BULK MAJOR AND TRACE ELEMENT ANALYSIS VERSUS ELEVATION OF CASTILLO TRANSECT (TORRES DEL PAINE INTRUSIVE COMPLEX)
SEM-EDS and laser ablation ICP-MS were used to collect bulk major and trace element data from glass fusions of nine samples. Compositional variations were plotted as a function of estimated elevation, in combination with data collected from a similar study across the same transect (Leuthold et al. 2013). Some systematic changes are evident, likely reflecting changes in rock type with position. The bulk data should primarily reflect changes in modal mineralogy; trace element analyses of certain phases (titanite) will be used to assess this.
The process by which magmatic differentiation and silicic pluton formation occurs is most often attributed to crustal assimilation, fractional crystallization, and fluid exsolution. While fractional crystallization involving mechanical separation of melt and solid is widely accepted as the most significant differentiation process, the complex mineral changes in Torres support thermal migration as a key player in granite production. Using the data described above, we plan on creating a model to test the validity of thermal migration as a major magmatic differentiation mechanism, specifically assessing the effect of titanite appearance on the whole rock trace element data.