Introduction

Mining and recovery of mineral resources has been with us for a long time. Early Paleolithic man found flint for arrowheads and clay for pottery before developing codes for warfare. And this was done without geologists for exploration, mining engineers for recovery or chemists for extraction techniques. Tin and copper mines were necessary for a Bronze Age; gold, silver, and gemstones adorned the wealthy of early civilizations; and iron mining introduced a new age of man.

Human wealth basically comes from agriculture, manufacturing, and mineral resources. Our complex modern society is built around the exploitation and use of mineral resources. Since the future of humanity depends on mineral resources, we must understand that these resources have limits; our known supply of minerals will be used up early in the third millennium of our calendar. Furthermore, modern agriculture and the ability to feed an overpopulated world is dependent on mineral resources to construct the machines that till the soil, enrich it with mineral fertilizers, and to transport the products. As geologists, we cannot tell you that mineral resources are finite. The presently available resources were created by earth processes and after we exhaust them, more will develop in a few tens of million years, which is not in human lifespans.

We are now reaching limits of reserves for many minerals . Human population growth and increased modern industry are depleting our available resources at increasing rates. Although objections have been made to the Rome Report of 1972, the press of human growth upon the planet's resources is a very real problem. The consumption of natural resources proceeded at a phenomenal rate during the past hundred years and population and production increases cannot continue without increasing pollution and depletion of mineral resources. The geometric rise of population has been joined by a period of rapid industrialization, which has placed incredible pressure on the natural resources. Limits of growth in the world are imposed not as much by pollution as by the depletion of natural resources. As the industrialized nations of the world continue the rapid depletion of energy and mineral resources, and resource-rich less-developed nations become increasingly aware of the value of their raw materials, resource driven conflicts will increase. By about the middle of the next century the critical factors come together to impose a drastic population reduction by catastrophe. We can avert this only if we embark on a planet-wide program of transition to a new physical, economic, and social world that recognizes limits of growth of both

link to population and resource use.

In a world that has finite mineral resources, exponential growth and expanding consumption is impossible. Fundamental adjustments must be made to the present growth culture to a steady-state system. This will pose problems in that industrialized nations are already feeling a loss in their standard of living and in non-industrialized nations that feel they have a right to achieve higher standards of living created by industrialization.

"Every effort to prevent pollution and produce more food and other resources is bound to be short-lived under present world population policies. Such temporary measures can provide lead time so that people can be educated to the need for limiting population to that number for which the world can provide. If this education is unsuccessful, all other measures are in vain."

This was written in 1975, and in 1999, the population growth continues upward and the supply of resources continues to diminish. With the increasing shortages of many minerals, we have been driven to search for new sources. Marine resources are the potential area for new mineral sources. In the 1960's, marine mining was a major issue among businessmen, politicians and scientists with a major push by scientists to make industry aware of the potential market opportunities from the ocean. At the time of this writing, resources from the sea draw less interest except for oil and gas exploration.

The conflict between exploration and production with environmental concerns and the costs of offshore exploration have led to a reduced drive to find offshore mineral resources. Resolving the conflicts will be an integral part of developing marine mineral sources. Legal, political, and social problems involved in marine mining are complex and more difficult to resolve. An ore body on land lies within a national boundary -- political boundaries may change and mining disruptions occur like those we have seen in Africa -- in fact governments may be manipulated to control mineral wealth, but in the end, someone owns the ore body and awards a mining lease. Recent treaties and proclamations have established zones of exclusive mineral rights to neighboring nations, and negotiations have established seaward boundaries between adjacent countries, but much of the ocean lies beyond national boundaries, creating major political and legal problems for mining activity.

Continental margins include an area that is almost 50% as large as the existing land areas. Mineral deposits from the shelf and slope could approximate those found in adjacent terrestrial areas. These will include unconsolidated deposits of heavy minerals mostly close inshore or in estuarine or drowned river valleys, sands, gravels, shells, and similar nonmetallic deposits laid down under shallow water or subaerial conditions. In deep water, deposits of phosphorite and ferromanganese oxides and sulfides with associated minerals are the main targets of exploration. As we gather more information about mineralization processes on the deep ocean ridge systems, we open new frontiers for mineral exploration.

In 1969, Christy predicted that in two decades fisheries, oil and gas and deep sea nodules would be the important marine assets. In 1999, fish stocks are showing serious depletion and the mining of deep sea nodules is a future concept, only petroleum and gas exploration has intensified.

As we increase our efforts in marine mining, we must understand that although many processes are common over the entire earth, the deep ocean crust and the continental crust are of different types of rock, and geochemical processes of enrichment and sedimentary processes of transport and concentration of minerals differ. The problems of searching for and extraction of marine mineral resources are different, more difficult, and more costly. The implications of the plate tectonics concept for mineral exploration must be understood to develop exploration strategies since localization of mineral deposits is governed by tectonic processes. Increasing knowledge of the mechanisms of plate tectonics has led to improved concepts for locating marine mineral deposits.