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By Alvis L. Lisenbee, Colin J. Paterson, Mustafa M. Hariri

"The schist-, sediment-, and intrusion-hosted Tertiary Au-Ag hydrothermal deposits of the northern Black Hills, South Dakota are localized and controlled by various types of fractures. This study is an attempt to distinguish between and discuss the possible causes of these fractures in three mines: Richmond Hill, Annie Creek – Foley Ridge (ACFR), and Gilt Edge.Five models based on the structural and tectonic settings of the northern Black Hills are proposed for the fracture origin. In Richmond Hill mine, mineralized fractures within the schist-hosted deposits are in the form of veinlets and stockworks. Larger veins filling open spaces along schistosity planes are also present. Fractures in Richmond Hill mine are related to breccia pipe emplacement and influenced by the Precambrian foliation.Fractures in sediment-hosted (ACFR) and intrusion-hosted (Gilt Edge) deposits are mode I systematic joints. These fractures, and similar ones examined in seven locations outside the mines, are related mostly to the formation of the Lead-Deadwood dome. Fracture trends vary from one area to another depending on their location with respect to the dome. Other factors, such as the Black Hills uplift, pluton emplacement, and Precambrian foliation, may also affect the fracture trends. The proximity of the mines to domes formed by multiple intrusions, the associated fracture patterns and density, and existence of breccias, may be used in exploration for similar deposits in the northern BlackHills or other areas of similar geologic settings."

Jan 1, 1995

By J. Malone, D. Loth, J. Palmer

WMC Resources' Kalgoorlie Nickel Smelter was commissioned in 1972 at a design capacity of 30,000 tpa of contained Nickel in matte. A series of upgrades and progressive improvements have resulted in a design capacity increase to 110,000 tpa of contained Nickel in matte. The smelter sources nickel-in-concentrate from three Mine / Concentrators and supplies nickel-in-matte to WMC's Nickel Refinery and export customers. The Flash Furnace was last rebuilt in 1999, and is over halfway through the 10-year campaign target. The many modifications over the previous campaigns, including the Integrated Flash Furnace, are reviewed. Recent operation of the smelter and the development of the process during the current campaign are detailed herein. An overview of key interfaces with the Nickel Business Unit Concentrators and Refinery operations is provided.

Jan 1, 2005

By Lev Filippov, Saeed Farrokhpay

"Flotation process has had less success to recover nickel from laterite ores. Nickel in laterite ores is often finely disseminated in various minerals in very fine size. Therefore, fine grinding should be used to liberate nickel containing particles. Particles resulted from fine grinding are often very fine, and recovery of such particles is generally low using conventional flotation methods. One option to overcome this problem is enhancing the particle-bubble interaction by increasing the particle size and forming flocs. Selective flocculation of fine particle can be therefore the key to enhance the flotation performance of low grade laterite ores.INTRODUCTIONThe majority of the world’s nickel resources occur as laterite ores which are complex, low grade and expensive to treat using conventional smelting and high temperature and/or high pressure autoclave methods (Xu et al., 2013). While about 70% of the nickel resources are contained in laterites, only 40% of the world’s nickel production comes from these ores. Researchers have tried to improve the nickel laterite flotation recovery by using a number of feed preparation techniques. For example, in a study on a laterite ore sample from Australia, flotation tests on a narrow sized fraction of 38-75 µm resulted in only a small increase in the nickel content, from 1.0% to 1.4% (Quast et al., 2015a). In fact, no physical separation technique (including flotation) has been able to dramatically upgrade nickel in laterite ores (Quast et al., 2015b). Thus the challenge of processing low grade nickel laterite ores still exists. This paper aims to explore the possibility of applying selective aggregation in pre-concentrating of valuable minerals in nickel laterite ores."

Jan 1, 2016

By Jan Drzymala, Przemyslaw B. Kowalczuk

"Flotation is possible when the forces operating between a bubble and the attached particle are properly balanced. There are many forces operating in the bubble-particle aggregate. The magnitude, location and direction of the forces depend on the type of process. The simplest arrangement in flotation is when a spherical bubble is attached to a spherical particle and both are immersed in water. In such a system there are four essential forces which shape the stability of the bubble-particle aggregate. They are excess pressure and interfacial solid/liquid, solid/gas and liquid/gas forces. A proper analysis and balance of the size, location and direction of these four principal forces lead to a general equation delineating the stability of the spherical particle–attached bubble system. Specific cross sections of the system and solution of the general equation lead to different relationships including the Young formula as well as the well-known geometrical relation between contact angle, particle and bubble radiuses. The arrangement of forces in the proposed graphical representation of the Young law is different from that presently used in literature for a bubble attached to an unmovable solid particle. Many real solid/liquid/gas systems are more complex due to the presence of additional forces which change the regular curvature of the liquid/gas interface leading to advancing and receding contact angles.INTRODUCTIONThere are numerous papers (Athukorallage, Aulisa, Iyer & Zhang, 2015; Chau, Bruckard, Koh & Nguyen, 2009; Drzymala, 1994; Lubarda, 2012; Pellicer, Manzanares & Mafe, 1995; Wang, Cui, Zhou, Xu, Sun, & Zhu, 2014; Young, 1804) and books (Davies & Rideal, 1963; Defay & Prigogine, 1966; Lee, 2013; Lyklema, 2000) dealing with the solid/liquid/gas system. Many of them concern the three involved phases having the shape of a sphere or spherical cap and the formed contact angle. The contact angle is usually measured through the liquid phase and can be either smaller or greater than 90o. The essential part of these publications is a graphical representation of the system with the Young equation shown as a result of balance of only three forces that is the excess Gibbs (or Helmholz) free energy per unit area of the three involved interfaces (Davies & Rideal, 1963; Defay & Prigogine, 1966; Israelachvili, 1985) (Figs. 1a-c). The Young equation, when the gravity force/buoyancy is neglected, is:"

Jan 1, 2016

By L. E. Gutiérrez

A new filtration model based on porous media transport theory is presented. It predicts capacity and final moisture content in the filtered cake as a function of design and operational variables at the plant. FilterSim® is the computer code where this new model is programmed. Application of FilterSim® to ten-month operation of an industrial copper concentrate filtration plant is shown on a daily basis and using a single set of internal parameters for the whole period. Average error is less than 5%, both in capacity and moisture estimation. FilterSim® abilities to optimize industrial filtration plants as well as to estimate future budgets are illustrated with several real examples.

Jan 1, 2007

By Christopher McElman

Real-time mine management solutions have evolved over time from closed, proprietary solutions, to a "system of systems" that may include a wide variety of off-the-shelf components and technologies. Modular Mining Systems has embraced open standards for their NextGen products to bridge the technology gaps between these systems. However, the remaining logical gaps must be overcome, in order to achieve truly seamless integration between discrete systems. When dealing with volatile real-time management problems, the effectiveness of business process modeling and middle-ware can break down. Scientific principles of military command and control applied to mining domain help to achieve better alignment and reach the highest level of integration. The combination of open standards and off-the-shelf hardware and software with a deliberately structured command-and-control approach provides a clear evolutionary path from ad-hoc connected systems towards real-time management of a seamlessly integrated digital mine.

Oct 1, 2009

By Timothy W. Ellis

Gold-based materials have been a mainstay of the electronics and semiconductor industry since the physics was just a laboratory curiosity. Gold is the workhorse material in wire bond, flip chip and off wafer interconnections due to its corrosion resistance, ability to form metallurgical bonds by soldering or cold welding, and ease of fabrication. As the electronics and semiconductor industries grew, so did the use, of Gold in spite of the feature size reduction so elegantly demonstrated in Moore?s law. However, several revolutions in the Silicon miracle are threatening Gold?s place as the material of choice. Although cost is always an issue, the limitations are associated with the chemistry of Gold based alloys. Will Gold remain? Emerging requirements of bioelectronics, photonics and power requirements in conventional device represent new opportunities for Gold to shine. Additionally, as the world market demand for electronic, semiconducting, bio-electronic and photonic technology increases, given the right technology, Gold still can provide value proposition.

Oct 1, 2003

By Chris M. Healey

"Perhaps the single most significant variable in the evaluation of a mining project is the reserve estimate. Many parameters are considered when estimating reserves, among them geology. This paper examines the link between the quality of a reserve estimate and a good understanding of the geological controls for the deposit. A clear understanding of the geometry is essential to the accurate definition of the shape and size of the deposit. This includes the definition of any structural controls as well as the proper interpretation of the stratigraphy. Further when the distribution of grades is erratic and there is consequently a high nugget effect, there are significant problems in estimating the true grade of the deposit.Two Saskatchewan examples are presented, one with good knowledge of the controls and therefore good estimates of reserves, and the other with a poor understanding of the geology and resultant problems in deriving good estimates. In both cases the reserve estimates at various stages in the project development are compared to actual results from underground work. The first example is the Star Lake Mine where just about all the estimates were within 10070 of the actual on both tonnage and grade. The Laurel Lake deposit is discussed to show how problems in interpreting the geological data make reserve estimation very difficult. Laurel Lake has the additional problem of erratic grade distribution."

Jan 1, 1992

By A. Torkian

Copper mining operations have increased in Iran in the past decades due to price increases and potential for creating jobs in developing countries. Iran consists of many copper mines. The mining operations have a positive economic impact on the region, but may also be the cause of adverse environmental effects. Environmental aspects and the health impact of respirable particulates on the communities and agricultural production in the immediate vicinities have been under scrutiny by the regulatory agencies to ensure sustainable development. The impact of an open-pit mine on the air quality and extent of particulate pollutant dispersion in different directions and times is the focus of this paper. The results of the modeling have been validated through ambient air monitoring. Monitoring stations were installed in different areas within the mine unit operations and around it including background areas where PM10 values were 7 µg/m3. Outside the Complex, particulate concentrations were monitored in 9 different stations and up to 25 km distance. Modeling of point, area, and volume sources was conducted using a 9- year meteorological database. The results showed that particulate quantity decreases rapidly below local standard value of 150 µg/m3 at 2.5 km around the mine and the main pollution is due to the crusher and tailings dump areas. Model outputs were compared to the actual values measured by the air quality monitoring network including villages and crop fields. High overall correlation of about 76% was obtained for most of the locations but lower values were reported for more complex terrain in the region. Remedial actions recommended included road water spraying and better management practices to avoid overloading trucks.

Aug 1, 2013

By Curtiss O. Ehrsam, M. Naseem Mian

Alaska’s Red Dog Mine is strengthening its position within Cominco’s “Vision 2000”strategic plan by continually improving quality and quantity of production while reducing costs. Red Dog has evolved into a stable and mature operation, after six years of milling experience. A high grade, partially oxidized orebody in the severe Arctic environment, along with competing producers in a volatile metals market, are the continuing challenges facing Red Dog. The Red Dog Mine is striving to meet these challenges with emphasis on operator training combined with creative systems development and increased production. This paper describes developments in operations along with future plans.

Jan 1, 1996

By W. J. Kuit

"Complex facilities which provide for the collection, management and treatment of effluents emanating from the Sullivan mine and concentrator tailings were made operational in October, 1979. Key features of the system are the use of upgraded tailings ponds for the storage of up to 800 million litres of metals-contaminated effluents, a treatment plant employing lime in a high density sludge process and a sludge-impoundment facility designed for maximum long-term environmental safety. The completed works are cap1ble of satisfying a difficult range of operating requirements imposed by highly variable weather conditions, drainage flows and soluble metals loadi11gs. Final capital expenditures for the project will approach $10 million and annual operating costs are estimated at $0.8 million.This paper discusses the Kimberley effluents treatment project and the major considerations in its development. The treatment process, major plant equipment and initial operating experience are also described."

Jan 1, 1980

By Chris Brothen

The introduction of new technology in mine operations has provided real opportunities for increased efficiencies and production gains which translate into enhanced profits. Computing and network technology usage has become integrated into surface mining operations and on average these investments in technology have proven beneficial for efficiency and productivity improvements. Embracing new technologies however, does not guarantee positive results. The expectations or improvements derived through the technology must be confirmed and clarified well before implementation. Tire Pressure and Temperature Monitoring Systems are an excellent example of an existing technology that can provide full time automated performance measurements of tires operating under harsh conditions and environments. Prompt warnings or alarms signaling when a tire has exceeded operating capacities will provide savings through lowered maintenance costs and increased productivity. To truly quantify the projected savings in tire life, fuel consumption, and increased levels of production, all costs associated with the technology, both direct and indirect must be considered. Apart from the initial cost of the system implementation, ongoing maintenance and support costs must be considered as well as the costs of system integration into existing mine operations

May 1, 2008

By Laxman M. Amaratunga

"The fine fraction of tailings is usually excluded from the backfill process and generally disposed on the surface in tailings ponds. Because of the ever increasing demand for fine grinding in the extraction process for improved liberation of valuables in the ore, increased production of fines in the tailings has resulted. The negative impact of surface impoundment of tailings on the environment is well known. Amaratunga and Annor (1989) first presented a concept of fine tailings agglomeration for backfill.This paper presents the development of the novel cold-bond tailings agglomeration (CBTA) technology for non-reactive fine gold mill tailings. For cold-bond agglomeration regular portland cement was used as a binder. In order to cut costs, alternate binders such as lime, and blast furnace slag cement were examined. The effects of binder dosage, curing time, and agglomerate size on the fracture load strength of the agglomerate were studied.Fine tailings agglomerates are mixed with coarse tailings or non-agglomerated fine tailings to make high density fill compositions to be used as underground backfill. Alternatively, the agglomerates can be used as aggregates for surface applications. The paper discusses the environmental and operational benefits of this total tailings utilization and disposal technology.IntroductionIn Canadian mines, mill tailings are probably the most commonly used material for backfill. However, only the coarse fraction of tailings is desirable for use as hydraulic fill or high density fills. The fines are disposed on the surface in tailings ponds since they are unsuitable for underground backfilling owing to the following factors:i) slow settling ratesii) longer percolation timeiii) excessive consumption of binder due to drainageiv) poor compactionFor improved value liberation more milling operations have resolved to fine grinding in their comminution circuits. Gold milling operations driven by down stream leaching processes grind their ores excessively fine. In general, gold mines use hardly any tailings for backfilling. This can result in periodic short falls and the need to search for alternate backfill material from other sources. Apparently, the gold producers are the most identifiable sector which suffer from a shortage of backfill materials ( Amaratunga and Annor, 1989)."

Jan 1, 1994

By L. I. Kiss, S. Perron, D. Toulouse, S. Poncsák, A. Perron

Bubbles play an important role in many industrial processes. In a Hall-Heroult cell, used for aluminum production, bubbles contribute to induce flow in the cell. The induced flow is important for the thermal balance of the cell as well as for the distribution and dissolution of the alumina. The existence of the bubble layer does not have advantages only. It increases the voltage of the cell and causes deformation along the cryolite-molten aluminum interface. The role of the anode inclination in the behaviour of the bubble layer as well as in the hydrodynamics of the bath is not clearly understood. In this work, the effect of the anode inclination angle on the bubble driven flow is studied in an industrial scale air-water model. The inclination angle is varied up to 5° from the horizontal. The instantaneous flow field is captured by Particle Image Velocimetry (PIV) system. The mean velocity fields were calculated by ensembleaveraging the instantaneous velocity fields measured at different time. The existence of the counter-flow in the interpolar space and the vortex in the side channel has been confirmed. Furthermore it has been observed that the effect of anode slope on the velocity field is weak.

Jan 1, 2006

Building block cave operations involves significant commitments to capital and time before arriving at completion or full scale production. The focus of the mine planners is habitually to minimize the upfront capital and achieve target development rates and construction dates. However, management of the construction of block cave projects requires understanding of the strategic/tactical decisions that the project planners can take to increase the value of the project and cope with schedule risks. As block cave projects involve development of vertical and lateral access to the underground footprint and ore body, more attention to uncertainties is required as most of those projects need to confront delays leading to a decrease in value. The standard process of development and construction scheduling is often not planned with provisions to realise uncertainties in the construction phase. Uncertainties and risks such as poor ground conditions and equipment breakdowns are the primary reasons for schedule slippage. As a result most of these projects experience delays. In order to mitigate risk to the project schedule, we centre our attention on increasing the value of the project by spending more money upfront and improving the schedule rather than focus on minimizing the upfront capital. Scenario-based simulations along with project appraisal methods hold great promise to address those challenges and enable mine planners to make better decision and enhancing project value. This paper will present a hybrid simulation based approach to model the process of development and construction based on discrete event (DES) and continuous based simulations (CBS). Such simulations will be conducted for scheduling multiple development headings (Apex, undercut, extraction, and haulage levels). Two scenarios are utilized to investigate the impact of risks on schedule and how flexibility in construction can be incorporated to minimize delays: (1) The bench mark scenario is created based on actual data from an existing case study. (2) The flexible scenario is an alternative way to use primary production infrastructure (Ore Handling System) including conveyer drifts, conveyer belt, and a gyratory crusher in the construction process and that requires the system to be in place before starting lateral development in the footprint. As a result, a truck-load system versus a conveying system will be studied to observe the gain in construction speed and to estimate the premium cost for mucking rock from headings and drawbells and transporting it to surface. Such strategic flexibility would be part of the original budget to make the tactical flexibility available during construction. Continuous cash flow models are used to evaluate and compare the scenarios. This study is an example of how new techniques in planning can be used to support decision-making processes in block cave design.

Aug 1, 2013

By John Rowson, Caitlin Brown, Kebbi Hughes, Joseph Esslifie-Dughan

The McClean Lake mill in northern Saskatchewan, Canada, is operated by Orano Canada Inc. and has been in production for the last 20 years. The tailings preparation process at the mill has been designed with decommissioning in mind, to produce tailings that are geochemically stable over the long-term within the site’s tailings management facility. Twenty years of study have contributed to a detailed understanding of geochemical and geotechnical properties of the McClean Lake tailings. Validation of the tailings properties has occurred through in-situ sampling campaigns conducted initially every year, and later every five years. Each sampling campaign has applied the same rigorous sampling procedure to provide data with useful correlations year over year. Each campaign result compares elements such as the inherent variability of the tailings, consolidation of the tailings and variations in the tailings placement methods. We will discuss lessons learned from seven sampling campaigns over 20 years and present data to show the reliable tracking of geochemical evolution of the in-situ tailings over time; providing opportunities for continuous improvements.

Jan 1, 2020

By Yusuke Yamamoto, Mineo Asano

"The present study investigated the texture transition during secondary recrystallization in the AA5182 sheet. During the initial stage of annealing, the texture showed a weak Cube orientation as the primary recrystallization texture. During the secondary recrystallization with abnormal grain growth, the area ratio of the {hkl} <011> orientations increased by consuming the other orientations. The texture transition was calculated by the 2-D Monte Carlo simulation with the misorientation dependency. When the higher grain boundary mobility was set in the specific range of the high angle misorientation, the orientation preferential growth of the RW {100} <011> orientation was reproduced. However, other {hkl} <110> orientations could not be well reproduced by the misorientation dependency.INTRODUCTION Crystal orientation and texture are important factors for aluminum sheet products from the standpoint of mechanical property, formability and isotropy. The recrystallization texture results from the orientation preferential growth from the rolling deformation microstructure and the texture (Alvi, Cheong, Suni, Weiland, & Rollett, 2008). Texture development has been a topic of intense research for decades with advances in analysis methods, e.g., orientation mapping (OIM) and computer simulations (Fjeldberg & Marthinsen, 2010; Ivasishin, Shevchenko, Vasiliev, & Semiatin, 2006). The grain boundary characteristic is considered to be a key for the orientation preferential growth. In the case of the recrystallization from the deformed microstructure, not only the grain boundary characteristic, but also the dislocation density and the subgrain size affect the nucleation and the grain growth (Engler, Löchte, & Hirsch, 2007). On the other hand, in the case of secondary recrystallization, the dislocation density and the subgrain size can be ignored and the effect of the grain boundary characteristic can play a significant role in the grain growth. There is intense research about the texture development during secondary recrystallization in aluminum alloys and it was reported that coarse {hkl} <011> grains were formed during the secondary recrystallization (Suk, Shin, & Huh, 2006; Rios, & Gottstein, 2001). However, the mechanism of forming the {hkl} <011> grains has not been fully clarified. In the present study, the effect of the grain boundary characteristic on the orientation preferential growth was investigated by EBSD analysis and Monte-Carlo (MC) simulation."

Jan 1, 2018

By László Guczi1

Nanosize model gold particles with varying size were fabricated by deposition of a 10 nm thick gold film onto SiO2/Si(100) substrate by electron beam evaporation followed by modification using low energy Ar+ ion bombardment. The change in particle size were monitored by the Au 5d valence band states determined by ultraviolet photoelectron spectroscopy (UPS). The gold/iron oxide interface was studied by iron oxide deposition on gold. It was found that the energy profile of Au 5d valence band states are strongly redistributed with decreasing the gold particle size mostly affecting at the lowest and at the highest binding energies. The size effect in the UPS spectra can be interpreted by the energy redistribution rather, than by narrowing the 5d states. The iron oxide deposition increases the catalytic activity in CO oxidation whether it is on gold nanoparticles or on a continuous 80 nm thick gold film. The activity enhancement is significantly larger in case of gold nanoparticles. The interface interaction is operative in enlargement of the catalytic activity even if gold particles are not exposed to the surface, but they are located below the iron oxide layer.

Oct 1, 2003

By J. Drenda

The model for methane removal from the workings directly behind an advancing longwall as presented in this paper may be used for U-ventilated cross or length-wise systems of longwall advance, starting from the boundaries of the extraction field. In mines with high methane concentrations, Uventilated longwall extraction from the boundary of the extraction field produces a methane risk. The risk is manifested by a higher methane concentration at the end of the longwall, upper gate and incline. The methane in increasing concentrations, which is emitted mainly from the workings with caved areas, appears towards the end of the longwall and in the upper gate. The graphical model of the longwall provided includes both the workspace of the longwall and the caved area. Based upon a model of the rock distribution in the cave, a ventilation model comprising two standard air splits and large number of crosswise air splits has been constructed. Simulations indicate that if the shearer is not present in the longwall, the air distribution in the caved area is symmetrical. The presence of the shearer, both at the bottom and the top of the longwall, causes an asymmetrical air distribution in the cave, that is the asymmetrical flows in the goaf and longwall workspace and in the inflows and outflow between those regions. This phenomenon causes an increase in methane concentration at the end of the wall and at the upper gate. The methane removal method proposed for workings with a caved area directly behind the advancing U-ventilated longwall, starting from the boundary of the field, consists of the removal of methane-air mixtures from the caved area with the boom pipes. These booms may be of several meters long and may be extended if necessary. The insertion of the boom pipes into the cave towards the end of the longwall and connecting them with the general methane removal system creates negative pressure causing a change in the depression field, which is the aerodynamic potential field in the goaf area around the ends of the boom pipes. This will promote the extraction of the methane-air mixture from voids and the goaf cracks, and the area from which methane is being extracted may extend to the side of the cave. This is a positive phenomenon, which could result in the methane flow from the goaf into the airflow in the longwall workspace decreasing or even stopping. A reduction in the methane flow into the longwall workspace with extractions booms will be advantageous for the production continuity. Based on the floor load model for the rocks in the cave and the methane-removal boom load model, the value of the force required to move the boom behind the advancing wall has been calculated. Strength calculations for the pipe were performed using a finite elements method. The analysis results, as well as the comparison of the pipe material effort to the strength parameters of steel, which can serve as piping material (for the assumed load conditions), lead to a belief that the proposed boom construction satisfies the strength requirements.

Aug 1, 2013

By K. J. Aglias, M. Jeffery, J. V. Simmons, J. A. Johnston, S. G. Fityus

"Shales and mudrocks undergo weathering in the near-surface geological environment, and degradation when directly exposed at the surface. Despite having superficially similar appearances, many shales have very different degradation behaviours. For example, some shales break down readily upon exposure whilst others remain more or less intact. Further, for those shales which break down, the style of degradation can vary greatly. A phenomenon is described where fresh shale blocks that are exposed at the surface undergo rapid breakdown to a fragmented texture which then persists for relatively long times, without further breakdown to finer soil particles. This is illustrated for some coal mine waste rocks. Furthermore, this metastable fragmented texture seems to be particular to each particular type of shale. The paper presents a conceptual model for this physical breakdown of shales which accounts for the differences in fragmental texture that are observed. The importance of several factors including strength, permeability and expansive clay content are identified for their contribution to the degradation behaviour of different shales.INTRODUCTIONShales and MudrocksThe term shale is applied widely to a class of mudrocks having a range of distinctive but gradational appearances and mechanical behaviours. Mudrocks are sedimentary rocks primarily composed of silt and clay sized particles (Tucker 1982). Mudrocks form in low to very low energy environments such as flood plains, lakes and deltaic environments, where the finest detrital particles are able to settle out of suspension (Reeves et al., 2006; Stow, 2005; Tucker, 2001).Unlike coarser siliciclastic sedimentary rocks, mudrocks do not present with a wide variety of sedimentary structures and textures. The most common texture is a preferred orientation of clays and micas parallel to the bedding plane. This textural component is related to the property of fissility or the ability for such textured mudrocks to split along smooth planes that are parallel to the bedding. Another common structure is lamination, formed by variations of grain sizes and types during deposition, Massive texture describes the situation where no sedimentary structures or textures are apparent (Boggs Jr., 2009; Tucker, 2001). The term shale varies between sources and contexts, with Reeves et al. (2006) stating that a shale is a fissile mudrock, where “fissility is a property that has developed at a certain stage of weathering”."

Jan 1, 2015