olvadásforrás

An olvadásforrás, often translated as "melting source" or "source of melt," refers to a location or geological setting where magma is generated beneath the Earth's crust. These sources are critical for understanding volcanic activity and the formation of igneous rocks.

Magma generation occurs primarily through processes of melting of the Earth's mantle or lower crust. The specific conditions that lead to melting vary depending on the tectonic setting. In subduction zones, where one tectonic plate slides beneath another, the descending plate carries water deep into the mantle. This water lowers the melting point of the surrounding mantle rock, leading to magma formation. At mid-ocean ridges, where tectonic plates are pulling apart, decompression melting occurs. As the mantle rises due to the reduced pressure, its melting point is lowered, causing it to melt and form magma. Hotspots, which are areas of volcanic activity not directly associated with plate boundaries, are thought to be caused by plumes of hot material rising from deep within the mantle, leading to localized melting.

The composition of the magma generated at an olvadásforrás is influenced by the source rock and the melting process. Different types of magma, such as basaltic, andesitic, and rhyolitic, originate from distinct melting sources and conditions. Studying these sources helps geologists understand the chemical evolution of the Earth's crust and mantle, as well as predict the types of volcanic eruptions that may occur. The location and characteristics of an olvadásforrás are key factors in determining the style and hazard potential of associated volcanism.