TITLE:
Mineralogy and Texture of the Weathered Products from Silicic Lavas in the Sabga Area, North West Cameroon
AUTHORS:
Edith Etakah Bate Tibang, Gideon Anoma Waji, Elisha Mutum Shemang, Cheo Emmanuel Suh
KEYWORDS:
Mineralogy, Texture, SEM, Clay
JOURNAL NAME:
International Journal of Geosciences,
Vol.12 No.6,
June
30,
2021
ABSTRACT: Products of weathering usually clay minerals, are commonly characterized
through mineralogical, chemical and geochemical analysis, emphasizing their
implications in industrial applications, initiation of landslides and their
impact on surface water geochemistry. In this study the vertical variations in
textural characteristics and clay mineral type within weathered profiles in the
Sabga area were investigated. Two exposed weathered profiles were logged from
bed rock to topsoil and each horizon was sampled
separately. Granulometric analysis on the samples indicated mixtures of clay,
silt and sand size particles in all horizons. Smectite and kaolinite were
identified by X-ray diffractometry (XRD) and scanning electron microscopy
(SEM). The two logs show that the lower horizons display whitish colors with
fine laminations, middle horizons are brownish and the upper horizons display
dark brown colors. Graphic mean values for both sections gave values that range
between 2.02 - 3.7f with an average standard deviation value of 1.9f, indicating that the grains are poorly sorted sand, silt and clay. SEM
micrographs show laths of smectite in the lower horizons, flakes of
kaolinite and laths of smectites in the middle horizons while the upper
horizons show flakes of kaolinite with microlites of quartz + feldspars. XRD
patterns show broad basal reflections for kaolinite at 2θ 36.8° (3.15 ?),
smectite at 2θ 33.5° (3.34 ?),
both contaminated with quartz at 2θ 36.5° (3.32 ?) typical for these minerals.