Geothermal energy is produced by steam and hot water reservoirs under but near the surface of the Earth. It can be used for heating or power generation. This energy source can become locally important in those areas where geothermal activity takes place, e.g. in Iceland, Italy, and in the United States, where the largest plant is at The Geysers in Sonoma County, Calif. The corrosive action caused by the high salt content of the water and the deposit of chemicals on the piping system lead to high construction and maintenance costs.
Impact On Soil Fertility and Agriculture
Clay particles form during the weathering of igneous rocks, such as granite and basalt. The particles are so small that they can be easily carried long distances by water or the wind. A handful of clay picked up anywhere may contain particles formed at different times from different igneous rocks.
Igneous can help the local economy by creating a tourist attraction, for example the Cascade Range extends about 700 miles from northern California through Oregon and Washington into British Columbia. The crest of the range lies from 100 to 150 miles from the Pacific coast. The Cascades begin where the Sierra Nevada ends. Separating the two mountain ranges is a gap, located south of Lassen Peak. To the north the Cascade Range joins the Canadian Rockies. The broad mass of the Cascade Range is composed of igneous and volcanic rock. Magnificent forests cover the slopes. Most of the heavily wooded range is within conservation and national forest areas. The trees are mostly evergreens such as the tamarack, the pine, the cedar, and the Douglas fir. This example of a mountain range is used for skiing and hiking. The igneous rocks forms peaks that are outstandingly beautiful, which attracts tourist from inner city area to visit. The local economy could be boosted by the introduction of cafeteria’s and ski lift operators, which would minimize unemployment.
An igneous rock provides a good source for building materials. The igneous rock is very tough and strong which is vital for infrastructure that would have to withstand the physical impacts of weathering. Granite is of a high density and is used for churches and historic building such as churches. The stone is also very cheap to purchase as there is no demand to the actual presence of the material and it is being made all the time. Marble is a type of igneous rock that is very perishable, though expensive. Igneous rocks are very heavy causing a problem in transportation. The rock is very acidic as well causing the surrounding area to loose vegetation etc.
The most valuable clay is China clay, or kaolin. When fired, it is almost pure white. It is used for fine china, porcelain, tile, and electric insulators and in making paper. Because it is not highly plastic, it is mixed with light-colored ball clay to make it easier to mold. Ball clay is so called because it is taken from clay pits in ball-like chunks. It is used in the tiles and sanitary fixtures in bathrooms. It is also the basis for most ordinary pottery. Chine clay is found in the south west of England e.g. Cornwall. The colour of the clay is a dark kind of red.