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.
3. accretion - (astronomy) the formation of a celestial object by the effect of gravity pulling together surrounding objects and gases. astronomy, uranology-the branch of physics that studies celestial bodies and the universe as a whole.ccretion. n. 1. any gradual increase in size, as through growth or external addition.