NIGERIAN GEOLOGICAL SURVEY AGENCY.
By
DAVID IFEOLUWA ANDREW
U18GL1011
CONTENTS
 About NGSA/Introduction
 Skills Acquired
 Introduction
 Soil Sampling
 Equipments
 Sampling Techniques
 Results & Importance of Soil Sampling.
 Conclusion
About NGSA/Introduction
 NGSA was created under the federal ministry of solid minerals with
statutory role of providing relevant and up to date geoscientific data in
the form of maps, journals and electronic information.
 This is accomplished through many activities carried out within the
agency. These activities includes;
 Geophysical Survey
 Geochemical Sampling methods
 Geological Sampling
 Hydrogeological survey
 Remote sensing
 Map Production
 Geochronology etc
Skills Acquired
 Gravity Survey Method
 Geological Sampling
 Geochemical Sampling
 Map Production
Introduction to Geological & Geochemical
Sampling
 Sampling of minerals deposit Is an important aspect of




geochemical and Geological exploration.
A geological sample is a representative unit of a soil, rock or ore
that is selected from a large mass.
Geochemical & Geological sampling simply involves collecting and
analysing various earth materials obtained from field including
Soil, sediments, water, vegetation & rocks samples for geological
analysis.
And all these is in a bid to determine the mineralogy, composition
and grade 0f minerals.
Geochemical Sampling Types
 Stream Sampling
 Soil sampling
 Rock sampling
 Vegetation sampling. etc
Main Focus on Field
Soil sample
being bagged.
Rock Sample
Rock Sample
Soil Sampling
 Soil Sampling: is widely used in Geochemical sampling and involves
getting or collecting soil samples in field which are then analyzed in the
laboratory.
 Soil Sampling is employed mainly to outline the general distribution of
mineralization at shallow depth where outcrop of bedrocks are
minimal or non existent.
Images of part of the study area
Soil Sampling
 Desktop Research, Team talk and review of previous work, Field work;
Sampling, sorting and data compilation.
 The Soil sampling was carried out in a grid pattern to delineate the
mineralized zone which is expected to be of GOLD MINERALIZATION
and parameters considered are
 Sample spacing, Sample Horizon, Sample Fraction to be analyzed and
method of sample analysis.
 Grid Map.
Geological Map of The Sample Location Points
Equipment Used during the course of the
field work
Geological Compass
Auger
GPS Device
Geologic hammer
Soil sampling techniques
 Augering & Pitting for the soil sediments
 An auger is a simple tool usually carrying an arrow at the tip and is
used to make HOLES within the soil in order to get fresh soil
samples which are then bagged in well-labelled sample bags.
Supervision of Augering process on the field
Sampling techniques
 Pitting: involves digging pits (about 1m deep) seldomly within
the study area in order to get fresh samples and determine the
thickness of the observable horizon and also logging.
Measurements of Horizon thickness from the Pit
Results
Legend
depth(m)
description
0-0.3
Soil is loose,
fine grained
0.3-0.7
soft, white,
sand.
0.7-1.1
medium-dense
to dense soil,
with clay properties.
An Example of a soil log from one of the pits
Results
Concentration Map of the Study Area.
Discussion
 Soil sampling is a cheap and effective way of kick-starting a
mineral exploration programme over an area previously
highlighted
by
historical
mineral
occurrences,
mapping/prospecting or regional airborne geophysical
surveys.
 However, for areas which may have the potential for hosting a
large ore body, soil sampling may be followed up by a closerspaced soil sampling survey, and – if this also proves
interesting – eventual drilling.
Conclusion
 The success of the field work provided sufficient data that
would be worked on to produce quality and up to date geoscientific information about the study area.
 NGSA helped bridge the gap between what I have been
learning in class and how it can be applied on the field.
 I was able to properly appreciate geology as a professional
course and understand some of the risks associated with it.
THANK YOU FOR LISTENING…