Australia is well endowed with stratiform and stratabound metal deposits, mainly sulfides. The known deposits of this type include concentrations of lead-zinc-silver, copper, copper-gold, copper-zinc-lead, tin, nickel, tungsten, gold, uranium, iron ore, and one of manganese. The last excepted, these are all Precambrian or Paleozoic in age.

Some of the names have become known to the world: Mount Morgan, Mount Lyell, Broken Hill, Mount Isa. Some of them cropped out prominently and were found 90 to 100 years ago. Some less obvious deposits have been found only in recent years after the area had been mined for the same or other metals for many decades.

As elsewhere in the world, these stratiform concentrations include some metal deposits of first magnitude, containing from millions up to tens of millions of tons of metal in high-grade deposits. The oldest deposits are still in full production today and some have contributed greatly to the development of the industry and the economy.

The search for new deposits of this type in Broken Hill led, 20 years ago, to the development of new concepts of origin and occurrence of these stratiform (as distinct from the classical vein-type) deposits. They now are regarded as normal if unusual products of the geologic history of their environments and as exhibiting world wide patterns of occurrence which are relevant to the potential of rocks of certain types and ages.

These concepts and patterns have provided new stimulus for study of the paleogeographic, chemical, and biologic conditions of these geologically ancient times.

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