The magma in a magma chamber usually exists in several layers, based upon the density of the materials composing the lava. The least-dense magma rises to the top, while the denser magma settles toward the bottom of the magma chamber.
Full Definition of ACCRETION. 1. : the process of growth or enlargement by a gradual buildup: as a: increase by external addition or accumulation (as by adhesion of external parts or particles) b: the increase of land by the action of natural forces. 2. â acÂ·creÂ·tionÂ·ary \-shÉ-Ëner-Ä, -Ëne-rÄ\ adjective.
acculturation The process of incorporating the culture, mores and values of another group; the exchange of cultural features (traditions, values, or religious beliefs comprising the way of life) that results when groups of individuals from different cultures come into continuous direct contact, resulting in an alteration in the cultural patterns of one or both groups.