and then silicate states. Strontium shows multiple modes of occurrence including carbonate, silicate, and exchangeable ion states, and Ag primarily occurs in sulfides followed by silicates. The terrigenous debris input from the Emeishan basalt is the major reason for the enrichment of above elements in the Zhongliangshan coal.

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