1. Introduction

OJG

Open Journal of Geology

2161-7570

Scientific Research Publishing

10.4236/ojg.2024.146028

OJG-133848

Articles

Earth&Environmental Sciences

Petrology and Structural Characterization of Post-Neoproterozoic Dolerites from the Kimberlite Fields in the Kéniéba Region (Western Mali)

Gbele

Ouattara

¹Baco

Traore

¹Ziandjêdé

Hervé Siagné

¹Aboubacar

Denon

¹Souleymane

Sangare

²Marc

Ephrem Allialy

Unit&#233; de Formation et de Recherche des Sciences de la Terre et des Ressources Mini&#232;res (UFR-STRM), University of Cocody, Abidjan, C&#244;te d&#8217;Ivoire

Laboratoire des Sciences G&#233;ographiques, du G&#233;nie Civil et des G&#233;osciences, Institut National Polytechnique F&#233;lix HOUPHOU&#203;T-BOIGNY (INP-HB), Yamoussoukro, C&#244;te d&#8217;Ivoire

EUREKAGEO Sarl Consulting Mining Company, Bamako, Republic of Mali

18062024

14066556708, May 202415, June 2024 18, June 2024

2014

This work is licensed under the Creative Commons Attribution-NonCommercial International License (CC BY-NC).http://creativecommons.org/licenses/by-nc/4.0/

Post-Neoproterozoic dolerites from the Kéniéba region (Western Mali) are often associated with kimberlites. The rarity of kimberlite outcrops led to the study of doleritic rocks, spatially associated with them. The petrographic and lithogeochemical study showed that the dolerites of the Kéniéba kimberlitic fields are of tholeiitic nature and of the E-MORB (Enriched-Mid Ocean Ridge Basalt) type. This reflects an enrichment over time, compared to the Birimian dolerites of the volcano-sedimentary greenstone belt of Toumodi, in central C?te d’Ivoire. Furthermore, these dolerites are enriched in SiO ₂, TiO ₂, Zr and poor in Fe ₂O ₃, MgO. These dolerites would have formed in a late to post-orogenic intracontinental context during the breakup of Gondwana. Structurally, Kéniéba dolerites are often associated with kimberlite pipes, fractures and large deep structures identified using aeromagnetic images. Taking into account the fact that kimberlites do not outcrop in the Kéniéba region, the geochemical study coupled with the interpretation of aeromagnetic data proved to be very useful for the search for pipes.

Dolerites Kimberlitic Fields Petrology Structures Kéniéba Mali

1. Introduction

The kimberlite fields of the Kéniéba region are located in western Mali where the first kimberlite was discovered between 1955 and 1957 by the DFGM. Numerous exploration works carried out by mining companies followed this discovery. Around thirty pipes and kimberlitic dikes have been revealed within the Birimian formations, mainly composed of metasediments and intrusions of granitoids covered by neoproterozoic sandstones formations. All of these formations are crossed by occurrences of doleritic to gabbroic nature which were established during magmatic activities, approximately 180 My ago [1] , following which the Gondwana was dislocated. The kimberlite occurrences of Kéniéba are often located along certain structures controlling the dolerites, some of which are of Turonian age (92 My), [2] .

Several generations of dolerite intrusions are present in the Kéniéba sector, of which eight (8) have been the subject of this study. These basic intrusions penetrate fractures and/or faults to form dikes which extend over large areas. The occurrences of dolerites correspond to the last phase of basic volcanism, and generally precede the kimberlite occurrences which appear in the form of explosions.

In the region, the kimberlites appear in the form of clusters forming groups of three (3) to five (5) kimberlite pipes and which are aligned on fractures oriented along the WNW-ESE direction (125˚ to 127˚) which intersect the NE-SW directions (15˚ to 20˚) which form a very tight network of dikes [3] .

The structural data clearly show control of kimberlite clusters by structures associated with dolerites which are distributed in two systems of different directions: latitudinal and sub-meridian. Many diamonds have been discovered at Kéniéba, in areas relatively close to the dolerite dikes. However, the petrographic and structural characteristics associated with the emplacement of these dolerites, as well as their relationships with the kimberlites, are not yet clearly established.

This work aims to establish the petrological and structural characteristics of these post-Neoproterozoic dolerites from the kimberlitic fields of the Kéniéba region, compared to certain Birimian dolerites from the West African craton.

2. Location and Geological Setting of the Study Area

The Kéniéba region is located in the west of Mali, on the border with Senegal (Figure 1). The study area is geologically associated with the Kédougou-Kéniéba Inlier (KKI) which is underlain by volcanic, volcano-sedimentary formations and granitoid intrusions [4] [5] .

Knowledge of the geology of the Malian part of the KKI has been greatly improved as part of a cooperation program between the government of the Republic of Mali and the BRGM/Geosystem Maps consortium, which led to the production of the geological map at 1/200,000 [3] . The establishment of the formations of the Kéniéba region are associated with the Eburnean orogeny dated approximately between 2030 and 1830 My [6] . These formations are represented by metamorphic rocks of the greenschist facies, namely, metagrauwackes as well as granitoid intrusions [7] . They are limited to the east by the vast sedimentary cover of the Neoproterozoic domain.

3. Materials and Methods

The material includes field data (samples), laboratory data and aeromagnetic images. The first phase consisted of the collection of field data, through sampling of dolerites (generally in the form of dikes), both in the Birimian formations and in the Neoproterozoic formations. The preparation of twelve (12) thin sections at the Basement Geology Laboratory of the Félix Houphouët-Boigny University of Abidjan (Côte d’Ivoire) made it possible to determine the petrographic characteristics of dolerites and surrounding rocks.

Geochemical analyzes (done at the Mineral Laboratories, Bureau Veritas Commodities, Vancouver, Canada) also made it possible to clarify the petrographic nature, lineages and environments of the establishment of these dolerites. A comparison of the lithogeochemical data of the dolerites of Kéniéba with those of other regions made it possible to better characterize them.

Structural data were collected in the immediate environment of these dolerites. An interpretation of aeromagnetic imagery made it possible to identify major geological structures.

4. Results4.1. Petrographic Characteristics of Dolerites

In the field, dolerites appear in the form of dikes and sometimes associated with microgabbros. The coloring oscillates between dark gray and black. These are micro-grained rocks reflecting their semi-depth origin. In thin sections, the mineralogy consists essentially of entangled plagioclase rods, pyroxenes (orthopyroxenes and clinopyroxenes), amphiboles and a few fine quartz crystals (Figure 2). These rocks present intergranular, microgabbro and subophitic textures.

4.2. Lithogeochemical Characteristics of Dolerites

The major element data (Table 1) show an average composition of SiO₂ (49.94% - 52.35%), MgO (5.94% - 8.62%), Fe₂O₃ (9.01% - 12.47%), Al₂O₃ (14.01% - 15.33%), Na₂O + K₂O (2.26% - 4.05%) and Na₂O/K₂O (0.5 - 3.71) and relatively low values of TiO₂ (0.76% - 1.3%) (Table 1).

A study of the chemical composition of basic rock dikes located in the fields of Bilali (Bilali south), Sékonomata and Kobato showed a slight increase in TiO₂

Table 1 Chemical composition in major elements (% by weight) of representative samples of dolerites across the Kéniéba kimberlite province

	DOL-1A %	DOL-1B %	DOL-1C %	DOL-1D %	DOL-2 %	DOL-3B %	DOL-4 %	DOL-5 %
SiO₂	51.99	49.94	52.23	51.92	52.08	51.29	49.95	52.35
Al₂O₃	14.05	15.33	14.02	14.55	14.2	15.1	14.93	14.01
Fe₂O₃	11.53	12.47	11.83	11.87	11.47	9.01	12.35	11.84
MgO	6.82	6.04	6.14	6.26	6.62	8.62	5.94	6.13
CaO	10.34	9.47	9.86	9.99	10.22	12.11	8.41	9.8
Na₂O	2.07	1.97	2.19	2.13	2.07	1.78	1.35	2.17
K₂O	0.94	0.97	0.98	0.93	0.82	0.48	2.7	1.18
TiO₂	1.22	1.28	1.29	1.27	1.3	0.76	1.26	1.26
P₂O₅	0.16	0.17	0.17	0.17	0.19	0.1	0.17	0.16
MnO	0.18	0.17	0.18	0.18	0.17	0.15	0.22	0.17
Cr₂O₃	0.023	0.019	0.011	0.015	0.037	0.079	0.018	0.014
LOI	0.5	2	0.9	0.9	0.6	0.4	2.5	0.7
Sum	99.91	99.92	99.91	99.92	99.92	99.94	99.9	99.91

inside and in the immediate vicinity of the kimberlites as well as the heavy rare earths like Hf, Y and Nd (Table 1 and Table 2). A dike located outside the kimberlite field shows a TiO₂ content of less than 1% (DOL-3B), which seems to correspond to normal levels in the Kéniéba dolerites.

The Batifara dolerite dike (DOL-2) located at 1.2 km from the kimberlite intrusion of the same name gives a content of 1.3% while the TiO₂ content in the Kassama dike (DOL-3B) located approximately 2.7 km to the East is 0.76%. For dikes located between 300 and 10 m from the kimberlite intrusion (in the field of influence), the grade reaches between 1.22% and 1.28%. It can be noted that chemical analyzes show that the composition of the dolerites is substantially identical in the Kéniéba area. Only the contents of samples DOL-4 and DOL-5 which come from the immediate environment of the kimberlites show relatively high K₂O contents compared to the other samples.

In the SiO₂ vs Na₂O + K₂O diagram (Figure 3(a)), the Kéniéba dolerites are located in tholeiitic rocks. Comparatively, the Birimian dolerites of the Toumodi region (in Côte d’Ivoire [8] ) are less alkaline and less siliceous than those of Kéniéba (more siliceous). This tholeiitic trend of dolerites is confirmed by the AFM diagrams of Irvine and Baragar ( [9] Figure 3(b)) and SiO₂ vs FeO_t/MgO (Figure 3(c)). The Kéniéba dolerites are more titaniferous (Figure 3(d) and Figure 3(e)), less chromiferous (Figure 3(f)) and richer in zirconium (Figure 3(g)) than those of Toumodi region. Furthermore, the dolerites of Kéniéba are more depleted in titanium than those of Nakyn in Siberia (2.17% - 4.69% [10] ) and those of Vilyui Middle Paleozoic paleorift of the east of the Siberian Platform, in Russia (2.48% - 2.6% [11] ). The Kéniéba dolerites have an affinity for sub-alkaline basalts (Figure 3(h)).

Table 2 Chemical composition of dolerites in trace elements of dolerites from certain kimberlite fields of Kéniéba

	DOL-1A ppm	DOL-1B ppm	DOL-1C ppm	DOL-1D ppm	DOL-2 ppm	DOL-3B ppm	DOL-4 ppm	DOL-5 ppm
Ba	198	205	200	213	258	142	346	220
Be	1	1	1	2	<1	1	1	2
Co	42.6	46.8	43.9	42.8	41.9	41.5	60.6	43.5
Cs	1.0	1.3	1.1	1.0	1.0	0.6	0.9	1.6
Ga	15.2	16.6	16.3	15.5	15.3	13.0	16.6	15.4
Hf	3.0	2.9	3.0	3.2	3.2	1.7	3.1	3.2
Nb	8.4	8.8	9.0	8.4	9.5	5.2	8.7	8.6
Rb	31.7	36.3	32.9	32.3	22.4	14.8	58.7	40.0
Sn	<1	1	<1	<1	<1	<1	<1	<1
Sr	187.5	173.7	197.3	183.2	220.6	176.3	195.5	199.8
Ta	0.6	0.6	0.6	0.6	0.5	0.4	0.6	0.5
Th	2.9	2.9	2.8	2.9	2.5	1.6	2.9	2.9
U	0.6	0.8	0.6	0.7	0.4	0.3	0.7	0.7
V	263	280	283	264	257	211	273	277
W	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	<0.5	0.5
Zr	106.0	112.9	115.6	113.3	113.6	61.9	111.7	112.8
Y	22.4	22.5	23.4	23.5	23.3	15.6	22.3	24.1
La	13.1	2.12	13.9	13.8	14.0	8.4	15.0	14.1
Ce	28.0	0.36	30.1	28.8	31.1	16.9	34.0	29.4
Pr	3.50	2.47	3.72	3.68	3.88	2.16	3.66	3.76
Nd	15.2	0.85	15.6	16.0	17.1	9.5	15.1	16.0
Sm	3.46	4.22	3.96	3.74	3.79	2.26	3.75	3.80
Eu	1.19	0.65	1.17	1.22	1.22	0.76	1.16	1.23
Gd	4.13	4.09	4.38	4.24	4.28	2.63	4.23	4.27
Tb	0.67	1.13	0.73	0.71	0.70	0.44	0.67	0.73
Dy	4.42	3.44	4.39	4.36	4.33	2.90	4.19	4.41
Ho	0.87	15.0	0.94	0.96	0.85	0.56	0.86	0.94
Er	2.49	3.48	2.74	2.64	2.50	1.76	2.45	2.59
Tm	0.34	28.7	0.39	0.38	0.37	0.24	0.37	0.37
Yb	2.23	13.1	2.31	2.34	2.21	1.45	2.16	2.39

In the diagrams normalized to the MORB (Mid Ocean Ridge Basalt) [14] , the Kéniéba dolerites are distinguished from the Birimian dolerites by a strong enrichment in light rare earths (Table 3). Compared to the primitive mantle and poorly mobile elements [15] , the Kéniéba dolerites are forty times more enriched in light rare earths than those of the Toumodi Birimian dolerites (Figure 4(a)). In the diagram of Anders and Grevesse [16] , the Kéniéba dolerites

Table 3 Pearson correlation matrix (n) of the major elements of the Kéniéba dolerites

Variables	SiO₂	Al₂O₃	Fe₂O₃	MgO	CaO	Na₂O	K₂O	TiO₂	P₂O₅	MnO	Cr₂O₃
SiO₂	1
Al₂O₃	−0.870	1
Fe₂O₃	−0.215	−0.159	1
MgO	0.116	0.243	−0.983	1
CaO	0.400	0.022	−0.924	0.920	1
Na₂O	0.770	−0.619	0.069	−0.116	0.280	1
K₂O	−0.535	0.148	0.534	−0.535	−0.809	−0.727	1
TiO₂	0.071	−0.414	0.942	−0.948	−0.810	0.284	0.364	1
P₂O₅	0.058	−0.374	0.865	−0.863	−0.748	0.231	0.327	0.964	1
MnO	−0.400	−0.010	0.644	−0.635	−0.846	−0.568	0.934	0.528	0.498	1
Cr₂O₃	−0.054	0.392	−0.936	0.956	0.825	−0.265	−0.428	−0.918	−0.787	−0.581	1

are sixty (60) times more enriched in light rare earths than the chondrites, while the Birimian dolerites show a weak fractionation of rare earths, with a slight positive anomaly in Europium (Figure 4(b)).

Research into the geotectonic environment of the Kéniéba dolerites, through different diagrams, shows that the Kéniéba dolerites belong to the late to post-orogenic intracontinental domain in a compressive to distensive context of the volcanic arc type on the edge of the continent [17] [18] (Figure 5(a)) and correspond to within-plate basalts ( [19] Figure 5(b)).

The statistical analysis of the relationships between chemical elements in dolerites required the use of principal components analysis or PCA [20] [21] . Regarding the major elements, the data matrix consists of eleven variables: SiO₂, Al₂O₃, Fe₂O₃, MgO, CaO, Na₂O, K₂O, TiO₂, P₂O₅, MnO, Cr₂O₃. The principal components were calculated from a correlation matrix. In the case of correlations, the most significant are displayed in bold (Table 3). The correlation matrix

gives a first idea of the existing associations between the different variables. Thus, we note the following correlations (Table 3).

- Strong positives correlations (0.9) between: Fe₂O₃ and TiO₂, P₂O₅; MgO and Cao, Cr₂O₃; K₂O and MnO; TiO₂ and P₂O₅;

- Strong negatives correlations (<−0.9) between: Fe₂O₃ and MgO, CaO, Cr₂O₃; MgO and TiO₂; TiO₂ and Cr₂O₃.

The correlation matrix indicates a strong correlation between: TiO₂ and P₂O₅; Na₂O and SiO₂; MgO and Cr₂O₃; MnO and K₂O; TiO₂ and Cr₂O₃ (Figure 6).

4.3. Structural Characterization of the Doleritic Dikes of Kéniéba

The establishment of West African dolerite dikes can be associated with the opening (rifting) of the Atlantic Ocean, on the one hand, and on the other hand, with late to post-Eburnean distensions [22] [23] . From the aeromagnetic image of Kéniéba, dolerites appear in the form of a network of lineaments affecting Birimian units, as well as intrusions and sedimentary covers (Neoproterozoic), (Figure 7).

The color contrast on the magnetic map draws a boundary between the two domains, and highlights the numerous dikes of basic rocks (grouped under the generic name of dolerites) in the form of lineaments.

A combination of airborne photo-geological and geophysical images (magnetic, electromagnetic, and radiometric) made it possible to trace major tectonic structures [24] . The interpretation of the map sheets shows an orientation of the major faults following a NW-SE direction with its different branches which are N-S, NE-SW, and E-W along which the dikes of a basic nature are set up. And it must be remembered that the kimberlites are arranged in a WNW-ESE orientation.

Three main directions frequently appear WNW-ESE, E-W, NE-SW for doleritic dikes which coincide with major fractures. The last two directions are the majority among which the almost E-W orientations are intersected by those of submeridian direction; which suggests different tectonic episodes [22] [24] [25] [26] .

The general interpretation of the different structural features of the aeromagnetic map made it possible to develop a synthetic structural model (Figure 8 [24] ). This model, whose major axis in the shape of a horse’s tail is oriented NE-SW, defines a set of dextral and sinistral faults. The correlative analysis of the spatial distribution of diamondiferous and non-diamondiferous dolerite and kimberlite samples collected in the study area, with the interpreted structures (Figure 8), shows that they are mainly located in fault zones.

5. Discussion

The study of doleritic rocks in the Kéniéba region was carried out in two stages during which we carried out an analysis of lithogeochemical (petrography and

petrology) and structural data. The results of the analysis during this study show similar values for dolerites located in the field of influence of kimberlites. Only one sample taken outside the field of influence of the kimberlites (DOL-3B) presents relatively low contents of major elements and certain rare earths compared to the others. Thus, we can retain the idea of partial mantle fusion at relatively high pressures. The kimberlites appear in the form of explosions in the dolerites which supposes that the dolerite dikes were already in place at the time of the intrusion of these kimberlites. The ascent of kimberlite magma enriched in certain major elements (TiO₂, Fe₂O₃, CaO and Zr) creates metasomatism in contact with dolerite with enrichment of these major elements at the level within the limits of the zones of influence of the kimberlites; as noted in Russia [11] . We do not notice any significant difference between the major elements in the dolerites located in the field of influence of the kimberlites unlike those located outside the field of influence. These dolerites are chemically enriched than those of the Birimian of Toumodi in Côte d’Ivoire [8] and those of Burkina Faso [27] . Therefore dolerites enriched in TiO₂, Fe₂O₃, CaO and Zr can be used in the Kéniéba area as a search criterion for kimberlite.

The reinterpretation of the aeromagnetic data highlighted three types of structures according to their direction, filled by dolerite dikes. Several generations of dolerites are each represented by a privileged direction. Among the three types of direction, we generally have East-West, NE-SW, WNW-ESE. This last direction corresponds to those that can be observed for the dolerite dikes in the southwest of Côte d’Ivoire [28] and those of Birimian in the north of Burkina Faso [27] .

The age of doleritiques intrusions is associated with tectono-magmatic events that appeared on the African plate at the time of the dislocation of Gondwana. Among these events, we note that which occurred in the Jurassic which saw the establishment of large swarms of dolerites oriented following NE-SW which appear on maps of the region [23] [29] [30] [31] [32] . The lineaments constitute networks of dikes following the WNW-ESE direction which are Cretaceous and which control the Kéniéba kimberlites. Elsewhere in the country, dolerites dating from the Carboniferous appear like those of the Taoudéni basin represented by E-W directions.

It is accepted that the kimberlites in this area are younger than the doleritic dikes they cross. However, the dating work of kimberlites using the Rb/Sr method on phlogopite showed an age of 1070 Ma for the Sékonomata pipe [33] ; which seems improbable when referring to the position of the kimberlites which intrude the dolerites. The significance of such an age could probably lie in contamination [34] .

Furthermore, we do not have recent dating concerning the kimberlites, however, elements of information could be provided by a more precise knowledge of the positions respective kimberlites and dolerites [35] . Kobato’s pipe, located on the Neoproterozoic plateau, is crossed by a dolerite dyke. It is the same for that of Bilali North in the Birimian plain. It’s necessary therefore admit, that at least these pipes predate the doleritic intrusions, at least to those of supposed age Middle or upper Cretaceous.

6. Conclusion

Post-Neoproterozoic dolerites from the Kéniéba region (Western Mali) are often associated with kimberlite pipes. They are tholeiitic in nature, of the E-MORB type and are more enriched in titanium than the Birimian dolerites of Toumodi, in central Côte d’Ivoire. These dolerites would have formed in a late to post-orogenic intracontinental context during the dislocation of Gondwana, according to the pre-rifting period of the Atlantic Ocean. Structurally, Kéniéba dolerites are often associated with kimberlite pipes, fractures and large deep structures identified using aeromagnetic images. Given the fact that the Kéniéba kimberlites are difficult to observe in the field, the study of certain dolerites can be a helping tool and an indicator in the search for kimberlites in the region.

Acknowledgements

This study was initiated as part of the thesis of Mr. Traore Baco at the Polytechnic Doctoral School of INP-HB in Yamoussoukro, Côte d’Ivoire.

Funding

Thanks to funding (for the field works) from the Eureka GEO Consulting Company of Bamako (Republic of Mali).

Conflicts of Interest

The authors declare no conflicts of interest regarding the publication of this paper.

Cite this paper

Ouattara, G., Traore, B., Siagné, Z.H., Denon, A., Sangare, S. and Allialy, M.E. (2024) Petrology and Structural Characterization of Post-Neopro- terozoic Dolerites from the Kimberlite Fields in the Kéniéba Region (Western Mali). Open Journal of Geology, 14, 655-670. https://doi.org/10.4236/ojg.2024.146028

References1

Dalrymphe, G.B., Gromme, C.S. and White, R.W. (1975) Potassium-Argon Age and Paleomagnetism of Diabase Dikes in Liberia: Initiation of Central Atlantic Rifting. GSA Bulletin, 86, 399-411. https://doi.org/10.1130/0016-7606(1975)86<399:PAAPOD>2.0.CO;2

Bardet, M.G. (1974) Géologie du Diamant, Deuxième Partie: Gisements de Diamant d’Afrique. Mémoires du B.R.G.M., 229 p.

Feybesse, J.-L., Billa, M., Guerrot, C., Duguey, E., Lescuyer, J.L., Milési, J.P. and Bouchot, V. (2006) The Palaeoproterozoic Ghanaian Province. Geodynamic Model and Ore Controls, Including Regional Stress Modelling. Precambrian Research, 149, 149-196. https://doi.org/10.1016/j.precamres.2006.06.003

Bassot, J.P. (1966) Etude géologique du Sénégal oriental et de ses confins Guinéo-Maliens. Mém. B.R.G.M., No. 40, 332 p.

Klöckner Industrie (1989) Etude géologique des fenêtres protérozoïques inférieures du secteur du projet (Kayes, Kenieba). Rapp. Techn., DNGM, Bamako, n° 1372.

Bessoles, B. (1977) Géologie de l’Afrique: Le Craton Ouest Africain. Mém. BRGM, No. 88, 403 p.

Milési, J.P., Feybesse, J.L., Ledru, P., Dommanget, A., Ouédraogo, M.F., Marcoux, E., Prost, A.E., Vinchon, C., Sylvain, J.P., Johan, V., Tegyey, M., Calvez, J.Y. and Lagny, Ph. (1989) Les minéralisations aurifères de l’Afrique de l’Ouest. Leur évolution lithostructurale au Protérozoïque inférieur. Chronique de la Recherche Minière, 497, 3-98.

Coulibaly, I. (2018) Pétrologie des volcanites et des plutonites du sud du sillon birimien de Toumodi-Fetekro (Côte d’Ivoire): Implications petrogénétique et tectonique. Thèse de Doctorat, Université Félix Houphouët-Boigny, Cocody-Abidjan, 218 p.

Irvine, T.N. and Baragar W.R.A. (1971) A Guide to the Chemical Classification of the Common Volcanic Rocks. The Canadian Journal of Earth Sciences, 8, 523-548. https://doi.org/10.1139/e71-055

Tomshin, M.D. Kopylova, A.G. and Gogoleva, S.S. (2019) Middle Paleozoic Basites of the Nakyn Kimberlite Field. IOP Conference Series: Earth and Environmental Science, 362, Article ID: 012066. https://doi.org/10.1088/1755-1315/362/1/012066

Tomshin, M.D. and Gogoleva, S. (2020) Behavior of TiO2 in Dolerits as a Possible Search Sign for Kimberlites. IOP Conference Series: Earth and Environmental Science, 609, Article ID: 012073. https://doi.org/10.1088/1755-1315/609/1/012073

Miyashiro, A. (1974) Volcanic Rock Series in Island Arcs and Active Continental Margins. American Journal of Science, 274, 321-355. https://doi.org/10.2475/ajs.274.4.321

Winchester, J.A. and Floyd, P.A. (1977) Geochemical Discrimination of Different Magma Series and Their Differentiation Product Using Immobile Elements. Chemical Geology, 20, 325-343. https://doi.org/10.1016/0009-2541(77)90057-2

Pearce, J. (1996) A User’s Guide to Basalt Discrimination Diagrams. In: Wyman, D.A., Ed., Trace Element Geochemistry of Volcanic Rocks: Applications for Massive Sulfide Exploration, Geological Association of Canada, St. John’s, Short Course Notes, Vol. 12, 79-113.

McDonough, W.F. and Sun, S.S. (1995) The Composition of the Earth. Chemical Geology, 120, 223-253. https://doi.org/10.1016/0009-2541(94)00140-4

Anders, E. and Grevesse, N. (1989) Abundances of the Elements: Meteoritic and Solar. Geochimica et Cosmochimica Acta, 53, 197-214. https://doi.org/10.1016/0016-7037(89)90286-X

Cabanis, B. and Lecolle, M. (1989) Le diagramme La/10-Y/15-Nb/8: Un outil pour la discrimination des séries volcaniques et la mise en évidence des processus de mélange et/ou de contamination crustales. Comptes Rendus de l’Académie de Sciences de Paris, Série II, 309, 2023-2029.

Saccani, E. (2015) A New Method of Discriminating Different Types of Post-Archean Ophiolitic Basalts and Their Tectonic Significance Using Th-Nb and Ce-Dy-Yb Systematics. Geoscience Frontiers, 6, 481-501. https://doi.org/10.1016/j.gsf.2014.03.006

Pearce, J.A. and Norry, M.J. (1979) Petrogenetic Implications of Ti, Zr, Y, and Nb Variations in Intrusive Rocks. Contributions to Mineralogy and Petrology, 69, 33-47. https://doi.org/10.1007/BF00375192

Dray, S. and Dufour, A.B. (2007) The ade4 Package: Implementing the Duality Diagram for Ecologists. Journal of Statistical Software, 22, 1-20. https://doi.org/10.18637/jss.v022.i04

Dufour, A.B. (2009) Fiche TD avec le logiciel R: Course 2. Principal Component Analysis (PCA). 17 p. http://pbil.univ-lyon1.fr/R/pdf/course2.pdf

Wenmenga, U., Kecir, M. and Affaton, P. (2009) Distribution des filons de dolérite d’après les interprétations géologiques de données aéromagnétiques et leur signification géodynamique. Bulletin du Service Géologique National de l’Algérie, 20, 245-261.

Jessell, M.W., Begg, G.C. and Miller, M.S. (2016) The Geophysical Signatures of the West African Craton. Precambrian Research, 274, 3-24. https://doi.org/10.1016/j.precamres.2015.08.010

Traoré, B., Ouattara, G., Allialy, M.E., Wane, O., Ndam-Njikam, M.M., Koné, A.Y. and Sangaré, S. (2023) Aeromagnetic Imagery as a Tool to Help Identify the Structures Controlling the Emplacement of the Kenieba Kimberlite Pipes (Western Mali, West African Craton). Open Journal of Geology, 13, 1177-1194. https://doi.org/10.4236/ojg.2023.1311050

Wenmenga, U. and Affaton, P. (2008) Igneous Structures, Deformation and Contact Metamorphism Associated with the Emplacement of Boussouma Dolerite Dyke (Burkina Faso, West-African Craton). Bulletin du Service Géologique de l’Algérie, 19, 3-16.

Diallo, M., Baratoux, L., Dufréchou, G., Jessell, M.W., Vanderhaeghe, O., Lyb, S. and Baratoux, D. (2020) Structure of the Paleoproterozoic Kédougou-Kenieba Inlier (Senegal-Mali) Deduced from Gravity and Aeromagnetic Data. Journal of African Earth Sciences, 162, Article ID: 103732. https://doi.org/10.1016/j.jafrearsci.2019.103732

Tapsoba, B., Lo, C.-H., Wenmenga, U., Iizuka, Y., Chung, S.-L. and Shellnutt, G. (2018) Chemical and Sr-Nd Compositions and 40Ar/39Ar Ages of NW-Trending Dolerite Dikes of Burkina Faso: Evidence for a Mesoproterozoic Magmatism in the West African Craton. Geoscience Frontiers, 9, 1957-1980. https://doi.org/10.1016/j.gsf.2017.12.015

Papon, A. (1973) Géologie et minéralisations du Sud-Ouest de la Côte-d’Ivoire. Mém. BRGM, No. 80, 284 p.

Morel, S.W. (1979) The Geology and Mineral Resources of Sierra Leone. Economic Geology, 74, 1563-1576. https://doi.org/10.2113/gsecongeo.74.7.1563

Deckart, K., Féraud, G. and Bertrand, H. (1997) Age of Jurassic Continental Tholeiites of French Guyana, Surinam and Guinea: Implications for the Initial Opening of the Central Atlantic Ocean. Earth and Planetary Science Letters, 150, 205-220. https://doi.org/10.1016/S0012-821X(97)00102-7

Jessell, M., Santoul, J., Baratoux, L., Youbi, N., Ernst, R.E., Metelka, V., Miller, J. and Perrouty, S. (2015) An Updated Map of West African Mafic Dykes. Journal of African Earth Sciences, 112, 440-450. https://doi.org/10.1016/j.jafrearsci.2015.01.007

Baratoux, L., Söderlund, U., Ernst, R.E., de Roever, E., Jessell, M., Kamo, W.S., Naba, S., Perrouty, S., Metelka, V., Yatte, D., Grenholm, M., Diallo, D.P., Ndiaye, P.M., Dioh, E., Cournède, C., Benoit, M., Baratoux, D., Youbi, N., Rousse, S. and Bendaoud, A. (2019) New U-Pb Baddeleyite Ages of Mafic Dyke Swarms of the West African and Amazonian Cratons: Implication for Their Configuration in Supercontinents through Time. In: Srivastava, R.K., Ernst, R.E. and Peng, P., Eds., Dyke Swarms of the World: A Modern Perspective, Springer, Singapore, 263-314. https://doi.org/10.1007/978-981-13-1666-1_7

Bardet, M. G. and Vachette, M. (1966) Détermination d’âges de kimberlites de l’ouest africain et essai d’interprétation des datations des diverses venues diamantifères dans le monde. BRGM Rapport inédit, DS 66 A 59, 15 p.

Pouclet, A., Allialy, M., Daouda-Yao, B. and Esso, B. (2004) Découverte d’un diatrème de kimberlite diamantifère à Séguéla en Côte-d’Ivoire. C. R. Geoscience, 336, 9-17. https://doi.org/10.1016/j.crte.2003.10.012

Chirico, P.G., Barthélémy, F. and Koné, F. (2010) Les ressources potentielles en diamants alluviaux et l’évaluation de la capacité de production du Mali. U.S. Geological Survey, B.R.G.M. (France), DNGM (Mali), Scientific Investigations Report 2010-5044, 26 p. https://pubs.usgs.gov/sir/2010/5044/french/pdf/sir2010-5044_french.pdf