Branches of geology:

1.    Mineralogy

2.    General geology

3.    Palentology or historical geology

4.    Petrology or petrography

5.    Economic geology: It is concerned with earth materials that can be used for economic or industrial purposes. These materials include precious and base used for economic or industrial purposes. These materials include precious and base metals, nonmetallic minerals, construction-grade stone, petroleum minerals, coal, and water.

6.    Structural geology

7.    Engineering geology

8.    Minig geology

9.    Petroleum geology

Weathering:

“it is the set of physical and biological processes that alter the physical and chemical state of rocks and soil at or near the earth’s surface.”

Or

“It is the breakdown and alteration of rocks and minerals at or near the Earth's surface into products that are more in equilibrium with the conditions found in the surrounding environment.”

Dependence:

Weathering mainly depends upon the atmospheric condition.

1.    Atmospheric condition:

2.    Erosion: It is the process of weathering and transport of solids (sediment, soil, rock and other particles) in the natural environment or their source and deposits them at any suitable place. It take place due to the action of wind, stream, rivers, glaciers, waves and landscaping etc.

3.    Deposition: It is the laying down of sediment carried by wind, water, or ice. Sediment can be transported as pebbles, sand & mud, or as salts dissolved in water. Salts may later be deposited by organic activity (e.g. as sea-shells) or by evaporation.

4.     Sedimentation: In geological sciences it is defined as the process of deposition of solid material from a state of suspension and solution of a fluid usually air or water.

Texture:

It is the description of small features of rocks.

Structure: It is the description of large features of rocks.

Rock forming minerals:

These are divided into six groups.

1.   

FELIS: LIGHT COLOUR

ACIDIC  light

Quarts:           Si.O2 (grey)----(M.P=low)

2.    Feldspar:

                      I.        Orthoclase:                (pink) K.Al.Si3.O8 (clay)

                    II.        Plagioclase:              (white) Na.Al.Si3.O8.----Ca.Al.Si3.O8

3.    Mica:

                      I.        Muscovite:     K.Al.Si3.O10

                    II.        Biotite:            K(Mg.Fe)3 AL.Si3.O10(OH)2

4.    Hornblende:  (black)

5.   

BASIC

Pyroxene:

6.   

MELFIC: DARK COLOUR

Olivine:          (Fe.Mg)2 Si.O4         (M.P=high)

Ferro-Magnesium Silicates: These are the silicates having Fe and Mg.They are dark in colour and more chemically reactive.

Properties of silicates:

Other rock forming minerals:

Carbonates calcite ca.co3 and Limestone

Rocks: In geology, rock or stone is a naturally occurring solid aggregate of minerals and or mineraloids. Types of rocks: 1.    Igneous: these are rocks that solidified directly from molten silicates, which geologists call magma. Examples are: granite, basalt, pumice and flint (which is a form of quartz). 2.    Sedimentary: these are formed by sediments or accumulation and consolidation of sediments. Examples are limestone, chalk, sandstone. 3.    Metamorphic: these are made up of igneous and sedimentary rocks of all ages which have been subjected to intense temperature and pressure. Examples are: slate, marble and quartz.

GEOLOGY LECTURE # 1

Geology:

“It is the study of solid earth & the process by which it is shaped and being changed.”

Terrestrial planet:

A terrestrial planet or rocky planet is a planet that is primarily composed of silicate rocks and or metals. Within the solar system, the terrestrial planets are the inner planets closest to the Sun.

The terrestrial planets are Mercury, Venus, Earth, and Mars.

Gas giants:

A gas giant is a large planet that is not primarily composed of rock or other solid matter. These are composed of different types of gases.There are four gas giants in our Solar System: Jupiter ,Saturn, Uranus, and Neptune.

Dwarf planets:

Planets usually of small size are called dwarf planets .I-e Pluto, Haumea, Make make and Eris.

Some important data about planets:

Properties	Mercury	Venus	Earth	Mars	Jupiter	Saturn	Uranus	Neptune
Equatorial diameter	0.382	0.949	1	0.532	11.209	9.44	4.007	3.883
mass	0.055	0.815	1	0.107	318	95	15	17
Orbital radius	0.39	0.72	1	1.52	5.20	9.54	19.18	30.06
orbital period (Earth years)	0.24	0.62	1	1.88	11.86	29.46	84.01	164.8
Moons	0	0	1	2	63	62	27	13

Dwarf Planets

Properties	Ceres	Pluto	Haumea	Makemake	Eris
Equatorial diameter	0.076	0.180	0.110 (average)	0.102-0.149	0.188-0.235
mass	0.00016	0.002	0.00070	0.00067	0.0028
Orbital radius	2.76596	39.44	43.335	45.791	67.6681
orbital period (Earth years)	4.599	247.7	285.4	309.88	557
number of moons	0	3	2	0	1

Light year (ly):

It is the unit of length equal to 10^6 meters. As defined by International Astronomical Union (IAU) that light year is the distance travel by light in vaccum in one year.1ly=9.46x10^15 meters.

Orbital period:

The orbital period is the time taken for a given object to make one complete orbit about another object. In solar system every planet is revolving around the sun. The orbital period of earth is 1day.

Permeable ground:

Ground which allow the water to pass through it is called permeable ground.

Impermeable ground:

Ground which do not allow the water to pass through it is called impermeable ground.

Minerals:

A mineral is a naturally occurring element or solid chemical substance having a definite composition, a highly ordered atomic structure, and specific physical properties.