scholarly journals SIT4ME: seismic imaging of mineral-hosting structures in Sotiel-Coronada (Spain)

2020 ◽  
Author(s):  
Yesenia Martínez ◽  
Juan Alcalde ◽  
David Martí ◽  
Puy Ayarza ◽  
Mario Ruiz ◽  
...  
Keyword(s):  
Seismic Imaging ◽  
Raw Materials ◽  
Imaging Techniques ◽  
Mineral Exploration ◽  
P Wave ◽  
Target Area ◽  
Source Imaging ◽  
The North ◽  
Imaging Results ◽  
East West

<p>In order to tackle the ever-increasing demand of raw materials, the European Institute of Technology (EIT) promotes research and innovation solutions for safe and sustainable mineral exploration through its Raw Materials Programme. The SIT4ME project (“Seismic Imaging Techniques for Mineral Exploration”) has been funded as part of this program to develop efficient techniques in seismic acquisition and imaging methods for mineral exploration in crystalline environments. Within SIT4ME, a multidisciplinary data acquisition experiment (i.e. 3D-3C active and passive source seismic datasets) took place in November 2009 in Sotiel-Coronada (Iberian Pyrite Belt, SW Spain). The aim of this experiment was to image a 300-500 m depth pyrite-rich massive sulfide orebody interbedded with felsic volcanic rocks and shales. The seismic dataset involves the recording of 875 vibration points in 653 seismic receivers, distributed in a 3D mesh around the target and six 2D crooked lines. Conventional processing workflow (such as static corrections, surface-consistent deconvolution, amplitude equalization, frequency filtering, and velocity analysis) was combined with more advance methods (e.g. ground roll attenuation or post-stack coherency filtering) to obtain robust images of the subsurface of the target area. The processing workflow has been applied to four 2D seismic sections, one in the North-South and three in the East-West directions, distributed across the study area. The preliminary imaging results show coherent reflective packages down to two seconds two-way traveltime (TWT). The North-South line contains a north-dipping ~400 m long highly reflective zone in the center at 130 ms TWT. The east-west profiles show a slightly folded structure (antiform and synform) which is evident down to 0.25 s TWT. Towards the north, the seismic lines become parallel to subsurface structures and therefore the track of these structures is lost. Current work involves the incorporation of well-log data to improve the quality and resolution of the interpretations. The next processing steps will involve pre-stack depth migration, P-wave travel-time tomography and a combined analysis of controlled source imaging and ambient noise interferometry data.</p><p>The SIT4ME project has been funded by EIT Raw Materials (17024).</p>

SIT4ME project: Up-scaling seismic methods for mineral exploration in the Zinkgruvan mining area, Sweden

2020 ◽  
Author(s):  
Alba Gil ◽  
Alireza Malehmir ◽  
Stefan Buske ◽  
Juan Alcalde ◽  
Puy Ayarza ◽  
...  
Keyword(s):  
Data Acquisition ◽  
Raw Materials ◽  
Imaging Techniques ◽  
Mineral Exploration ◽  
Mineral Resources ◽  
Modern Society ◽  
Careful Analysis ◽  
Mining Area ◽  
Massive Sulphide ◽  
Up Scaling

<p>Mineral resources are used in large quantities than ever before because they are fundamental to our modern society. To this front and facing an up-scaling challenge, the EIT Raw-Materials funded project SIT4ME (Seismic Imaging Techniques for Mineral Exploration) was launched involving several European institutions. As part of the project, a dense multi-method seismic dataset was acquired in the Zinkgruvan mining area at the Bergslagen mineral district of Sweden, which hosts one of the largest volcanic-hosted massive sulphide (VMS) deposits in the country.</p><p>In November 2018, a dense multi-method seismic dataset was acquired in the Zinkgruvan mining area, in a joint collaborative approach among Swedish, Spanish and German partners. A combination of sparse 3D grid and dense 2D profiles in an area of approximately 6 km<sup>2 </sup>was acquired using a 32t seismic vibrator (10-150 Hz) of TU Bergakademie Freiberg, enabling reasonable pseudo-3D sub-surface illumination. For the data acquisition, a total of approximately 1300 receiver positions (10-20 m apart), using different recorders, and 950 source positions were surveyed. All receivers were active during the data acquisition allowing a combination of 2D and semi-3D data to be obtained for various imaging and comparative studies. The main objective of the study, apart from its commercial-realization approach, was also to provide information useful for deep-targeting and structural imaging in this complex geological setting. The main massive-sulphide bearing horizon, Zinkgruvan formation, is strongly reflective as correlated with the existing boreholes in the mine. Careful analysis of the seismic sections suggests a dominant northeast-dipping structure, consistent with the general plunge of the main Zinkgruvan fold that has been suggested in the area.</p><p>Acknowledgements: EIT-RawMaterials is gratefully thanked for funding this up-scaling project 17024.</p>

Seismic detection and characterization of a man-made karst analog — A feasibility study

Geophysics ◽  
2021 ◽  
Vol 86 (3) ◽  
pp. WB35-WB48
Author(s):  
Roland Gritto ◽  
Ali Elobaid Elnaiem ◽  
Fateh Alrahman Mohamed ◽  
Fadhil Sadooni
Keyword(s):  
Ambient Noise ◽  
Seismic Imaging ◽  
Imaging Techniques ◽  
A Priori ◽  
Low Frequency ◽  
Sharp Decrease ◽  
Seismic Velocities ◽  
Water Drainage ◽  
Imaging Results ◽  
Noise Data

At the site of a water drainage shaft on the campus of Qatar University that serves as a man-made karst analog, two seismic imaging techniques were adapted to use resonant scattered waves recorded during active-source seismic surveys and during passive ambient-noise surveys. Data acquisition included two seismic transmission surveys that encompassed the shaft and a passive ambient-noise survey that extended across the top of the shaft. Seismic imaging of band-pass-filtered resonance waves correctly estimated the location and dimension of the shaft. Furthermore, the method detected the presence and the location of a horizontal drainage pipe and gravel bed connecting neighboring water shafts. Ambient-noise data were analyzed by computing amplitude values of the seismic records in spectral passbands. The results indicated an amplification of seismic amplitudes above the shaft for low-frequency passbands and a sharp decrease in amplitude values for high-frequency passbands. The high- and low-amplitude values displayed as a function of the receiver position allowed for accurate detection and location of the shaft in space. Ground truthing of the imaging results confirmed the accuracy of the seismic techniques, whereas numerical modeling supported the interpretation of the ambient-noise data. The techniques used do not require knowledge of the seismic velocities in the subsurface, but they depend on a priori information about the approximate location of the target.

scholarly journals A Low frequency Southern Sky Survey Using the Mauritius Radio Telescope

2002 ◽  
Vol 199 ◽  
pp. 25-31
Author(s):  
N. Udaya Shankar
Keyword(s):  
Radio Telescope ◽  
Low Frequency ◽  
Fourier Synthesis ◽  
North East ◽  
The North ◽  
Sky Survey ◽  
Correlation Receiver ◽  
Complex Correlation ◽  
Right Ascension ◽  
East West

The Mauritius Radio Telescope (MRT) is a Fourier synthesis instrument which has been built to fill the gap in the availability of deep sky surveys at low radio frequencies in the southern hemisphere. It is situated in the north-east of Mauritius at a southern latitude of 20°.14 and an eastern longitude of 57°.73. The aim of the survey with the MRT is to contribute to the database of southern sky sources in the declination range −70° ≤ δ ≤ −10°, covering the entire 24 hours of right ascension, with a resolution of 4' × 4'.6sec(δ + 20.14°) and a point source sensitivity of 200 mJy (3σ level) at 151.5 MHz.MRT is a T-shaped non-coplanar array consisting of a 2048 m long East-West arm and a 880 m long South arm. In the East-West arm 1024 fixed helices are arranged in 32 groups and in the South arm 16 trolleys, with four helices on each, which move on a rail are used. A 512 channel, 2-bit 3-level complex correlation receiver is used to measure the visibility function. At least 60 days of observing are required for obtaining the visibilities up to the 880 m spacing. The calibrated visibilities are transformed taking care of the non-coplanarity of the array to produce an image of the area of the sky under observation.This paper will describe the telescope, the observations carried out so far, a few interesting aspects of imaging with this non-coplanar array and present results of a low resolution survey (13' × 18') covering roughly 12 hours of right ascension, and also present an image with a resolution of 4' × 4'.6sec(δ + 20.14°) made using the telescope.

scholarly journals Optimal design of the solar tracking system of parabolic trough concentrating collectors

2020 ◽  
Vol 15 (4) ◽  
pp. 613-619
Author(s):  
Li Kong ◽  
Yunpeng Zhang ◽  
Zhijian Lin ◽  
Zhongzhu Qiu ◽  
Chunying Li ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Solar Radiation ◽  
Tracking System ◽  
Low Cost ◽  
Parabolic Trough ◽  
The North ◽  
Tracking Mode ◽  
Solar Tracking ◽  
East West

Abstract The present work aimed to select the optimum solar tracking mode for parabolic trough concentrating collectors using numerical simulation. The current work involved: (1) the calculation of daily solar radiation on the Earth’s surface, (2) the comparison of annual direct solar radiation received under different tracking modes and (3) the determination of optimum tilt angle for the north-south tilt tracking mode. It was found that the order of solar radiation received in Shanghai under the available tracking modes was: dual-axis tracking > north-south Earth’s axis tracking > north-south tilt tracking (β = 15°) > north-south tilt tracking (β = 45) > north-south horizontal tracking > east-west horizontal tracking. Single-axis solar tracking modes feature simple structures and low cost. This study also found that the solar radiation received under the north-south tilt tracking mode was higher than that of the north-south Earth’s axis tracking mode in 7 out of 12 months. Therefore, the north-south tilt tracking mode was studied separately to determine the corresponding optimum tilt angles in Haikou, Lhasa, Shanghai, Beijing and Hohhot, respectively, which were shown as follows: 18.81°, 27.29°, 28.67°, 36.21° and 37.97°.

scholarly journals Magnetic source imaging for the surgical evaluation of electroencephalography-confirmed secondary bilateral synchrony in intractable epilepsy

2009 ◽  
Vol 111 (6) ◽  
pp. 1248-1256 ◽  
Author(s):  
Edward F. Chang ◽  
Srikantan S. Nagarajan ◽  
Mary Mantle ◽  
Nicholas M. Barbaro ◽  
Heidi E. Kirsch
Keyword(s):  
Mr Imaging ◽  
Intractable Epilepsy ◽  
Focal Lesion ◽  
Seizure Type ◽  
Source Imaging ◽  
Magnetic Source Imaging ◽  
Ms Imaging ◽  
Epileptiform Discharges ◽  
Magnetic Source ◽  
Imaging Results

Object Routine scalp electroencephalography (EEG) cannot always distinguish whether generalized epileptiform discharges are the result of primary bilateral synchrony or secondary bilateral synchrony (SBS) from a focal origin; this is an important distinction because the latter may be amenable to resection. Whole-head magnetoencephalography (MEG) has superior spatial resolution compared with traditional EEG, and can potentially elucidate seizure foci in challenging epilepsy cases in which patients are undergoing evaluation for surgery. Methods Sixteen patients with medically intractable epilepsy in whom SBS was suspected were referred for magnetic source (MS) imaging. All patients had bilateral, synchronous, widespread, and most often generalized spike-wave discharges on scalp EEG studies, plus some other clinical (for example, seizure semiology) or MR imaging feature (for example, focal lesion) suggesting focal onset and hence possible surgical candidacy. The MS imaging modality is the combination of whole-head MEG and parametric reconstruction of corresponding electrical brain sources. An MEG and simultaneous EEG studies were recorded with a 275-channel whole-head system. Single-equivalent current dipoles were estimated from the MEG data, and dipole locations and orientations were superimposed on patients' MR images. Results The MS imaging studies revealed focal dipole clusters in 12 (75%) of the 16 patients, of which a single dipole cluster was identified in 7 patients (44%). Patient age, seizure type, duration of disease, video-EEG telemetry, and MR imaging results were analyzed to determine factors predictive of having clusters revealed on MS imaging. Of these factors, only focal MR imaging anatomical abnormalities were associated with dipole clusters (chi-square test, p = 0.03). Selective resections (including the dipole cluster) in 7 (87%) of 8 patients resulted in seizure-free or rare seizure outcomes (Engel Classes I and II). Conclusions Magnetic source imaging may provide noninvasive anatomical and neurophysiological confirmation of localization in patients in whom there is a suspicion of SBS (based on clinical or MR imaging data), especially in those with an anatomical lesion. Identification of a focal seizure origin has significant implications for both resective and nonresective treatment of intractable epilepsy.

Overburden geochemical signature of the Lac des Iles platinum group element deposit, northwestern Ontario, Canada

2007 ◽  
Vol 44 (8) ◽  
pp. 1151-1168 ◽  
Author(s):  
Peter J Barnett
Keyword(s):  
Mineral Exploration ◽  
Shallow Groundwater ◽  
Soil System ◽  
Near Surface ◽  
Rock Fragments ◽  
The North ◽  
Northwestern Ontario ◽  
Airborne Contamination ◽  
The Many ◽  
Lac Des Iles

Many previously published studies of the behaviour of Pt and Pd in till and soils have been done in areas of complex stratigraphy or very thin overburden cover, making the interpretation of soil results difficult because of the many variables associated with these settings. At the Lac des Iles mine site in northwestern Ontario, there are excellent exposures of the overburden in a series of exploration trenches. Glacial dispersal trains can be observed in till (C horizon) geochemistry (e.g., Ni, Cr, Cu, and Co). Regional geochemical dispersal trains of elements, such as Ni, Cr, Mg, and Co associated with the North Lac des Iles intrusion, can be detected for about 4 km beyond the western margin of the Mine Block intrusion. Entire dispersal trains range from 5 to 7 km in length and about 1 to 2 km in width. The dispersal of North Lac des Iles intrusion rock fragments tends to mask the response of the Mine Block intrusion. Dispersal trains of Pt and Pd are not well defined and tend to be very short, <1 km in length, due to the initial low concentrations of these elements in C-horizon till samples from the Lac Des Iles area. An exception to this is the Pd dispersal train originating from the high-grade zone that is up to 3 km long. Pd, Pt, Ni, and Cu appear to be moving both within and out of the soil system downslope into surface and shallow groundwater. It is suggested that these elements, to varying degrees, are moving in solution. Airborne contamination from mine operations of the humus has adversely affected the ability to determine the effectiveness of humus sampling for mineral exploration at Lac des Iles. The airborne contamination likely influences the geochemical results from surface water, shallow groundwater, and near-surface organic bog samples, particularly for the elements Pd and Pt.

The mineralogical composition of some Scottish soils

1925 ◽  
Vol 15 (3) ◽  
pp. 257-271 ◽  
Author(s):  
James Hendrick ◽  
George Newlands
Keyword(s):  
Mineralogical Composition ◽  
Fine Sand ◽  
Plant Food ◽  
Sand Fraction ◽  
Extensive Survey ◽  
North East ◽  
The North ◽  
Local Origin ◽  
East West ◽  
Made In

1. Previous investigations showed that certain Scottish soils were of glacial drift origin, that they were comparatively rich in unweathered silicates and therefore in reserves of plant-food, that they showed considerable variation in such silicates and were capable of classification accordingly. Some indication was also shown that the glacial drift, and hence the resulting soil, was sometimes of local origin, its character being determined by the underlying rock. In the present investigation a more extensive survey of Scottish soils has been made in order to discover to what extent these preliminary findings might be applicable generally.2. For this purpose soils have been collected from various localities in the north, north-east, west and south of Scotland, and have been analysed mechanically and the “fine sand” fraction examined mineralogically.

Main directions of searching for hydrocarbons in Nadym-Pursk oil and gas region

2021 ◽  
pp. 23-31
Author(s):  
Y. I. Gladysheva
Keyword(s):  
Oil And Gas ◽  
Raw Materials ◽  
Accumulation Rate ◽  
Sedimentary Basins ◽  
Seismic Exploration ◽  
Research Approach ◽  
Field Development ◽  
The North ◽  
The Sixties ◽  
Hydrocarbon Deposits

Nadym-Pursk oil and gas region has been one of the main areas for the production of hydrocarbon raw materials since the sixties of the last century. A significant part of hydrocarbon deposits is at the final stage of field development. An increase in gas and oil production is possible subject to the discovery of new fields. The search for new hydrocarbon deposits must be carried out taking into account an integrated research approach, primarily the interpretation of seismic exploration, the creation of geological models of sedimentary basins, the study of geodynamic processes and thermobaric parameters. Statistical analysis of geological parameters of oil and gas bearing complexes revealed that the most promising direction of search are active zones — blocks with the maximum sedimentary section and accumulation rate. In these zones abnormal reservoir pressures and high reservoir temperatures are recorded. The Cretaceous oil and gas megacomplex is one of the main prospecting targets. New discovery of hydrocarbon deposits are associated with both additional exploration of old fields and the search for new prospects on the shelf of the north. An important area of geological exploration is the productive layer of the Lower-Berezovskaya subformation, in which gas deposits were discovered in unconventional reservoirs.

New insights into the Hercynian Orogeny, and their implications for the Paleozoic Hydrocarbon System in the Arabian Plate

GeoArabia ◽  
2009 ◽  
Vol 14 (3) ◽  
pp. 199-228 ◽  
Author(s):  
Mohammad Faqira ◽  
Martin Rademakers ◽  
AbdulKader M. Afifi
Keyword(s):  
Oil And Gas ◽  
Seismic Imaging ◽  
Structural Features ◽  
Source Rocks ◽  
Arabian Plate ◽  
Arabian Shield ◽  
Tectonic Event ◽  
Angular Unconformity ◽  
The North ◽  
Hercynian Orogeny

ABSTRACT During the past decade, considerable improvements in the seismic imaging of the deeper Paleozoic section, along with data from new well penetrations, have significantly improved our understanding of the mid-Carboniferous deformational event. Because it occurred at the same time as the Hercynian Orogeny in Europe, North Africa and North America it has been commonly referred to by the same name in the Middle East. This was the main tectonic event during the late Paleozoic, which initiated or reactivated many of the N-trending block uplifts that underlie the major hydrocarbon accumulations in eastern Arabia. The nature of the Hercynian deformation away from these structural features was poorly understood due to inadequate seismic imaging and insufficient well control, along with the tectonic overprint of subsequent deformation events. Three Hercynian NE-trending arches are recognized in the Arabian Plate (1) the Levant Arch, which extended from Egypt to Turkey along the coast of the Mediterranean Sea, (2) the Al-Batin Arch, which extended from the Arabian Shield through Kuwait to Iran, and (3) the Oman-Hadhramaut Arch, which extended along the southeast coast of Oman and Yemen. These arches were initiated during the mid-Carboniferous Hercynian Orogeny, and persisted until they were covered unconformably by the Khuff Formation during the Late Permian. Two Hercynian basins separate these arches: the Nafud-Ma’aniya Basin in the north and Faydah-Jafurah Basin in the south. The pre-Hercynian Paleozoic section was extensively eroded over the arches, resulting in a major angular unconformity, but generally preserved within the basins. Our interpretation suggests that most of the Arabian Shield, except the western highlands along the Red Sea, is the exhumed part of the Al-Batin Arch. The Hercynian structural fabric of regional arches and basins continue in northern Africa, and in general appear to be oriented orthogonal to the old margin of the Gondwana continent. The Hercynian structure of arches and basins was partly obliterated by subsequent Mesozoic and Cenozoic tectonic events. In eastern Saudi Arabia, Qatar, and Kuwait, regional extension during the Triassic formed N-trending horsts and graben that cut across the NE-trending Hercynian mega-structures, which locally inverted them. Subsequent reactivation during the Cretaceous and Neogene resulted in additional growth of the N-trending structures. The Hercynian Arches had major impact on the Paleozoic hydrocarbon accumulations. The Silurian source rocks are generally preserved in the basins and eroded over the arches, which generally confined Silurian-sourced hydrocarbons either within the basins or along their flanks. Furthermore, the relict Hercynian paleo-topography generally confined the post-Hercynian continental clastics of the Unayzah Formation and equivalents to the Hercynian basins. These clastics contain the main Paleozoic oil and gas reservoirs, particularly along the basin margins where they overlie the sub-crop of the Silurian section with angular unconformity, thus juxtaposing reservoir and source rock.

Assessment of the representation of non-resource export priorities in the conceptual documents of the NWFD region

2021 ◽  
pp. 743-760
Author(s):  
Pavel Leonidovich Glukhikh
Keyword(s):  
Development Strategy ◽  
Raw Materials ◽  
Institutional Support ◽  
Federal District ◽  
Scientific Concept ◽  
The North ◽  
Export Strategy ◽  
Russian Economy ◽  
Target Indicator ◽  
First Time

The problem of dependence of the Russian economy on raw materials remains. The growth of non-primary non-energy exports was approved as one of the priorities in Russia. Updating the national project increases the importance of its institutional support in legislation. The question arises of the sufficiency of institutional reflection of non-resource exports. The purpose of the article is to generalize approaches to the priorities of non-resource exports, to develop methodological tools and to assess the representation of the topic in conceptual documents on the example of the regions of the North-Western Federal District. The research methodology is based on the content analysis of documents using the Istio service. The basis of the study was the conceptual documents of the NWFD regions with export topics. The categories of non-primary exports are highlighted. The socio-economic Development Strategy is the main document approving the region’s non-resource exports. A research program and methodological support for assessing the representation of non-primary exports in documents have been developed. The differences in the institutional support of non-primary exports are revealed. Of the 11 regions, 8 contain a target indicator of non-primary non-energy exports. Kaliningrad and Murmansk oblasts are recommended to include it in the Strategy in order to form institutional support for overcoming the problem of commodity dependence. A classification of regional documents providing institutional support for the export strategy has been developed. For the first time, the assessment contains scientific novelty and can help to understand the need to form a scientific concept of non-resource exports.

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