Precambrian granulites of the Aldan shield in southern Yakutia, USSR, form a massif of 200,000 km' bounded by younger fold-belts to the south, west and east. The massif consists of several blocks that reflect a primary heterogeneity of composition and differences in structural and thermodynamic evolution ofdifferent parts of the area. According to structural and petrological data the massif can be divided into two megablocks: eastern Aldan and western Aldan. They are separated by a narrow meridional fold-belt. Structural evolution of this central zone was determined by the geodynamics of the megablocks and was completed in the late Archaean. Towards the south, this central zone is 'transformed' into the relatively small Sutam block adjoining the Stanovoy fold-belt that bounds the Aldan shield on the south. The Sutam block is separated from t.he other structural units of the Aldan shield by a system of north trending grabens filled by post-Archaean sediments.The Aldan shield is composed of Archaean high-grade granulites, while the Stanovoy foldbelt, to the south, consists of highly foliated Proterozoic rocks metamorphosed under relatively lower-grade conditions. However, relics of the granulites are mapped within the fold-belt.

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