PETROLOGY AND GEOCHEMISTRY OF MONTANA GUAZA; ASSIMILATION AND FRACTIONAL CRYSTALLIZATION OF THE MAGMA CHAMBER, TENERIFE (CANARY ISLANDS)
XRF and petrographic analyses were carried out on nine stratographically different samples from Mt. Guaza. Field evidence shows as Mt. Guaza evolved, clear stratographic layering resulted from the progressive extrusions. Major, minor, and trace element analysis trends show an evolved magma. XRF evidence suggests the volcano deposited layers of enriched lava followed by progressively more basic lava compositions, issuing support for a zoned magma chamber. In addition, XRF data show evidence of assimilation of the thick overlying lithosphere contaminating the magma chamber in addition to fractional crystallization. Trace element data plotted against volcano height show similar evidence. XRF data analyzed during this fieldwork on Mt. Guaza further support results of Santin and Lopez (1978).