Petrology and Au-PGE investigation dataset of the recent alluvial sediments from the Ngaye River watershed, northern Cameroon

Abstract

Petrological data of the recent alluvial sediments from the Ngaye River watershed in the Northern Cameroon were used in order to infer their origin with the probable source rocks as gneisses, amphibolites, and granites; and to investigate the occurrence of precious metals like Gold and Platinum Group Elements (Au-PGE). The Ngaye River watershed is located in the Adamawa plateau from the Adamawa-Yade Domain (AYD) in the Central Cameroon, Central Africa. This region is characterized by two contrasted seasons which induce a savanna vegetation cover with gallery forests along the rivers. The field works were done during the dry season. During this season, several whole fractions of sediments were sampled at six vertical lithological sequences along the right terrace of the Ngaye Rivers. The selection of samples was linked to their grain size and color. To better understand the origin of sediments, twenty-one rock samples (gneisses, amphibolites, and granites) were also collected. The grain size distribution was done using the Robinson's standard Pipetting Method. Thin sections were done for the determination of mineral assemblages and textural features of rocks using Leica DM 750P optic microscope. Mineralogical compositions of sediments were obtained using the X-ray diffraction (XRD) instrument. The major elements data were determined using the X-ray Fluorescence spectrometry (XRF). The Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) was used to obtain the concentrations of trace elements including rare earth elements and Au-PGE. The investigation of Au-PGE was done only in amphibolites as well as in the concentrate heavy minerals (160–100 µm) from sediments of lithological sequence A. Data of this paper are further presented and discussed in Ndjigui et al. [1].