scholarly journals Implication of geological domains data for modeling and estimating resources from Nkout iron deposit (South-Cameroun)

2021 ◽  
Vol 57 (1) ◽  
pp. 1-17
Author(s):  
A.W. Boroh ◽  
K.Y. Sore-Gamo ◽  
Ngounouno Ayiwouo ◽  
Mbowou Gbambie ◽  
I. Ngounouno
Keyword(s):  
Geochemical Modeling ◽  
Mineral Resources ◽  
Point Clouds ◽  
Geochemical Data ◽  
Iron Deposit ◽  
Global Estimate ◽  
Rich Domain ◽  
The Rich ◽  
Geochemical Analyses ◽  
Domain Block

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.

scholarly journals Implication Of Geological Domains Data For Modeling And Estimating Resources From Nkout Iron Deposit (South-Cameroun)

2021 ◽  
Author(s):  
Boroh Andre William ◽  
Sore-Gamo Koutou Yvan ◽  
Ayiwouo Ngounouno Mohamed ◽  
Gbambié Mbowou Isaac Bertrand ◽  
Ngounouno Ismaïla
Keyword(s):  
Mineral Resources ◽  
Point Clouds ◽  
Geochemical Data ◽  
Iron Deposit ◽  
Global Estimate ◽  
Rich Domain ◽  
Southern Cameroon ◽  
The Rich ◽  
Geochemical Analyses ◽  
Domain Block

Abstract This paper is devoted to determine 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 in particular, the saprolitic domain; 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 modelling provides the best results.

scholarly journals The Rich Domain of Ambiguity Explored

2018 ◽  
Vol 64 (7) ◽  
pp. 3227-3240 ◽  
Author(s):  
Zhihua Li ◽  
Julia Müller ◽  
Peter P. Wakker ◽  
Tong V. Wang
Keyword(s):  
Rich Domain ◽  
The Rich

scholarly journals Leveraging Domain Context for Question Answering Over Knowledge Graph

2019 ◽  
Vol 4 (4) ◽  
pp. 323-335 ◽  
Author(s):  
Peihao Tong ◽  
Qifan Zhang ◽  
Junjie Yao
Keyword(s):  
Information Needs ◽  
Question Answering ◽  
Knowledge Graph ◽  
New Approach ◽  
Rich Domain ◽  
Complex Information ◽  
Question And Answer ◽  
Knowledge Graphs ◽  
The Rich ◽  
Matching Models

Abstract With the growing availability of different knowledge graphs in a variety of domains, question answering over knowledge graph (KG-QA) becomes a prevalent information retrieval approach. Current KG-QA methods usually resort to semantic parsing, search or neural matching models. However, they cannot well tackle increasingly long input questions and complex information needs. In this work, we propose a new KG-QA approach, leveraging the rich domain context in the knowledge graph. We incorporate the new approach with question and answer domain context descriptions. Specifically, for questions, we enrich them with users’ subsequent input questions within a session and expand the input question representation. For the candidate answers, we equip them with surrounding context structures, i.e., meta-paths within the targeting knowledge graph. On top of these, we design a cross-attention mechanism to improve the question and answer matching performance. An experimental study on real datasets verifies these improvements. The new approach is especially beneficial for specific knowledge graphs with complex questions.

scholarly journals TLS and SfM Approach for Bulk Density Determination of Excavated Heterogeneous Raw Materials

Minerals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 174 ◽  
Author(s):  
Peter Blistan ◽  
Stanislav Jacko ◽  
Ľudovít Kovanič ◽  
Julián Kondela ◽  
Katarína Pukanská ◽  
...  
Keyword(s):  
Bulk Density ◽  
Laser Scanning ◽  
Large Scale ◽  
Raw Materials ◽  
Terrestrial Laser Scanning ◽  
Mineral Resources ◽  
Point Clouds ◽  
Raw Material

A frequently recurring problem in the extraction of mineral resources (especially heterogeneous mineral resources) is the rapid operative determination of the extracted quantity of raw material in a surface quarry. This paper deals with testing and analyzing the possibility of using unconventional methods such as digital close-range photogrammetry and terrestrial laser scanning in the process of determining the bulk density of raw material under in situ conditions. A model example of a heterogeneous deposit is the perlite deposit Lehôtka pod Brehmi (Slovakia). Classical laboratory methods for determining bulk density were used to verify the results of the in situ method of bulk density determination. Two large-scale samples (probes) with an approximate volume of 7 m3 and 9 m3 were realized in situ. 6 point samples (LITH) were taken for laboratory determination. By terrestrial laser scanning (TLS) measurement from 2 scanning stations, point clouds with approximately 163,000/143,000 points were obtained for each probe. For Structure-from-Motion (SfM) photogrammetry, 49/55 images were acquired for both probes, with final point clouds containing approximately 155,000/141,000 points. Subsequently, the bulk densities of the bulk samples were determined by the calculation from in situ measurements by TLS and SfM photogrammetry. Comparison of results of the field in situ measurements (1841 kg∙m−3) and laboratory measurements (1756 kg∙m−3) showed only a 4.5% difference in results between the two methods for determining the density of heterogeneous raw materials, confirming the accuracy of the used in situ methods. For the determination of the loosening coefficient, the material from both large-scale samples was transferred on a horizontal surface. Their volumes were determined by TLS. The loosening coefficient for the raw material of 1.38 was calculated from the resulting values.

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.

Depositional environments, sediment characteristics, palaeoecological analysis and environmental assessment of an internationally protected shallow Mediterranean lagoon, Gialova Lagoon – Navarino Bay, Greece

2014 ◽  
Vol 105 (3) ◽  
pp. 189-206 ◽  
Author(s):  
P. Avramidis ◽  
G. Iliopoulos ◽  
N. Kontopoulos ◽  
D. Panagiotaras ◽  
P. Barouchas ◽  
...  
Keyword(s):  
Natura 2000 ◽  
Enrichment Factors ◽  
Depositional Environments ◽  
Geochemical Characteristics ◽  
Geochemical Data ◽  
Sediment Characteristics ◽  
Protection Area ◽  
Moment Measures ◽  
Geochemical Analyses ◽  
International Conventions

ABSTRACTThis study presents sedimentological, palaeoecological and geochemical data from a shallow Mediterranean coastal lagoon which has been severely influenced by human intervention over the last 70 years. The Gialova Lagoon is protected by international conventions and is listed in the Natura 2000 European Community Network as Special Protection Area (SPA) and Site of Community Importance (SCI). The spatial variability of sediment characteristics such as grain size, total organic carbon (TOC) and moment measures, mean, sorting, kurtosis and skewness were calculated. Moreover, micro- and macrofossil and sediment geochemical analyses were carried out on six gravity core samples. Study of the above parameters indicates that the anthropogenic impact and intervention are reflected in the micro- (ostracods, foraminifera, charophytes) and macrofossil (molluscs) taxa corresponding to different depositional environmental facies, representing a brackish lagoon with the influence of (a) fresh water inflow, (b) shallow marine environment and (c) hypoxic and dystrophic conditions. The geochemical characteristics and the calculation of the degree of sediment contamination using enrichment factors (EF), contamination factors (Cif) and the index of geo-accumulation (Igeo) indicate a recent relative improvement of the lagoon towards the upper layers of the gravity cores, rendering the lagoon as unpolluted to moderately polluted. This combinatorial study of sediment geochemical characteristics, as well as the downcore micro- and macrofossil assemblages, can be considered as a baseline for future monitoring in accordance with European Union directives, and for any future engineering interventions for the lagoon environmental maintenance and conservation; as this is the first time that geochemical and downcore palaeoecological data have been presented from this lagoon.

Oxygen and carbon stable isotopes of Mytilus galloprovincialis Lamarck, 1819 shells as environmental and provenance proxies

The Holocene ◽  
2019 ◽  
Vol 30 (1) ◽  
pp. 65-76 ◽  
Author(s):  
Stefania Milano ◽  
Bernd R Schöne ◽  
Igor Gutiérrez-Zugasti
Keyword(s):  
Stable Isotopes ◽  
Mytilus Galloprovincialis ◽  
Shell Growth ◽  
Geochemical Data ◽  
Carbon Stable Isotopes ◽  
Northern Spain ◽  
Mollusc Shell ◽  
Geochemical Composition ◽  
Mussel Shells ◽  
Geochemical Analyses

Mollusc shell stable isotopes are commonly used to reconstruct past environmental conditions. However, despite being abundant components of natural and anthropogenic fossil accumulations, the geochemical composition of mussel shells ( Mytilus spp.) has rarely received attention in palaeoenvironmental studies. This study tests the suitability of oxygen isotopes (δ18Os) of Mytilus galloprovincialis as palaeothermometer. For 1 year, mussels and water samples were collected twice a month from Berria Beach, in Northern Spain. The geochemical data of the shells indicate that water temperatures can be reconstructed with an average offset of 1.2 ± 0.7°C with respect to the measured values. Furthermore, no prolonged shell growth cessations are observed. These results validate M. galloprovincialis as reliable recorders of seasonal water temperature fluctuations, supporting their use in palaeoenvironmental studies. In addition, further shell and water collections were carried out in the upper and lower areas of a nearby estuary. The geochemical analyses of these shells were aimed to test whether oxygen and carbon stable isotopes (δ13Cs) may be used as novel proxies to identify the shell provenance at local scale. The results show that the δ18Os versus δ13Cs correlation direction varies along the coast–upper estuary geographical gradient, suggesting it to be a potential new proxy to distinguish between marine and estuarine mussel specimens.

Factor-Universal Kriging Model in the Geochemical Combination Anomaly

2013 ◽  
Vol 807-809 ◽  
pp. 2139-2146
Author(s):  
Meng Xue Cao ◽  
Lai Jun Lu ◽  
Guo Qiang Chen
Keyword(s):  
Factor Analysis ◽  
Spatial Distribution ◽  
Spatial Structure ◽  
Spatial Variation ◽  
Mineral Resources ◽  
Kriging Model ◽  
Universal Kriging ◽  
Geochemical Data ◽  
Geochemical Elements ◽  
Anomaly Analysis

Geochemical elements combination anomaly is one of three basic theories in the mineral resources prediction, considering the autocorrelation and structure of elements spatial distribution, comprehensive spatial structure simplified for Factor analysis and spatial variation metric thought for Universal Kriging, mixing together two methods constructs the so-called Factor-Universal Kriging model, for combination anomaly analysis of regional geochemical data. This article emphatically introduces the principle and application of the model.

Extraction of Prospecting Information for Sedimentary-Metamorphic Type Iron Deposit Based on Ziyuan-3 Satellite Data — Taking Xinjiang Taxkorgan Area as an Example

2014 ◽  
Vol 1010-1012 ◽  
pp. 1365-1371
Author(s):  
Ling Chen ◽  
Yan Zhou ◽  
Wei Zhang
Keyword(s):  
Satellite Data ◽  
High Spatial Resolution ◽  
Control Structure ◽  
Mineral Resources ◽  
Ratio Method ◽  
Iron Deposit ◽  
Control Structures ◽  
Iron Mineral ◽  
High Resolution Image ◽  
Spectrum Characteristics

In this study, the significance and content of prospecting information of sedimentary-metamorphic type iron deposit are expounded. Ziyuan-3 high spatial resolution satellite data are used to extract the prospecting information of sedimentary-metamorphic type iron deposit in taxkorgan area in Xinjiang. By using the pertinent methods of image processing, the information of ore-bearing bed, ore-control structures have been extracted, and based on the ferric altered mineral spectrum characteristics, the ratio method also has been used to extract iron mineral anomalies in study area. Based on the ore-control structure, ore-bearing rocks and ferric anomalies information, 2 remote sensing prospecting targets have been circled. Our research have laid foundation for the evaluation of mineral resources in this region, and also broadened the thinking for domestic high resolution image scale application in geology and mineral resources.

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