Magma is a mixture of molten and semi-molten rock found below Earth's surface. Most magma consists of four types of materials: liquid rock, crystallized minerals, solid pieces of rock, and dissolved gases. When magma escapes through a volcano onto Earth's surface, scientists call it lava.
Download the Accretion of Duties Form (PDF, 8K) An accretion of duties is a promotion resulting from the upgrading of an employee's position because of additional duties and responsibilities. Jobs change and evolve for many reasons.
accretion in Medicine. accretion acÂ·creÂ·tion (É-krÄ'shÉn) n. Growth or increase in size by gradual external addition, fusion, or inclusion. Increase by addition to the periphery of material of the same nature as that already present, as in the growth of crystals.