Adventitiously introduced metals and grinding grit, dried immersion oil and amalgam(b,c,f)

Tin-niobium mineralization in granites(a-f)

Cassiterite, zircon and thorites in greisenized granite(a-e)

Unmineralized sandstones(a,e)

Oxide placer deposits(b,d,e)

Precious metal placer(b-d)

Fossil placer(a-c)