Stephen Dutch – Earth Science. Earth Materials and Resources

Автор: Stephen Dutch
Название книги: Earth Science. Earth Materials and Resources
Формат: PDF
Жанр: Геология и Геодезия
Страницы: 691
Качество: Изначально компьютерное, E-book

Salem Press’s Earth’s Materials and Resources provides
a two-volume introduction to the major topics
of study in the earth’s physical processes and structures
and offers a comprehensive revision and update
to an earlier edition, published by Salem Press
in 2001.
The essays in this collection cover a wide range
of subject areas, including economic and energy
resources; minerals, soil, and rock; and issues surrounding
such fields as petroleum geology and engineering.
Areas of special attention include developments
in resource use and its environmental impact,
which is a major field of study that continues to show
rapid growth. The editor, Steven I. Dutch, Ph.D., has
reviewed each article for scientific authority and ensured
each essay’s currency.
Designed for high school and college students and
their teachers, these volumes provide hundreds of
expertly written essays supplemented by illustrations,
charts, and useful reference materials, resulting in
a comprehensive overview of each topic. Librarians
and general readers alike will turn to this reference
work for both foundational information and current
developments.
Each essay topic begins with helpful reference information,
including a summary statement that explains
its significance in the study of the earth and
its processes. Principal Terms define key elements or
concepts related to the subject. The background and
history of each subject are provided and detail important
contextual information on the topic. The
text itself is organized with informative subheadings
that guide readers to areas of particular interest.
An annotated Bibliography closes each essay and refers
the reader to external sources for further study
that are useful to both students and nonspecialists.
Finally, a list of cross-references directs the reader
to other subject-related essays within the set. At the
end of each volume, several appendices are designed
to assist in the retrieval of information, including a
Glossary that defines key terms contained in each set,
a Periodic Table of Elements, the Mohs Scale of mineral
hardness, and an Energy Source Comparison.
Salem Press’s Earth’s Materials and Resources is part
of a series of Earth science books that includes Physics
and Chemistry of the Earth, Earth’s Surface and History,
and Earth’s Weather, Water, and Atmosphere.
Many hands went into the creation of these volumes.
Special mention must be made of its editor,
Steven I. Dutch, who played a principal role in
shaping the reference work and its contents. Thanks
are also due to the academicians and professionals
who communicated their expert understanding of
Earth science to the general reader; a list of these
individuals and their affiliations appears at the beginning
of the volume. The contributions of all are
gratefully acknowledged.

In the eleven years since this volume was first
published, there have been many dramatic changes
in our understanding of Earth materials and in the
availability of Earth resources. This revised volume
reflects those changes.
First is that many statistics on resource availability
needed to be updated; articles mentioning
oil at $35 per barrel seem almost quaint in 2012.
Resources that were nearly unknown in 2001 have
emerged as vital today. Foremost among them are
lithium, used in rechargeable batteries, and other
rare earth elements used in electronics. Known
supplies of lithium are sufficient for consumer
electronics, but if lithium batteries become widely
used for powering automobiles, these lithium resources
could become severely strained. Rare earth
elements are produced in many places, but virtually
all of the world’s refining capacity is in China,
a geopolitical fact with far-reaching strategic
consequences.
Resource issues are tied to social issues as well.
Conflict or “blood” diamonds were used to finance
civil wars in parts of Africa and were frequently
mined by slave labor. A system of international regulations
on the import of diamonds has significantly
curtailed the conflict diamond trade. Although many
are aware of blood diamonds, notably from films like
Die Another Day (2002) and Blood Diamond (2006),
not many know of a similar problem with rare earth
minerals used in electronics. This issue is most acute
in the Congo region of central Africa where small,
hand-dug mines extract columbite and tantalite,
known as “col-tan” in mining circles. The col-tan is
frequently stolen by military and paramilitary groups
and sold either to buy weapons or simply to enrich
the thieves.
Other important updates relate to the future availability
of resources. Oil is just as finite in 2012 as it was
in 2001, and despite new discoveries and improved
methods of exploiting unconventional resources, we
are still using oil several times faster than it is being
discovered. For example, in June 2011, an oil field
was discovered in the Gulf of Mexico that would provide
700 million barrels of oil, which was the largest
discovery in the Gulf in twelve years. However, the
United States uses 20 million barrels of oil per day, so
to stay abreast of U.S. energy demand, we would have
to find an oil field that size every thirty-five days, not
every twelve years.
One development that was all but unknown in
2001 but that is very much in the news today is
“fracking,” or fracturing reservoir rocks to liberate
oil and natural gas. One potential belt of rocks
suitable for fracking extends along the west side of
the Appalachians through highly populated states,
where the notion has raised fears of contamination
of groundwater and other hazards. “Peak oil”—the
point where global demand will exceed the physical
capability to extract oil from the ground—is widely
expected to occur in the first half of the twentyfirst
century. But a new resource peak has begun
to cause concern: peak phosphorus. Our ability
to feed our population is critically dependent on
phosphorus fertilizers, and five countries hold
90 percent of the world’s known phosphate rock.
Much of our phosphate fertilizer is lost to runoff
and carried out to sea by rivers. There, it can cause
the eutrophication of coastal waters and create
dead zones, and much of it ends up in deep water
where it remains indefinitely. Fortunately, phosphorus,
unlike oil, can be recycled from human
and animal wastes or from plant matter through
no-till agriculture. Although the idea of recycling
wastes for fertilizer may seem unappetizing, it is a
millennia-old practice in many regions.
Resource use also entails risk, and several dramatic
disasters in the past decade require inclusion in this
revised volume. Foremost is probably the Deepwater
Horizon drilling disaster of 2010, in which an oil rig
in the Gulf of Mexico blew up, burned, and sank,
releasing the largest oil spill in history. The great
Japanese earthquake of 2011 caused immense loss
of life from tsunamis, but it also severely damaged
the nuclear power plant at Fukushima, releasing
radiation comparable to that from the infamous
Chernobyl disaster of 1986. The Japanese disaster,
however, was better contained, and most of the radiation
dispersed into the Pacific rather than over populated
landmasses. Mining mishaps continue to claim
lives, notably in China, which accounts for 80 percent
of the world’s mining fatalities and where over 2,400
miners died in 2010.
In editing the revised volume, my goals were first
to ensure that the coverage was up-to-date. Several articles that were appropriate for the first edition
were no longer relevant, or they required such extensive
revision that they needed to be rewritten. A
number of new essays have also been included to
reflect recent developments, and statistics and data
have been updated throughout. I have also strived to
keep the target audience in mind at all times. This
reference set is intended primarily for students at
secondary and introductory college levels, and in
reviewing the articles, the foremost question in my
mind was “Would this material make sense to a high
school or college student without an extensive science
background?” For the most part, the authors of
the original articles satisfied that objective admirably,
but there were several instances where changes were
made to better reflect the needs of the target audience,
and concepts and material that may have been
too advanced or potentially confusing for nonspecialists
were clarified.
My personal philosophy when choosing material
to include in courses, textbooks, or reference works is
that the material satisfies at least one of four criteria:
The material is of broad general interest.
Gemstones are a relatively small part of the world’s
mineral wealth, but they interest nonscientists in a
manner that is far greater than their total economic
value.
The material is of great practical value. Most of
the articles in this volume satisfy this criterion easily.
Civilization is based on oil, iron, copper, aluminum,
and a host of other metals. Soils and groundwater are
not glamorous topics, but they are absolutely essential
to human survival.
The material is needed to understand subjects in
either of the first two categories. In order to understand
how iron is deposited, for example, it is essential
to know that iron loses electrons, or ionizes, in
two different ways, one of which is highly soluble in
water and one of which is not.
The material illustrates how science works. All the
articles include sections on how the particular subject
of the article is researched, so there are many
references to geologic mapping, the petrographic
microscope, X-ray diffraction, and so on. Geologic
mapping is how geologists synthesize information
from a vast region into a concise and easily visualized
form. The petrographic microscope and other
analytical techniques are precise ways of identifying
minerals.
It is our hope that this revised Earth science encyclopedia
will give readers an accessible and current
picture of the geological sciences.