Petrogenesis and geodynamic environment of the Recent pyroclastic deposits from Baïgom and Petpenoun volcanoes of the Noun Plain, Cameroon Volcanic Line, Central Africa
This study presents petrography, mineral chemistry, whole-rock major and trace elemental systematics for Recent pyroclastic deposits from volcanic edifices of Baïgom and Petpenoun, located in the Noun Plain graben along the Cameroon Volcanic Line (CVL), Central Africa, to better understanding their...
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| Format: | Article |
| Language: | English |
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Elsevier
2023-11-01
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| Series: | Geosystems and Geoenvironment |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2772883823000365 |
| _version_ | 1827803615459278848 |
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| author | Luc Achille Ziem A Bidias Mekala Ram Mohan N.V. Chalapathi Rao Amidou Moundi |
| author_facet | Luc Achille Ziem A Bidias Mekala Ram Mohan N.V. Chalapathi Rao Amidou Moundi |
| author_sort | Luc Achille Ziem A Bidias |
| collection | DOAJ |
| description | This study presents petrography, mineral chemistry, whole-rock major and trace elemental systematics for Recent pyroclastic deposits from volcanic edifices of Baïgom and Petpenoun, located in the Noun Plain graben along the Cameroon Volcanic Line (CVL), Central Africa, to better understanding their petrogenesis and geodynamic environment. The samples are mainly ash, lapilli and scoria, belonging to two different magmatic series: an alkaline series and a sub-alkaline series. Petrographic and mineralogical evidence in alkaline samples show a common crystallizing mineral assemblage of olivine, clinopyroxene and/or plagioclase, scattered in a fine-grained to glassy matrix. Clinopyroxene occurs in variable sizes, and includes megacrysts, which show either little or strong zonation, and thus represent different processes. The large, unzoned crystals provide clear evidence for prolonged magma chamber processes involving high and near-constant melt/Clinopyroxene ratios. The megacryst abundances are interpreted as crystal accumulation. The thermobarometry results in alkaline samples provide temperatures of 1188–1267 °C and pressure estimates in the range of 10.3–23.8 kbar. All the Recent pyroclastic deposits display high (La/Yb)N (11.20–20.35) and (Tb/Yb)N ratios (1.93–2.64), suggesting that their parental magmas originated from partial melting in the garnet-bearing mantle zone, at a depth > 80 km. The near-constant Ce/Y (3.14–3.76) and the higher Zr/Nb (5.85–10.71) ratios in sub-alkaline lava samples adequately fit with derivation of the magmas from a melt column extending across the garnet-spinel transition zone. Our results suggest two distinct origins for Recent pyroclastic samples from volcanic edifices of Baïgom and Petpenoun and imply an underlying heterogeneous mantle source beneath the CVL. |
| first_indexed | 2024-03-11T20:56:58Z |
| format | Article |
| id | doaj.art-a0e5d133c05d45968c1b1338e85604a7 |
| institution | Directory Open Access Journal |
| issn | 2772-8838 |
| language | English |
| last_indexed | 2024-03-11T20:56:58Z |
| publishDate | 2023-11-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Geosystems and Geoenvironment |
| spelling | doaj.art-a0e5d133c05d45968c1b1338e85604a72023-09-30T04:55:51ZengElsevierGeosystems and Geoenvironment2772-88382023-11-0124100213Petrogenesis and geodynamic environment of the Recent pyroclastic deposits from Baïgom and Petpenoun volcanoes of the Noun Plain, Cameroon Volcanic Line, Central AfricaLuc Achille Ziem A Bidias0Mekala Ram Mohan1N.V. Chalapathi Rao2Amidou Moundi3Geology Laboratory, Higher Teacher Training College, University of Yaounde 1, PO Box 047, Yaounde, Cameroon; Geochemistry Division, CSIR-National Geophysical Research Institute, Uppal Road, Hyderabad 500007, Telangana, India; Corresponding author.Geochemistry Division, CSIR-National Geophysical Research Institute, Uppal Road, Hyderabad 500007, Telangana, IndiaCentre of Advanced Study in Geology, Institute of Science, Banaras Hindu University, Varanasi 221005, IndiaDepartment of Earth Sciences, Faculty of Science, University of Yaounde 1, PO Box 812, Yaounde, CameroonThis study presents petrography, mineral chemistry, whole-rock major and trace elemental systematics for Recent pyroclastic deposits from volcanic edifices of Baïgom and Petpenoun, located in the Noun Plain graben along the Cameroon Volcanic Line (CVL), Central Africa, to better understanding their petrogenesis and geodynamic environment. The samples are mainly ash, lapilli and scoria, belonging to two different magmatic series: an alkaline series and a sub-alkaline series. Petrographic and mineralogical evidence in alkaline samples show a common crystallizing mineral assemblage of olivine, clinopyroxene and/or plagioclase, scattered in a fine-grained to glassy matrix. Clinopyroxene occurs in variable sizes, and includes megacrysts, which show either little or strong zonation, and thus represent different processes. The large, unzoned crystals provide clear evidence for prolonged magma chamber processes involving high and near-constant melt/Clinopyroxene ratios. The megacryst abundances are interpreted as crystal accumulation. The thermobarometry results in alkaline samples provide temperatures of 1188–1267 °C and pressure estimates in the range of 10.3–23.8 kbar. All the Recent pyroclastic deposits display high (La/Yb)N (11.20–20.35) and (Tb/Yb)N ratios (1.93–2.64), suggesting that their parental magmas originated from partial melting in the garnet-bearing mantle zone, at a depth > 80 km. The near-constant Ce/Y (3.14–3.76) and the higher Zr/Nb (5.85–10.71) ratios in sub-alkaline lava samples adequately fit with derivation of the magmas from a melt column extending across the garnet-spinel transition zone. Our results suggest two distinct origins for Recent pyroclastic samples from volcanic edifices of Baïgom and Petpenoun and imply an underlying heterogeneous mantle source beneath the CVL.http://www.sciencedirect.com/science/article/pii/S2772883823000365Recent pyroclastic depositsCameroon Volcanic LinePetrogenesis and geodynamic environmentHeterogeneous mantle |
| spellingShingle | Luc Achille Ziem A Bidias Mekala Ram Mohan N.V. Chalapathi Rao Amidou Moundi Petrogenesis and geodynamic environment of the Recent pyroclastic deposits from Baïgom and Petpenoun volcanoes of the Noun Plain, Cameroon Volcanic Line, Central Africa Geosystems and Geoenvironment Recent pyroclastic deposits Cameroon Volcanic Line Petrogenesis and geodynamic environment Heterogeneous mantle |
| title | Petrogenesis and geodynamic environment of the Recent pyroclastic deposits from Baïgom and Petpenoun volcanoes of the Noun Plain, Cameroon Volcanic Line, Central Africa |
| title_full | Petrogenesis and geodynamic environment of the Recent pyroclastic deposits from Baïgom and Petpenoun volcanoes of the Noun Plain, Cameroon Volcanic Line, Central Africa |
| title_fullStr | Petrogenesis and geodynamic environment of the Recent pyroclastic deposits from Baïgom and Petpenoun volcanoes of the Noun Plain, Cameroon Volcanic Line, Central Africa |
| title_full_unstemmed | Petrogenesis and geodynamic environment of the Recent pyroclastic deposits from Baïgom and Petpenoun volcanoes of the Noun Plain, Cameroon Volcanic Line, Central Africa |
| title_short | Petrogenesis and geodynamic environment of the Recent pyroclastic deposits from Baïgom and Petpenoun volcanoes of the Noun Plain, Cameroon Volcanic Line, Central Africa |
| title_sort | petrogenesis and geodynamic environment of the recent pyroclastic deposits from baigom and petpenoun volcanoes of the noun plain cameroon volcanic line central africa |
| topic | Recent pyroclastic deposits Cameroon Volcanic Line Petrogenesis and geodynamic environment Heterogeneous mantle |
| url | http://www.sciencedirect.com/science/article/pii/S2772883823000365 |
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