SMS deposits are formed on the seafloor when hot water comes out of the seabed, hits the cold seawater and deposits its mineral load. 


This process results in “black smokers” which are the visual appearance of minerals precipitating in the cold water. They were first discovered in 1979 at 21 degrees north on the East Pacific Rise near Baja, California, and they have since been found in all the world’s oceans.  Black smokers are arguably one of the great natural scientific discoveries of the 20th Century.  It can take hundreds of years for SMS deposits to form in this way and eventually, they become inactive.

A feature of SMS deposits is their high content of copper, gold, zinc and silver.

The SMS deposits form where tectonic plates under the seafloor are moving apart (called spreading centres) and where tectonic plates converge (called convergent plate margins).   In simple terms, they form hills on the seafloor.  Up to now, some 300 sites have been found in the world’s oceans.  Due to complex tectonic and geological processes, convergent plate margins appear to host SMS deposits with higher concentrations of copper and gold compared with those deposits forming at divergent plate margins.

Neptune Minerals is focusing its efforts at SMS sites at the more prospective convergent plate margin sites which are dominant in the “West Pacific Ring of Fire” in water depths between approximately 500 and 2500 meters.

SMS deposits are considered by geologists to be the modern equivalents of ancient massive sulfide deposits that have been, and continue to be, mined on land today.