to the development of geological models of ore-forming systems. Recent
discoveries of significant ores have been strongly influenced by a basic
understanding of Earth processes, including diamonds (mantle petrology),
magmatic nickel (large igneous provinces), copper deposits (fluid-rock
interaction), volcanic-hosted massive sulfide deposits (seafloor hydrothermal
systems), and sediment-hosted lead-zinc deposits (basin-scale hydrology). Future
discoveries may result from a better understanding of the physical, chemical, and
biological processes involved in the formation and preservation of ore systems.
Because the spatial and temporal distribution of mineral resources is highly
variable, a key problem is to determine what controls the distribution of oregrade
mineralization. Large deposits of tungsten-tin and copper ( Figure 1.2 ) are
associated with periods of global arc volcanism, for example, but it remains
unclear whether special conditions were necessary to create large upper crustal
magma chambers or to trigger fluid release required to produce the ore. Research
is also needed to determine the role of microbes in the modification and
dispersion of ores in magmatic systems and associated hydrothermal
environments, and the biological influences on the formation of sedimentary iron
and uranium. Detailed, atomic-scale investigations of minerals, fluids, and
mineral-fluid interfaces play a central role in this domain. However, with the
continued success of science-based exploration, perhaps the greatest challenges
for Earth scientists are not to find more resources— although this will surely
remain important—but to produce them more efficiently and safely, to mitigate
long-term environmental impacts, and to provide a scientific basis for long-term
land-use decisions.
Water
According to the United Nations Environment Program, more than one-third
of all people are without a safe water supply, and one-quarter will suffer from
chronic water shortages during the next decade. By 2025, it is projected that 15
countries worldwide will have encountered water stress (i.e., consumption levels
exceeding 20% of available supply), 9 will suffer from water scarcity, and 22
will have run up against a “water barrier” to further development. 6
Informed decision making on water resources requires knowledge of the
complex hydrologic systems operating within the Critical Zone and a predictive
understanding of how they respond to natural and human modifications. At the
Science and Technology Center (STC) for Sustainability of Semi-Arid
6 Population change-natural resources-environment linkages in the Arab states region.
Food and Agriculture Organization, 1996 ( http://www.fao.org ).
BASIC EARTH SCIENCE AND SOCIETY
17
About this PDF file: This new digital representation of the
original work has been recomposed from XML files created
from the original paper book, not from the original
typesetting files. Page breaks are true to the original; line lengths,
word breaks, heading styles, and other typesetting-specific
formatting, however, cannot be retained,
and some typographic errors may have been accidentally inserted.
Please use the print version of this publication as the authoritative
version for attribution.
discoveries of significant ores have been strongly influenced by a basic
understanding of Earth processes, including diamonds (mantle petrology),
magmatic nickel (large igneous provinces), copper deposits (fluid-rock
interaction), volcanic-hosted massive sulfide deposits (seafloor hydrothermal
systems), and sediment-hosted lead-zinc deposits (basin-scale hydrology). Future
discoveries may result from a better understanding of the physical, chemical, and
biological processes involved in the formation and preservation of ore systems.
Because the spatial and temporal distribution of mineral resources is highly
variable, a key problem is to determine what controls the distribution of oregrade
mineralization. Large deposits of tungsten-tin and copper ( Figure 1.2 ) are
associated with periods of global arc volcanism, for example, but it remains
unclear whether special conditions were necessary to create large upper crustal
magma chambers or to trigger fluid release required to produce the ore. Research
is also needed to determine the role of microbes in the modification and
dispersion of ores in magmatic systems and associated hydrothermal
environments, and the biological influences on the formation of sedimentary iron
and uranium. Detailed, atomic-scale investigations of minerals, fluids, and
mineral-fluid interfaces play a central role in this domain. However, with the
continued success of science-based exploration, perhaps the greatest challenges
for Earth scientists are not to find more resources— although this will surely
remain important—but to produce them more efficiently and safely, to mitigate
long-term environmental impacts, and to provide a scientific basis for long-term
land-use decisions.
Water
According to the United Nations Environment Program, more than one-third
of all people are without a safe water supply, and one-quarter will suffer from
chronic water shortages during the next decade. By 2025, it is projected that 15
countries worldwide will have encountered water stress (i.e., consumption levels
exceeding 20% of available supply), 9 will suffer from water scarcity, and 22
will have run up against a “water barrier” to further development. 6
Informed decision making on water resources requires knowledge of the
complex hydrologic systems operating within the Critical Zone and a predictive
understanding of how they respond to natural and human modifications. At the
Science and Technology Center (STC) for Sustainability of Semi-Arid
6 Population change-natural resources-environment linkages in the Arab states region.
Food and Agriculture Organization, 1996 ( http://www.fao.org ).
BASIC EARTH SCIENCE AND SOCIETY
17
About this PDF file: This new digital representation of the
original work has been recomposed from XML files created
from the original paper book, not from the original
typesetting files. Page breaks are true to the original; line lengths,
word breaks, heading styles, and other typesetting-specific
formatting, however, cannot be retained,
and some typographic errors may have been accidentally inserted.
Please use the print version of this publication as the authoritative
version for attribution.