Oluseyi Bamisaiye - Academia.edu (original) (raw)
Papers by Oluseyi Bamisaiye
Arabian Journal of Geosciences, 2021
The Zuru Schist Belt is one of the gold-bearing schist belts in northwestern Nigeria. The gold mi... more The Zuru Schist Belt is one of the gold-bearing schist belts in northwestern Nigeria. The gold mineralisation is mainly associated with NE-trending shear zones and is hosted in veins of quartz, quartz-tourmaline and quartz-feldspar. In this study, the spatial pattern of gold and associated elements was identified and delineated through statistical analysis of trace element geochemical data. Statistical analyses including spearman correlation, principal component analysis and hierarchical cluster analysis were applied on the geochemical data to decipher and interpret multi-element association related with gold mineralisation. Spearman correlation revealed significant positive correlation amongst Co, Mn, Fe, V, Ni and Zn (>0.70), while Au has moderate correlation with Ag, Bi and Cu (>0.30). Based on principal component analysis and hierarchical cluster analysis, three element associations can be recognised: (a) Zn-Ni-Co-Mn-Fe-V, (b) Au-Ag-Bi-Pb and (c) Zn-U-Th-Sr-La-Ba. The first two multielement associations are related to gold mineralisation. The multi-element association of Zn-Ni-Co-Mn-Fe-V signifies lithogenic factor and associated hydrothermal alteration, while Au-Ag-Bi-Pb is indicative of gold mineralisation. The combination of Au and associated elements (Ag, Bi and Pb), which was achieved through the use of uni-element thresholds (median+2 median absolute deviation) in multi-element halo technique, enabled the mapping of multi-element geochemical anomaly. The uni-and multi-element geochemical anomaly maps show geochemical anomalies in the northern, central and southern parts of the area. These anomalies, largely restricted to metasedimentary rocks notably foliated quartzite, schist, and phyllite, represent where further exploration should be focused with more attention particularly in the northern part where higher concentration than previously reported was observed. Keywords Geochemical anomaly. Pathfinder elements. Zuru Schist Belt. Orogenic gold Highlights • Multivariate statistical analysis of trace element geochemical data was employed to identify pathfinder elements associated with gold mineralization. • The multivariate analysis revealed Au-Ag-Bi-Pb as the multi-element association indicative of gold mineralisation. • Median absolute deviation and multi-element halo technique were combined to elicit spatial pattern of uni-and multi-element geochemical anomalies.
Spatial Information Research, 2018
Selection of the best interpolation method as well as the appropriate software parameters that gi... more Selection of the best interpolation method as well as the appropriate software parameters that give the closest approximation to known geology is usually a difficult task. This is because geologic factors such as lithologic and structural feature occurrences are not easily predictable, especially where outcrop occurrences are fortuitous. Borehole data provides an alternative to sparse outcrops especially in areas where the borehole occurrence is well-distributed. However, most boreholes were drilled for exploration purposes and may not be well-distributed over all the study areas. Getting information in-between boreholes becomes a big challenge, especially in areas where we have very large volume of borehole data that are randomly distributed. The use of interpolation technique to estimate in-between borehole points becomes imperative. Comparison of interpolation techniques was carried out with borehole log data so as to determine the best interpolation method output that is closest to known geology. The test area is located in the southwestern part of the Western Bushveld Complex and the northeastern part of the Eastern Bushveld Complex in South-Africa. Eight interpolation tools available in Rockworks Ò 15 were evaluated and utilized in contouring the major stratigraphic peaks within the area. The best results were achieved with Kriging and trend surface analysis interpolation methods. The resultant maps were interpreted and compared with geology and structures inferred from existing geological and geophysical records and a good correlation is present.
Journal of African Earth Sciences, 2017
Highlights • Unsubstantiated inferences about the RLS subsurface structures are made evident. • P... more Highlights • Unsubstantiated inferences about the RLS subsurface structures are made evident. • Possible magma transport direction are highlighted. • A summary of the major structural trends and their interpretations is given. • Better understanding of local and regional structural trends is provided. • A new way of mapping subsurface geological features in detail is provided.
Open Journal of Geology, 2016
The focus of this paper is on determination of the geometry and stratigraphic contact pattern of ... more The focus of this paper is on determination of the geometry and stratigraphic contact pattern of the Rustenburg Layered Suite (RLS) in the Northern Bushveld Complex area using available borehole data and trend surface analysis technique. This technique was used to analyse over one hundred borehole log data in the Northern Bushveld Complex in order to describe the geometric pattern and trends of the RLS rocks. The results demonstrate the usefulness of this technique in identifying structural features. Regional trends of each of the stratigraphic units reveal the presence of regional structures that were not obvious at the surface. This first part of the paper focused on the Northern Bushveld Complex, while the second and the third part focused on the eastern and western Bushveld limbs respectively.
Open Journal of Geology, 2016
The focus of this paper is on determination of the geometry and stratigraphic contact pattern of ... more The focus of this paper is on determination of the geometry and stratigraphic contact pattern of the Rustenburg Layered Suite (RLS) in the Northern Bushveld Complex area using available borehole data and trend surface analysis technique. This technique was used to analyse over one hundred borehole log data in the Northern Bushveld Complex in order to describe the geometric pattern and trends of the RLS rocks. The results demonstrate the usefulness of this technique in identifying structural features. Regional trends of each of the stratigraphic units reveal the presence of regional structures that were not obvious at the surface. This first part of the paper focused on the Northern Bushveld Complex, while the second and the third part focused on the eastern and western Bushveld limbs respectively.
Journal of Geography and Geology, 2015
Trend surface analysis (TSA) was used to investigate the structure and thickness variation patter... more Trend surface analysis (TSA) was used to investigate the structure and thickness variation pattern and to resolve trend and residual component of the structure contours and isopach maps of the Rustenburg Layered Suite (RLS) across the Bushveld Igneous Complex (BIC). The TSA technique was also employed in extracting meter scale structures from the regional structural trends. This enables small-scale structures that could only be picked through field mapping to be observed and scrupulously investigated. Variation in the structure and thickness was used in timing the development of some of the delineated structural features. This has helped to unravel the progressive development of structures within the RLS. The results indicate that present day structures shows slight changes in both regional and local trends throughout the stratigraphic sequence from the base of the Main Zone to the top of the Achaean floor. Structures around the gap areas are also highlighted. This paper represents ...
SN Applied Sciences, 2019
Landslides represent "structural failures" with great risk to the environment, and this makes the... more Landslides represent "structural failures" with great risk to the environment, and this makes the study of the mechanism of formation of landslides very important. Most parts of the Okemesi ridge are inherently dangerous areas, at high risk of sliding. This research is one of the first detailed geological investigations of landslides in this area. This research evaluates the importance of the lithological, structural and geomorphological factors to landslide activities in parts of southwestern Nigeria with the aim of designing a susceptibility map which is intended to serve as an early warning and mitigation measures. The result revealed that the latest landslide was caused by the release of intensely fractured rocks along adjacent blocks of a fault plane, and prevalent tectonic stress condition set the stage for the landslide, while slope instability in conjunction with prolonged high-intensity rainfall triggered the movement. The most susceptible area of landslide is within the slope angles of between 45° and 75° with an elevation of between 514 and 666 m. The research further revealed that the landslide occurred about 500 m to the road. The landslide-prone location is within the 0-200 m from the hill; hence, human settlements and activities should be sited at least 500 m away from the hill.
Geocarto International, 2020
Mapping of the major structures in the Zuru schist belt and preliminary evaluation of distributio... more Mapping of the major structures in the Zuru schist belt and preliminary evaluation of distribution of the locations of gold mineralization relative to these structures was achieved using remote sen...
The Zuru Schist Belt is one of the gold-bearing schist belts in northwestern Nigeria. The gold mi... more The Zuru Schist Belt is one of the gold-bearing schist belts in northwestern Nigeria. The gold mineralisation is mainly associated with NE-trending shear zones and is hosted in veins of quartz, quartz-tourmaline and quartz-feldspar. In this study, the spatial pattern of gold and associated elements was identified and delineated through statistical analysis of trace element geochemical data. Statistical analyses including spearman correlation, principal component analysis and hierarchical cluster analysis were applied on the geochemical data to decipher and interpret multi-element association related with gold mineralisation. Spearman correlation revealed significant positive correlation amongst Co, Mn, Fe, V, Ni and Zn (>0.70), while Au has moderate correlation with Ag, Bi and Cu (>0.30). Based on principal component analysis and hierarchical cluster analysis, three element associations can be recognised: (a) Zn-Ni-Co-Mn-Fe-V, (b) Au-Ag-Bi-Pb and (c) Zn-U-Th-Sr-La-Ba. The firs...
Ore Geology Reviews
Abstract The Trans-Sahara belt is one of the mobile belts formed during the Pan African orogeny t... more Abstract The Trans-Sahara belt is one of the mobile belts formed during the Pan African orogeny that spans between ~870 and ~550 Ma. The Trans-Sahara belt was formed as result of the collision between the converging West African craton, Congo craton, and the Sahara metacraton continental blocks. The belt, with major exposure in the Tuareg and Dahomeyan, consists of pre-Neoproterozoic basement which were thoroughly reworked during the Pan African orogeny, Neoproterozoic metasedimentary and metavolcanics, and syn-tectonic Pan African granitoids which intrude Archean and Paleoproterozoic rocks. The Trans-Sahara belt, though less endowed when compared to older Archean orogenic greenstone belts in terms of gold mineralization, displays reasonable gold mineralization in both the Tuareg shield and Dahomeyan shield with about 160 tons of gold reported so far across the belt. Mineralization is associated with varying lithologies across the belt and appears to have been regionally controlled by N-S trending Pan African shear zones. In the Tuareg shield, mineralized quartz veins are associated with syntectonic granitoids, mylonitic and meta-volcanosedimentary rocks. Conversely, gold mineralization is only associated with metasediments and migmatite gneisses in the Dahomeyan shield, with occurrences largely confined to metasedimentary sequence in Benin and Nigeria. The prevailing tropical climate in the Dahomeyan shield has also facilitated secondary concentration of gold in alluvial bed of river draining supracrustal rocks hosting primary gold mineralizations. The occurrence of primary mineralization in variety of rocks across the Tuareg and Dahomeyan shield and widespread occurrence of placer gold deposits in the Dahomeyan shield justifies the need for further exploration and evaluation of mineralization potential. The emplacement of gold, which occur between 535 and 500 Ma is controlled by N-S trending Pan African mega-shear zones. However, at the district scale, it is evident that the Pan African mega-shear zones are not the only important structures. Lower order faults and shear zones are important structures to consider in exploration targeting. Exploration particularly at district-scale might benefit from GIS-based prospectivity mapping, considering the mineralizations are generally structural controlled. GIS-based prospectivity mapping which integrates multifaceted digital data sets can provide a foundation for vectoring towards explorations targets in many mineralized districts within the Trans-Sahara belt.
The Okemesi area, southwestern Nigeria, is part of the Ilesha schist belt and play host to the Ok... more The Okemesi area, southwestern Nigeria, is part of the Ilesha schist belt and play host to the Okemesi fold belt and the Ifewara Shear Zone. Nappe structures had been proposed for some parts of Southwestern Nigeria without very clear meso or micro structural evidence. This study provides a lot of new structural evidences to substantiate the inferred Nappe structures within the Okemesi fold belt. Mapping of the Okemesi fold has been hampered by thick vegetation in the past. However, a major deformation zone was exposed by the recent landslide activities in the area, structures and lithologies exposed by the landslide were studied and structural features that are typical of transtensional and transpressional settings were observed. This paper presents the result of the systematic filed mapping which revealed the complete, fold transposition, elements of internal strain such as cleavages and mineral lineation, intrafolial folds, flexure slip, sheath, recumbent and conjugate kink folds,...
Bulletin of the Geological Society of America, Jan 1, 1937
... Theory of scale models as applied to the study of geologic structures. Marion King Hubbert. T... more ... Theory of scale models as applied to the study of geologic structures. Marion King Hubbert. This record provided courtesy of AGI/GeoRef. This article has been cited by other articles: Home page, AAPG Bulletin Home page JF ...
Arabian Journal of Geosciences, 2021
The Zuru Schist Belt is one of the gold-bearing schist belts in northwestern Nigeria. The gold mi... more The Zuru Schist Belt is one of the gold-bearing schist belts in northwestern Nigeria. The gold mineralisation is mainly associated with NE-trending shear zones and is hosted in veins of quartz, quartz-tourmaline and quartz-feldspar. In this study, the spatial pattern of gold and associated elements was identified and delineated through statistical analysis of trace element geochemical data. Statistical analyses including spearman correlation, principal component analysis and hierarchical cluster analysis were applied on the geochemical data to decipher and interpret multi-element association related with gold mineralisation. Spearman correlation revealed significant positive correlation amongst Co, Mn, Fe, V, Ni and Zn (>0.70), while Au has moderate correlation with Ag, Bi and Cu (>0.30). Based on principal component analysis and hierarchical cluster analysis, three element associations can be recognised: (a) Zn-Ni-Co-Mn-Fe-V, (b) Au-Ag-Bi-Pb and (c) Zn-U-Th-Sr-La-Ba. The first two multielement associations are related to gold mineralisation. The multi-element association of Zn-Ni-Co-Mn-Fe-V signifies lithogenic factor and associated hydrothermal alteration, while Au-Ag-Bi-Pb is indicative of gold mineralisation. The combination of Au and associated elements (Ag, Bi and Pb), which was achieved through the use of uni-element thresholds (median+2 median absolute deviation) in multi-element halo technique, enabled the mapping of multi-element geochemical anomaly. The uni-and multi-element geochemical anomaly maps show geochemical anomalies in the northern, central and southern parts of the area. These anomalies, largely restricted to metasedimentary rocks notably foliated quartzite, schist, and phyllite, represent where further exploration should be focused with more attention particularly in the northern part where higher concentration than previously reported was observed. Keywords Geochemical anomaly. Pathfinder elements. Zuru Schist Belt. Orogenic gold Highlights • Multivariate statistical analysis of trace element geochemical data was employed to identify pathfinder elements associated with gold mineralization. • The multivariate analysis revealed Au-Ag-Bi-Pb as the multi-element association indicative of gold mineralisation. • Median absolute deviation and multi-element halo technique were combined to elicit spatial pattern of uni-and multi-element geochemical anomalies.
Spatial Information Research, 2018
Selection of the best interpolation method as well as the appropriate software parameters that gi... more Selection of the best interpolation method as well as the appropriate software parameters that give the closest approximation to known geology is usually a difficult task. This is because geologic factors such as lithologic and structural feature occurrences are not easily predictable, especially where outcrop occurrences are fortuitous. Borehole data provides an alternative to sparse outcrops especially in areas where the borehole occurrence is well-distributed. However, most boreholes were drilled for exploration purposes and may not be well-distributed over all the study areas. Getting information in-between boreholes becomes a big challenge, especially in areas where we have very large volume of borehole data that are randomly distributed. The use of interpolation technique to estimate in-between borehole points becomes imperative. Comparison of interpolation techniques was carried out with borehole log data so as to determine the best interpolation method output that is closest to known geology. The test area is located in the southwestern part of the Western Bushveld Complex and the northeastern part of the Eastern Bushveld Complex in South-Africa. Eight interpolation tools available in Rockworks Ò 15 were evaluated and utilized in contouring the major stratigraphic peaks within the area. The best results were achieved with Kriging and trend surface analysis interpolation methods. The resultant maps were interpreted and compared with geology and structures inferred from existing geological and geophysical records and a good correlation is present.
Journal of African Earth Sciences, 2017
Highlights • Unsubstantiated inferences about the RLS subsurface structures are made evident. • P... more Highlights • Unsubstantiated inferences about the RLS subsurface structures are made evident. • Possible magma transport direction are highlighted. • A summary of the major structural trends and their interpretations is given. • Better understanding of local and regional structural trends is provided. • A new way of mapping subsurface geological features in detail is provided.
Open Journal of Geology, 2016
The focus of this paper is on determination of the geometry and stratigraphic contact pattern of ... more The focus of this paper is on determination of the geometry and stratigraphic contact pattern of the Rustenburg Layered Suite (RLS) in the Northern Bushveld Complex area using available borehole data and trend surface analysis technique. This technique was used to analyse over one hundred borehole log data in the Northern Bushveld Complex in order to describe the geometric pattern and trends of the RLS rocks. The results demonstrate the usefulness of this technique in identifying structural features. Regional trends of each of the stratigraphic units reveal the presence of regional structures that were not obvious at the surface. This first part of the paper focused on the Northern Bushveld Complex, while the second and the third part focused on the eastern and western Bushveld limbs respectively.
Open Journal of Geology, 2016
The focus of this paper is on determination of the geometry and stratigraphic contact pattern of ... more The focus of this paper is on determination of the geometry and stratigraphic contact pattern of the Rustenburg Layered Suite (RLS) in the Northern Bushveld Complex area using available borehole data and trend surface analysis technique. This technique was used to analyse over one hundred borehole log data in the Northern Bushveld Complex in order to describe the geometric pattern and trends of the RLS rocks. The results demonstrate the usefulness of this technique in identifying structural features. Regional trends of each of the stratigraphic units reveal the presence of regional structures that were not obvious at the surface. This first part of the paper focused on the Northern Bushveld Complex, while the second and the third part focused on the eastern and western Bushveld limbs respectively.
Journal of Geography and Geology, 2015
Trend surface analysis (TSA) was used to investigate the structure and thickness variation patter... more Trend surface analysis (TSA) was used to investigate the structure and thickness variation pattern and to resolve trend and residual component of the structure contours and isopach maps of the Rustenburg Layered Suite (RLS) across the Bushveld Igneous Complex (BIC). The TSA technique was also employed in extracting meter scale structures from the regional structural trends. This enables small-scale structures that could only be picked through field mapping to be observed and scrupulously investigated. Variation in the structure and thickness was used in timing the development of some of the delineated structural features. This has helped to unravel the progressive development of structures within the RLS. The results indicate that present day structures shows slight changes in both regional and local trends throughout the stratigraphic sequence from the base of the Main Zone to the top of the Achaean floor. Structures around the gap areas are also highlighted. This paper represents ...
SN Applied Sciences, 2019
Landslides represent "structural failures" with great risk to the environment, and this makes the... more Landslides represent "structural failures" with great risk to the environment, and this makes the study of the mechanism of formation of landslides very important. Most parts of the Okemesi ridge are inherently dangerous areas, at high risk of sliding. This research is one of the first detailed geological investigations of landslides in this area. This research evaluates the importance of the lithological, structural and geomorphological factors to landslide activities in parts of southwestern Nigeria with the aim of designing a susceptibility map which is intended to serve as an early warning and mitigation measures. The result revealed that the latest landslide was caused by the release of intensely fractured rocks along adjacent blocks of a fault plane, and prevalent tectonic stress condition set the stage for the landslide, while slope instability in conjunction with prolonged high-intensity rainfall triggered the movement. The most susceptible area of landslide is within the slope angles of between 45° and 75° with an elevation of between 514 and 666 m. The research further revealed that the landslide occurred about 500 m to the road. The landslide-prone location is within the 0-200 m from the hill; hence, human settlements and activities should be sited at least 500 m away from the hill.
Geocarto International, 2020
Mapping of the major structures in the Zuru schist belt and preliminary evaluation of distributio... more Mapping of the major structures in the Zuru schist belt and preliminary evaluation of distribution of the locations of gold mineralization relative to these structures was achieved using remote sen...
The Zuru Schist Belt is one of the gold-bearing schist belts in northwestern Nigeria. The gold mi... more The Zuru Schist Belt is one of the gold-bearing schist belts in northwestern Nigeria. The gold mineralisation is mainly associated with NE-trending shear zones and is hosted in veins of quartz, quartz-tourmaline and quartz-feldspar. In this study, the spatial pattern of gold and associated elements was identified and delineated through statistical analysis of trace element geochemical data. Statistical analyses including spearman correlation, principal component analysis and hierarchical cluster analysis were applied on the geochemical data to decipher and interpret multi-element association related with gold mineralisation. Spearman correlation revealed significant positive correlation amongst Co, Mn, Fe, V, Ni and Zn (>0.70), while Au has moderate correlation with Ag, Bi and Cu (>0.30). Based on principal component analysis and hierarchical cluster analysis, three element associations can be recognised: (a) Zn-Ni-Co-Mn-Fe-V, (b) Au-Ag-Bi-Pb and (c) Zn-U-Th-Sr-La-Ba. The firs...
Ore Geology Reviews
Abstract The Trans-Sahara belt is one of the mobile belts formed during the Pan African orogeny t... more Abstract The Trans-Sahara belt is one of the mobile belts formed during the Pan African orogeny that spans between ~870 and ~550 Ma. The Trans-Sahara belt was formed as result of the collision between the converging West African craton, Congo craton, and the Sahara metacraton continental blocks. The belt, with major exposure in the Tuareg and Dahomeyan, consists of pre-Neoproterozoic basement which were thoroughly reworked during the Pan African orogeny, Neoproterozoic metasedimentary and metavolcanics, and syn-tectonic Pan African granitoids which intrude Archean and Paleoproterozoic rocks. The Trans-Sahara belt, though less endowed when compared to older Archean orogenic greenstone belts in terms of gold mineralization, displays reasonable gold mineralization in both the Tuareg shield and Dahomeyan shield with about 160 tons of gold reported so far across the belt. Mineralization is associated with varying lithologies across the belt and appears to have been regionally controlled by N-S trending Pan African shear zones. In the Tuareg shield, mineralized quartz veins are associated with syntectonic granitoids, mylonitic and meta-volcanosedimentary rocks. Conversely, gold mineralization is only associated with metasediments and migmatite gneisses in the Dahomeyan shield, with occurrences largely confined to metasedimentary sequence in Benin and Nigeria. The prevailing tropical climate in the Dahomeyan shield has also facilitated secondary concentration of gold in alluvial bed of river draining supracrustal rocks hosting primary gold mineralizations. The occurrence of primary mineralization in variety of rocks across the Tuareg and Dahomeyan shield and widespread occurrence of placer gold deposits in the Dahomeyan shield justifies the need for further exploration and evaluation of mineralization potential. The emplacement of gold, which occur between 535 and 500 Ma is controlled by N-S trending Pan African mega-shear zones. However, at the district scale, it is evident that the Pan African mega-shear zones are not the only important structures. Lower order faults and shear zones are important structures to consider in exploration targeting. Exploration particularly at district-scale might benefit from GIS-based prospectivity mapping, considering the mineralizations are generally structural controlled. GIS-based prospectivity mapping which integrates multifaceted digital data sets can provide a foundation for vectoring towards explorations targets in many mineralized districts within the Trans-Sahara belt.
The Okemesi area, southwestern Nigeria, is part of the Ilesha schist belt and play host to the Ok... more The Okemesi area, southwestern Nigeria, is part of the Ilesha schist belt and play host to the Okemesi fold belt and the Ifewara Shear Zone. Nappe structures had been proposed for some parts of Southwestern Nigeria without very clear meso or micro structural evidence. This study provides a lot of new structural evidences to substantiate the inferred Nappe structures within the Okemesi fold belt. Mapping of the Okemesi fold has been hampered by thick vegetation in the past. However, a major deformation zone was exposed by the recent landslide activities in the area, structures and lithologies exposed by the landslide were studied and structural features that are typical of transtensional and transpressional settings were observed. This paper presents the result of the systematic filed mapping which revealed the complete, fold transposition, elements of internal strain such as cleavages and mineral lineation, intrafolial folds, flexure slip, sheath, recumbent and conjugate kink folds,...
Bulletin of the Geological Society of America, Jan 1, 1937
... Theory of scale models as applied to the study of geologic structures. Marion King Hubbert. T... more ... Theory of scale models as applied to the study of geologic structures. Marion King Hubbert. This record provided courtesy of AGI/GeoRef. This article has been cited by other articles: Home page, AAPG Bulletin Home page JF ...