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.
Accretion expenses are generally offset against increases in the liability account, allowing the company to fully amortize the cost of the asset retirement in advance of the requirement for those funds. The same principle is applied to financial instruments conveying a future financial obligation.