Chiueca (Monte Chiueca)

This occurrence forms a hill some 2 km in diameter rising 140 m above the plain. The core of the hill is a coarse syenite which becomes finer grained towards the margins. Andrade (1954) briefly describes a collection of rocks from this locality which vary from aphanitic to porphyritic the latter with phenocrysts of nepheline and sodic pyroxene. One described rock consists of 60% orthoclase, 21% nepheline, 14% aegirine plus aegirine-augite, the latter sometimes zoned, and accessory titanite, magnetite, calcite, cancrinite and apatite. A chemical analysis is given.