Oxidation of black shale and its deterioration mechanism in the slip zone of the Xujiaping landslide in Sichuan Province, Southwestern China

CATENA ◽  
2021 ◽  
Vol 200 ◽  
pp. 105139
Author(s):  
Chunwei Sun ◽  
Sixiang Ling ◽  
Xiyong Wu ◽  
Xiaoning Li ◽  
Jiannan Chen ◽  
...  
Keyword(s):  
Black Shale ◽  
Sichuan Province ◽  
Slip Zone ◽  
Southwestern China ◽  
Deterioration Mechanism

Oxidative weathering deterioration of black shale and its bedding shear failure modeling

2021 ◽  
Author(s):  
Chunwei Sun ◽  
Marc-Henri Derron ◽  
Michel Jaboyedoff ◽  
Xiyong Wu
Keyword(s):  
Black Shale ◽  
Chemical Weathering ◽  
Shear Failure ◽  
Theoretical Models ◽  
Slip Zone ◽  
Iron Sulfate ◽  
Failure Modeling ◽  
Rock Structure ◽  
Degradation Models ◽  
Deterioration Mechanism

<p>This work investigated the oxidative weathering deterioration of black shale along a bedding slip zone and how it affects the bedding shear failure in the Xujiaping landslide, southern Sichuan Province in China. Many dissolved pits were found on the limestone, and part of the black shale in the slip zone is mud-like and clastic, showing local shear failure, which can be one of the main reasons of slope instabiliy. The microstructure of black shale under oxidative weathering condition was observed by scaning electron microscopy (SEM), characterized by dissolved pores, weathering crust (iron sulfate) of pyrite crystals, and the filling gypsum crystal in the bedding foliation. The deterioration mechanism was expanded: (i) rock-forming and carbonate minerals were especially prone to dissolution by sulfuric acid from black shale oxidation in the slip zone, and (ii) volume expansion due to the crystallization force of precipitated minerals caused further fracture expansion and deformation. Therefore, two theoretical models were developed that use stoichiometric calculations of pyrite and calcite to determine the dissolution rate and the rock structure after chemical weathering; and establish a rock structure model characterized by foliation weakening of gypsum crystallization. In order to analyze the landslide failure, discrete element method (DEM) is used to analyze the black shale shear failure mechanism of the two degradation models after oxidative weathering. It will be useful to better understand how these oxidative weathering deterioration contribute to bedding shear failure in natural hazards.</p>

Oxidation of black shale and its deterioration mechanism in Xujiaping rockslide, Southwestern China

2020 ◽  
Author(s):  
Chunwei Sun ◽  
Marc-Henri Derron ◽  
Michel Jaboyedoff ◽  
Sixiang Ling
Keyword(s):  
Sulfuric Acid ◽  
Black Shale ◽  
Chemical Interaction ◽  
Major Elements ◽  
Slip Zone ◽  
Acid Water ◽  
Secondary Mineral ◽  
Mineral Phases ◽  
Deterioration Mechanism ◽  
Fissure Water

<p>The water-rock chemical interaction of black shale interbedded with limestone along the bedding slip zone and its deterioration to the surrounding rock mass in Xujiaping rockslide is studied. As an important rock-forming mineral in black shale, pyrite is known for being easily oxidized to produce sulfuric acid in water, and sulfuric acid is a significant factor that leads to the dissolution of minerals. Significant number of erosion pits on the limestone were found and many geochemical phenomenon such as extremely low pH fissure water and the secondary mineral phases were investigated. Rock and water samples from this site were analyzed to determine mineralogy, chemical composition and hydrochemistry. The results indicate that many major elements and heavy elements are dissolved, such as Fe, Mn, Si, Zn, Ni, Al, S, Mg, Ca, Na, K, Co and Sr, because of the strong dissolution ability of acid water from black shale.The acid water migrates along the slip zone to exposed surface of cliff and fractures, where it evaporates to form the secondary mineral phases including melanterite, rozenite, szomolnokite, and gypsum etc. The water-rock chemical interaction in Xujiaping rockslide is a combination of dissolution, oxidation, dehydration, and neutralization reactions. Besides, the deterioration mechanism is expanded on two aspects: (1) rock-forming minerals, carbonate minerals especially are prone to be dissolved by sulfuric acid from oxidation of black shale in the slip zone; (2) the crystallization volume expansion of minerals precipitated, which leads to the further expansion and deformation of fractures.</p>

A new cockroach (Blattaria: Caloblattinidae) from the Upper Triassic Xujiahe Formation of Sichuan Province, southwestern China

2013 ◽  
Vol 44 (2) ◽  
pp. 167-174
Author(s):  
Yan Fang ◽  
Haichun Zhang ◽  
Bo Wang ◽  
Daran Zheng
Keyword(s):  
Elemental Analysis ◽  
Anterior Margin ◽  
New Genus ◽  
Sichuan Province ◽  
Upper Triassic ◽  
Southwestern China ◽  
New Taxon ◽  
New Genus And Species ◽  
X Ray ◽  
Xujiahe Formation

A new genus and species of the cockroach family Caloblattinidae, Dazhublattella lini gen. et sp.n., is described from the Upper Triassic Xujiahe Formation of Sichuan Province, in southwestern China. The new taxon is similar to the Triassic Caloblattina mathildae (Geinitz, 1883) (Vršanský & Ansorge 2007) in the venation and pattern, but differs in the less elongated forewing with arched anterior margin. An elemental analysis of the wing is undertaken using Energy Dispersive X-ray analysis.

scholarly journals Prevalence and new genotypes of Enterocytozoon bieneusi in sheltered dogs and cats in Sichuan province, southwestern China

Parasite ◽  
2021 ◽  
Vol 28 ◽  
pp. 31
Author(s):  
Yalin Zhong ◽  
Ziyao Zhou ◽  
Lei Deng ◽  
Haifeng Liu ◽  
Zhijun Zhong ◽  
...  
Keyword(s):  
Sequence Analysis ◽  
Internal Transcribed Spacer ◽  
Companion Animals ◽  
Sichuan Province ◽  
Enterocytozoon Bieneusi ◽  
Southwestern China ◽  
Intracellular Parasite ◽  
Type Iv ◽  
Wide Range ◽  
Epidemiological Information

Enterocytozoon bieneusi is a common intracellular parasite that infects a wide range of hosts, including humans and companion animals, raising concerns of zoonotic transmission. However, there is limited epidemiological information on the prevalence and genotypes of E. bieneusi in sheltered dogs and cats in Sichuan province, southwestern China. A total of 880 fecal samples were collected from shelters in different cities of Sichuan province, including 724 samples from dogs, and 156 samples from cats. Enterocytozoon bieneusi was determined by sequence analysis of the ribosomal internal transcribed spacer (ITS). Overall, the prevalence of E. bieneusi was 18% (158/880), and the parasite was detected in 18.8% (136/724) and 14.1% (22/156) of the dogs and cats examined, respectively. Sequence analysis revealed the presence of five genotypes in dogs, including three known genotypes CD9 (n = 92), PtEb IX (n = 41), and Type IV (n = 1), and two novel genotypes SCD-1 (n = 1) and SCD-2 (n = 1). Similarly, four genotypes were identified in cats, including CD9 (n = 11), Type IV (n = 6), D (n = 4), and PtEb IX (n = 1). Genotypes D and Type IV have previously been identified in humans and are reported in sheltered dogs and cats in the present study, indicating that these animals could be as potential sources of human microsporidiosis infections.

A new species of Protonemura (Plecoptera: Nemouridae) from China and new images of three other species of the genus

Zootaxa ◽  
2020 ◽  
Vol 4802 (2) ◽  
pp. 250-260
Author(s):  
MENG-YUAN ZHAO ◽  
YU-ZHOU DU
Keyword(s):  
New Species ◽  
Sichuan Province ◽  
Southwestern China ◽  
Adult Males ◽  
Outer Lobe ◽  
Basal Portion ◽  
A New Species

A new nemourid species, Protonemura longispina sp. nov. from Sichuan Province of southwestern China is described. The outer lobe of the paraprocts with numerous long spines and the basal portion divided into two lobes, distinguishes the new species from all congeners. New images of three other species, P. bidigitata Du & Wang, P. biintrans Li & Yang, and P. macrodactyla Du & Zhou are given. Additionally, a key to the adult males of Protonemura known from China is provided. 

First chirothere and possible grallatorid footprint assemblage from the Upper Triassic Baoding Formation of Sichuan Province, southwestern China

2014 ◽  
Vol 412 ◽  
pp. 169-176 ◽  
Author(s):  
Lida Xing ◽  
Hendrik Klein ◽  
Martin G. Lockley ◽  
Zezhong Kan ◽  
Jianping Zhang ◽  
...  
Keyword(s):  
Sichuan Province ◽  
Upper Triassic ◽  
Southwestern China

A new Chinese species of Indonemoura (Plecoptera: Nemouridae) and a new subspecies of I. nigrihamita Li & Yang

Zootaxa ◽  
2017 ◽  
Vol 4311 (2) ◽  
pp. 255 ◽  
Author(s):  
WEIHAI LI ◽  
QIN ZHANG ◽  
DING YANG ◽  
GANG YAO
Keyword(s):  
New Species ◽  
Related Species ◽  
Southern China ◽  
Sichuan Province ◽  
Southwestern China ◽  
Autonomous Region ◽  
New Subspecies ◽  
Guangxi Zhuang Autonomous Region ◽  
A New Species

A new species of Nemouridae of the genus Indonemoura Baumann 1975, I. furcoloba Li & Yang, sp. nov., is described from both sexes from Guangxi Zhuang Autonomous Region of southern China. The relationships with related species are discussed. Additionally, a new subspecies is proposed for a population of I. nigrihamita Li & Yang, 2008 from northern Sichuan Province of southwestern China.

scholarly journals A new species of the genus Kurixalus (Anura, Rhacophoridae) from Sichuan Province, southwestern China

2021 ◽  
Vol 43 (1) ◽  
pp. 90-94
Author(s):  
Chun-Peng Guo ◽  
◽  
◽  
Mao-Jun Zhong ◽  
Ka Wah Leung ◽  
...  
Keyword(s):  
New Species ◽  
Sichuan Province ◽  
Southwestern China ◽  
A New Species
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