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Artisanal and small-scale mining (ASM) is an important and growing economic activity throughout the Global South. ASM can provide livelihoods where few alternative economic opportunities exist, but it can also cause significant social and environmental problems, creating a need for effective regulation. State authorities have, however, struggled to control an activity that is dynamic, has few barriers to entry, and often occurs in remote areas far from national capitals. One potential regulatory tool involves allocating land to establish ‘designated areas’ for ASM in order to contain operations within discrete zones, facilitating government control, managing relations between ASM and Large Scale Mining (LSM), and mitigating its negative effects. This article explains the rationale for use of designated areas, identifies key policy issues and choices involved in creating them, and provides examples of legislation providing for their establishment. It documents the fact that such provisions are in reality rarely implemented and that, where they are, they generally fail to meet demand for ASM land and are not effectively managed. It identifies a number of proximate causes for these failures, including competition for land, overlapping and ambiguous jurisdiction between different levels of government, resource constraints facing regulators and political ambivalence towards ASM at the national level. It argues that these causes can only be addressed by realigning the governance of land so as to give local and customary authorities a much greater role in land allocation and management, and if national governments overcome their ambivalence towards ASM and accept it as a vital source of economic activity that requires effective regulation. [ABSTRACT FROM AUTHOR]

Processing and interpretation of huge array of mine seismicity data obtained in mines of Norilsk Nickel Mining and Metallurgical Company has revealed the “pulsating” mode of seismic energy release on the background of an increase in the strata pressure and, based on the information on monthly migration of reduced centers of seismic energy release within the mine fields, enabled development of a rockburst hazard criterion for individual rock mass areas. The prognostic criterion of the limiting state of a rock mass area is developed based on the ratio of kinematic characteristics of seismic events, which are the velocity of a reduced center of seismic energy release and the apparent velocity of “migration” of individual seismic events closely timed within the ranges of stress concentration zones inside the mine fields. Verification of this criterion using an ample seismic data base accumulated for a number of years in a mine of Norilsk Nickel has displayed high sensitivity of the criterion towards the change in the stress state of rock mass areas under monitoring. [ABSTRACT FROM AUTHOR]

Highwall mining involves driving a series of parallel entries with web pillars in between. These entries are driven by using a continuous miner with attached conveying system to extract locked up coal behind the highwall slope when the open cut coal mine reaches its ultimate limit. These entries are driven unmanned, unventilated and unsupported. Therefore, a detailed knowledge of structural features ahead of operations is essential in assessing the stability of these entries. Highwall mining operations can greatly benefit from accurate structural mapping of rock mass defects. The stability of these entries can be suitably assessed for any major roof failure by adopting discrete fracture network based structural modelling to characterize and delineate the regions of possible major roof failures to prevent damage to the conveyor and burial of the expensive continuous miner. In this paper, a generalized framework is described based on photogrammetric survey, digital mapping and discrete fracture network based structural modelling to characterise such failures for an Indian highwall mining operation. A sensitivity analysis is undertaken to demonstrate the significance of structure persistence in the geotechnical assessment. Such analysis would provide more insight into designing highwall mining layouts and in predicting possible impending highwall failures, and indirectly facilitates reducing machine downtime for better management of highwall mining operations. [ABSTRACT FROM AUTHOR]

Axial splitting is an important failure mechanism in rock engineering. This failure mechanism is particularly observed in the vicinity of free surfaces of rock structures. Different possibilities such as existence of defects, pores and micro-cracks in the rock specimen have been attributed as the cause of axial splitting in the literature. Based on some physical uniaxial compression tests on Pennsylvania blue sandstone, an alternative theory for axial splitting is proposed. In this theory, axial shear cracks are considered that are induced because of non-uniform deformation of the specimen ends. Dislocation along these axial shear cracks is the cause of rock lateral dilation which results in radial stresses. The radial stresses push out the cylindrical thin shells of the specimen. Consequently, radial cracks are developed which subsequently cause rock spalling in mode-I fracture. The proposed failure mechanism is discussed within the framework of a simplified theoretical model. The prediction of the model is then compared with the physical observations. In addition, a discrete element bonded particle system is utilized for rock simulation in uniaxial compression testing. The prediction of the numerical model is consistent with the physical observations. [ABSTRACT FROM AUTHOR]

Development of deposits of water-soluble minerals is connected with the risk of the accidents caused by the destruction of the waterproof stratum, and, as a consequence, water breakthrough into the mines. Thereupon, besides the problem of the mine's loss the problem of stability of the massif uppermost part appears. This part includes the foundations of buildings and serves as the base for railways and highways, bridges, dams, pipelines and etc. At the present stage of remote geophysical techniques of monitoring and prediction of such negative natural and technic origin, processes methods of high-resolution seismic survey on reflected waves have been developed most of all. In addition to prompt acquisition of physical and geological models of the section, the results of seismic observation's interpretation are proposed to be used as a part of parametric support for geomechanical calculations, which makes possible to predict rock mass stability in the range of transport facilities located above the mines. [ABSTRACT FROM AUTHOR]

The subject of this article is an estimation of the initial capacity of a gas storage cavern, depending on the thickness and the depth of a bedded salt deposit, and the cavern's capacity decrease in time due to its convergence. It was assumed that the relative rate of convergence depends on the depth, the range of the storage pressure and the cavern diameter to height ratio. The discussion will consider the shape of the cavern and the pressure range of natural gas storage. Also, potential locations in Poland for natural gas storage in bedded rock salt deposits in terms of geological and mining criteria are presented in this article. Based on Zechstein isopach maps, as well as maps of its top depth, potential storage capacity maps per unit area were developed. Presented examples will cover two potential regions i.e., bedded salt deposit in the Zatoka Gdańska region and Fore-Sudetic Monocline. These maps will be the basis for the analysis of the suitability of the bedded rock salt Zechstein deposit for natural gas storage. [ABSTRACT FROM AUTHOR]

Mining exploration was very active during the first decade of the twenty-first century because there were numerous advances in the science and technology that geophysicists were using for mineral exploration. Development came from different sources: instrumentation improvements, new numerical algorithms, and cross-fertilization with the seismic industry. In gravity, gradiometry kept its promise and is on the cusp of becoming a key technology for mining exploration. In potential-field methods in general, numerous techniques have been developed for automatic interpretation, and 3D inversion schemes came into frequent use. These inversions will have even greater use when geologic constraints can be applied easily. In airborne electromagnetic (EM) methods, the development of time-domain helicopter EM systems changed the industry. In parallel, improvements in EM modeling and interpretation occurred; in particular, the strengths and weaknesses of the various algorithms became better understood. Simpler imaging schemes came into' standard use, whereas layered inversion seldom is used in the mining industry today. Improvements in ground EM methods were associated with the development of SQUID technology and distributed-acquisition systems; the latter also impacted ground induced-polarization (IP) methods. Developments in borehole geophysics for mining and exploration were numerous. Borehole logging to measure physical properties received significant interest. Perhaps one reason for that interest was the desire to develop links between geophysical and geologic results, which also is a topic of great importance to mining geologists and geophysicists. [ABSTRACT FROM AUTHOR]

Discovery and recognition of the Yanacocha district as a belt of northeast-trending, near-surface, high sulfidation-type epithermal gold deposits with strong supergene oxidation was made over a four-year period (1984-1988) through a joint-venture alliance operated by Newmont Mining Corporation with partners Compañia de Minas Buenaventura and CEDIMIN (BRGM). Open-pit mining began in the district in late 1993 with initial full-year gold production in 1994 of 300,000 oz and a reported end-of-year reserve of 4 Moz. The production growth curve at Yanacocha over 15 years (1994-2008) has been about 10 times the first full year of production in 1994. In February 2007, Minera Yanacocha (Newmont 51%; Buenaventura 44%; International Finance Coip 5%) poured its 20-millionth gold ounce life-of-mine. Reported 2008 end-of-year oxide reserves within the operating district are >13 Moz gold. Since exploration began in the district, over 20 hard-rock deposits and two gravel fan deposits (La Quinua, La Quinua Sur) have been developed. Cumulative historical discovery-to-reserve conversion costs average <$10/oz An. The estimated oxide plus sulfide drill-indicated gold endowment within the district exceeds 70 Moz (2,170 tonnes). The high-sulfidation epithermal gold deposits are hosted by volcanic rocks that occur at the southern terminus of the northern Peruvian volcanic belt, a continuous sequence of a north-northwest-trending Miocene-Pliocene suite of bimodal andesite to rhyolite volcanic rocks that extend into southern Ecuador. In the Yanacocha district, the volcanic pile has been subdivided into three groups: (1) the lower andesite sequence, consisting of an intercalated sequence of block and ash flow tuffs, flow sequences with rare, associated flow domes, and an upper zone dominated by ignimbrites and fine-grained, laminated epiclastic sequences that show a transition into the overlying Yanacocha pyroclastic sequence; (2) the Yanacocha pyroclastic sequence, a variable sequence of lithic to lithic crystal tuffs, extensively altered in the central portion of the district and primary host to the majority of gold deposits within the district; (3) the upper andesite-dacite sequence, consisting of intercalated units of andesite to dacite flows, dominated by multiple flow dome complexes in its upper portion. Ar-Ar age dating within the district has yielded ages ranging from 19 Ma (basal lower andesite) to >12 Ma (upper andesite sequence). The entire volcanic pile has been crosscut by multiple phases of phreatic (vapor phase dominant), phreatomagmatic (intrusive component) and hydrothermal breccias, and intruded by multiple late-stage phases of andesite dikes and dacite to quartz dacite plugs, dikes and stocks (10-8 Ma), the latter of which are associated with shallow Au-Cu porphyry-style mineralization that underlies the high-sulfidation epithermal deposits. Alteration in the district consists of multiple stages of advanced argillic assemblages, typical in nature, that are zoned outward from a central core of massive to vuggy quartz to broader envelopes of advanced argillic alteration (alunite-pyrophyllite) to still broader zones of intermediate argillic and propylitic alteration halos. On a district scale, a generally southwest to northeast progression of multiple alteration centers with various timing has been documented through Ar-Ar dating of hydrothermal alunite, with ages ranging from 11.5 to 8.5 Ma. In places the advanced argillic alteration assemblage is overprinted by a later event consisting of creamy colored cryptocrystalline chalcedony plus barite associated with intermediate sulfklation type feeders. Gold mineralization is a late-stage event that was superimposed over all alteration types, most commonly occurring in late-stage fractures with massive, vuggy, and granular quartz, and especially where higher grade gold mineralization (>3.0 g/t Au) is associated with indurated replacement zones of creamy chalcedony. Mineral deposits are commonly localized within pyroclastic host rocks and phreatic breccias that envelop the margins of less permeable phreatomagmatic and within hydrothermal breccia pipes and andesite-dacite dome margins. Geophysical surveys have been employed as part of an integrated approach from the earliest exploration stages in the district. Resistivity and magnetic and potassium radiometric response anomalies are spatially associated with gold on a district-wide and deposit scale. Gravity surveys have added to understanding of basement geometry and have outlined volcanic subbasins. The east-northeast alignment of the Yanacocha gold deposits is interpreted to have been caused by the intersection of a northeast-trending trans-arc crustal break (Chicama-Yanacocha structural corridor). This is superimposed over older, north-northwest to northwest Andean-parallel folded and thrusted Cretaceous-age sedimentary basement terrane (Paleocene-Eocene). Both structural orientations dominate in the Yanacocha district, controlling emplacement of breccias and intrusions as well as formation of gold mineralization. Discontinuous east-west-oriented faults and fracture zones are interpreted to be extensional and control gold mineralization on a deposit scale. The transition from near-surface, gold-dominant mineralization to underlying copper-dominant sulfide mineralization associated with shallow quartz eye-bearing monzonite to tonalite intrusions has been documented by deep (500-1,200 m) diamond drilling beneath the Yanacocha complex (Sur-Norte-Oeste), the largest single gold deposit in the district with an endowment exceeding 18 Moz. [ABSTRACT FROM AUTHOR]

A calendar of international events related to geology from 2013-2014 is presented which include the Precambrian Research Center Professional Workshop Series, the Exploration, Resource and Mining Geology Conference, and the North Adantic Craton Conference.

A calendar of events for the materials industry in 2011 is presented, including the International Conference on Environmental Engineering and Applications in Shanghai, China, the International Mining Geology Conference in Queenstown, New Zealand , and the Conference of the Society of Medical Innovation and Technology in Tel Aviv, Israel.