scholarly journals Objective Domain Boundaries Detection in New Caledonian Nickel Laterite from Spectra Using Quadrant Scan

Minerals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 49
Author(s):  
Ayham Zaitouny ◽  
Erick Ramanaidou ◽  
June Hill ◽  
David M. Walker ◽  
Michael Small
Keyword(s):  
New Caledonia ◽  
Mineral Exploration ◽  
Standard Procedure ◽  
Hyperspectral Data ◽  
Recurrence Plots ◽  
Nickel Laterite ◽  
Domain Boundaries ◽  
Interpretation Process ◽  
Drill Holes ◽  
Objective Methodology

Modelling of 3D domain boundaries using information from drill holes is a standard procedure in mineral exploration and mining. Manual logging of drill holes can be difficult to exploit as the results may not be comparable between holes due to the subjective nature of geological logging. Exploration and mining companies commonly collect geochemical or mineralogical data from diamond drill core or drill chips; however, manual interpretation of multivariate data can be slow and challenging; therefore, automation of any of the steps in the interpretation process would be valuable. Hyperspectral analysis of drill chips provides a relatively inexpensive method of collecting very detailed information rapidly and consistently. However, the challenge of such data is the high dimensionality of the data’s variables in comparison to the number of samples. Hyperspectral data is usually processed to produce mineral abundances generally involving a range of assumptions. This paper presents the results of testing a new fast and objective methodology to identify the lithological boundaries from high dimensional hyperspectral data. This method applies a quadrant scan analysis to recurrence plots. The results, applied to nickel laterite deposits from New Caledonia, demonstrate that this method can identify transitions in the downhole data. These are interpreted as reflecting mineralogical changes that can be used as an aid in geological logging to improve boundary detection.

scholarly journals IDENTIFICATION OF A ROBUST LICHEN INDEX FOR THE DECONVOLUTION OF LICHEN AND ROCK MIXTURES USING PATTERN SEARCH ALGORITHM (CASE STUDY: GREENLAND)

2016 ◽  
Vol XLI-B7 ◽  
pp. 973-979
Author(s):  
S. Salehi ◽  
M. Karami ◽  
R. Fensholt
Keyword(s):  
Search Algorithm ◽  
Mineral Exploration ◽  
Optimization Procedure ◽  
Hyperspectral Data ◽  
Pattern Search ◽  
Rock Outcrops ◽  
Bare Rock ◽  
Mixed Pixel ◽  
Mixing Ratios ◽  
Linear Mixtures

Lichens are the dominant autotrophs of polar and subpolar ecosystems commonly encrust the rock outcrops. Spectral mixing of lichens and bare rock can shift diagnostic spectral features of materials of interest thus leading to misinterpretation and false positives if mapping is done based on perfect spectral matching methodologies. Therefore, the ability to distinguish the lichen coverage from rock and decomposing a mixed pixel into a collection of pure reflectance spectra, can improve the applicability of hyperspectral methods for mineral exploration. The objective of this study is to propose a robust lichen index that can be used to estimate lichen coverage, regardless of the mineral composition of the underlying rocks. The performance of three index structures of ratio, normalized ratio and subtraction have been investigated using synthetic linear mixtures of pure rock and lichen spectra with prescribed mixing ratios. Laboratory spectroscopic data are obtained from lichen covered samples collected from Karrat, Liverpool Land, and Sisimiut regions in Greenland. The spectra are then resampled to Hyperspectral Mapper (HyMAP) resolution, in order to further investigate the functionality of the indices for the airborne platform. In both resolutions, a Pattern Search (PS) algorithm is used to identify the optimal band wavelengths and bandwidths for the lichen index. The results of our band optimization procedure revealed that the ratio between R<sub>894-1246</sub> and R<sub>1110</sub> explains most of the variability in the hyperspectral data at the original laboratory resolution (R<sup>2</sup>=0.769). However, the normalized index incorporating R<sub>1106-1121</sub> and R<sub>904-1251</sub> yields the best results for the HyMAP resolution (R<sup>2</sup>=0.765).

scholarly journals ALTERATION MINERALS EXTRACTION USING AIRBORNE HYPERSPECTRAL DATA CASI AND SASI IN WUYI METALLOGENIC BELT, CHINA

2018 ◽  
Vol XLII-3 ◽  
pp. 601-605
Author(s):  
Z. Huang ◽  
J. Zheng
Keyword(s):  
Hyperspectral Image ◽  
Gold Mineralization ◽  
Mineral Exploration ◽  
Geological Structure ◽  
Hyperspectral Data ◽  
Coverage Area ◽  
Metallogenic Belt ◽  
Forest Coverage ◽  
Alteration Minerals ◽  
Regional Forest

Hydrothermal alteration is an important content in the study of epithermal deposit, and its deep part is often accompanied by porphyry mineralization. The objective of research is to mapping the alteration minerals for mineral exploration using mixture tuned matched filtering (MTMF) approach based on airborne hyperspectral data CASI and SASI in Wuyi metallogenic belt, China, which has complex geological structure and excellent mineralization conditions and high regional forest coverage rate. Gold mineralization is closely related to the Yanshan period epithermal intrusive rocks, and often exists in external contact zone of allgovite, monzomite porphyrite, granite porphyry, quarz porphyry, et al.. The main mineral alteration types include silicification (quartz), sericitization (sericite, illite), pyritization (pyrite), chloritization (chlorite), and partial calcitization (calcite). The alteration minerals extraction based on integrated CASI_SASI reflectance data were processed by MTMF algorithm with the input imagery which was pre-processed by MNF and the input endmember spectra measured by SVC spectrometer to performs MF and add an infeasibility image. The MTMF results provide an estimate to mineral subpixel fractions leading to the abundances of alteration minerals at each pixel and alteration minerals distribution. The accuracy of alteration mineral extraction refers to the extent which it agrees with a set of reference data measured in the field reconnaissance. So the CASI_SASI airborne hyperspectral image provides the efficient way to map the detailed alteration minerals distribution for mineral exploration in high forest coverage area.

scholarly journals A rich fauna of subterranean short-range endemic Anillini (Coleoptera, Carabidae, Trechinae) from semi-arid regions of Western Australia

ZooKeys ◽  
2021 ◽  
Vol 1044 ◽  
pp. 269-337
Author(s):  
Pier Mauro Giachino ◽  
Stefan Eberhard ◽  
Giulia Perina
Keyword(s):  
New Species ◽  
Leaf Litter ◽  
Western Australia ◽  
Short Range ◽  
Mineral Exploration ◽  
Great Majority ◽  
New Genera ◽  
Eastern Australia ◽  
Drill Holes ◽  
Semi Arid

Globally, the great majority of Anillini species are endogean, adapted to live in the interstices of soil and leaf litter, while the extremely low vagility of these minute ground beetles gives rise to numerous shortrange endemic species. Until recently the Australian Anillini fauna was known only from leaf litter in rain forests and eucalypt forests in the wetter, forested regions of eastern and south eastern Australia, as well as Lord Howe and Norfolk islands. The first hypogean Anillini in Australia (17 species in six genera) were described in 2016 from mineral exploration drill holes in iron-ore bearing rocks of the Pilbara region in Western Australia, representing the first finding of the tribe deep underground in a semi-arid climate region. A further eight new genera and 20 new species are described herein, mostly from the Pilbara region as well as the semi-arid Kimberley and Goldfields regions; all were collected in mineral exploration drill holes. The following new genera are described: Erwinanillusgen. nov., Gregorydytesgen. nov., Pilbaraphanusgen. nov., Neoillaphanusgen. nov., Kimberleytyphlusgen. nov., Gilesdytesgen. nov., Pilbaradytesgen. nov., and Bylibaraphanusgen. nov. The following new species are described: Erwinanillus baehrisp. nov.; Gracilanillus hirsutussp. nov., G. pannawonicanussp. nov.; Gregorydytes ophthalmianussp. nov.; Pilbaraphanus chichesterianussp. nov., P. bilybarianussp. nov.; Magnanillus firetalianussp. nov., M. sabaesp. nov., M. salomonissp. nov., M. regalissp. nov., M. serenitatissp. nov.; Neoillaphanus callawanussp. nov.; Kimberleytyphlus carrboydianussp. nov.; Austranillus jinayrianussp. nov.; Gilesdytes pardooanussp. nov., G. ethelianussp. nov.; Pilbaradytes abydosianussp. nov., P. webberianussp. nov.; Bylibaraphanus cundalinianussp. nov.; and Angustanillus armatussp. nov. Identification keys are provided for all Australian anilline genera, and Western Australian species. All the described species are known from a single locality and qualify as short-range endemics. The Anillini are recognised as a significant and diverse element making up part of Western Australia’s remarkable subterranean fauna, and whose conservation may potentially be impacted by mining developments.

scholarly journals Application of airborne hyperspectral data to mineral exploration in North-East Greenland

1969 ◽  
Vol 20 ◽  
pp. 71-74 ◽  
Author(s):  
Tapani Tukiainen ◽  
Bjørn Thomassen
Keyword(s):  
Spectral Analysis ◽  
Solar Radiation ◽  
Spatial Resolution ◽  
Wavelength Range ◽  
Imaging System ◽  
Mineral Exploration ◽  
Hyperspectral Data ◽  
East Greenland ◽  
North East ◽  
Arctic Conditions

An airborne hyperspectral survey was organised by the Geological Survey of Denmark and Greenland (GEUS) and carried out in 2000 to test the use of spectral analysis in mineral exploration under Arctic conditions. The hyperspectral data were acquired by using the HyMap imaging system consisting of sensors that collect reflected solar radiation in 126 bands covering the 440–2500 nm wavelength range (Bedini & Tukiainen 2008). The spatial resolution was 4 × 4 m (Tukiainen 2001). Eight sites underlain by Caledonian or post-Caledonian rocks with known mineral occurrences (Fig. 1) were tested. The project was financially supported by the Greenland Bureau of Minerals and Petroleum and the data were analysed by GEUS. Here we provide a summary of the results.

scholarly journals Towards Multiscale and Multisource Remote Sensing Mineral Exploration Using RPAS: A Case study in the Lofdal Carbonatite-Hosted REE Deposit, Namibia

2019 ◽  
Vol 11 (21) ◽  
pp. 2500 ◽  
Author(s):  
Booysen ◽  
Zimmermann ◽  
Lorenz ◽  
Gloaguen ◽  
Nex ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Mineral Exploration ◽  
Field Work ◽  
Relevant Information ◽  
Hyperspectral Data ◽  
Multiscale Approach ◽  
Carbonatite Complex ◽  
Lithological Mapping ◽  
Aircraft System ◽  
Difficult Terrain

Traditional exploration techniques usually rely on extensive field work supported by geophysical ground surveying. However, this approach can be limited by several factors such as field accessibility, financial cost, area size, climate, and public disapproval. We recommend the use of multiscale hyperspectral remote sensing to mitigate the disadvantages of traditional exploration techniques. The proposed workflow analyzes a possible target at different levels of spatial detail. This method is particularly beneficial in inaccessible and remote areas with little infrastructure, because it allows for a systematic, dense and generally noninvasive surveying. After a satellite regional reconnaissance, a target is characterized in more detail by plane-based hyperspectral mapping. Subsequently, Remotely Piloted Aircraft System (RPAS)-mounted hyperspectral sensors are deployed on selected regions of interest to provide a higher level of spatial detail. All hyperspectral data are corrected for radiometric and geometric distortions. End-member modeling and classification techniques are used for rapid and accurate lithological mapping. Validation is performed via field spectroscopy and portable XRF as well as laboratory geochemical and spectral analyses. The resulting spectral data products quickly provide relevant information on outcropping lithologies for the field teams. We show that the multiscale approach allows defining the promising areas that are further refined using RPAS-based hyperspectral imaging. We further argue that the addition of RPAS-based hyperspectral data can improve the detail of field mapping in mineral exploration, by bridging the resolution gap between airplane- and ground-based data. RPAS-based measurements can supplement and direct geological observation rapidly in the field and therefore allow better integration with in situ ground investigations. We demonstrate the efficiency of the proposed approach at the Lofdal Carbonatite Complex in Namibia, which has been previously subjected to rare earth elements exploration. The deposit is located in a remote environment and characterized by difficult terrain which limits ground surveys.

An emerging shale gas play in the Northern Territory

2012 ◽  
Vol 52 (2) ◽  
pp. 672
Author(s):  
Ray Johnson ◽  
Geoff Hokin ◽  
David Warner ◽  
Rod Dawney ◽  
Mike Dix ◽  
...  
Keyword(s):  
Shale Gas ◽  
Oil And Gas ◽  
Mineral Exploration ◽  
Northern Territory ◽  
Gas Flows ◽  
Oil And Gas Resources ◽  
Unconventional Oil And Gas ◽  
Shale Reservoirs ◽  
Drill Holes ◽  
Live Oil

As attention to unconventional oil and gas resources increases, historical oil and gas flows in shale reservoirs across the world are being given renewed attention. Such is the case of the shaly and carbonate deposits of the McArthur and Nathan groups in the Northern Territory. The Batten Trough is a Proterozoic depocenter with potential for a shale gas play in the Barney Creek Shale and potential for conventional gas accumulations in the underlying Coxco Dolomite. This Barney Creek Shale gas play is evidenced by a number of mineral exploration drill holes that encountered live oil and gas shows within the McArthur Group. The most prominent was a mineral exploration hole drilled at the Glyde River prospect by Amoco in 1979. This well reportedly flowed gas and condensates at 140 psi for six months before it was sealed at the surface, which certainly shows permeability values greater than micro-darcies reported for many North American shale plays; thus, an exploration program of this prospective area has been planned by Armour Energy in EP 171 on several targets adjacent to the Emu Fault Zone near both Glyde and Caranbirini, along with other anticline related targets adjacent to the Abner Range. This extended abstract details how the targets were identified, the plan for data acquisition (e.g. seismic, drilling, logging and testing), and the proposed completion strategy to test this highly prospective target.

Projects MINEO and HyperGreen : airborne hyperspectral data acquisition in East Greenland for environmental monitoring and mineral exploration

2001 ◽  
pp. 122-126 ◽  
Author(s):  
Tapani Tukiainen
Keyword(s):  
Environmental Monitoring ◽  
Data Acquisition ◽  
Mineral Exploration ◽  
Hyperspectral Data ◽  
Sensor Technology ◽  
Radiometric Calibration ◽  
Advanced Technique ◽  
East Greenland ◽  
Environmental Mapping ◽  
Wide Range

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Tukiainen, T. (2001). Projects MINEO and HyperGreen: airborne hyperspectral data acquisition in East Greenland for environmental monitoring and mineral exploration. Geology of Greenland Survey Bulletin, 189, 122-126. https://doi.org/10.34194/ggub.v189.5167 _______________ In remote sensing terminology the word ‘hyperspectral’ is used to distinguish sensors with several tens or hundreds of bands from the traditional ‘multispectral’ sensors such as Landsat TM or Landsat MSS. The success of hyperspectral techniques relies on the detection of subtle variations in the spectral properties of one or more of the components being imaged. The advances of worldwide research and development in sensor technology to achieve higher signal to noise ratios, good operational stability and improved levels of spectral and radiometric calibration have provided the instrumental basis for the deployment of this advanced technique to a number of earth resource and environmental mapping and monitoring tasks. The analysis and interpretation of hyperspectral data are extensively based on the use of spectral libraries covering a wide range of inorganic and organic natural materials and comparison of data between different areas and sensor systems.

Application of plurigaussian simulation to delineate the layout of alteration domains in Sungun copper deposit

2013 ◽  
Vol 5 (4) ◽  
Author(s):  
Hassan Talebi ◽  
Omid Asghari ◽  
Xavier Emery
Keyword(s):  
Numerical Models ◽  
Porphyry Copper ◽  
Copper Deposit ◽  
Ore Deposits ◽  
Accurate Estimation ◽  
Deterministic Models ◽  
Plurigaussian Simulation ◽  
Domain Boundaries ◽  
Drill Holes

AbstractAn accurate estimation of mineral grades in ore deposits with heterogeneous spatial variations requires defining geological domains that differentiate the types of mineralogy, alteration and lithology. Deterministic models define the layout of the domains based on the interpretation of the drill holes and do not take into account the uncertainty in areas with fewer data. Plurigaussian simulation (PGS) can be an alternative to generate multiple numerical models of the ore body, with the aim of assessing the uncertainty in the domain boundaries and improving the geological controls in the characterization of quantitative attributes. This study addresses the application of PGS to Sungun porphyry copper deposit (Iran), in order to simulate the layout of four hypogene alteration zones: potassic, phyllic, propylitic and argillic. The aim of this study is to construct numerical models in which the alteration structures reflect the evolution observed in the geology.

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