Journal articles on the topic 'Geological domains'
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Kasmaee, Sara, Giuseppe Raspa, Chantal de Fouquet, Francesco Tinti, Stefano Bonduà, and Roberto Bruno. "Geostatistical Estimation of Multi-Domain Deposits with Transitional Boundaries: A Sensitivity Study for the Sechahun Iron Mine." Minerals 9, no. 2 (February 16, 2019): 115. http://dx.doi.org/10.3390/min9020115.
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In mineral resource estimation, identification of the geological domains to be used for modeling, and the type of boundaries dividing them, is a major concern. Generally, the variables within a domain are estimated with an assumption of the hard boundaries (sharp contact). However, in many cases, the geologic structures that generate a deposit are transitional (overlapping of several geologic domains). Consequently, boundary identification of the geological domains is essential for an accurate estimate of resources. This paper considers a real application to examine whether the addition of geologic information benefits grade estimation in the presence of transitional boundaries. Results proved that the accuracy of the grade estimation can be improved by adding geological information and there is a significant sensitivity in grade estimation results in the existence of transitional boundaries.
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MacCormack, Kelsey, Emmanuelle Arnaud, and Beth L. Parker. "Using a multiple variogram approach to improve the accuracy of subsurface geological models." Canadian Journal of Earth Sciences 55, no. 7 (July 2018): 786–801. http://dx.doi.org/10.1139/cjes-2016-0112.
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Subsurface geological models are often used to visualize and analyze the nature, geometry, and variability of geologic and hydrogeologic units in the context of groundwater resource studies. The development of three-dimensional (3D) subsurface geological models covering increasingly larger model domains has steadily increased in recent years, in step with the rapid development of computing technology and software, and the increasing need to understand and manage groundwater resources at the regional scale. The models are then used by decision makers to guide activities and policies related to source water protection, well field development, and industrial or agricultural water use. It is important to ensure that the modelling techniques and procedures are able to accurately delineate and characterize the heterogeneity of the various geological environments included within the regional model domain. The purpose of this study is to examine if 3D stratigraphic models covering complex Quaternary deposits can be improved by splitting the regional model into multiple submodels based on the degree of variability observed between surrounding data points and informed by expert geological knowledge of the geological–depositional framework. This is demonstrated using subsurface data from the Paris Moraine area near Guelph in southern Ontario. The variogram models produced for each submodel region were able to better characterize the data variability, resulting in a more geologically realistic interpolation of the entire model domain as demonstrated by the comparison of the model output with preexisting maps of surficial geology and bedrock topography as well as depositional models for these complex glacial environments. Importantly, comparison between model outputs reveals significant differences in the resulting subsurface stratigraphy, complexity, and variability, which would in turn impact groundwater flow model predictions.
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De La Rosa, Roberto, Raimon Tolosana-Delgado, Moritz Kirsch, and Richard Gloaguen. "Automated Multi-Scale and Multivariate Geological Logging from Drill-Core Hyperspectral Data." Remote Sensing 14, no. 11 (June 2, 2022): 2676. http://dx.doi.org/10.3390/rs14112676.
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Hyperspectral drill-core scanning adds value to exploration campaigns by providing continuous, high-resolution mineralogical data over the length of entire boreholes. However, multivariate mineralogical data must be transformed into lithological domains such that it is compatible with interpolation techniques and be usable for geomodeling. Manual interpretation of multivariate drill-core data is a challenging, time-consuming and subjective task, and automated or semi-automated approaches are needed. However, naive machine-learning techniques that ignore the distinct spatial structure and multi-scale nature of geological systems tend to produce geologically unreasonable results. Automated geological logging and multi-scale hierarchical domaining of drill-cores has been previously addressed in several studies by means of scalograms from a wavelet transform and tessellation, albeit exploiting only univariate information. The methodology involves the extraction of the local first principal component at a neighborhood of each observation, and the segmentation of the resulting series of scores with a continuous wavelet transform for boundary detection. In this way, the correlation pattern between the variables is incorporated into the segmentation. The scalogram accurately locates the geological boundaries at depth and yields hierarchical geological domains with mineralogical composition characteristics. The performance of this approach is demonstrated on a synthetic as well as a real multivariate dataset. The real dataset consists of mineral abundances derived from drill-core hyperspectral imaging data acquired in Elvira, a shale-hosted volcanogenic massive sulfide deposit located in the Iberian Pyrite Belt, where 7000 m of drill-core were acquired along 80 boreholes. The extracted domains are sensible from a geological point of view and spatially coherent across the boreholes in cross-sections. The results at relevant scales were qualitatively validated by comparing against the lithological log. This method is fast, is appropriate for multivariate geological data along boreholes, and provides a choice of scales for hierarchical geological domains along boreholes with mineralogical composition characteristics that can be modeled in 3D. Our approach provides an automatic way to transform hyperspectral image-derived mineral maps into vertically coherent geological units that are appropriate inputs for 3D geological modeling workflows. Moreover, the method improves the boundary detection and geological domaining by making use of multivariate information.
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Madani, Nasser, Mohammad Maleki, and Fatemeh Sepidbar. "Integration of Dual Border Effects in Resource Estimation: A Cokriging Practice on a Copper Porphyry Deposit." Minerals 11, no. 7 (June 22, 2021): 660. http://dx.doi.org/10.3390/min11070660.
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Hierarchical or cascade resource estimation is a very common practice when building a geological block model in metalliferous deposits. One option for this is to model the geological domains by indicator kriging and then to estimate (by kriging) the grade of interest within the built geodomains. There are three problems regarding this. The first is that sometimes the molded geological domains are spotty and fragmented and, thus, far from the geological interpretation. The second is that the resulting estimated grades highly suffer from a smoothing effect. The third is related to the border effect of the continuous variable across the boundary of geological domains. The latter means that the final block model of the grade shows a very abrupt transition when crossing the border of two adjacent geological domains. This characteristic of the border effect may not be always true, and it is plausible that some of the variables show smooth or soft boundaries. The case is even more complicated when there is a mixture of hard and soft boundaries. A solution is provided in this paper to employ a cokriging paradigm for jointly modeling grade and geological domains. The results of modeling the copper in an Iranian copper porphyry deposit through the proposed approach illustrates that the method is not only capable of handling the mixture of hard and soft boundaries, but it also produces models that are less influenced by the smoothing effect. These results are compared to an independent kriging, where each variable is modeled separately, irrespective of the influence of geological domains.
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Ekolle-Essoh, Franklin, Arsène Meying, Alain Zanga-Amougou, and Xavier Emery. "Resource Estimation in Multi-Unit Mineral Deposits Using a Multivariate Matérn Correlation Model: An Application in an Iron Ore Deposit of Nkout, Cameroon." Minerals 12, no. 12 (December 12, 2022): 1599. http://dx.doi.org/10.3390/min12121599.
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Modeling the spatial dependence structure of metal grades in the presence of soft boundaries between geological domains is challenging in any mineral resource estimation strategy. The aim of this work was to propose a structural model adapted to this type of geological boundary, based on a multivariate Matérn model that fits the observed direct (within domain) and cross (between domains) correlation structures of metal grades. The methodology was applied to a case study of an iron deposit located in southern Cameroon. Cross-validation scores show that accounting for the grade correlation across domain boundaries improved the traditional workflow, where the grade was estimated in each domain separately. The scores were significantly better when we also ensured that the mean grade was locally invariant from one domain to another to reflect the grade continuity across the domain boundary.
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Fillion, Marie-Hélène, and John Hadjigeorgiou. "Quantifying influence of drilling additional boreholes on quality of geological model." Canadian Geotechnical Journal 56, no. 3 (March 2019): 347–63. http://dx.doi.org/10.1139/cgj-2017-0653.
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Geotechnical stability analysis in open-pit mines requires access to a representative geotechnical model. The confidence level in the collected geotechnical data influences slope design. This paper investigates the influence of the number of boreholes, drilled to collect geological information, on the quality of one component of the geotechnical model, the geological model. The number of boreholes influences the number of rock core samples collected for the identification of rock type, and the definition of geotechnical domains and their boundaries within the rock mass. A challenge in the definition of the geotechnical domains is the determination of the drill hole density that minimizes the variation in the interpreted geological model from the actual rock mass. To quantify the influence of the drill hole density, boreholes are simulated in the most recently updated geological model for three mine sites. The simulated drill hole density is increased progressively until the variation of the interpreted section, compared with the original section, is minimized. A classification strategy was developed to determine the complexity level for each geotechnical domain. Furthermore, a series of empirical quantitative guidelines are presented prescribing the minimum drill hole density per domain complexity, while limiting variations from the actual rock mass.
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Boroh, A. W., K. Y. Sore-Gamo, Ngounouno Ayiwouo, Mbowou Gbambie, and I. Ngounouno. "Implication of geological domains data for modeling and estimating resources from Nkout iron deposit (South-Cameroun)." Journal of Mining and Metallurgy A: Mining 57, no. 1 (2021): 1–17. http://dx.doi.org/10.5937/jmma2101001b.
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This paper is devoted to determining whether the addition of geological information can improve the resource estimate of mineral resources. The geochemical data used come from 116 drill holes in the Nkout East iron deposit in southern Cameroon. These geochemical data are modeled on Surpac and Isatis softwares to represent the 3D geochemical distribution of iron in the deposit. Statistical analysis and then a variographic study is performed to study the spatial variability of iron. Estimation domains were defined based on the results of geological and geochemical analyses. Four domains were determined. These domains are the saprolitic domain in particular; the poor domain or fresh rocks such as amphibolites, granites, and gneisses; the rich domain or oxidized rocks (BIF) and the metasediment domain. Block modeling of the deposit is performed to estimate the resource. The grade of each block was estimated by using ordinary kriging and composites from each domain. This study also consisted of comparing two types of estimate, notably the domain estimate and the global estimate. The cross-validation made it possible to authenticate the obtained models. From this comparison, the domain estimation brings more precision the global estimate precisely on the error analysis while if we take into account the point clouds of the predicted and estimated values, the estimation by geochemical modeling provides the best results.
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Palomo, I. "Geochemical Characteristics of Toarcian Sedimentation in Alpine Geological Domains." Mineralogical Magazine 58A, no. 2 (1994): 684–85. http://dx.doi.org/10.1180/minmag.1994.58a.2.94.
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Rogova, Tamara, and Sergey Shaklein. "Adjustment of the Exploration Grids and its use to increase the Reliability of Geological Models of Coal Deposits." E3S Web of Conferences 174 (2020): 01063. http://dx.doi.org/10.1051/e3sconf/202017401063.
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The current procedure for determining the boundaries of geological domains, the allocation of which is the mandatory element of digital geological modelling, does not entirely take into account the specifics of coal deposits. Without its improvement, it is impossible to increase the reliability of geological models used in the implementation of the “Industry 4.0ˮ strategy. A new method for analysis of geological data is supposed – the adjustment of the exploration grids method. It is to determine the corrections for values of measured parameters, the use of which eliminates the uncertainty of geological data interpretation. The correction values determined by the method of conditional measurements, which used at equalization geodetic networks. Corrections are considered as an indicator of the significance of measurement and interpolation errors which occurs in the vicinity of specific measurement points. The measured values of parameters are not corrected. Geological domains are the areas with close in values corrections, whose boundaries are corrections isolines. Separate single corrections of anomalous magnitude indicate the presence of extreme values parameters.
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CARPENTER, R. L., and N. A. DUKE. "Geological Setting of the West Meliadine Gold Deposits, Western Churchill Province, Nunavut, Canada." Exploration and Mining Geology 13, no. 1-4 (January 1, 2004): 49–65. http://dx.doi.org/10.2113/gsemg.13.1-4.49.
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Abstract The West Meliadine area is underlain by structurally interleaved panels of mafic and minor ultramafic metavolcanic rocks and metasedimentary rocks that occur along the northern margin of the Neoarchean Rankin Inlet greenstone belt. Three structural and metamorphic domains are recognized: (1) the easterly Wesmeg domain; (2) the central Barracuda-Ridge domain; and (3) the westerly Peter Lake domain. The Wesmeg domain is characterized by a series of southeast-trending, north-dipping, foliation-parallel panels of greenschist facies mafic metavolcanic and metasedimentary rocks. The Barracuda-Ridge domain is comprised of greenschist to amphibolite facies mafic metavolcanic rocks that define an east-northeast-trending structural grain. The Peter Lake domain consists of amphibolite facies mafic metavolcanic rocks and minor metasedimentary rocks intruded by a monzonite pluton. West Meliadine hosts the economically significant Wesmeg gold deposits, as well as other important gold showings across the Barracuda-Ridge and Peter Lake domains. The geological setting of the Wesmeg gold deposits resembles that of a break or fault zone. The Pyke Break is a major geophysical discontinuity (>65-km strike length) and is the first-order structural control on gold mineralization at West Meliadine. It is several kilometers wide and characterized by polyphase deformation and shear zone development accompanied by lode-gold mineralization. In general, gold concentration is related to quartz and iron-carbonate veining, iron sulfides (mainly arsenopyrite and pyrrhotite), and accompanying silicate alteration minerals that overprint favorable chemical and structural traps late in the history of deformation.
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Hitchings, Victor H., and Hans Potters. "Production and Geological Implications of the Natih 9C3D Seismic Survey." GeoArabia 5, no. 4 (October 1, 2000): 511–24. http://dx.doi.org/10.2113/geoarabia0504511.
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ABSTRACT The Natih Formation in the Natih field is a heterogeneously fractured reservoir being developed by gas/oil gravity drainage. An understanding of the degree and orientation of the fracturing is essential for the optimum development of the reservoir. In order to better understand the fracturing in the reservoir, conventional 3-D (compressional) and limited 9C3D (nine-component, three-dimensional) seismic surveys were made of the Natih field. A revised fault/fracture model was developed from the conventional 3-D survey results in which ‘domains’ of similar fault/fracture character have been defined. Comparison with well-production data indicates that the domains associated with strike-slip or rotational movements (interpreted as being more fractured than adjacent areas) are zones of significantly higher productivity. The 9C3D seismic survey results also show areas or ‘domains’ of variable shear-wave time splitting. A comparison of the fault/fracture domains with the shear-wave time-splitting domains shows a close relationship in which areas of highest shear-wave time splitting coincide with those in which fracturing is most intense. The integration of fault/fracture modeling, well-production characteristics and the 9C3D survey results indicate the potential of the latter as a field-development tool in terms of optimizing well locations, well planning and reservoir management decision making.
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Tschirhart, Peter, William A. Morris, John Mims, and Hernan Ugalde. "Applying laterally varying density corrections to ground gravity and airborne gravity gradiometry data: a case study from the Bathurst Mining Camp." Canadian Journal of Earth Sciences 56, no. 5 (May 2019): 493–503. http://dx.doi.org/10.1139/cjes-2018-0046.
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The influence of topography on gravity and gravity gradiometry measurements is profound and should be minimized prior to geological interpretation. The standard way of minimizing these effects is through the computation of a terrain correction. Terrain corrections require two inputs: topography and density. Often, geology and topography are inextricably intertwined: topography is caused by a change in geology. In geologic environments where there is a structural and (or) stratigraphic control on the near-surface mass distribution, using a single density value in the corrections leads to removal of the topographic effect of rocks having the chosen density. Any remaining gravity signal that correlates with topography is providing geological information. If the objective is to produce a gravity map with minimal topographic signal, then a regionally variable density correction is a means of compensating for this effect. In this paper, we demonstrate how to apply a spatially variable density correction using ground gravity and airborne gravity gradiometry data for the geologically complex Bathurst Mining Camp, northern New Brunswick, Canada. Ground gravity and airborne full tensor gravity gradiometry measurements are subdivided into a series of domains on the basis of the underlying tectonostratigraphic group. Terrain and Bouguer corrections are calculated for each domain using representative density values obtained from drill core and surface sampling throughout the Bathurst Mining Camp. The output from the spatially variable density correction is then compared with previous maps. Overall, the differences are subtle, but the spatially variably density allows for isolated anomalies to be better resolved.
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Savyolova, T. I. "Calculation of Domains of Dependence for Pole Figures With an Ultrahyperbolic Differential Equation." Textures and Microstructures 23, no. 3 (January 1, 1995): 185–99. http://dx.doi.org/10.1155/tsm.23.185.
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X-ray and neutron methods of texture investigation are used to get experimental pole figures (PF) of polcrystalline samples and geological materials (Bunge, 1982). Usually several PF are used, 1–4 for polycrystalline samples with cubic, hexagonal lattice symmetry (copper, iron, beryllium...), 6–19 for low-symmetry materials of geological samples (quartz, biotite...). Pole figures are the sum of solutions of two ultrahyperbolic equations (Savyolova, 1982). If the solutions of ultrahyperbolic equations are known in some domains we can determine them uniquely in other domains using the Asgeirsson's theorem (Courant, 1962) and their generalizations by ultra-Lorentz transformations. We get the domains of dependence of pole figures and the methods of continuations of solutions of ultrahyperbolic equations.
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Fuerst, John A., and Euan G. Nisbet. "Buds from the tree of life: linking compartmentalized prokaryotes and eukaryotes by a non-hyperthermophile common ancestor and implications for understanding Archaean microbial communities." International Journal of Astrobiology 3, no. 3 (July 2004): 183–87. http://dx.doi.org/10.1017/s1473550404002150.
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The origin of the first nucleated eukaryote and the nature of the last common ancestor of the three domains of life are major questions in the evolutionary biology of cellular life on Earth, the solutions to which may be linked. Planctomycetes are unusual compartmentalized bacteria that include a membrane-bounded nucleoid. The possibility that they constitute a very deep branch of the domain Bacteria suggests a model for the evolution of the three domains of life from a last common ancestor that was a mesophile or moderate thermophile with a compartmentalized eukaryote-like cell plan. Planctomycetes and some members of the domain Archaea may have retained cell compartmentalization present in an original eukaryote-like last common ancestor of the three domains of life. The implications of this model for possible habitats of the early evolution of domains of cellular life and for interpretation of geological evidence relating to those habitats and the early emergence of life are examined here.
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Punnam, Pradeep Reddy, Balaji Krishnamurthy, and Vikranth Kumar Surasani. "Influence of Caprock Morphology on Solubility Trapping during CO2 Geological Sequestration." Geofluids 2022 (June 25, 2022): 1–15. http://dx.doi.org/10.1155/2022/8016575.
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Carbon capture and sequestration (CCS) technology is one of the indispensable alternatives to reduce carbon dioxide (CO2) emissions. In this technology, carbon capture and transport grid will send CO2 to the storage facilities that are using various storage techniques. Geologic carbon sequestration (GCS) is one such storage technique where CO2 is injected into a deep geological subsurface formation. The injected CO2 is permanently stored in the formation due to structural, residual, solubility, and mineral trapping phenomena. Among different trapping mechanisms, solubility trapping plays a significant role in the safe operation of GCS. In this work, the study is conducted to elucidate the influence of top surface caprock morphology on the solubility trapping mechanism. The simulation results show that the naturally available heterogeneous formations with anticline and without anticline structure influence the solubility fingering phenomena and solubility entrapment percentage over a geological time scale. The lateral migration and sweeping efficiency results of both the synthetic domains for the injected CO2 have shown the importance of caprock morphology on solubility trapping and selection of injection rate. Quantification of solubility trapping in two morphological structures revealed that the synthetic domain without anticline morphology had shown higher solubility trapping. In the future, the simulation data using Artificial Neural Networks can be applied to predict the structural and solubility trapping of geological formations. This analysis further helps incorporating the interaction of CO2 with porous media leading to a mineral trapping mechanism.
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Ortega, M., I. Palomo, F. Martinez, and I. Gonzalez. "Geological factors controlling clay mineral patterns across the Cretaceous-Tertiary boundary in Mediterranean and Atlantic sections." Clay Minerals 33, no. 3 (September 1998): 483–500. http://dx.doi.org/10.1180/000985598545651.
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AbstractThe clay mineral associations in the Cretaceous-Tertiary Boundary (KTB) and in the Danian and Maastrichtian levels of sections from the Mediterranean and the Atlantic Domains have been studied. The Mediterranean sections have a single mineral association consisting of smectiteiltite and kaolinite, whereas the Atlantic sections have several associations: illite-chlorite, illite-R1 I-S-kaolinite and illite-R 1 I-S-chlorite. Data are presented relating to the influence of K-feldspars and Fe oxide sphemles on the clay mineral associations. Study of rare-earth elements shows that regional geological factors affect the clay mineralogy of the KTB, examples showing significant anthigenesis in the Mediterranean sections, and important detrital supply in all the Atlantic sections. We propose that the KTB studied in these marine sections is equivalent to the uppermost layer of the two-layered clay unit originating in a cloud of a vapourized bolide. Regional tectonic conditions have been responsible for differences in clay sedimentation in these geological domains and among the stratigraphic sections of the Atlantic Domain.
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Van Gool, Jeroen A. M., and Sandra Piazolo. "Presentation and interpretation of structural data from the Nagssugtoqidian orogen using a GIS platform: general trends and features." Geological Survey of Denmark and Greenland (GEUS) Bulletin 11 (December 5, 2006): 125–44. http://dx.doi.org/10.34194/geusb.v11.4921.
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In this contribution we present data collected by more than 50 international geologists involved in geological mapping and research projects in the Nagssugtoqidian orogen of West Greenland, organised by the Geological Survey of Denmark and Greenland and the Danish Lithosphere Centre. Using a geographical information system (GIS) as a framework for visualisation and analysis of structural and lithological data, it is now possible to give a unique overview of thousands of data points, employed here within a study area of approximately 160 × 180 km in the central and northern Nagssugtoqidian orogen. The GIS methodology allows comparison, integration and analysis of datasets in terms of subject, space, and scale. This is extremely helpful in the recognition of geological patterns, such as terrain or domain boundaries and map-scale structures. Analysis of the available structural data shows clear differences in deformation patterns between the core and the northern segment of the Nagssugtoqidian orogen. One of the most prominent features is the ENE-striking Nordre Strømfjord shear zone, which transects the orogen from the coast to the Inland Ice. The data also clearly document a change from predominantly steeply dipping, ENE–WSW-trending fabrics and large, elongate structural domains in the core of the orogen, to large, open fold patterns and moderately to shallowly dipping fabrics in smaller structural domains in the north.
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Bruneton, P. "Geological environment of the Cigar Lake uranium deposit." Canadian Journal of Earth Sciences 30, no. 4 (April 1, 1993): 653–73. http://dx.doi.org/10.1139/e93-054.
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The Cigar Lake uranium deposit occurs within the Athabasca Basin of northern Saskatchewan, Canada. Like other major uranium deposits of the basin, it is located at the unconformity separating Helikian sandstones of the Athabasca Group from Aphebian metasediments and plutonic rocks of the Wollaston Group. The Athabasca Group was deposited in an intra-continental sedimentary basin that was filled by fluviatile terrestrial quartz sandstones and conglomerates. The group appears undeformed and its actual maximum thickness is about 1500 m. On the eastern side of the basin, the detrital units correspond to the Manitou Falls Formations where most of the uranium deposits are located. The Lower Pelitic unit of the Wollaston Group, which lies directly on the Archean basement, is considered to be the most favourable horizon for uranium mineralization. During the Hudsonian orogeny (1800–1900 Ma), the group underwent polyphase deformation and upper amphibolite facies metamorphism. The Hudsonian orogeny was followed by a long period of erosion and weathering and the development of a paleoweathering profile.On the Waterbury Lake property, the Manitou Falls Formation is 250–500 m thick and corresponds to units MFd, MFc, and MFb. The conglomeratic MFb unit hosts the Cigar Lake deposit. However, the basal conglomerate is absent at the deposit, wedging out against an east–west, 20 m high, pre-Athabasca basement ridge, on top of which is located the orebody.Two major lithostructural domains are present in the metamorphic basement of the property: (1) a southern area composed mainly of pelitic metasediments (Wollaston Domain) and (2) a northern area with large lensoid granitic domes (Mudjatik Domain). The Cigar Lake east–west pelitic basin, which contains the deposit, is located in the transitional zone between the two domains. The metamorphic basement rocks in the basin consist mainly of graphitic metapelitic gneisses and calcsilicate gneisses, which are inferred to be part of the Lower Pelitic unit. Graphite- and pyrite-rich "augen gneisses," an unusual facies within the graphitic metapelitic gneisses, occur primarily below the Cigar Lake orebody.The mineralogy and geochemistry of the graphitic metapelitic gneisses suggest that they were originally shales. The abundance of magnesium in the intercalated carbonates layers indicates an evaporitic origin.The structural framework is dominated by large northeast–southwest lineaments and wide east–west mylonitic corridors. These mylonites, which contain the augen gneisses, are considered to be the most favourable features for the concentration of uranium mineralization.Despite the presence of the orebody, large areas of the Waterbury Lake property remain totally unexplored and open for new discoveries.
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Hók, Jozef, Robert Kysel, Michal Kováč, Peter Moczo, Jozef Kristek, Miriam Kristeková, and Martin Šujan. "A seismic source zone model for the seismic hazard assessment of Slovakia." Geologica Carpathica 67, no. 3 (June 1, 2016): 275–90. http://dx.doi.org/10.1515/geoca-2016-0018.
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Abstract We present a new seismic source zone model for the seismic hazard assessment of Slovakia based on a new seismotectonic model of the territory of Slovakia and adjacent areas. The seismotectonic model has been developed using a new Slovak earthquake catalogue (SLOVEC 2011), successive division of the large-scale geological structures into tectonic regions, seismogeological domains and seismogenic structures. The main criteria for definitions of regions, domains and structures are the age of the last tectonic consolidation of geological structures, thickness of lithosphere, thickness of crust, geothermal conditions, current tectonic regime and seismic activity. The seismic source zones are presented on a 1:1,000,000 scale map.
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Moreira, Gabriel de Castro, Rudi César Comiotto Modena, João Felipe Coimbra Leite Costa, and Diego Machado Marques. "A workflow for defining geological domains using machine learning and geostatistics." Tecnologia em Metalurgia, Materiais e Mineração 18 (2021): e2472. http://dx.doi.org/10.4322/2176-1523.20212472.
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Martin, C. D. "Characterizing in situ stress domains at the AECL Underground Research Laboratory." Canadian Geotechnical Journal 27, no. 5 (October 1, 1990): 631–46. http://dx.doi.org/10.1139/t90-077.
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The Underground Research Laboratory access shaft was excavated from the surface to about the 185 m depth in jointed pink granite. Below this depth to the 443 m depth the shaft was excavated in massive grey granite. The grey granite is essentially unjointed, except for a major low-dipping thrust fault and associated minor splays. Overcoring, hydraulic fracturing, convergence measurements, microseismic monitoring, and observations of shaft-wall failure and core discing indicate that unusually high in situ stresses can be associated with large volumes of massive, unjointed granite at fairly shallow depth. The database of in situ stress measurements collected at the Underground Research Laboratory indicates that major geological features, such as thrust faults, can act as boundaries for in situ stress domains and that both the magnitude and direction of the in situ stress state can change when these geological features are traversed. Key words: in situ stress, anisotropy, stress domains, thrust faults, overcoring, hydraulic fracturing, convergence measurements, excavation damage zones.
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Faraj, Fouad, and Julian M. Ortiz. "A Simple Unsupervised Classification Workflow for Defining Geological Domains Using Multivariate Data." Mining, Metallurgy & Exploration 38, no. 3 (April 16, 2021): 1609–23. http://dx.doi.org/10.1007/s42461-021-00428-5.
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Moyano-Nieto, Ismael E., Germán A. Prieto, and Mauricio Ibañez-Mejia. "Tectonic domains in the NW Amazonian Craton from geophysical and geological data." Precambrian Research 377 (August 2022): 106735. http://dx.doi.org/10.1016/j.precamres.2022.106735.
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Ramos, Lara Nigro Rodrigues Alves, Augusto César Bittencourt Pires, and Catarina Labouré Benfica Toledo. "AIRBORNE GAMMA-RAY SPECTROMETRIC AND MAGNETIC SIGNATURES OF FAZENDA NOVA REGION, EAST PORTION OF ARENÓPOLIS MAGMATIC ARC, GOIÁS." Revista Brasileira de Geofísica 32, no. 1 (March 1, 2014): 123. http://dx.doi.org/10.22564/rbgf.v32i1.401.
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ABSTRACT. Airborne geophysical data are an important tool for the interpretation of geological features. The variations observed in airborne magnetic and gamma-ray spectrometric data are typically used to differentiate geological units and delimit structures. In this context, this study aims to use gamma-ray spectrometric and magnetic airborne data to support the geological mapping in the Fazenda Nova region, located in the east portion of the Arenópolis Magmatic Arc. The processing of the gamma-ray spectrometric data consisted of generating K, U, Th, total count, gamma-ray spectrometric ratios and ternary images. The anomalous magnetic field processing and enhancing generated the magnetic maps, which provided information about the structural framework of the area, while the gamma-ray profiles and images allowed the delineation of the geologic-geophysical domains. Fifteen domains were individualized, interpreted especially from ternary images, which displayed a good relation with the granite bodies mapped and indicated different rocks associated with the Goiás Alkaline Province, contributing to improving the geological knowledge of the area. Keywords: airborne geophysics, gamma-ray spectrometric, Arenópolis Magmatic Arc. RESUMO. Dados aerogeofísicos consistem em uma importante ferramenta para a interpretação de feições geológicas. Variações observadas em dados magnéticos e de espectrometria gama aéreos são usualmente utilizadas para a discriminação de unidades geológicas e delimitação de estruturas. Neste contexto, este estudo tem como objetivo o uso de imagens derivadas do processamento de dados magnéticos e gamaespectrométricos aéreos no suporte ao mapeamento geológico na região de Fazenda Nova, localizada na porção leste do Arco Magmático de Arenópolis. Para os dados gamaespectrométricos, o processamento consistiu na geração de imagens dos canais K, U, Th e Contagem Total, além das razões entre os canais e as imagens ternárias. O processamento e realce do campo magnético anômalo geraram as imagens magnéticas, as quais forneceram informações sobre o arcabouço estrutural da área, enquanto que imagens e perfis aeroradiométricos permitiram a delimitação dos domínios litogeofísicos. Foram individualizados 15 domínios, interpretados principalmente a partir das imagens ternárias, os quais apresentaram forte correlação com os corpos graníticos mapeados na região e delimitaram diferentes rochas associadas à Província Alcalina de Goiás, contribuindo para o aprimoramento do conhecimento geológico da região.Palavras-chave: aerogeofísica, gamaespectrometria, Arco Magmático de Arenópolis.
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SUTEANU, CRISTIAN, and JÖRN H. KRUHL. "INVESTIGATION OF HETEROGENEOUS SCALING INTERVALS EXEMPLIFIED BY SUTURED QUARTZ GRAIN BOUNDARIES." Fractals 10, no. 04 (December 2002): 435–49. http://dx.doi.org/10.1142/s0218348x02001312.
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Quartz grain boundaries from metamorphic and igneous rocks may emphasize a complex geometry, characterized by self-similarity over one to two orders of magnitude. Their fractal analysis highlights scaling sub-domains, i.e. scale intervals with a particularly good correlation. Given the importance of these aspects for the deciphering of geological microstructures, the paper is dedicated to the detection and the objective depiction of the features of heterogeneous scaling intervals. A fractal analysis based on the divider method was followed by processing methods that (i) offer a global evaluation of the curve geometry from the point of view of the correlation sub-domains, and (ii) allow a local characterization of the curves in terms of scale, with special concern for the scaling intervals heterogeneity. The application of the proposed approach was exemplified both on natural and synthetic curves. On one hand, the grain boundary analysis highlighted scaling sub-domains most obviously in the case of microstructures that were subject to overprinting, due to successive processes. On the other hand, a pattern superposition in the case of the synthetic curves strongly emphasized scaling sub-domains, as compared to the unperturbed (recursively generated) curve geometry. These aspects were expressed quantitatively and highlighted in more detail on isocorrelation maps. The importance of a rigorous characterization of these sub-domains and, eventually, the detection of pattern overprinting phenomena in geological microstructures emphasize the relevance of such an approach.
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Tschirhart, Victoria, Sally Pehrsson, Colin Card, Eric G. Potter, Jeremy Powell, and Dinu Pană. "Interpretation of buried basement in the southwestern Athabasca Basin, Canada, from integrated geophysical and geological datasets." Geochemistry: Exploration, Environment, Analysis 21, no. 1 (February 24, 2020): geochem2019–061. http://dx.doi.org/10.1144/geochem2019-061.
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Recent discoveries of basement-hosted uranium deposits in the Patterson Lake corridor in the southwestern Athabasca Basin of Canada have brought vigorous exploration interest to the region. New lithostratigraphic constraints, geochronology and airborne geophysical surveys have dramatically improved the understanding of the host basement geology, warranting a re-examination of the remote predictive mapping and geophysical responses of the buried basement rocks. This study took a two-step approach to examine the regional basement geology and architecture. First, a mosaic of the long-wavelength response of potential field (gravity and magnetic) datasets was examined to divide the basement into regional domains based on bulk physical property variations. The interpretive geological model was then refined using textural and lineament analysis of new airborne gravity and magnetic datasets, geological drill hole logs and magnetic susceptibility measurements. The new basement map identifies and updates major features including a crustal-scale structure that separates the southern Tantato Domain from the newly defined eastern Taltson Domain. This structure may have played a role in localizing fluid flow in the Patterson Lake corridor, defining the spatial extents of structurally controlled buried felsic intrusions, and redefines the boundaries of the Taltson, Clearwater and Tantato Domains. In addition, the potential field enhancements delineated significant regional faults that controlled the geometry of Paleoproterozoic cover sequences and have implications for understanding the crustal architecture of the southern Rae Province. These new interpretations shed light on the tectonic history of the region to support on-going exploration activities and delineate regionally prospective areas in this understudied area of the Canadian Shield.Thematic collection: This article is part of the Uranium Fluid Pathways collection available at: https://www.lyellcollection.org/cc/uranium-fluid-pathways
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Deckers, Jef, Bernd Rombaut, Koen Van Noten, and Kris Vanneste. "Influence of inherited structural domains and their particular strain distributions on the Roer Valley graben evolution from inversion to extension." Solid Earth 12, no. 2 (February 9, 2021): 345–61. http://dx.doi.org/10.5194/se-12-345-2021.
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Abstract. The influence of strain distribution inheritance within fault systems on repeated fault reactivation is far less understood than the process of repeated fault reactivation itself. By evaluating cross sections through a new 3D geological model, we demonstrate contrasts in strain distribution between different fault segments of the same fault system during its reverse reactivation and subsequent normal reactivation. The study object is the Roer Valley graben (RVG), a middle Mesozoic rift basin in western Europe that is bounded by large border fault systems. These border fault systems were reversely reactivated under Late Cretaceous compression (inversion) and reactivated as normal faults under Cenozoic extension. A careful evaluation of the new geological model of the western RVG border fault system – the Feldbiss fault system (FFS) – reveals the presence of two structural domains in the FFS with distinctly different strain distributions during both Late Cretaceous compression and Cenozoic extension. A southern domain is characterized by narrow (<3 km) localized faulting, while the northern is characterized by wide (>10 km) distributed faulting. The total normal and reverse throws in the two domains of the FFS were estimated to be similar during both tectonic phases. This shows that each domain accommodated a similar amount of compressional and extensional deformation but persistently distributed it differently. The faults in both structural domains of the FFS strike NW–SE, but the change in geometry between them takes place across the oblique WNW–ESE striking Grote Brogel fault. Also in other parts of the Roer Valley graben, WNW–ESE-striking faults are associated with major geometrical changes (left-stepping patterns) in its border fault system. At the contact between both structural domains, a major NNE–SSW-striking latest Carboniferous strike-slip fault is present, referred to as the Gruitrode Lineament. Across another latest Carboniferous strike-slip fault zone (Donderslag Lineament) nearby, changes in the geometry of Mesozoic fault populations were also noted. These observations demonstrate that Late Cretaceous and Cenozoic inherited changes in fault geometries as well as strain distributions were likely caused by the presence of pre-existing lineaments in the basement.
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Emery, Xavier. "Simulation of geological domains using the plurigaussian model: New developments and computer programs." Computers & Geosciences 33, no. 9 (September 2007): 1189–201. http://dx.doi.org/10.1016/j.cageo.2007.01.006.
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Balamurali, M., and A. Melkumyan. "Automated update of geological domains using blast-hole assays and minimum covariance determinant." Applied Earth Science 129, no. 1 (November 11, 2019): 9–14. http://dx.doi.org/10.1080/25726838.2019.1686102.
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JIA, Cheng-zao, Zheng-zhang ZHAO, Jin-hu DU, Wen-zhi ZHAO, Cai-neng ZOU, and Su-yun HU. "PetroChina key exploration domains: geological cognition, core technology, exploration effect and exploration direction." Petroleum Exploration and Development 35, no. 4 (August 2008): 385–96. http://dx.doi.org/10.1016/s1876-3804(08)60087-7.
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Sengupta, P., J. Sanwal, N. L. Dudwadkar, S. C. Tripathi, and P. M. Gandhi. "Adsorption of actinides within speleothems." Mineralogical Magazine 80, no. 5 (August 2016): 765–80. http://dx.doi.org/10.1180/minmag.2016.080.013.
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AbstractStalagmites and stalactites, as observed within natural caves, may develop inside geological repositories during constructional and post-operational periods. It is therefore important to understand actinide sorption within such materials. Towards this, experimental studies were carried out with 233U, 238Np (VI), 238Np (IV), 239Pu and 241Am radiotracers using natural speleothem samples collected from the Dharamjali cave of the Kumaon Lesser Himalayas, India. Petrological/mineralogical studies showed that natural speleothems have three general domains: (1) columnar calcite; (2) microcrystalline calcite; and (3) botryoidal aragonite – each with ferruginous materials. Results showed that all domains of speleothems can take up >99% actinides, irrespective of valence state and pH (1–6 range) of the solution. However, distribution coefficients were found to be at a maximum in aragonite for most of the actinides. Such data are very important for long-term performance and safety assessments of the deep geological repositories planned for the disposal of high-level nuclear wastes.
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Jovanovic, Velimir, Ivana Carevic, Dragana Vuskovic, and Khalil Abad. "Review and protection possibilities of some trans-border (East Serbia-West Bulgaria) stratigraphic/palaeontological geosites." Glasnik Srpskog geografskog drustva 92, no. 1 (2012): 171–84. http://dx.doi.org/10.2298/gsgd1201171j.
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Stratigraphic/palaeontological geosites of Stara Planina Mountain in east Serbia are well developed in the area of Serbian/Bulgarian state border, where with this occassion, three sections of exeptional geological and scientific interest are selected: Jelovica, Rosomac and Senokos. These geosites represent the important localities for study of Triassic and Jurassic terrigene-carbonate deposits, for which the scientific value from the domains of palaeontology, stratigraphy and sedimentology is widely known. The aim of this work is to represent the main scientific arguments for inventory and protection of detached transborder geological sites that are unique according to their composition and content.
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Relf, C., H. A. Sandeman, and M. E. Villeneuve. "Tectonic and thermal history of the Anialik River area, northwestern Slave Province, Canada." Canadian Journal of Earth Sciences 36, no. 7 (July 1, 1999): 1207–26. http://dx.doi.org/10.1139/e99-050.
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The Anialik River area in the northwestern Slave Province comprises two geological domains of different age and origin that were tectonically juxtaposed at ca. 2650 Ma. The older domain, the Kangguyak gneiss belt, comprises ca. 3300-2700 Ma orthogneisses and paragneisses, interpreted as the remnants of a Mesoarchean continental margin. The younger domain, the Anialik River greenstone belt, consists of ca. 2680 Ma mafic to felsic volcanic rocks interpreted to have formed in an ensimatic island-arc setting. Structural and geochronological evidence suggest collision of the two domains began around 2650 Ma in a transpressive regime that involved oblique (sinistral) subduction of the greenstone belt beneath the Kangguyak domain along the Tokhokatak shear zone. Displacement continued until at least ca. 2600 Ma, when late, two-mica granites intruded along and were deformed in the shear zone. Following ca. 2600 Ma, rocks in both domains and along the fault cooled rapidly to about 350°C. Strongly overprinted muscovite spectra and the young ages for biotite throughout the region imply that a thermal event reset all biotites (but not muscovite) at ca. 2000-1900 Ma, possibly associated with crustal thickening associated with Wopmay (Calderian) orogenesis. The tectonic history of the Anialik River area is significantly different from that documented in the south-central part of the Slave Province, suggesting the Kangguyak domain is a distinct fragment of continental crust that accreted independently from continental crust in the southern Slave Province.
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Giallini, Silvia, Enrico Paolucci, Pietro Sirianni, Dario Albarello, Iolanda Gaudiosi, Federica Polpetta, Maurizio Simionato, et al. "Reconstruction of a Reference Subsoil Model for the Seismic Microzonation of Gori (Georgia): A Procedure Based on Principal Component Analysis (PCA)." Bulletin of the Seismological Society of America 111, no. 4 (July 6, 2021): 1921–39. http://dx.doi.org/10.1785/0120200341.
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ABSTRACT This article focuses on the full exploitation of geological and economically viable geophysical surveys for the seismic characterization of the shallow subsoil in the frame of microzonation studies in urban areas where economic resources for detailed seismic response analyses are scarce. In these conditions, the outcomes of inexpensive geophysical surveys (e.g., based on ambient vibration monitoring or surface-wave prospecting) must be fully exploited. To reduce the uncertainties related to these kinds of procedures, their joint interpretation in the light of geological evidence is mandatory. To this purpose, we propose the application of principal component analysis to combine the results of distributed single-station ambient vibration measurements (horizontal-to-vertical spectral ratio [HVSR] technique) to provide a preliminary zonation of the study area. The zones identified in this way are then characterized by considering the available geognostic boreholes, VS profiles deduced by the joint inversion of HVSR curves, and available Rayleigh-wave dispersion curves deduced from active seismic prospecting (multichannel analysis of surface-waves technique). The final outcome allows the definition of a preliminary seismic model of the study area, which is also constrained by the available geological data deduced from on-purpose surveys. The proposed approach has been applied to the city of Gori (Georgia). The proposed approach allowed a reliable assessment of buried geometries, geological domains, and the distribution of lithofacies, which can control the local seismic response. In detail, the major role of paleovalley infills and interfluve domains has been enlightened by adding in evidence concerning the peculiar stratigraphic relationships and buried morphologies, which may determine 1D and 2D resonance effects.
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Acharyya, Subhrangsu K., and Babar A. Shah. "Groundwater arsenic contamination affecting different geologic domains in India—a review: influence of geological setting, fluvial geomorphology and Quaternary stratigraphy." Journal of Environmental Science and Health, Part A 42, no. 12 (October 16, 2007): 1795–805. http://dx.doi.org/10.1080/10934520701566744.
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Way, David, Don McKee, and Joe Pease. "Comminution and Mineral Separation—Geological Input to Metallurgy." SEG Discovery, no. 126 (July 1, 2021): 28–41. http://dx.doi.org/10.5382/geo-and-mining-12.
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Editor’s note: The aim of the Geology and Mining series is to introduce early-career professionals and students to various aspects of mineral exploration, development, and mining, in order to share the experiences and insight of each author on the myriad of topics involved with the mineral industry and the ways in which geoscientists contribute to each. Abstract Communication and collaboration during mine development and operation are essential if the maximum value of a mineral deposit is to be realized, since there are many links between the geology and mineralogy of an orebody and the complex task of an effective plant design. This is only achieved when geologists, metallurgists, and mining and environmental engineers jointly assess the results of metallurgical characterization. This requirement is examined here, albeit for only two of the three metallurgical ore-processing activities—comminution and mineral separation. Wealth is not captured (i.e., is destroyed) unless the most efficient and effective methods for comminuting and separating the mineral(s) of value in a deposit are identified. Benchmarking metallurgical test work requirements for the next mine development based solely on past experience does not address the variability that is unique to the mineralogy of each mineral deposit. Metallurgists are now slowly advancing from using a few (so-called) representative samples to assess the processing characteristics of a deposit to applying metallurgical testing to tens, or hundreds, of samples, with the increase in number of samples allowed by technological advances. More still needs to be done. Identifying the characteristics of different mineralization types of a deposit and grouping it into domains are crucially important. These steps simplify processing by separating ore into relatively few (4–6) types with similar expected metallurgical performance. Understanding what metallurgical tests are measuring and how representative the samples and tests are of the orebody domains are essential considerations for a testing program. No knowledge is bad; some is better or more useful than other. Testing for penalty elements (As, Bi, Hg, F, etc.) and, more importantly, for penalty-element minerals allows their effects to be mitigated during design of the processing plant; this should start during the early exploration stage. Continued evolution of orebody knowledge and confidence in processing ores will lead to better performance of the processing plant, thereby reducing investment risk.
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Gallwey, J., C. Yeomans, M. Tonkins, J. Coggan, D. Vogt, and M. Eyre. "USING DEEP LEARNING AND HOUGH TRANSFORMATIONS TO INFER MINERALISED VEINS FROM LIDAR DATA OVER HISTORIC MINING AREAS." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLIII-B2-2020 (August 14, 2020): 1561–68. http://dx.doi.org/10.5194/isprs-archives-xliii-b2-2020-1561-2020.
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Abstract. This paper presents a novel technique to improve geological understanding in regions of historic mining activity. This is achieved through inferring the orientations of geological structures from the imprints left on the landscape by past mining activities. Open source high resolution LiDAR datasets are used to fine-tune a deep convolutional neural network designed initially for Lunar LiDAR crater identification. By using a transfer learning approach between these two very similar domains, high accuracy predictions of pit locations can be generated in the form of a raster mask of pit location probabilities. Taking the raster of the predicted pit location centres as an input, a Hough transformation is used to fit lines through the centres of the detected pits. The results demonstrate that these lines follow the patterns of known mineralised veins in the area, alongside highlighting veins which are below the scale of the published geological maps.
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Плёнкин, А. В., А. Ю. Чернышенко, В. Н. Чугунов, and И. В. Капырин. "Adaptive unstructured mesh generation methods for hydrogeological problems." Numerical Methods and Programming (Vychislitel'nye Metody i Programmirovanie), no. 4 (December 18, 2015): 518–33. http://dx.doi.org/10.26089/nummet.v16r449.
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Рассматриваются два сеточных генератора, внедренных в программный комплекс GeRa, предназначенный для решения задач геофильтрации и геомиграции радионуклидов. Это треугольно-призматический генератор с возможностью вырождения ячеек и генератор многогранных сеток с измельчением на основе восьмеричного дерева и возможностями скалывания ячеек. Генераторы позволяют автоматически строить конформные многогранные адаптивные сетки в трехмерных геологических областях с учетом сложной конфигурации внешних границ, кровель и подошв геологических пластов, выклинивания слоев и геологических неоднородностей. Two mesh generators embedded in the GeRa code for the solution of groundwater flow and radionuclide transport problems are discussed. The first one is a triangular-prismatic generator with the ability of cell degeneration; the second one is the polyhedral octree mesh generator implementing the cut-cell technology. These generators allow the user to automatically create conformal polyhedral adaptive grids in three-dimensional geological domains with consideration of complex boundaries, top and bottom geological layer surfaces, pinch-outs, and geological heterogeneities.
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Santibáñez, Isabel, José Cembrano, Tiaren García-Pérez, Carlos Costa, Gonzalo Yáñez, Carlos Marquardt, Gloria Arancibia, and Gabriel González. "Crustal faults in the Chilean Andes: geological constraints and seismic potential." Andean Geology 46, no. 1 (September 28, 2018): 32. http://dx.doi.org/10.5027/andgeov46n1-3067.
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The Chilean Andes, as a characteristic tectonic and geomorphological region, is a perfect location to unravel the geologic nature of seismic hazards. The Chilean segment of the Nazca-South American subduction zone has experienced mega-earthquakes with Moment Magnitudes (Mw) >8.5 (e.g., Mw 9.5 Valdivia, 1960; Mw 8.8 Maule, 2010) and many large earthquakes with Mw >7.5, both with recurrence times of tens to hundreds of years. By contrast, crustal faults within the overriding South American plate commonly have longer recurrence times (thousands of years) and are known to produce earthquakes with maximum Mw of 7.0 to 7.5. Subduction-type earthquakes are considered the principal seismic hazard in Chile, with the potential to cause significant damage to its population and economy. However crustal (non-subduction) earthquakes can also cause great destruction at a local scale, because of their shallower hypocentral depth. Nevertheless, the nature, timing and slip rates of crustal seismic sources in the Chilean Andes remain poorly constrained. This work aims to address the seismic potential of the crustal faults in Chile, contributing to the estimation of key fault parameters for the seismic hazard assessment. We have examined the main parameters involved in the magnitude of an earthquake, including length, width and mean displacement of some case studies crustal faults and their morphotectonic settings, exposing the parametrical similarities in longitudinal domains (N-S stripes) and disparity from W to E, across latitudinal domains. The maximum hypocentral depths for crustal earthquakes vary across margin parallel tectonic domains aligned parallel, from 25-30 km in the outer forearc to 8-12 km in the volcanic arc, thus allowing for a first-order approach for seismic potential assessment. Current structural, paleoseismological and geodetic data, although sparse and limited, suggest that slip rates of Chilean crustal faults range from 0.2 mm/yr (in the forearc region) to up to 7.0 mm/yr (in the intra-arc region). The different tectonic modes for crustal fault reactivation and their wide range of slip rates complicates the estimation of seismic hazard. A rigorous seismic hazard assessment must therefore consider the different tectonic settings, timing and slip rates of Andean crustal faults. Understanding the nature of these faults will allow a better evaluation of the associated seismic hazard, and better constraints to be placed on their relationship with the subduction seismic cycle.
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Andini, Mutiara, Niki Rahma Rizkita, Pherto Rimos, Febri E. Prihasto, Ahmad R. Trilaksana, and Novi F. R. Dewi. "KAJIAN PENGARUH MATERIAL PROPERTIS DOMAIN BATUAN DASAR TERHADAP KESTABILAN LERENG PADA NIKEL LATERIT DI SITE POMALAA , SULAWESI TENGGARA, PT ANTAM Tbk." Prosiding Temu Profesi Tahunan PERHAPI 1, no. 1 (March 29, 2020): 453–62. http://dx.doi.org/10.36986/ptptp.v1i1.88.
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ABSTRAK Untuk mendukung kegiatan operasional penambangan, perlu dilakukan pembuatan kajian geoteknik yang bertujuan sebagai rencana awal desain lereng tambang maupun mengevaluasi kestabilan lereng pada saat kegiatan penambangan berlangsung. Untuk pembuatan kajian geoteknik di Site Pomalaa, dilakukan pengambilan 15 sampel untuk masing-masing domain (Hazburgit, Dunit, Serpentinit dan Peridotit) yang dibagi menjadi 5 sampel limonit, 5 sample saprolit dan 5 sampel bedrock. Selanjutnya, sampel tersebut dilakukan pengujian di laboratorium untuk mendapatakan nilai material properties. Material propertis limonit pada setiap domain memiliki rentang nilai kohesi 31,22 kN/m2- 40,49 kN/m2, sudut geser dalam 31,30o-37,36o, berat jenis basah 11,56 kN/m2-12,89 kN/m2, UCS 0,11Mpa – 0,59 Mpa.Sedangkan nilai material propertis pada saprolit memiliki rentang nilai kohesi 31,22 kN/m2-39,18 kN/m2, sudut geser dalam 34,71o-39,11o, berat jenis basah 10,86 kN/m2-13,52 kN/m2, UCS 0,19Mpa – 0,29 MPa. Material propertis tersebut selanjutnya digunakan sebagai parameter dalam melakukan analisis kestabilan lereng dengan mengeluarkan nilai faktor keamanan (FK) dan probability of failure (PoF). Pada kajian ini dilakukan simulasi dengan 4 pendekatan : (a) Pertama, menganalisis lereng dengan domain geologi tunggal, (b)Kedua, menganalisis lereng dengan menggabungkan 2 domain geologi yang berbeda, (c) Ketiga, menganalisis lereng dengan menggabungkan 3 domain geologi yang berbeda, (d) Menganalisis lereng dengan menggabungkan 4 domain geologi yang berbeda. Hasil simulasi dengan menggunakan 4 pendekatan tersebut menunjukkan nilai rata-rata FK limonit secara berturut sebesar 1.72, 1.71,1.73, dan 1.73 . Sedangkan nilai FK saprolit secara berturut sebesar 1.74, 1.78 , 1.75 dan 1.74. Rata-rata probability of failure pada simulasi ini dibawah 1%. Dari hasil simulasi dapat dilihat bahwa nilai faktor keamanan dari hasil simulasi beberapa material menunjukkan nilai yang konsisten, sehingga dapat dikatakan bahwa nilai material propertis nikel laterit pada batuan dasar yang berbeda cenderung sama (homogen), oleh karena itu pengambilan sampel geoteknik di site pomalaa tidak sensitif terhadap domain batuan. Key words: Domain Batuan Dasar, Kohesi, Sudut Geser Dalam, Berat Jenis Basah, UCS, Faktor Keamanan, Probability of Failure. ABSTRACT Concerning mining operations activities, geotechnical analysis should be carried out with the aim of planning the initial design of slope and evaluating the stability of the slope during mining activities. For making geotechnical studies at the Pomalaa Site, 15 samples were taken for each domain (Hazburgit, Dunit, Serpentinit and Peridotit) which were allocated into 5 samples for limonite, 5 samples for saprolite and 5 samples for bedrock. Furthermore, the sample is tested in a laboratory to obtain the value of material properties. Limonite property material in each domain has a range of cohesion values of 31.22 kN / m2-40.49 kN / m2, friction angle at 31.30o-37.36o, wet density 11.56 kN / m2-12.89 kN / m2, UCS 0.11Mpa - 0.59 Mpa. While the value of proper material in saprolite has a range of cohesion values of 31.22 kN / m2-39.18 kN / m2, shear angle in 34.71o-39.11o, wet specific gravity 10.86 kN / m2-13.52 kN / m2, UCS 0.19Mpa - 0.29 Mpa. The property material is then used as a parameter input to obtain slope stability analysis by issuing factor of safety (FK) and probability of failure (PoF) values ). In this case a simulation was conducted to 4 approaches: (a) First, analyzing slopes with a single geological domain, (b) Second, analyzing slopes by combining 2 different geological domains, (c) Third, analyzing slopes by combining 3 different geological domains , (d) Analyze slopes by combining 4 different geological domains. The simulation results using the 4 approaches show the average value of FK limonite which are 1.72, 1.71.1.73, and 1.73 respectively. While FK saprolite values were 1.74, 1.78, 1.75 and 1.74 respectively. The average probability of failure in this simulation is below 1%. From the simulation results it can be seen that the value of the safety factor from the simulation results of several materials shows a consistent value, so it can be said that the material value of laterite nickel properties in different bedrock tends to be the same (homogeneous), therefore geotechnical sampling at the Pomalaa site is not sensitive to the rock domain. Key words: Host Rock Domain, Cohesion, Friction angle, Wet Specific Gravity, UCS, Safety Factor, Probability of Failure.
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Zhu, L., J. Yu, Y. Liu, H. Gong, Y. Chen, and B. Chen. "Visualization of three dimensional earth fissures in geological structure." Proceedings of the International Association of Hydrological Sciences 372 (November 12, 2015): 227–29. http://dx.doi.org/10.5194/piahs-372-227-2015.
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Abstract. This paper proposes a new method for visualizing the earth fissures of geological structure in three dimensional (3-D) domains on the basis of the seismic data and features information of earth fissures. The seismic data were interpreted for obtaining the stratagraphic data with various lithological information and the depth of the earth fissures. The spatial distribution of the ground fissures including the dip, strike and width were digitalized on an ArcGIS platform. Firstly, the 3-D geological structure was rebuilt using the Generalized Tri-Prism (GTP) method which is a real solid method for displaying geological structures. The GTP method can reflect the inner material of the strata and can simulate complicated geological structures such as faults and stratagraphic pinch outs. The upper and lower surfaces of each stratum consist of Triangle Irregular Networks (TIN). The inner solid between the two surfaces are a series of triangular prisms. Secondly, since the width of the ground fissure gradually decreases with depth, multiple edge lines of the earth fissures on the bottom stratum surface are deduced on the basis of the fissure characteristics. Then, the model of the earth fissures consisting of a series of triangular pyramids can be constructed using these points and the edge lines. A cutting operation was carried out on the 3-D geological structure using this ground fissures model. If the surfaces of the ground fissures model intersects with the GTPs in the geological structure model, new GTPs were generated within the local regions. During this process, the topological relations between TIN, triangular prism and lines were reconstructed so that the visualization of ground fissures in the geological structure model is realized. This method can facilitate the mechanism for studying fissures and avoid the gaps between the fissure solid and the geological structure to accurately reflect their 3-D characteristics.
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Zheng, X., and C. Xiao. "TYPICAL APPLICATIONS OF AIRBORNE LIDAR TECHNOLAGY IN GEOLOGICAL INVESTIGATION." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLII-3 (May 2, 2018): 2459–63. http://dx.doi.org/10.5194/isprs-archives-xlii-3-2459-2018.
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The technology of airborne light detection and ranging (LiDAR), also referred to as Airborne Laser Scanning, is widely used for high-resolution topographic data acquisition (even under forest cover) with sub-meter planimetric and vertical accuracy. This contribution constructs the real digital terrain model to provide the direct observation data for the landscape analysis in geological domains. Based on the advantage of LiDAR, the authors mainly deal with the applications of LiDAR data to such fields as surface land collapse, landslide and fault structure extraction. The review conclusion shows that airborne LiDAR technology is becoming an indispensable tool for above mentioned issues, especially in the local and large scale investigations of micro-topography. The technology not only can identify the surface collapse, landslide boundary and subtle faulted landform, but also be able to extract the filling parameters of collapsed surface, the geomorphic parameters of landslide stability evaluation and cracks. This technology has extensive prospect of applications in geological investigation.
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Hernández, Heber, Elisabete Alberdi, Aitor Goti, and Aitor Oyarbide-Zubillaga. "Application of the k-Prototype Clustering Approach for the Definition of Geostatistical Estimation Domains." Mathematics 11, no. 3 (February 1, 2023): 740. http://dx.doi.org/10.3390/math11030740.
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The definition of geostatistical domains is a stage in the estimation of mineral resources, in which a sample resulting from a mining exploration process is divided into zones that show homogeneity or minimal variation in the main element of interest or mineral grade, having geological and spatial meaning. Its importance lies in the fact that the quality of the estimation techniques, and therefore, the correct quantification of the mineral resource, will improve in geostatistically stationary areas. The present study seeks to define geostatistical domains of estimation for a mineral grade, using a non-traditional approach based on the k-prototype clustering algorithm. This algorithm is based on the k-means paradigm of unsupervised machine learning, but it is exempt from the one-time restriction on numeric data. The latter is especially convenient, as it allows the incorporation of categorical variables such as geological attributes in the grouping. The case study corresponds to a hydrothermal gold deposit of high sulfidation, located in the southern zone of Peru, where estimation domains are defined from a historical record of data recovered from 131 diamond drill holes and 37 trenches. The characteristics directly involved were the gold grade (Au), silver grade (Ag), type of hydrothermal alteration, and type of mineralization. The results obtained showed that clustering with k-prototypes is an efficient approach and can be used as an alternative or complement to the traditional methodology.
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Nikic, Zoran, Ljubomir Letic, and Vesna Nikolic. "Formation of useful waters on the Stara Planina mountain, in the area Visok Kraj." Bulletin of the Faculty of Forestry, no. 105 (2012): 139–56. http://dx.doi.org/10.2298/gsf110919001n.
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Formation and discharge of useful waters was studied on southwestern slopes of the Stara Planina Mountain, in the area Visok Kraj that is the typical hilly-mountainous region in East Serbia. The catchment?s area of Dojkinacka River was chosen due to numerous and specific edaphic properties. Pump forests (association: Fagetum moesiacea serbicum Rud.) dominate here and were mostly developed on slightly acidic, humus-silicate or on acidic brownish soil. Soils are of a range of depths and development of pedogenetic processes. The aim of this work is to highlight elements that have pronounced influence on supply of useful and small water bodies in the catchment area of Dojkinacka River. Complex relations between geological setting, climate conditions, pedological characteristics, hydrological and hydrogeological conditions, forest vegetation etc. were analyzed. Elements that are significant for proper evaluation of useful water or small domains supply were in this case detected through water balance methods, geological mapping and tracking. It was deduced that the disagreement of topographic and hydrological catchment?s area of Dojkinacka River represents the significant element which should be taken into consideration in order to determine the real reserves of useful, i.e. small water domains.
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Neto, José Alves Ferreira, Igor Henrique Fernandes Silva, Juscelina Rosiane Ferreira, and Rafael Aldighieri Moraes. "Geoconservation: Research and extension in the context of the Iron Quadrangle, Brazil." International Journal of Advanced Engineering Research and Science 9, no. 9 (2022): 535–43. http://dx.doi.org/10.22161/ijaers.99.58.
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Brazil has a great geological potential, however there are only three geoparks recognized by UNESCO: Araripe, Seridó and Caminhos dos Cânions. Several studies show the potential of the Brazilian region, located at Minas Gerais state, named Iron Quadrangle to be incorporated in the Global Geopark Network,, where its conservation has importance in the geological, historical and social scene. The State University of Minas Gerais (UEMG), through its trajectory, has developed extension and research projects linked to the history of each region, with themes related to geodiversity, geoeducation, environmental preservation. This paper aims to demonstrate how the academy, especially the UEMG, can promote the conservation of the Iron Quadrangle. The city of João Monlevade has received special attention since this city integrates the Iron Quadrangle and it has important geological sites as Areão Park and Serra do Seara. João Monlevade city has an economy around the steel industry, metallurgy and mining, activities that interpose intensively in the landscape. . Research and extension works in these domains are essential, since they represent an important tool for its conservation. The institution can extend to the society the scientific knowledge about geological historical, economic heritage, space alteration and environment preservation as a whole creating an important way for local and regional sustainability.
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Li, Jian, Xiaobo Wang, Guoqi Wei, Wei Yang, Zengye Xie, Zhisheng Li, Jianying Guo, et al. "New progresses in basic geological theories and future exploration domains of natural gas in China." Natural Gas Industry B 5, no. 5 (October 2018): 434–43. http://dx.doi.org/10.1016/j.ngib.2018.04.012.
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Madani, Nasser, and Xavier Emery. "Plurigaussian modeling of geological domains based on the truncation of non-stationary Gaussian random fields." Stochastic Environmental Research and Risk Assessment 31, no. 4 (December 2, 2016): 893–913. http://dx.doi.org/10.1007/s00477-016-1365-9.
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Corrigan, D., Z. Hajnal, B. Németh, and S. B. Lucas. "Tectonic framework of a Paleoproterozoic arc-continent to continent-continent collisional zone, Trans-Hudson Orogen, from geological and seismic reflection studies." Canadian Journal of Earth Sciences 42, no. 4 (April 1, 2005): 421–34. http://dx.doi.org/10.1139/e05-025.
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Vertical incidence seismic data were collected along a 300 km-long profile across the northwestern flank of the Trans-Hudson Orogen in Saskatchewan (line S2b). The present study integrates the seismic data with previously published geological maps and recent results from the La Ronge Lynn Lake Bridge Project that provide new constraints on the lithological, structural, and tectonic framework of this collisional zone. An interpretative section, based on the seismic reflectivity and surface geological constraints, is presented. The integrated data suggest the following key elements. (1) Although an early foreland-vergent accretion history is suggested by surficial geological constraints, the predominant fabric is reflected by penetrative hinterlandward vergence. (2) A zone of more reflective lower crust with hinterland-verging fabric may represent "fossil" reflectors from a pre-collisional accretionary phase. (3) The Archean to Paleoproterozoic Sask Craton may extend in the lower middle crust to at least beneath Rottenstone Domain, consistent with what is observed along strike on other Lithoprobe seismic profiles. (4) The Needle Falls and Parker Lake shear zones do not appear to be associated with obvious reflectors, consistent with observations from Reindeer Lake, suggesting that they merely rework the Wathaman Batholith intrusive margin and are not fundamental sutures. (5) The La Ronge and Rottenstone domains show nearly identical seismic properties, consistent with recent mapping results in the Reindeer Lake area that suggest that they are temporally and, at least in part, lithologically related in the area covered by, and to the east of, seismic line S2b.
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Misseri, Maxime, and Didier Lahondere. "Characterisation of chemically related asbestos amphiboles of actinolite: proposal for a specific differentiation in the diagram (Si apfu versus Mg/Mg+Fe2+)." International Journal of Metrology and Quality Engineering 9 (2018): 16. http://dx.doi.org/10.1051/ijmqe/2018014.
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Aggregates and rocks from quarries located in metropolitan France and New Caledonia, all likely to contain asbestiform amphiboles, were analysed by a routine laboratory (AD-LAB). Morphological observations were made using transmission electron microscopy and chemical analyses were obtained with energy dispersive X-ray spectroscopy. The chemical analyses obtained from amphiboles were treated in such a way that they could be plotted in a diagram (Si apfu versus Mg/Mg+Fe2+). The points corresponding to analysed particles, classified as asbestos, define a broader compositional domain than that corresponding to the compositional areas of actinolite and tremolite. The creation of two new domains is proposed. Samples of basic metavolcanics and amphibolites collected by the Geological and Mining Research Bureau (BRGM) in different quarries of the Armorican Massif and the Massif Central containing calcic amphibole fibres have been the subject of polarized light microscope and electron microprobe analyses. The representative points of the spot chemical analyses performed on the very fine and ultrafine fibres are contained in the range defined previously. The diagram that has been determined from chemical analyses coupled with morphological and dimensional observations can help the “routine laboratories” to better characterise asbestiform calcic amphiboles, but it also allows comparisons with geological observations.
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Pollock, Jeffrey C., James P. Hibbard, and Cees R. van Staal. "A paleogeographical review of the peri-Gondwanan realm of the Appalachian orogen1This article is one of a series of papers published in this CJES Special Issue: In honour of Ward Neale on the theme of Appalachian and Grenvillian geology." Canadian Journal of Earth Sciences 49, no. 1 (January 2012): 259–88. http://dx.doi.org/10.1139/e11-049.
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The eastern edge of the Appalachian orogen is composed of a collection of Neoproterozoic – early Paleozoic domains, Avalonia, Carolinia, Ganderia, Meguma, and Suwannee, which are exotic to North America. Differences in the geological histories of these peri-Gondwanan domains indicate that each separated independently from Gondwana, opening the Rheic Ocean in their wake. Cambrian departure of Ganderia and Carolina was followed by the Ordovician separation of Avalonia and Silurian separation of Meguma. After separation in the early Paleozoic, these domains constituted the borderline between the expanding Rheic Ocean and contracting Iapetus Ocean. They were transferred to Laurentia by early Silurian closure of Iapetus and Devonian–Carboniferous closure of the Rheic Ocean during the assembly of Gondwana and Laurentia into Pangaea. The first domain to arrive at Laurentia was Carolinia, which accreted in the Middle Ordovician during the Cherokee orogeny. Salinic accretion of Ganderia occurred shortly thereafter and was followed by the Acadian accretion of Avalonia. The Acadian orogeny was immediately followed by Middle Devonian – Early Carboniferous accretion of Meguma and possibly Suwannee which led to the Fammenian orogeny. The episodicity of orogeny suggests that the present location of these domains parallels their order of accretion. However, each of these crustal blocks was translated along strike by large-scale Late Devonian – Carboniferous dextral strike–slip motion. The breakup of Pangaea occurred outboard of the Paleozoic collision zones that accreted Carolinia, Ganderia, Avalonia, Meguma, and Suwannee to Laurentia, leaving these terranes appended to North America during the Mesozoic opening of the Atlantic.