Instead, it occurs 120 m above the base of the 200-m-thick section. This can only mean ... Once this connection is made, the plagioclase-chain network in the colonnade has a simple explanation.

Figure 3: Section through La Paloma and Los Sulfatos ... Coupled CaAl–NaSi diffusion in plagioclase feldspar: experiments and applications to cooling rate speedometry. Geochim.