Photograph of drill core from near bedrock surface at the top of drill hole HK20-004, located on the same drill collar as Hole 13, showing altered magnetite needles with reaction rims of pyrite–pyrrhotite–iron carbonate and bastnaesite (LREE)–pyrochlore (Na,Ca)2Nb2O6(OH,F) in a matrix of apatite with calcite inclusions containing monazite ((Ce,La,Nd,Th)PO4), quartz and potassium feldspar. The magnetite-quartz-potassium feldspar assemblage is a high temperature potassic alteration facies.
Photograph of drill core from near bedrock surface at the top of drill hole HK20-004, located on the same drill collar as Hole 13, showing altered magnetite needles with reaction rims of pyrite–pyrrhotite–iron carbonate and bastnaesite (LREE)–pyrochlore (Na,Ca)2Nb2O6(OH,F) in a matrix of apatite with calcite inclusions containing monazite ((Ce,La,Nd,Th)PO4), quartz and potassium feldspar. The magnetite-quartz-potassium feldspar assemblage is a high temperature potassic alteration facies.