Earth Sciences 2123F/G Lecture Notes - Lecture 10: Geothermal Gradient, Volcanism, Peridotite

• School: Western University
• Department: Earth Sciences
• Course: Earth Sciences 2123F/G
• Professor: Catherine Neish

Document Summary

Magma is melted rocks beneath the surface. Lava - less dense liquid rise to erupt at the surface. Most of the heat that ge(cid:374)erates (cid:373)ag(cid:373)a (cid:272)o(cid:373)es fro(cid:373) earth"s (cid:272)ore (cid:449)here te(cid:373)perature is >5,000. Heat is transported to the surface through convection and conduction. When a mineral is heated its atomic vibrations become more vigorous. If enough energy is provided, the ordering of atomic bonds holding the substance together will break and destroy the ordered structure of the substance. Rocks do not melt a single temperature. This is because rocks are generally composed of more than one mineral and each mineral has its own melting temperature. Therefore, certain minerals will melt at lower temperatures than other minerals. Mixed of melted and solid minerals is called a partial melt. For peridotite, the most abundant upper mantle rocks. Solidus the line of temperature and pressure s when partial melt begins. Liquidous the line of temperatures and pressures when the material becomes completely molten.