A mineral is mostly a compound that is usually crystalline in nature and is a result of geological progressions.
The structure of earth is in spherical form and is composed of four layers, three solid and one liquid.
A continent is one of several very large landmasses on Earth.
Continents are understood to be large, continuous, discrete masses of land, ideally separated by expanses of water.
The continents are the great land masses of the earth. There are seven continents on Earth.
A magnet produces a vector field, the magnetic field, at all points in the space around it. It can be defined by measuring the force the field exerts on a moving charged particle, such as an electron.
The lithosphere is the outer solid part of the earth, including the crust and uppermost mantle.
The Cryosphere is an Imperial space station in the Music star system, which is considered to be of major strategic importance.
A tectonic plate is a massive, irregularly shaped slab of solid rock, generally composed of both continental and oceanic lithosphere.
The earth is an oblate spheroid. It is almost spherical, flattened a little at the poles with a slight bulge at the centre (equator). The structure of earth’s interior is layered.
Soil is the uppermost layer of the earth’s crust. It contains a mixture of fine powdered rock material and humus. Humus is the organic matter which is added to the soil by the decayed and decomposed remains of plants and animals.
Down to a depth of 16 km from the surface of land, 95 per cent of the earth materials found in the earth’s crust consist of rocks. Rocks are made up of individual substances, called minerals, found mostly in solid state.
Earth’s axis is an imaginary line which runs right across and passes through the centre of the earth. The earth spins round its axis which always remains inclined at an angle of 661/2° to the plane of the Earth’s orbit.
Vegetation comprises of plants growing over the surface of the earth. The plant geographers have divided the vegetation of the world into four great biochores :
The Forest Biochore : Defined as plant formation consisting of trees growing close together nd forming a layer of foliage that shades the ground.
A globe has two fixed points—the North Pole and the South Pole. An imaginary line equator is drawn in such a way that at all points it lies exactly halfway between the two poles. It divides the earth into two equal parts i.e., the Northern Hemisphere and the Southern Hemisphere.
There are three major Landforms : mountains, plateaus and plains. Mountains An uplifted portion of the earth’s surface is called a hill or a mountain. Mountains are classified into the following four types.
The earth is believed to have originated about 4600 million years ago.The main geological events in the history of earth can be categorized into the following eras.
The sequence of eating and being eaten and the resultant transfer of energy from one level to another is known as the food chain. The plants and algae are the first level in food chain and are known as primary producers.
When the light of the sun or the moon is blocked by another body, the sun or moon is said to be in eclipse.
Any sudden disturbance below the earth’s surface may produce vibration or shaking in earth’s crust and some of these vibrations when reaches the surface, are known as earthquakes.
Alfred Wegener was the geologist who in 1924 propagated the theory of continental drift which is very much in vogue now. According to this theory, nearly 150 million years ago,there was a single continent on earth known as ‘pangaea’ which broke into several pieces and began to drift apart.