ABSTRACT
As far as heavy minerals are concerned, aggregates such as sand and gravel, shells and coral debris have for long been extracted from nearshore, and the heavy minerals industry is growing as the demand for building materials grows. Quantitatively, they comprise the most important offshore mineral resources, and at this time tin, monazite, ilmenite, and others are being extracted. These minerals are extracted from the ocean other than oil and gas (Chapter 6). The reserves are enormous, although there are significant problems in some parts of the world because of legal, political, taxation, and regulatory concerns. The impacts of extraction on the neighboring coasts and the rates of replenishment are extremely hard to predict, even though considerable research has been devoted to quantifying the processes and modeling the effects.
Although phosphorite, which forms as an authigenic mineral on the continent shelf, is currently being mined onshore, the increased demand is also being met from land resources and significant offshore mining is not yet taking place.
