INTRODUCTION TO GEOLOGY
SCOPE & APPLICATION
Dr. Thungyani N Ovung
Assistant Professor
Department of Earth and Atmospheric Sciences
NIT Rourkela
What is Geology?
Geo = Earth
Logos = Science
Geology is the study of the Earth
• the materials of which it is made
• the structure of those materials
• the processes acting upon them
It includes the study of organisms
that have inhabited our planet.
An important part of geology is
the study of how Earth's materials,
structures, processes and
organisms have changed over time.
PHYSICAL GEOLOGY
It deals with—
Different physical features of the earth, such as mountains, plateaus, valleys,
rivers, lakes, glaciers and volcanoes in terms of their origin and development.
The different changes occurring on the
earth surface like marine transgression,
marine regression, formation or
disappearance of rivers, springs and lakes.
Geological work of wind, glaciers, rivers,
oceans, and groundwater and their role
in constantly moulding the earth surface
features.
Natural phenomena like landslides,
earthquakes and weathering.
MINERALOGY
Minerals are basic units of rocks and ores.
It deals with the study of minerals.
This includes study of—
• mode of formation,
• composition,
• occurrence,
• types,
• association,
• properties,
• uses etc.
PETROLOGY
Petrology deals with the study of rocks.
The earth’s crust is made up of different types of rocks.
Hence petrology deals with the mode of formation,
structure, texture, composition, occurrence, and types of rocks.
STRUCTURAL GEOLOGY
The rocks undergo various deformations,
dislocations and disturbances under the
influence of tectonic forces.
The result is the occurrence of different
geological structures such as folds, fault,
joints and unconformities in rocks.
The details of mode of formation, causes, types,
classification, importance etc of these geological
structures form the subject matter of
structural geology.
STRATIGRAPHY
Stratigraphy is a branch of Geology that deals with
the study of stratified rocks and their correlation.
The climatic and geological changes
including tectonic events in the geological
past can also be known from these
investigations.
PALEONTOLOGY
Scientific study of life of geologic past.
Involves analyses of plant and
animal fossils.
ECONOMIC GEOLOGY
Economic geology is the study of Earth materials that can be
used for economic or industrial processes.
Some of the economic minerals such as talc,
graphite, mica, asbestos, gypsum, magnesite,
diamond and gems.
ORES
Study involves mode of formation,
occurrence, classification, association,
varieties, concentration, properties,
uses, form etc of the economic substances.
ENGINEERING GEOLOGY
“Engineering Geology” is defined by the Association of Engineering Geologists (USA)
as the discipline of applying geologic data, techniques, and principles to the study of—
(a) naturally occurring soils and rock materials, and surface and subsurface fluids,
and
b) the interaction of introduced materials and processes with the geologic environment,
so that geologic factors affecting, the planning, design, construction, operation,
and maintenance of engineering structures (fixed works) and the development,
production, and remediation of ground-water resources, are adequately recognized,
interpreted, and presented for use in engineering and related practice.
It is aimed at studying the geology of an area for the purpose of assuring
that the geological factors regarding the location, design, construction, operation
and maintenance of engineering works, are perfect for the project implementation.
It is also done during post-construction and forensic phases of the projects.
Engineering geologists provide geological and geotechnical recommendations,
analysis, and design associated with human development and
various types of structures.
Engineering geology is a promising subject for operational applications of
geological knowledge.
In engineering geology basic knowledge is required of the following:
• Soil mechanics
• Hydrology
• Foundation engineering
• Concrete and roadstone technology
• Mining technology
• Seismology
A much greater knowledge is required of site investigation practice such as:
• boring
• engineering geophysics
• sampling
• photogeology
• lab in situ testing
• engineering geological mapping
This knowledge is printed on background of geology with emphasis on
structural geology, geomorphology and sedimentology.
MINING GEOLOGY
This deals with the application of geological knowledge in the field of mining.
A mining engineer is interested in the mode and extent of occurrence of ores,
their association, properties etc.
MINING GEOLOGY
It is also necessary to know other physical
parameters like depth direction
inclination thickness and
reserve of the bodies for efficient utilization.
Such details of mineral exploration,
estimation and exploration are dealt
within mining geology.
GEOPHYSICS
The study of physical properties like density and magnetism of the earth or its parts.
To know its interior form the subject matter of geophysics.
There are different types of geophysical investigations based on the physical
property utilized gravity methods, seismic methods, magnetic methods.
Engineering geophysics is a branch of exploration geophysics, which aims at
solving civil engineering problems by interpreting subsurface geology of the
area concerned.
Electrical resistivity methods and seismic refraction methods are commonly
used in solving civil engineering problems
HYDROGEOLOGY
It deals with occurrence, movement
and nature of groundwater in an area.
It also includes:
Atmospheric water
Surface water
It has applied importance because
ground water has many advantages
over surface water.
In general geological and geophysical
studies are together taken up for
groundwater investigations.
GEOCHEMISTRY
This branch deals with the occurrence, distribution, abundance,
mobility etc, of different elements in the earth’s crust.
It is not very important from the civil engineering point of view.
