Relations between structural geomorphology and lithology in the Nkogam plutovolcanic complex (Cameroon Line).

Autor: Kenzo, Henri Appolinaire, Metang, Victor, Segue, Willy Stephane, Tchop, Legrand Joseph, Mouafo, Lucas, Mbakam, Diane Marilyn Nkamga, Tchouankoué, Jean Pierre, Njonfang, Emmanuel, Kamgang, Pierre
Zdroj: Arabian Journal of Geosciences; May2022, Vol. 15 Issue 9, p1-17, 17p
Abstrakt: Brittle deformation and geomorphological studies were carried out to better understand the morphostructure and spatial distribution of rocks of the Nkogam anorogenic complex, located between 5° 35′ 52″ and 5° 47′ 20″ N and 10° 37′ 16″ and 10° 48′ 37″ E. The objective of this study is to correlate the distribution of the main petrographic units with the orientations of major regional fractures and understand the shape of the Nkogam massif. The methodology used to enhance the quality of the images and the extraction of lineaments are pre-processing and processing, performed with Erdas Images 2014. The data used are SRTM and Landsat 8 OLI images acquired by satellites on December 29, 2018. The results highlight a U-shaped form and a central depression that opens to the SW. Major lineaments directions are NE-SW and ENE-WSW which are respectively similar to that of the Cameroon Line and Central Cameroon Shear Zone. However, a fault corridor oriented N170°E cuts across massive basalts, ignimbrites, and granites. The emplacement of all the rocks in the field indicates the following relative chronology: older Pan-African gneissic basement, plateau basalts, granites, syenogranites, ignimbrites, and massive basalts. Granites and syenogranites, then ignimbrites and basalts, cut through the Pan-African basement in three mountain ranges among which two are roughly parallel, one oriented NNE-SSW and the other oriented NE-SW. All these directions locally represent the N070°E-trending Adamawa shear zone on a regional scale. Volcanites overlap plutonites at the northeastern end of the Nkogam anorogenic complex giving the U-shaped form to the massif. This study helps to understand the subcircular shape of the Nkogam massif bearing a central depression and the major directions of the lineaments in order to compare them to similar massifs along the Cameroon Line and elsewhere. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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