Ann: A Focus on Niobium Presentation, page-12

Not necessarily cause I reckon its all part of the same area (see 'old report from 1977') which has historically gone relatively unexplored/ignored/not drilled because of environmental concerns and thick cover. I've done a bit of online research and found the following:

1. "Both [the Salitre Complex and Serra Negra Complex] have a comparable composition, although only the smaller Salitre intrusive has been shown to host economic grade mineralisation, with testing of the mineralogically similar Serra Negra complex having been hampered by environmental considerations and thicker cover. (link to source)

2. "Figure 3.2 shows a geological sketch of the [Serra Negra Complex] SNC based on drill core information, petrography and exploration geochemical data. The alkaline-carbonatite complexes of the APIP are covered with laterite deposits up to 200 m thick, which severely restricts the access to fresh samples. Unlike other APIP complexes, such as Araxá, Tapira, and Catalão I and II, where good exposures are found at the bottom of phosphate and niobium mining pits, in the [Serra Negra Complex] SNC outcrops are extremely scarce, restricted to a few serpentinized dunites in the northwest portion of the SNC." (link to source) (pages 72 and 73). See Figure 3.2 below which has locations of the sampled drill cores. To me, it looks like the sampled drill cores are around 8-10kms away to the West from OZM's UV Target 1 (which is somewhere around where that big black arrow is pointing to the N).

3. See my next post for the sampled drill core Nb results.