{"title":"Morphometry of the Mt Manengouba volcano: Insights into tephrostratigraphy of Eboga maars (South West Cameroon)","authors":"","doi":"10.1016/j.jafrearsci.2024.105411","DOIUrl":null,"url":null,"abstract":"<div><p>The GIS-based geomorphological and morphometric approaches were combined with field- and tephrostratigraphic analyses to reconstruct the history of the Mt Manengouba volcano including the Eboga maars in the southwestern part of the Cameroon Volcanic Line (CVL). The elevation, slope, relative relief, topographic position and terrain ruggedness indexes from the Digital Elevation Model (DEM, 12.5 m) were determined to constrain two main geomorphic units corresponding to the Elengoum and Eboga nested stratovolcanoes which were affected by differential erosional processes. The studied grain size, shape, vesicularity, structure, degree of lithification, sorting, thickness, grading patterns, sedimentary features, spatial distribution revealed three tephrostratigraphic units: U1 (U<sub>1-1</sub>, lithic and juvenile; U<sub>1-2</sub> dominantly juvenile), U2 (U<sub>2-1</sub> ash- and juvenile rich-deposits; U<sub>2-2</sub>, juvenile-scoria with few lithic) and U3 (scoria cone deposits). The total volume of ∼0.199 km<sup>3</sup> of tephra deposits ranges the Eboga maars volcanoes within the small-volume monogenetic types. These results revealed dry/wet phreatomagmatism and strombolian activity as a contribution to the seven phases-eruptive history of the Mt Manengouba volcano: the pre-Manengouba; emplacement of Elengoum stratovolcano; collapse of Elengoum summit and formation of Elengoum caldera; emplacement of Eboga stratovolcano; the collapse of Eboga summit and formation of Eboga caldera; a phreatomagmatic phase and emplacement of Female and Male maars ending with an explosive stage associated with the formation of scoria and parasitic cones.</p></div>","PeriodicalId":14874,"journal":{"name":"Journal of African Earth Sciences","volume":null,"pages":null},"PeriodicalIF":2.2000,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S1464343X24002449/pdfft?md5=cddc54edcbceda16270840a00e77c8f5&pid=1-s2.0-S1464343X24002449-main.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of African Earth Sciences","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1464343X24002449","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"GEOSCIENCES, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
The GIS-based geomorphological and morphometric approaches were combined with field- and tephrostratigraphic analyses to reconstruct the history of the Mt Manengouba volcano including the Eboga maars in the southwestern part of the Cameroon Volcanic Line (CVL). The elevation, slope, relative relief, topographic position and terrain ruggedness indexes from the Digital Elevation Model (DEM, 12.5 m) were determined to constrain two main geomorphic units corresponding to the Elengoum and Eboga nested stratovolcanoes which were affected by differential erosional processes. The studied grain size, shape, vesicularity, structure, degree of lithification, sorting, thickness, grading patterns, sedimentary features, spatial distribution revealed three tephrostratigraphic units: U1 (U1-1, lithic and juvenile; U1-2 dominantly juvenile), U2 (U2-1 ash- and juvenile rich-deposits; U2-2, juvenile-scoria with few lithic) and U3 (scoria cone deposits). The total volume of ∼0.199 km3 of tephra deposits ranges the Eboga maars volcanoes within the small-volume monogenetic types. These results revealed dry/wet phreatomagmatism and strombolian activity as a contribution to the seven phases-eruptive history of the Mt Manengouba volcano: the pre-Manengouba; emplacement of Elengoum stratovolcano; collapse of Elengoum summit and formation of Elengoum caldera; emplacement of Eboga stratovolcano; the collapse of Eboga summit and formation of Eboga caldera; a phreatomagmatic phase and emplacement of Female and Male maars ending with an explosive stage associated with the formation of scoria and parasitic cones.
期刊介绍:
The Journal of African Earth Sciences sees itself as the prime geological journal for all aspects of the Earth Sciences about the African plate. Papers dealing with peripheral areas are welcome if they demonstrate a tight link with Africa.
The Journal publishes high quality, peer-reviewed scientific papers. It is devoted primarily to research papers but short communications relating to new developments of broad interest, reviews and book reviews will also be considered. Papers must have international appeal and should present work of more regional than local significance and dealing with well identified and justified scientific questions. Specialised technical papers, analytical or exploration reports must be avoided. Papers on applied geology should preferably be linked to such core disciplines and must be addressed to a more general geoscientific audience.