Amalat

This is a group of lens- and sheet-like bodies within an area of about 1.0 x 1.5 km which cut Upper Proterozoic marbles. Geophysical data indicate that at depth these minor bodies coalesce into a monolithic intrusion. Nepheline syenites are the most extensively developed rock type of the occurrence among which foyaites and miaskitic varieties are present, the latter being particularly concentrated in the marginal zones where they are gneissose in appearance. Smaller areas are occupied by members of the urtite-jacupirangite series in which nepheline and pyroxene are irregularly distributed. Lamprophyres are also found.