Minerals from the ocean

Mineral resources are present offshore either as bedrock or superficial
Bedrock deposits include petroleum, coal, sulphur, evaporites, and metals. Many of
these deposits can be exploited in shallow water using currently-available technology
including drilling platforms, solution extraction, and underground mining from onshore
installations which extend offshore. Genetically, there are two kinds of superficial
deposits; those which formed on the continent but which were subsequently submerged by
the post-glacial rise in sea level (lateritic deposits and some types of placer
deposits), and those which have formed under submarine conditions at the present time
or in the recent past. Deposits of this second group include construction materials,
some placer deposits, phosphorites, and glauconite, all of which are found primarily
on the shelf and upper slope; and deposits of the deeper oceans, including deep-sea
oozes, manganese nodules, and metalliferous muds and brines. Dredging techniques are
used for exploiting superficial deposits in shallow waters; various types of dredges
are being tested, or are planned for the deeper-water deposits. Although it is
probable that many offshore mineral deposits will not be exploited in the near future,
they nevertheless constitute long-term resources of considerable importance.