These are three small intrusions of syenite for which no detailed description is available.
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Itabuna comprises a complex of syenite, diorite, monzodiorite and granite, with associated dykes, of approximately 18x40 km, intruding a broad range of Precambrian granulite facies rocks, but is overlapped on its eastern margin by Mesozoic sediments.
A number of small intrusions occur composed principally of nepheline syenite with biotite and sodalite and cut by pegmatites of the same mineralogy; not investigated in detail.
These two intrusions, which are emplaced in Precambrian gneisses, granulites and metamorphosed ultrabasic rocks, are composed mainly of litchfieldite and pyroxene, amphibole and sodalite litchfieldite, but also sodalite syenites, tawite and alkaline pegmatites.
One large and a number of smaller bodies extend north-south over some 40 km and cover about 26 km2. They comprise principally a variable suite of nepheline syenites including variants rich in sodalite and arfvedsonite. Some varieties have a strongly developed gneissose fabric.
Itarantim comprises a major intrusion some 16 km in diameter together with two smaller intrusions to the southeast, all emplaced in a varied suite of Precambrian gneisses and granites which are extensively fenitized adjacent to the complex.