Velasco-Tapia, "A revised CIPW norm," Schweizerische Mineralogische und Petrographische Mitteilungen, vol.
TABLE 2: Major element composition (% m/m) and CIPW norm for the Volcanic rocks from the Sierra de las Cruces range (a).
Palabras clave: Composicion modal, composicion normal, domos, erupcion freatomagmatica, flujos piroclasticos, ignimbritas, norma CIPW textura de pared de burbuja, pyroclastic flows, shards.
Chemical classification was given by TAS diagram (Le Maitre, 1989) and CIPW norm was calculated using Norma.xsl.
Na2O + K2O (8.8 wt%) and contains small amounts of diopside acmite and hypersthene in the CIPW norms that are dominated by albite quartz and orthoclase.
The CIPW norms of the rocks are dominated by sodic plagioclase followed by quartz albite minor hypersthene etc.
Most rocks are peralkaline with a high agpaitic index (AI = mole (Na+K)/A1; Shand 1951) and acmite in their CIPW
The major and trace element data and CIPW
norms composition of the volcanic rocks of BASD and IVC / TVF of the Ghizar Formation and diorites of the Kohistan batholiths in the study area are given in Table 2 and are graphically presented in Figures 4-6.
norms contain hypersthene (rocks are subalkaline; assuming [Fe.sub.2][O.sub.3]/FeO = 0.18; Irvine and Baragar 1971) which is consistent with tholeiitic Nb/Y ratios of ~0.3 and Ti[O.sub.2] concentrations (~1.3 wt.
The whole rock geochemical data including major and trace elements and CIPW
norms are presented in the Table 2.
The calculated CIPW
norm indicates they are quartz-, hypersthene- and corundum-normative.