Regional Geochemical Stream Sediment Survey for Gold Exploration in the Upper Lom Basin, Eastern Cameroon

Abstract

Stream sediments are widely employed in reconnaissance exploration for gold especially in areas where outcrops are scarce and the overburden thick such as in the eastern Cameroon goldfields. In this study, 337 stream sediment samples were collected from the Lom river drainage basin. The study aims at identifying the main geological processes affecting the geochemical data from the sediments by considering the multi-elements relationships and spatial features of single elements. The samples were collected in duplicate. One set was panned, gold grains picked and weighed while the second set was wet sieved and the ≤100 microns size fraction retained. This fraction was eventually analyzed for gold by fire assay and a suite of elements by inductively coupled plasma mass spectrometry (ICP-MS). Single element maps were constructed using ArcGIS and the relationship between elements measured using Pearson correlation and principal component analysis (PCA). Gold concentrations in the samples are erratic, most below the detection limit and attain a high of 450 ppm. Five factors are derived from the PCA including single element factors for As and Au reflecting bedrock-hosted mineralization. The Cu-Zn-Y-Nb-Pb factor suggests sulphide mineralization perhaps related to felsic intrusions while the Sr-Ba-La-Ce-Zr factor is linked to lithologic control. These results demonstrate the usefulness of multi-element analysis and data interpretation using GIS tools in the exploration efforts for gold worldwide.

Regional Hydrogeochemical Mapping for Environmental Studies in the Mineralized Lom Basin, East Cameroon: A Pre-industrial Mining Survey

“…This single variable correlated with the presence of sulphide bearing minerals and gold deposits. Gold occurs as quartz veins associated with vug-filling early pyritization in the Lom Basin [9]. …”

“…Also, it has a long artisanal and semimechanized mining history and is currently a target for industrialized mining. Consequently, research reporting the rock type, age, and the formation history or the reconnaissance gold investigations in this region are numerous [6][7][8][9]. Despite this extensive coverage, there is no available data on the chemical composition of streamwater required to establish quality criteria for water in the area.…”

Seasonal Hydrological Inputs of Major Ions and Trace Metal Composition in Streams Draining the Mineralized Lom Basin, East Cameroon: Basis for Environmental Studies

“…The negative contribution of Zn suggests no co-precipitation effect of Fe on it. In contrast, Mn plays a major role in scavenging As in F2 which represents a different phase of mineralization (Omang et al 2014). Also, Mn hydroxides have been reported to precipitate at high pH than Fe (Siegel 2002) which implies that Fe and Mn scavenge at different pH of streamwater within the Lom Basin.…”

“…This seasonal variability suggests that diverse geological and geochemical conditions probably govern the observed drainage signatures (Omang et al 2014). Concentrations of Cl -, which is of anthropogenic origin , were invariable throughout the sampling seasons (Table 1) due to its conservative nature and limited potential sources (Grasby et al 1997;Garizi et al 2011).…”

Geochemical investigation of stream sediments from the nlonako area; littoral, Cameroon: implications for Au, Ag, Cu, Pb and Zn mineralization potentials

“…The use of stream sediments in mineral exploration in Cameroon has so far received little attention. However some examples include Embui et al, (2013), Soh et al, (2014), Mumbfu et al, (2014) and Omang et al, (2014). These works have investigated the concentrations of gold and associated elements in stream sediment in some areas of Cameroon with some giving clues on future exploration guides (e.g.…”