The Sibley Group is an unmetamorphosed Mesoproterozoic red bed sequence, commonly flat lying, that formed in an intracratonic basin between 1450 Ma and 1500 Ma. It covers an area o f 15,000 km^, and reaches a total ...

A representative collection of minerals &om two niobium deposits found within the Oka carbonatite complex: the Bond Zone deposit; and the NIOC AN deposit, were analysed using an electron microprobe, and compared with ...