Changes

==Kinds of Geothermal Deposits==

==Kinds of Geothermal Deposits==

=== Very low temperature deposits (T<30ºC) ===

=== Very low temperature deposits (T < 30°C) ===

: It is generally considered that temperature seasonal variations are percived only over the first 10 meters f the soil. After that there is a interval where the temperature is almost constant and it is considered that below 20 meters, the temperature increases three grades every 100 meters.Therefore ,all the planet is a source of geotermal resources of low temperature.These resources have domestic use.

It is generally considered that temperature seasonal variations are perceived only over the first 10 m of the soil. After that there is a interval where the temperature is almost constant and it is considered that below 20 m, the temperature increases three degrees every 100 m. Therefore, the whole planet is a source of geothermal resources of low temperature. These resources have domestic uses.

=== Low temperature fields (30ºC<T<90ºC) ===

=== Low temperature fields (30°C < T < 90°C) ===

: They are found in sedimentary basins with normal o hightly superior geotermal gradient.The sole condition is the existence of one or more aquifer horizons in adequate depths.Ej Paris Basin (France) ;Boise (EEUU) (Figure 4). [[File:Goethermal heating district, City of Boise, EEUU.png|thumbnail|center|Figure 4: Goethermal heating district. City of Boise. EEUU. [http://energy.ltgovernors.com/geothermal-resource-descriptions.html].]]

Low temperature fields are found in sedimentary basins with normal to high geothermal gradient. The sole condition is the existence of one or more aquifer horizons in adequate depths ([[:File:Goethermal heating district, City of Boise, EEUU.png|Figure 4]]).  

[[File:Goethermal heating district, City of Boise, EEUU.png|frame|center|{{figure number|4|}}Geothermal heating district, Boise, Idaho.<ref>[http://energy.ltgovernors.com/geothermal-resource-descriptions.html Ltgovernors]</ref>]]

=== Medium temperature deposits (90ºC<T<150ºC) ===

=== Medium temperature deposits (90ºC<T<150ºC) ===

: They are foundin various places of our planet.They usually belong to áreas with specific geologic characteristics such as áreas of thin crust,higher concentration of radioactive isotopes or áreas close to or near [[igneous]] bodies.They can also be found over regions with higher gradient but a lower depth.They generally need an igneous intrusión and it is usual that,in this kind of field,water comes up to the surface forming hot springs.

: They are foundin various places of our planet.They usually belong to áreas with specific geologic characteristics such as áreas of thin crust,higher concentration of radioactive isotopes or áreas close to or near [[igneous]] bodies.They can also be found over regions with higher gradient but a lower depth.They generally need an igneous intrusión and it is usual that,in this kind of field,water comes up to the surface forming hot springs.