2. With respect to trace elements: a. The general factors controlling trace element substitution into minerals. Illustrate your answer using an Onuma diagram (ionic radii vs. partition coefficient) for 15, 2 and 3* cations b. Discuss the normalized trace element figure below. Describe (1) how the figure is constructed, and (ii) how the different trace element abundances shown relate to the plate tectonic cycle and mantle convection. 100 -MORB -OIB ARC 10 rock / MORB 1 0.1 Cs Rb THU K ND Ta La Ce PD PSP No Sm 2 H Eu Ti Gd Tb Dy Ho Er Tm Yb Lu PNd Y 2. With respect to trace elements: a. The general factors controlling trace element substitution into minerals. Illustrate your answer using an Onuma diagram (ionic radii vs. partition coefficient) for 15, 2 and 3* cations b. Discuss the normalized trace element figure below. Describe (1) how the figure is constructed, and (ii) how the different trace element abundances shown relate to the plate tectonic cycle and mantle convection. 100 -MORB -OIB ARC 10 rock / MORB 1 0.1 Cs Rb THU K ND Ta La Ce PD PSP No Sm 2 H Eu Ti Gd Tb Dy Ho Er Tm Yb Lu PNd Y