Abstract

Mbalangi and its environs are found in the northern portion of Douala basin. This area was studied with the aim of mapping the study area. Some of the methods used in the field include surface traversing.

It consists of two formations; the Mundeck and the Mungo formations. The Mundeck formation rest on the Pre-Cambrian basement rock. It is characterized by basal unconsolidated sandstones succession with fining upward cycles and intercalation of mudstones. Some sandstone beds consist of mud pockets and cross-structures.

This succession is overlain by the younger Mungo formation consisting principally of sandstones with intercalations of limestones, presence of dark shale (in some cases). Other parts of the formation are characterized by marls, coal, conglomerates.

A few basalts are in some part of the studied area. The rocks in the Mundeck formation were not fossilized while those of the Mungo Formation are fossilized. The fossilize rocks in the Mungo formation are principally Limestone and shale and the fossils were basically mould and cast. The shale, marl and limestone were generally dark in colour while the mudstones and sandstones were grey and brownish in colour respectively.

The sandstones vary from fine to very coarse grains while the mudstones were medium to fine grain. The cretaceous Clastic sediments have been interpreted as deposits of a fluviatile environment of deposition while limestone and shale have been interpreted as deposits of a marine environment of deposition.

Some structures such as layering, lamination, cross bedding amongst others were encountered in some outcrops. The   Access to outcrops was mainly by foot and most of the outcrops are found along river, banks, railway cuts and farms.

The outcrops encountered were studied; samples collected and well labeled then put in sample bags. Sieve analysis of some sandstone samples were being carried out in the laboratory and the result revealed that most of the samples were transported by rivers and streams and the shape of the grains reveal that they are deposited not far from their source.

The sandstones are not good reservoir rocks because they are poorly sorted. Some of the shale encountered in the field contains some fossils in them and were dark in colour thus can be potential source rocks for petroleum.

General Introduction

Geology is the study of the earth, structure, composition and history. It deals with the processes that shaped the earth of the past and those that continue to mold the present earth.

Field geology (GLY 498) course carried out by level 400 students in the Department of geology at the University of Buea as a partial fulfillment of the requirements for the award of a Bachelor of Science (B.Sc) degree in geology.

It enables students to better understand and analyze geological features in the field .This project involves identification and description of geologic features and structures, determination of their locations using Global positioning system (GPS) and distribution of the different rock type as well as locating them on a geologic map, and finally collecting and correctly labeling samples for further studies in the laboratory. It is the only twelve credit value course and therefore it is of prime interest to students.

The work was done for about ten (10) working days resulting to different logs and lithology drawn from the field.

Aspects like graphs, histograms and pie charts were plotted from the data obtained. The results were interpreted by the use of granulometric and geochemical analysis, pictures inserted were necessary and different maps produced independently.

Outcrops encounter in the area were mainly along river channels notably, the Ediki and Kendonge river and their tributaries and other exposures in farmlands.  Some of the samples in this area were seen containing fossils especially in the limestones and shales. The fossils are bivalves, moulds and casts. Faults were also observed.

Objectives Of The Field Work

1. a) Main Objective

To map the study area which include Mbalangi and Ediki.

1. b) Specific Objectives

In order to achieve the main objectives, proper use of some geological equipment such as compass clinometers, global positioning system (GPS) and geologic hammer was implemented. Also some samples were described in hand specimen in terms of the grain size and texture.

The main objective can be attained through the application of methods related to obtain field data and interpretation. A description of features such as faults, laminations, some fractures and pot holes.

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