This diagram shows the ratio (Ci/Co) of the concentration (Ci) of an element (i) in the liquid of a batch melt (Ci = CiL) relative to the total original concentration (Co) in a rock (Co = CiTotal) as a function of the fraction (F) of the rock that is melted based on a crystal-liquid distribution coefficient Di. In the batch melting model, the liquid remains in equilibrium contact with the rock as it melts. Fractionation occurs if the liquid is removed after only part of the rock is melted. To change the distribution coefficient Di, enter a number or use the slider. To follow the progress of of the batch melting for a specific Di, move the F slider. To see other partial melting models click on the appropriate check box: (1) Instantaneous removal of melt as it is formed with no interaction of the removed melt with the remaining solid; the Ci/Co value is just for the "drop" removed. Or (2) an Aggregate of the melt removed instantaneously. The equations used for these melting models are derived in White (2013, Section 7.6.2) and appear on the diagrams. Notice that for small values of Di and F, some of the Ci/Co values will be so large that they are outside the range of the Ci/Co axis. Note also that the symbols for CiL and CiTotal in equation (4) of the text have been replaced by Ci and Co here to simplify the expressions.