Calistus Gentry FUH

Four Pan-African plutonic sets of the Colomines gold district (East-Cameroon): Petrogenesis, K-Ar dating and geodynamic significance

Fuh Calistus Gentry, Numbem Jacqueline Tchakounté, Okia Mukete Kundu, Joseph Legrand Tchop, Charles Nkoumbou

Journal of African Earth Sciences

• #geological and geochemical analysis
• #geochemistry and geologic mapping
• #high-pressure geophysics and materials
• #mafic

Petrography and geochemistry of sulfurous volcanic scoria from mount Cameroon area, Central Africa: Implications for Au-PGE exploration

Elisé Sababa, Fuh Calistus Gentry, Paul‐Désiré Ndjigui, Pierre Noah Onana, Djimet Tetedjima Seyoa

Journal of African Earth Sciences

• #geochemistry and geologic mapping
• #geological and geochemical analysis
• #geochemistry and elemental analysis
• #geology

Petrography and geochemistry of weathered pyroxenite boulders from Mamb, Ngong and Nkolmbong (Pan-African Yaoundé group, Cameroon): tracking the Ni, Co, Cr and Cu mineralization processes during the alteration of ultramafic rocks

Célérine Henriette Malla Noubisi, Rose Yongue-Fouateu, Fuh Calistus Gentry, Wilfried Frank Nguimatsia Dongmo, Charles Nkoumbou

Arabian Journal of Geosciences

• #geological and geochemical analysis
• #geochemistry and elemental analysis
• #geochemistry and geologic mapping
• #geology

Petrological features of volcanic scoriae from the southern part of the Cameroon Volcanic Line and their supplementary cementations application

Estelle Huguette Ngono Onana, Fuh Calistus Gentry, Paul‐Désiré Ndjigui

Heliyon

Volcanic scoriae from the southern part of the Cameroon Volcanic Line (Limbé, Loum-Tombel, Yamba, Doupé, Njinkouo, Foumbot, Manjo-manengollé, Galim and Djoungo) were investigated in order to determine their chemical and mineralogical composition, to deduce their origin and to identify their natural characteristics which may be useful to the cement industry. The mineralogical composition was determined by X-ray Diffractometer (XRD); X-ray Fluorescence (XRF) and Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) instruments provided geochemical data. In order to establish the relationship between the natural characteristics of volcanic scoriae and the properties of cements, the amount of amorphous phases was determined by dissolution using sodium hydroxide solution and the pozzolanic activity by thermogravimetric analysis. Field observations show that these rocks are basalts, basanites, hawaiites and picrobasalts. Their mineralogical composition includes augite, olivine, plagioclase, enstatite, feldspars, ettringite, portlandite and Fe–Ti minerals. Overall, they are characterized by high MgO, Fe 2 O 3 , CaO, and TiO 2 contents. The behavior of major and trace elements suggests that volcanic scoriae have an evolution dominated by partial melting. Besides, high chondrite normalized La/Yb (8–22), Tb/Yb (>1.9) and Dy/Yb (>2) values suggest that the melting corresponds to the garnet lherzolite stability field. The scoriae exhibit good pozzolanic reactivity after 28 days according to their considerable amount of amorphous phases, low CaO contents and their large specific surface area. According to ASTM C618 standard, the sum of SiO 2 , Al 2 O 3 and Fe 2 O 3 (SAI = 65.96–76.34 wt.%); LOI (-0.1–16.99 wt.%), and of CaO, Fe 2 O 3 and MgO (CIM = 23.43–34.06 wt.%) suggest that those less weathered materials seem appropriate as an additive in cement manufacture. The suitable use of volcanic scoriae in the cement industry closely depends on the petrological features of amorphous phases.

• #geological and geochemical analysis
• #geochemistry and elemental analysis
• #geochemistry and geologic mapping
• #augite

Petrology and geochemistry of the Pan-African high-K calc-alkaline to shoshonitic–adakitic Bapé plutonic suites (Adamawa-Yade block, Cameroon): evidence of a hot oceanic crust subduction

Jacqueline Numbem Tchakounté, Fuh Calistus Gentry, Aurélie Ngamy Kamwa, Victor Metang, Joseph Mvondo Ondoa, Charles Nkoumbou

International Journal of Earth Sciences

• #geological and geochemical analysis
• #geochemistry and geologic mapping
• #earthquake and tectonic studies
• #geology

Petrology, geochemistry, Ar Ar isotopes of an arc related calk-alkaline pluton from Mamb (Pan-African Yaounde group, Cameroon): A testimony to the subduction of a hot oceanic crust

Fuh Calistus Gentry, Charles Nkoumbou, Jacqueline Tchakounté Numbem, Kundu Okia Mukete, Jean Pierre Tchouankoué

Lithos

• #geological and geochemical analysis
• #geochemistry and geologic mapping
• #earthquake and tectonic studies
• #geology

Geology and geotechnical characteristics of the Gbago and Ngouaka plutonic rocks, North East of Bangui, Central Africa Republic

David Christian Vonto, Numbem Jacqueline Tchakounté, Fuh Calistus Gentry, Raoul Ludovic Zaguy-Guerembo, Philémon Zo’o Zame, S. Djanarthany et 1 autre(s)

Journal of African Earth Sciences

• #geological and geochemical analysis
• #geological and geophysical studies worldwide
• #earthquake and tectonic studies
• #geology

Petrology and geochemistry of REE-rich Mafé banded iron formations (Bafia group, Cameroon)

Charles Nkoumbou, Fuh Calistus Gentry, Jacqueline Tchakounté Numbem, Yolande Vanessa Belle Ekwe Lobé, Christin Steve Nwagoum Keyamfé

Comptes Rendus Géoscience

Archaean–Paleoproterozoic foliated amphibole-gneisses and migmatites interstratified with amphibolites, pyroxeno-amphibolites and REE-rich banded-iron formations outcrop at Mafé, Ndikinimeki area. The foliation is nearly vertical due to tight folds. Flat-lying quartz-rich mica schists and quartzites, likely of Pan-African age, partly cover the formations. Among the Mafé BIFs, the oxide BIF facies shows white layers of quartz and black layers of magnetite and accessory hematite, whereas the silicate BIF facies is made up of thin discontinuous quartz layers alternating with larger garnet (almandine–spessartine) + chamosite + ilmenite ± Fe-talc layers. REE-rich oxide BIFs compositions are close to the East Pacific Rise (EPR) hydrothermal deposit; silicate BIFs plot midway between EPR and the associated amphibolite, accounting for a contamination by volcanic materials, in addition to the hydrothermal influence during their oceanic deposition. The association of an oceanic setting with alkaline and tholeiitic magmatism is typical of the Algoma-type BIF deposit. The REE-rich BIFs indices recorded at Mafé are interpreted as resulting from an Archaean–Paleoproterozoic mineralization.

• #geological and geochemical analysis
• #earthquake and tectonic studies
• #geochemistry and elemental analysis
• #banded iron formation