This form creates an input spreadsheet for UserCalc for a simple 2 layer model illustrated in Figure 1. The lower layer extends from pressure Pmax to P1 and the upper layer extends from P1 to Pmin. F1 is the amount of melting that occurs in layer 1, Fmax is the total amount of melting in the column. Each element in the decay chain can have one bulk partition coefficient in each layer. In addition, the lower layer can have an enhanced (or diminished) permeability relative to the upper layer. E.g. a permeability factor of 10 implies that the lower layer has an intrinsic permeability that is 10 times higher than the upper layer at the same porosity. The transition interval Delta P (in kb) controls the width of the pressure interval over which a smooth transition between the two layers takes place.