According to [R.sub.1]-[R.sub.2] discrimination diagram [26] and the classification diagram for plutonic rocks [28], the Chah Anjir intrusive rocks can be classified as diorite, monzodiorite (Figure 7(a)), and diorite to
syenodiorite, respectively (Figure 7(b)), with subalkaline to alkaline affinity (Figure 8(a)).
aIe (as in fire) ye io i iro
syenodiorite (a type of rock) tiring-irons
Figure 5 shows the extent of the favourable brucite-bearing zone in the Marble Canyon area of Texas, which developed in dolomitic rocks that surrounded an elliptically shaped intrusive complex, consisting of horn-blende-bearing granite,
syenodiorite and syenogabbro (Newman and Hoffman 1996).