gaps in rock layers

The disintegration of igneous or metamorphic rocks and their subsequent re-solidification sedimentation form these rocks. They form layer-upon-layer in a somewhat horizontal plane. Examples: Limestone, Dolomite, Sandstone, Shale e..

Coal is formed in layers called seams. Layers of other rocks are there amidst coal seams. A mine shaft is dug through these rocks and the coal seam is reached. Then tunnels are dug into the co..

Petroleum occurs in nature, trapped between two layers of impervious (non-porous) rocks, usually under the sea. Natural gas collects above the surface of petroleu..

Soil Erosion - Land is also a precious resource. Land is needed for agriculture and occupation. Land is under pressure due to increasing population. Land for agriculture has to be fertile in order to be able to support a good crop. The fertility of land lies in the quality of the soil. Soil is form..

In Louisiana (USA) and Gulf of Mexico large sulphur deposits occur at a depth of about 300-400 metres below the earth's surface. Layers of soft sand, clay and rocks over these sulphur beds make it practically impossible to extract sulphur from the deposits. Hermen Frasch in 189..

The mantle is a thick layer of rock below the crust. It is the central region between the crust and the core of the earth. It is about 2,900 km deep. The rock in the mantle is made of silicon, oxygen, aluminium, iron and magnesium. The upper part of the mantle has a te..

Geothermal Energy - 'Geo' means earth and 'thermal' means heat. Thus geothermal energy is that heat energy obtained from hot rocks present inside the earth. This heat can be used as a source of energy to produce electricity. You know that the innermost layer of the earth is call..

Geothermal Energy - Ever since the earth was formed, huge amount of heat energy has been stored in its molten core. Some of this heat is always flowing towards the surface. This heat is called Geothermal Energy. The hot interior of the earth heats up the layers of rocks above it..

Oxygen Cycle - Oxygen is another essential element for living organisms. It is present in large quantities (20.95% v/v) in the atmosphere and is also seen in bound state in water and as oxides and carbonates in rocks. Dissolved oxygen in water is the source of oxygen for aquatic organisms..

Scientists theorize that the earth began as a waterless mass of rock surrounded by a cloud of gas. Radioactive materials in the rock and increasing pressure in the earth's interior gradually produced enough heat to melt the interior of the earth. The heavy materials such as iron..