Tracing the Source of Illicit Sand—Can it be Done?
Boulder, Colo., USA: If you’ve visited the beach recently, you might think sand is ubiquitous.
But in construction uses, the perfect sand and gravel is not always an easy
resource to come by. “Not all sand is equal in terms of what it can be used
for,” notes Zack Sickman, coauthor of a new study to be presented on
Thursday at the Geological Society of America annual meeting. He says
concrete aggregate needs sand with a certain size and angularity—the kind
that is considered “immature” and often, but not always, found in rivers.
The demand for sand has exploded since WWII. “The consumption of sand and
gravel and crushed rock started accelerating [after the Second World War]
as a result of all the construction and infrastructure development and
urbanization that was happening in many areas,” says Aurora Torres,
coauthor of the study.
Although construction in Europe and North America has slowed, Torres notes
that developing nations are experiencing rapid urbanization, and with it,
an increased need for resources. The projected amounts of sand and gravel
will likely jump from 35 gigatons per year (2011 levels) to 82 gigatons per
year by 2060.
Sand mining, whether legal or illegal, has environmental and social
impacts. Sand removal can affect agriculture, water quality, air pollution,
sediment availability, and human health issues. While regulations can help
lessen impacts, some of this extraction and transport is illegal and
unmonitored. It’s this illicit trade that the team is focusing on.
The answer might be in the grains themselves. Sand is a strong forensic
marker—it reflects the unique rocks within a drainage basin and keeps the
record from extraction to construction. “There's no reason why I couldn't
go take a core of concrete of an existing skyscraper and take that same
compositional signature and tie it back to a source,” notes Sickmann.
Being able to quickly determine if mined sand is from an illegal area is an
important step in tamping down illicit sand trade. Sickmann says that it’s
possible to determine which river produced a truckload of sand, but “the
real crux of the issue is finding the most effective way to use the method
in a regulatory capacity.”
Sickmann and Torres want to find the most cost effective way to quickly and
effectively fingerprint sand from different sources. They plan to start a
proof-of-concept test on domestic (U.S.) sand first, where the sources and
processing locations are well known. They and colleagues around the U.S.
will collect concrete from home improvement stores and see if they can
trace back the source of the sand. If they can successfully identify the
catchment where the sand was sourced, they can move their methods to other
Eradicating Illicit Sand
The team thinks a quick sand fingerprinting method would be perfect for
areas in Southeast and South Asia. “Not only are there areas of concern
there with respect to illicit supply networks, the geology of Southeast
Asia and South Asia is complex, and should provide a lot of leverage in
distinguishing sand from different regional areas of concern,” notes
Sickmann. The more diverse the rocks are in a basin, the easier it is to
distinguish where the sand originated from.
Sand provenance identification is critical for reducing the impacts of
illegal sand mining. “This is a very important issue,” says Torres. “I see
this as a valuable tool that will be that will complement other strategies
that are being put in place to track and monitor these illicit supply
Zachary T. Sickmann
University of Texas at Austin
Paper No. 247-13:
Mass Extinctions and Climate Change: Analogs of Today’s Rapid Climate
Warming and Potential Biotic Catastrophe
Thursday, 29 Oct., 11:15 a.m. EDT
Session 187: T147. Anthropocene Sedimentology: Exploring Human-Sediment
# # #
The Geological Society of America, founded in 1888, is a scientific society
with members from academia, government, and industry in more than 100
countries. Through its meetings, publications, and programs, GSA enhances
the professional growth of its members and promotes the geosciences in the
service of humankind. Headquartered in Boulder, Colorado, USA, GSA
encourages cooperative research among earth, life, planetary, and social
scientists, fosters public dialogue on geoscience issues, and supports all
levels of earth science education.