SOME ASPECTS OF ORE DEPOSITS IMPORTANT IN GEOPHYSICAL WORK

Geophysics ◽  
1948 ◽  
Vol 13 (4) ◽  
pp. 540-549
Author(s):  
George M. Schwartz
Keyword(s):  
Geophysical Methods ◽  
Petroleum Industry ◽  
Genetic Variations ◽  
Ore Deposits ◽  
Mineral Deposits ◽  
Detailed Knowledge ◽  
New Methods ◽  
Horizontal Extent ◽  
Definite Relation ◽  
Great Complexity

The application of geophysics to mining problems is much more difficult than is the case with the petroleum industry. The fundamental contrasts between the occurrence of petroleum and ores are outlined. Difficulties arise because of the great complexity and variation in occurrence and size of deposits of commercial metallic and non‐metallic minerals. These complexities are discussed and illustrations cited in terms of mineralogic, petrographic, structural, and genetic variations in ores. The relatively large horizontal extent of petroleum deposits, as compared with many mineral deposits is emphasized. One of the important problems in the application of geophysics to ore‐finding is determining the definite relation of ore to specific geologic features, so that the results of geophysical work can be interpreted in terms of the probable location of more ore. This is essentially a geologic problem, and one not easily solved in many districts. For the successful application of geophysics and interpretation of the results, a very detailed knowledge and understanding of the geology is fundamental. Also additional geophysical methods are required, particularly those which might locate ore directly rather than indirectly through the geology as is largely the case in petroleum. Because of the complexities involved, no one method should be considered a true test of an area but several methods should be utilized. Much more extensive and intensive application of geophysics to problems of ore‐finding, as well as new methods are demanded by the rapid depletion of present ore reserves.

scholarly journals Geophysical identification of voids and loosened zones in the shallow subsurface of post-mining areas

2018 ◽  
Vol 66 ◽  
pp. 01001 ◽  
Author(s):  
Zenon Pilecki
Keyword(s):  
Rock Mass ◽  
Geophysical Methods ◽  
Ore Deposits ◽  
Hard Coal ◽  
Shallow Subsurface ◽  
Mining Areas ◽  
Upper Silesian Coal Basin ◽  
Discontinuous Deformation ◽  
Ground Penetrating ◽  
Terrain Surface

The shallow historic exploitation of Zn-Pb/Fe ore deposits as well as hard coal has generated many discontinuous deformations on the terrain surface in the Upper Silesian Coal Basin/Poland. Discontinuous deformations occur in different forms as sinkholes, synclines, cracks, faults or ditches. The basic cause of their occurrence is the presence of void and loosened zones in the shallow subsurface. If the appropriate conditions arise, the sinkhole process begins to move upwards and may cause a discontinuous deformation on the terrain surface. Typically, geophysical methods are used for void and loosened zone identification. The most effective methods are gravimetric, seismic, electric resistivity and ground penetrating radar (GPR). Geophysical testing, requires distinct changes in the physical properties in the rock mass. The identified geophysical anomalies should be verified by control borehole and borehole tests to confirm the presence of the void and loosened zones in the rock mass. The results of control drilling and borehole tests determine the need to apply treatment works. In order to assess the threat of the occurrence of discontinuous deformations in the areas of historical shallow mining in Upper Silesia, a classification system based on geophysical tests has also been developed.

scholarly journals Seismic Methods in Geothermal Water Resource Exploration: Case Study from Łódź Trough, Central Part of Poland

Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Tomasz Maćkowski ◽  
Anna Sowiżdżał ◽  
Anna Wachowicz-Pyzik
Keyword(s):  
Estimation Error ◽  
Geophysical Methods ◽  
Petroleum Industry ◽  
Geological Structure ◽  
Seismic Survey ◽  
Energy Potential ◽  
Geothermal Resources ◽  
Geothermal Waters ◽  
Seismic Methods ◽  
Geophysical Surveys

The geothermal waters constitute a specific type of water resources, very important from the point of view of their thermal energy potential. This potential, when utilized, supplies an ecological and renewable energy, which, after effective development, brings many environmental, social, and industrial benefits. The key element of any geothermal investment is the proper location of geothermal installation, which would guarantee the relevant hydrogeothermal parameters of the water intake. Hence, many studies and analyses are carried out in order to characterize the reservoir parameters, including the integrated geophysical methods. For decades, the geophysical surveys have been the trusty recognition methods of geological structure and petrophysical parameters of rock formations. Thus, they are widely applied by petroleum industry in exploration of conventional and unconventional (shale gas/oil, tight gas) hydrocarbon deposits. Advances in geophysical methods extended their applicability to many other scientific and industrial branches as, e.g., the seismic survey used in studies of geothermal aquifers. The following paper presents the opportunities provided by seismic methods applied to studies of geothermal resources in the central Poland where the geothermal waters are reservoired in both the Lower Cretaceous and the Lower Jurassic sedimentary successions. The presented results are obtained from a network of seismic profiles. An important advantage of the seismic survey is that they may support the selection of an optimal location of geothermal investment and determination of the geometry of geothermal aquifer. Furthermore, the application of geophysical methods can significantly contribute to the reduction of estimation error of groundwater reservoir temperature.

scholarly journals Feature space of the Atasu type deposits (Сentral Kazakhstan)

2020 ◽  
pp. 5-10
Author(s):  
N. S. Askarova ◽  
A. T. Roman ◽  
V.S. Portnov ◽  
A.N. Kpobayeva
Keyword(s):  
Feature Space ◽  
Ore Deposits ◽  
Mineral Deposits ◽  
Complex Composition ◽  
Lower Carboniferous ◽  
Geological Factors ◽  
Close Time ◽  
Different Depths ◽  
Geological Formations ◽  
Visean Stage

Purpose. Studying geological formations of the Atasu type deposits to identify prospecting criteria. Methodology. Analysis of literature and fund materials, comparative analysis of geological factors characteristic of stratiform ores, stage formation and metamorphism. Findings. The main features characteristic of the deposits of the Atasu type have been formed: their belonging to the lower strata of the Upper Famennian, Upper Devonian to the Visean stage of the Lower Carboniferous; complex composition of ferromanganese and polymetallic ores formed in three hydrothermal stages (sedimentary, metasomatic and vein ones), stratiform, lenticular, localized near volcanic edifices. Originality. The main geological criteria have been established that determine the belonging of the Uspensky ore belt in Central Kazakhstan deposits to the stratiform deposits of the Atasu type formed at different depths in continental rift valleys. The criteria include the age interval of the formation of ore deposits of the stratiform type, hydrothermal staging of mineralization (sedimentary, metamorphic, metamorphic (hydrothermal, dislocation multistage and dynamothermal)); localization of folded and post-folded subvolcanic intrusions near former volcanic edifices. Practical value. The main prospecting geological criteria (features) established for the Atasu type deposits can be used to form a feature space for predicting the areas of mineral deposits localization of the Uspensky ore belt of Central Kazakhstan formed in close time periods, in similar geological-geochemical, thermodynamic and geodynamic conditions.

The ROBOMINERS project: a promising tool for the re-evaluation of “non-economical” deposits. Aiming at the development of a joined European database of potentially suitable ore deposits for the utilization of the Robominers technology.

2021 ◽  
Author(s):  
Eleni Koutsopoulou ◽  
Aikaterini Servou ◽  
George Aggelopoulos
Keyword(s):  
Spatial Distribution ◽  
National Level ◽  
Ore Deposits ◽  
Advanced Technology ◽  
Mineral Deposits ◽  
Innovative Technology ◽  
Exploration And Exploitation ◽  
Epithermal Deposits ◽  
European Database ◽  
The Creation

<p>The ROBOMINERS (Resilient Bio-inspired Modular Robotic Miner) project aims at developing new methods and technologies (prototype automation and robotics technology) to locate and exploit underground mineral deposits and is funded under the European Union’s Research and Innovation programme Horizon 2020. The project targets mineral deposits that are generally considered “non-economical” either because they are not accessible anymore for conventional mining techniques, or they have been previously explored but exploitation was considered uneconomic due to the small size of the deposits or the difficulty to access them (abandoned, small, ultra-depth deposits).</p><p> </p><p>The European Federation of Geologists (EFG) is part of the Robominers consortium and its role includes the collection of publicly available data at a national level on mineral deposits which are potential targets on the developed mining technology. The Association of Greek Geologists (AGG) is participating as an EFG Linked Third Party in the project aiming, among others, at the creation of a European database of potentially suitable ore deposits for the utilization of the Robominers technology.</p><p> </p><p>The creation of an ore deposits’ European database is a crucial procedure for the best possible design of exploration and exploitation applying the Robominers innovative approach. The AGG has contributed in the building of a database at a national level (for Greece), of the major and most important mineral deposits, according to the project requirements. A number of ore deposits in which Robominers advanced technology may provide a unique solution to mineral extraction, include porphyry and epithermal deposits and especially vein-like types, but volcanogenic massive sulphide (VMS-type) and lense-like or layered orthomagmatic deposits can also be of high importance. From the above mentioned ore deposits the most abundant in Greece are epithermal deposits, deposits in hydrothermal veins, porphyry copper, as well as chromites in ophiolite complexes. Regarding the spatial distribution vein-type or metasomatic deposits are located mostly in Northern Greece (Western Macedonia and Thrace regions) while significant variable-mineralization deposits are related with the Attico-Cycladic belt volcanism (mainly Lavrion, Evia, and islands in the Aegean Sea). Finally, PGE bearing chromite deposits and bauxite deposits, located mainly in Central Greece, may also be significant for the project.</p><p> </p><p>The establishment of a joined European Robominers database is of great significance for the progress of the project since it will provide essential information on key outputs such as the deposit type and commodities, the host rock, and the spatial distribution of the project’s targeted ore deposits and will provide valuable knowledge regarding the future planning of the exploration and exploitation from the developed Robominers innovative technology approach.</p><p>Dr Eleni Koutsopoulou</p><p>Coordinator of the project</p><p>On Behalf of the:</p><p>Association of Greek Geologists</p><p>Didotou 26,10680, Athens, Greece</p><p>VAT ID: EL-999600130</p><p> </p><p> </p>

Mineral deposits and chalcogen gases

1993 ◽  
Vol 57 (389) ◽  
pp. 599-606 ◽  
Author(s):  
Martin Hale
Keyword(s):  
Ore Deposits ◽  
Anomalous Dispersion ◽  
Mineral Deposits ◽  
Oxidation Reactions ◽  
Sulphide Minerals ◽  
Sulphide Ore ◽  
Dispersion Patterns ◽  
Sulphide Deposits ◽  
High Concentrations ◽  
And Migration

AbstractSulphide minerals and their analogues yield gases as a result of oxidation reactions. Even where sulphide minerals are in contact with mildly reducing groundwaters, S2- ions pass into solution and their dispersion patterns can be detected in soil as acid-released H2S. In more oxidising conditions, the metastable gases COS and CS2 are generated. Anomalous dispersion patterns of COS have been reported in soils above more than ten sulphide ore deposits, many of them concealed beneath transported exotic overburden. High concentrations of CS2 occur in the soils over several of the same deposits and uniquely reflect others. Anomalies of SO2 over sulphide deposits are confined to arid terrains. Certain anomalous dispersion patterns of arsenic and tellurium in soils are attributed to the generation and migration of unspecified gases from the oxidation of arsenide and telluride minerals.

Mapping Magmatic and Hydrothermal Processes from Routine Exploration Geochemical Analyses

2020 ◽  
Vol 115 (3) ◽  
pp. 489-503 ◽  
Author(s):  
Scott Halley
Keyword(s):  
Inductively Coupled Plasma ◽  
Mining Industry ◽  
Analysis Data ◽  
Ore Deposits ◽  
Mineral Deposits ◽  
Geochemical Data ◽  
High Quality ◽  
Inductively Coupled ◽  
Hydrothermal Processes ◽  
Geochemical Analyses

Abstract Analytical methods used by commercial assay laboratories have improved enormously in recent years. Inductively coupled plasma-atomic emission spectroscopy and inductively coupled plasma-mass spectrometry methods now report analyses for half of the periodic table with exceptional detection limits and precision. It is becoming commonplace for mining companies to use such methods routinely for the analysis of drill samples throughout mineral deposits. Improvements in software and computing power now allow rapid interrogation of upward of 100,000 assay samples. Geochemical analyses are quantitative, are independent of observer bias, and can form the basis for robust geologic and mineralogical models of mineral deposits, as well as shed light on scientific questions. In particular, consistently collected, high-quality geochemical analyses can significantly improve and systematize logging of lithological and hydrothermal alteration mineralogic changes within drill core. In addition, abundant, high-quality geochemical data provide insights into magmatic and hydrothermal processes that were previously difficult to recognize and that have obvious applications to mineral exploration and improved genetic models of ore deposits. This paper describes a workflow that mining industry geologists can apply to their multielement analysis data to extract more information about magma compositions and gangue mineralogy.

K–Ar ages of clay concentrates from Irish orebodies and their bearing on the timing of mineralisation

1983 ◽  
Vol 74 (1) ◽  
pp. 1-14 ◽  
Author(s):  
A. N. Halliday ◽  
J. G. Mitchell
Keyword(s):  
Base Metal ◽  
Early Carboniferous ◽  
Hydrothermal Activity ◽  
Ore Deposits ◽  
Mineral Deposits ◽  
Powerful Method ◽  
Lower Carboniferous ◽  
Hercynian Orogeny ◽  
Vein Deposits

ABSTRACTThe K–Ar ages of 117 clay concentrates from samples associated with mineral deposits in Ireland indicate that most, if not all of the major ore deposits were formed during Carboniferous times or earlier. The Avoca orebodies are pre-400 Ma in age. Many of the vein deposits traversing Palaeozoic rocks were either formed or rejuvenated during the Hercynian orogeny c. 300 Ma ago. The SW Ireland Cu–Ba ores are 290 Ma old, and the major, frequently stratiform, base metal deposits stratabound in the Lower Carboniferous were, at least largely, formed during the Carboniferous period. In the case of the Navan orebody, an early Carboniferous age is indicated. Previous models invoking major mineralisations during Mesozoic or Tertiary times are rendered invalid. However, in some areas there appears to have been hydrothermal activity during the Triassic and possibly the Permian. The Triassic event is thought to be genetically related to coeval hydrothermal avtivity found throughout the N Atlantic regions. The data suggest that probably <10 km of cover has been removed from the majority of Ireland since Lower Carboniferous times. K–Ar dating of clays is shown to be a powerful method for constraining the ages of oredeposits.

scholarly journals A new model for quantifying subsurface ice content based on geophysical data sets

2010 ◽  
Vol 4 (2) ◽  
pp. 787-821 ◽  
Author(s):  
C. Hauck ◽  
M. Böttcher ◽  
H. Maurer
Keyword(s):  
Seismic Velocity ◽  
Geophysical Methods ◽  
Geophysical Data ◽  
Swiss Alps ◽  
Unfrozen Water ◽  
Detailed Knowledge ◽  
Data Sets ◽  
Rock Glacier ◽  
Heterogeneous Distribution ◽  
Rock Glaciers

Abstract. Detailed knowledge of the material properties and internal structures of frozen ground is one of the prerequisites in many permafrost studies. In the absence of direct evidence, such as in-situ borehole measurements, geophysical methods are an increasingly interesting option for obtaining subsurface information on various spatial and temporal scales. The indirect nature of geophysical soundings requires a relation between the measured variables (e.g. electrical resistivity, seismic velocity) and the actual subsurface constituents (rock, water, air, ice). In this work we present a model, which provides estimates of the volumetric fractions of these four phases from tomographic electrical and seismic images. The model is tested using geophysical data sets from two rock glaciers in the Swiss Alps, where ground truth information in form of borehole data is available. First results confirm the applicability of the so-called 4-phase model, which allows to quantify the contributions of ice-, water- and air within permafrost areas as well as detecting the firm bedrock. Apart from a similarly thick active layer with enhanced air content for both rock glaciers, the two case studies revealed a heterogeneous distribution of ice and unfrozen water within rock glacier Muragl, where bedrock was detected at depths of 20–25 m, but a comparatively homogeneous ice body with only minor heterogeneities within rock glacier Murtèl.

Sign in / Sign up

Export Citation Format

Share Document