Secular Change in Mineral Composition of A Mesoproterozoic Black Shale Predating the Advent of Terrestrial Life and Soil-Formed Clay Minerals

2019 ◽  
Author(s):  
M. Rafiei ◽  
M. Kennedy
Keyword(s):  
Clay Minerals ◽  
Mineral Composition ◽  
Black Shale ◽  
Secular Change ◽  
Terrestrial Life

scholarly journals Pore Structure and Fractal Characteristics of Organic-Rich Lacustrine Shales of the Kongdian Formation, Cangdong Sag, Bohai Bay Basin

2021 ◽  
Vol 9 ◽  
Author(s):  
Shouxu Pan ◽  
Ming Zha ◽  
Changhai Gao ◽  
Jiangxiu Qu ◽  
Xiujian Ding
Keyword(s):  
Organic Matter ◽  
Specific Surface ◽  
Pore Structure ◽  
Surface Area ◽  
Clay Minerals ◽  
Mineral Composition ◽  
Fractal Dimensions ◽  
Nitrogen Adsorption ◽  
Thermal Maturity ◽  
Pore Types

In order to examine the pore structure and reveal the fractal geometric nature of shales, a series of laboratory experiments were conducted on lacustrine shale samples cored from the Kongdian Formation. Based on the low temperature nitrogen adsorption, fluorescent thin section and field emission scanning electronic microscope, a comprehensive pore structure classification and evaluation were conducted on shale samples. Fractal dimensions D1 and D2 (with relative pressure of 0–0.45 and 0.45–1.00, respectively) were obtained from the nitrogen adsorption data using the fractal Frenkel-Halsey-Hill (FHH) method. With additional means of X-ray diffraction analysis, total organic carbon content analysis and thermal maturity analysis, the relationships between pore structure parameters, fractal dimensions, TOC content and mineral composition are presented and discussed in this paper. The results show that interparticle pores and microfractures are predominant, whereas organic matter pores are rarely found. The pore morphology is primarily featured with wide-open ends and slit-shaped structures. In terms of pore scale, mesopores and macropores are predominant. The value of fractal dimension D1 representing small pores ranges from 2.0173 to 2.4642 with an average of 2.1735. The value of D2 which represents large pores ranges from 2.3616 to 2.5981 with an average of 2.4960. These low numbers are an indication of few pore types and relatively low heterogeneity. In addition, smaller D1 values reveal that large pores have more complicated spatial structures than smaller ones. The results of correlation analysis show that: 1) D2 is correlated positively with specific surface area but negatively with average pore diameter; 2) D1 and D2 literally show no obvious relationship with mineral composition, TOC content or vitrinite reflectance (Ro); 3) both total Barrett-Joyner-Halenda (BJH) volume and specific surface area show a positive relationship with dolomite content and a negative relationship with felsic minerals content. These results demonstrate that the pore types are relatively few and dominated by mesopores, and the content of brittle minerals such as dolomite and felsic minerals control the pore structure development whilst organic matter and clay minerals have less influence due to low thermal maturity and abundance of clay minerals.

scholarly journals MINERAL COMPOSITION OF SOME LATGALE LAKE SEDIMENTS

2019 ◽  
Vol 1 ◽  
pp. 304
Author(s):  
Rasma Tretjakova ◽  
Andris Karpovičs
Keyword(s):  
Grain Size ◽  
Lake Sediments ◽  
Size Distribution ◽  
Clay Minerals ◽  
Mineral Composition ◽  
Grain Size Distribution ◽  
Sandy Loam ◽  
Clay Fraction ◽  
Fine Grained ◽  
Two Samples

Our research is focused on sedimentological conditions and postdepositional changes of recent fine grained lake sediments. We used bulk sediment mineralogical composition and grain size distribution as indicators to identify sediment source areas and possible changes during Holocene. We analysed fine grained (clayey) sediments from three Latgale lakes - Zeili, Pauguļi and Plusons, situated in Latgale upland. Lake sediments cover Late Pleistocene glacial deposits – loam and sandy loam. Bulk mineral composition of 6 sediment samples was determined by X-ray diffraction (XRD). Sediments contained typical minerals found in surrounding glacial sediments: rock-forming minerals as quartz, plagioclase, albite, enstatite, dolomite, calcite, and clay minerals - illite, kaolinite. To identify postdepositional changes in lake sediments of Holocene age clay minerals in clay fraction (<2 mkm) should be analysed. Particularly illite, smectite mixed layered minerals - illite/smectite (I/Sm) and chlorite. Additionally, grain size distribution of studied lake sediments was analysed. Accordingly, our studied sediments are clays, silty clays and clayey silts with bimodal particle distribution, except two samples from Zeiļi and Plusons with unimodal distribution.

Mineral Composition and Its Control on Nanopores of Marine-Continental Transitional Shale from the Ningwu Basin, North China

2021 ◽  
Vol 21 (1) ◽  
pp. 168-180
Author(s):  
Bao-Xin Zhang ◽  
Xue-Hai Fu ◽  
Yu-Lin Shen ◽  
Qing-Hui Zhang ◽  
Ze Deng
Keyword(s):  
Clay Minerals ◽  
Mineral Composition ◽  
Shale Gas ◽  
Gas Adsorption ◽  
Sedimentary Environment ◽  
Nitrogen Adsorption ◽  
Shanxi Province ◽  
Parallel Plates ◽  
Carbonate Minerals ◽  
Quartz Content

There is a large difference between the sedimentary environment and maturity of organic matter between marine shale and marine-continental transitional shale. It is of great significance to discuss the effect of inorganicminerals on the pores for marine-continental transitional shale gas exploration. In this study, scanning electron microscopy (SEM), low temperature liquid nitrogen adsorption and Xray diffraction (XRD) were conducted on eight marine-continental transitional shale samples from the Ningwu Basin, Shanxi Province, China. The pore structure differences in the different minerals were discussed, and the relationship between the mineral content and pore parameters was analysed. The results show that the mineral composition of shale is dominated by clay minerals, quartz, carbonate minerals and a small amount of pyrite. The clay minerals content is between 39.5% and 77.0%, with an average of 59.9%. The quartz content ranges from 21.8% to 47.8%, with an average of 31.9%. The carbonate minerals content in shale is between 0.6% and 23.9%, and the average is 6.3%. The clay minerals are composed of mixed illite-montmorillonite layer, kaolinite and chlorite. The content of mixed illite-montmorillonite layer is between 13.8% and 27.4%, with an average of 20.4%. The kaolinite content ranges from 57.0% to 86.2%, with an average of 76.0%. The content of chlorite is between 0 and 15.6%, with an average of 5.7%. The types of pores are mainly intergranular pores and interlaminar pores, which are mostly presented as slit and parallel plates. The mixed illite-montmorillonite layer contributes more to the specific surface area, which is favourable for shale gas adsorption. The pores in kaolinite are more developed than those of the mixed illite-montmorillonite layer, but the pore diameter is relatively large. The quartz granule has a complete crystal type, and intergranular pores with a large pore size are often developed at the mineral contacts. Compared with clay minerals and quartz, the pore development in the carbonate minerals is relatively poor and develops more micro-fractures. The pyrite contributes a certain number of intergranular pores and mold pores.

Mineral Composition of Araripe Black Shale by X-ray Microct

2017 ◽  
Author(s):  
Endyara de Morais Cabral ◽  
Isis da Silva Rodrigues ◽  
Leyllanne Renalle Batista de Almeida ◽  
José Agnelo Soares
Keyword(s):  
Mineral Composition ◽  
Black Shale ◽  
X Ray

scholarly journals Controls of Distinct Mineral Compositions on Pore Structure in Over-Mature Shales: A Case Study of Lower Cambrian Niutitang Shales in South China

Minerals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 51
Author(s):  
Xing Niu ◽  
Detian Yan ◽  
Mingyi Hu ◽  
Zixuan Liu ◽  
Xiaosong Wei ◽  
...  
Keyword(s):  
Organic Matter ◽  
Pore Structure ◽  
Clay Minerals ◽  
Mineral Composition ◽  
South China ◽  
Lower Cambrian ◽  
Great Influence ◽  
Rock Composition ◽  
Niutitang Formation ◽  
Siliceous Shale

Investigating the impacts of rock composition on pore structure is of great significance to understand shale gas occurrence and gas accumulation mechanism. Shale samples from over-mature Niutitang formation of Lower Cambrian in south China were measured by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), low pressure N2 and CO2 adsorption to elucidate the controls of distinct mineral composition on pore development. Two distinct lithofacies, namely siliceous shale and argillaceous shale, were ascertained based on their mineral composition. Due to the variability of mineral composition in different lithofacies, pore structure characteristics are not uniform. Pores in siliceous shales are dominated by interparticle pores and organic matter (OM) pores, among which the interparticle pores are mainly developed between authigenic quartz. Furthermore, most of these interparticle pores and cleavage-sheet intraparticle pores within clay minerals are usually filled by amorphous organic matter that is host to OM pores. Due to the lack of rigid minerals, argillaceous shale was cemented densely, resulting in few interparticle pores, while cleavage-sheet intraparticle pores within clay minerals are common. Comparing siliceous shales with argillaceous shales, specific surface areas and pore volumes are higher on the former than on the latter. The content of total organic carbon (TOC) and authigenic quartz have a great influence on micropore structures, but less on mesopore structure for siliceous shales. The rigid framework structure formed by authigenic quartz is believed to be able to prevent primary interparticle pores from mechanical compaction and facilitate the formation of organic matter-associated pores. In terms of argillaceous shales, due to the lack of authigenic quartz, interparticle pores were rarely developed and its pore structure is mainly controlled by illite content.

scholarly journals Correlation Study Between Minerals Composition and Porosity Evolution of Black Shale Under Different Oxidation Mechanisms

2020 ◽  
Author(s):  
Baolong Zhu ◽  
Jing Li ◽  
Qi Li
Keyword(s):  
Clay Minerals ◽  
Black Shale ◽  
Biological Effects ◽  
Correlation Study ◽  
Chemical Effect ◽  
Rock Surface ◽  
Porosity Evolution ◽  
Surface Areas ◽  
Oxidation Mechanisms ◽  
Biological Group

Abstract The correlation between rock minerals composition and porosity evolution is essential to black shale oxidation,chemical and biological effects may act different roles which is unclear. In present study, the acid solution and Acidithiobacillus ferrooxidans was applied to simulate the chemical and biological effects, the total organic carbon (TOC), pyrite and clay minerals content, porosity characteristics, micro-surfacemorphologyof black shale sampleswere employed to analyze the minerals-porosity correlation. Results showed that the chemical effect led to a greaterdecrease of pyrite and increase of clay minerals content than biological effect, which accompanied by a higherspecific surface areas and pore volume. These difference may attribute to the TOCcontent, which decreasedby acid erosion and led to the increase of macropores in chemical group, then promoted the minerals reactions; whereas the TOC content increased byattached and dead bacteria cell bodies on rock surface, led to the increase of micropores and less minerals reactions in biological group. It suggests that the correlation between minerals composition and porosity evolution is different in chemical and biological effects, is mainly due to the different alter trends of TOC content.

scholarly journals Significance of Rock Mineral Composition On Rock Mechanical Properties And Brittleness Evaluation of Roof And Floor of Broken Soft Coal Seam

2021 ◽  
Author(s):  
Guangqing Hu ◽  
Wenxu Liang ◽  
Qingting Shan ◽  
Meng Zhao ◽  
Xianzeng Shi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Elastic Modulus ◽  
Coal Seam ◽  
Clay Minerals ◽  
Mineral Composition ◽  
Evaluation Method ◽  
Coalbed Gas ◽  
Soft Coal ◽  
Soft Coal Seam

Abstract Fracture of coal structure and low permeability were the main reasons for the “difficult to released gas” in broken soft coal seam. Exploration of horizontal well coalbed gas technology of roof and floor of broken soft coal seam provided a new technical way for coalbed gas development in broken soft coal seam. In this paper, taking Xinxie -1 drilling as an example, the evaluation method of fractured reservoirs in roof and floor of broken soft coal seam was improved. By systematic studied on mineralogy, petrology and engineering mechanics characteristics of top and bottom plates in broken soft coal seam, the influence of rock mineral composition on the rock mechanics properties of the roof and floor of coal seam was explored. In addition, By used correlation analysis and grey relational analysis, a brittle evaluation method of coal seam top and bottom plates based on mineral composition was established. The research results showed that: ①The main components of rock minerals in the top and bottom plates of broken soft coal seam were quartz and clay minerals, followed by plagioclase, siderite and pyrite. The main types of rock cementation were quartz enlargement and siderite cementation, and the pore damage caused by cementation was much greater than that of compaction; ②With the increased of rock particle size, compressive strength (CS) and elastic modulus (E) showed a gradual increase trend, Poisson's ratio (μ) showed a gradual decrease trend, other rock mechanical parameters had no obvious changes. The difference of mineral composition and cementation type was the key factor cause abnormal mechanical properties of rocks; ③Compared with clay minerals, the change of brittle mineral content such as quartz, plagioclase and siderite in rocks were sensitive to the mechanical properties of rocks. The sensitive minerals of compressive strength, shear strength, elastic modulus and softening coefficient were quartz, the sensitive minerals of compressive strength were plagioclase and siderite, and the sensitive minerals of Poisson's ratio are quartz and clay; ④The calculation results of the established mineral weight analysis method were more realistic. It could be concluded that the roof of 13-1 coal, 11-2 coal, 9-2 coal and 4-2 coal seams were more inclined to form fracture network during fracturing, which had guiding significance for the optimization of fracturing horizon.

Experimental study of gydrotermal production of oil from Domanik Formation rocks

2017 ◽  
pp. 64-69
Author(s):  
A. V. Stennikov ◽  
I. A. Bugaev ◽  
A. G. Kalmykov ◽  
A. Yu. Bychkov ◽  
E. V. Kozlova ◽  
...  
Keyword(s):  
Experimental Study ◽  
Clay Minerals ◽  
Mineral Composition ◽  
Sodium Carbonate ◽  
Oil Recovery ◽  
Oil Products ◽  
Hydrothermal Conditions ◽  
Synthetic Oil ◽  
Oil Fractions ◽  
Domanik Formation

The experimental results on the synthetic oil production from Domanik Formation rocks under hydrothermal conditions are given. Oil fractions extracting potential of the rocks under hydrothermal was shown to be up to 60 mg/g or 6,0 wt.%. Inorganic additives (sodium carbonate or silica) incorporation does not influence on the oil recovery factor. Meanwhile the amount of recoverable oil products depends on the mineral composition of the rock. The dependence between the percentage of hydrocarbons emission and mineral composition of the rocks was determined. Clay minerals and silica increase the yield of synthetic oil, carbonates, conversely, inhibit the process.

Some factors affecting the relation between the clay minerals in soils and their plasticity

Clay Minerals ◽  
1966 ◽  
Vol 6 (3) ◽  
pp. 179-193 ◽  
Author(s):  
M. J. Dumbleton ◽  
G. West
Keyword(s):  
Physical Properties ◽  
Clay Minerals ◽  
Mineral Composition ◽  
Clay Content ◽  
Liquid Limit ◽  
Particle Aggregation ◽  
Sedimentation Analysis ◽  
Factors Affecting ◽  
Artificial Mixtures ◽  
Clay Mineral Composition

AbstractThe clay mineral composition is one of the factors that affect the physical properties of soils, and a knowledge of it is required to promote a fuller understanding of the origin of these properties. The relationships between the clay content and the plastic and liquid limits of natural montmorillonitic and kaolinitic soils and of artificial mixtures have been examined and compared. Factors affecting the relationships are discussed, and illustrated by the effect of particle aggregation on the measurement of the liquid limit of tropical red clays and on the sedimentation analysis of the Keuper Marl. The effect of muscovite and of silt-sized material on the position of soils on the Casagrande classification chart has also been examined.

Adverse Engineering Properties of Banxi Group Slatealong Changsha Metro Line 2

2012 ◽  
Vol 204-208 ◽  
pp. 1401-1404
Author(s):  
Chen An
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Rock Mass ◽  
Clay Minerals ◽  
Mineral Composition ◽  
Physical And Mechanical Properties ◽  
Engineering Properties ◽  
Test Results ◽  
Softening Coefficient ◽  
Comprehensive Study

For comprehensive study the adverse engineering properties of Banxi Group slate along Changsha Metro Line 2, slate samples were tested and analyzed to research their mineral composition, physical and mechanical properties, weathered properties and disintegration. Test results show that sandy slate and argillite interbedded with each other, the main minerals of slate are quartz and clay minerals, the oxide are SiO2、Al2O3, the natural compressive strength of sandy slate is five to eight times that of argillite, its softening coefficient is less than 0.75, slate is easy to soften, argillite is easy to disintegration and the disintegration of sandy slate is medium grade. The adverse engineering characteristics lead to slate rock mass uneven with hard-soft. Differential weather of slate causes there are some bedrock weathered slots along Changsha Metro Line 2. So during construction, appropriate process and tool must be selected, control the tunnel oriented, strengthen the protection and shorten the bare time of rock mass.

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