1. Geology is the science that studies the physical structure and composition of the Earth, as well as the processes that act on it.
2. Geology provides knowledge about construction materials like stones and clay that are important for civil engineering projects. It also helps understand natural geological processes like erosion that impact projects.
3. Geology is important for understanding groundwater resources and interpreting drilling data for projects like dams and bridges to ensure stable foundations.
2. Definition:-
• The science which deals with the physical
structure and substance of the earth, their
history, and the processes which act on them.
• The geological features of a district.
• The geological features of a planetary body.
Geo
logous
Geology Earth science
3. The importance of geology in civil engineering may
briefly as follows:
• Geology provides a systematic knowledge of construction
material, its occurrence, composition, durability and other
properties. Example of such construction materials is building
stones, road metal, clay, limestones and laterite.
4. • The knowledge of the geological work of natural agencies
such as water, wind, ice and earthquakes helps in planning
and carrying out major civil engineering works. For example
the knowledge of erosion, transportation and deposition helps
greatly in solving the expensive problems of river control,
coastal and soil conservation.
5. • Ground water is the water which occurs in the
subsurface rocks. The knowledge about its
quantity and depth of occurrence is required in
connection with water supply, irrigation,
excavation and many other civil engineering
works.
6. • The foundation problems of dams, bridges and buildings are
directly concerned with the geology of the area where they are
to be built. In these works drilling is commonly undertaken to
explore the ground conditions. Geology helps greatly in
interpreting the drilling data.
• In tunneling, constructing roads, canals, docks and in
determining the stability of cuts and slopes, the knowledge
about the nature and structure of rocks is very necessary.
• Before staring a major engineering project at a place, a
detailed geological report which is accompanied by geological
maps and sections, is prepared. Such a report helps in planning
and constructing the projects.
7. Physical Geology:
• Physical Geology uses the scientific method to
explain natural aspects of the Earth - for example,
how mountains form or why oil resources are
concentrated in some rocks and not in others.
• This chapter briefly explains how and why Earth's
surface, and its interior, are constantly changing. It
relates this constant change to the major geological
topics of interaction of the atmosphere, water and
rock.
9. Petrology:-
• Petrology is the branch of geology that studies the
origin, composition, distribution and structure
of rocks.
• (from the Greek language : petra-"rock" and logos-
"study")
• “Lithology” was once approximately synonymous
with petrography, but in current usage, lithology
focuses on macroscopic hand-sample or outcrop-scale
description of rocks while petrography is the specialty
that deals with microscopic details.
10. Branches:
• There are three branches of petrology, corresponding
to the three types of rocks:
Igneous, metamorphic, and sedimentary.
• Igneous petrology focuses on the composition and
texture of igneous rocks (rocks such
as granite or basalt which have crystallized from
molten rock or magma). Igneous rocks
include volcanic and plutonic rocks.
11. • Sedimentary petrology focuses on the composition and
texture of sedimentary rocks (rocks such
as sandstone, shale, or limestone which consist of
pieces or particles derived from other rocks or
biological or chemical deposits, and are usually bound
together in a matrix of finer material)
12. • Metamorphic petrology focuses on the composition and
texture of metamorphic rocks (rocks such
as slate, marble, gneiss, or schist which started out as
sedimentary or igneous rocks but which have undergone
chemical, mineralogical or textural changes due to
extremes of pressure, temperature or both).
• Metamorphic rocks arise from the transformation of
existing rock types, in a process called metamorphism,
which means "change in form". The original rock
(protolith) is subjected to heat (temperatures greater
than 150 to 200 °C) causing profound physical and/or
chemical change.
14. Structural geology:
• Structural geology is the study of the three-
dimensional distribution of rock units with respect to
their deformational histories.
• The primary goal of structural geology is to use
measurements of present-day rock geometries to
uncover information about the history of deformation
(strain) in the rocks, and ultimately, to understand
the stress field that resulted in the observed strain and
geometries.
16. Weathering of Rocks:
• Weathering breaks down and loosens the surface minerals
of rock so they can be transported away by agents of
erosion such as water, wind and ice.
• There are two types of weathering: mechanical and
chemical.
• Mechanical or physical weathering involves the breakdown
of rocks and soils through direct contact with atmospheric
conditions, such as heat, water, ice and pressure.
• The second classification, chemical weathering involves the
direct effect of atmospheric chemicals or biologically
produced chemicals also known as biological weathering in
the breakdown of rocks, soils and minerals.