UMass Amherst researchers find Chilean salt flat drains a surprisingly vast area
A recent research report about one of the largest lithium brine and salt deposits in the world in Chile's Atacama Desert by geoscientists from the University of Massachusetts Amherst is the first to show that water and solutes flowing into the basin originate from a much larger than expected portion of the Andean Plateau.
UMass Amherst graduate student Lilly Corenthal making notes at one of the largest lithium brine and salt deposits in the world, a deposit 3,900 feet thick in Chile's Atacama Desert, with the Andes Mountains in the background. The basin drains a surprisingly larger area of the Andean Plateau than geoscientists had expected.
Credit: UMass Amherst
The astonishingly massive evaporite deposit, 3,900 feet (1,200 m) thick, appears to be draining an area far larger than a map-based or topographic watershed would suggest, says lead hydrologist David Boutt.
The brine volume present, contrasted with the relatively small surface drainage in such an arid area, poses fundamental questions about both the hydrologic and solute budgets at plateau margins, that is the relationship between input and accumulation, the authors say. Their answers should aid understanding of the water and mineral resources in one of the world's driest regions.
As Boutt explains, "The amazing finding is the fact that most of the water is originating from outside the topographic watershed, on the Andean Plateau, and it's draining an area four or five times bigger than the watershed. There is no outlet to this basin and it is capturing an unbelievably huge volume of water in an otherwise extremely arid environment." Details appear in a recent early online edition of Geophysical Research Letters.
Boutt and first author Lilly Corenthal, his former graduate student, say the physical and chemical connections between active tectonics, slopes, discharge zones and aquifers are not well characterized. In fact, they do not yet understand the conditions under which the massive evaporate deposit formed. Thus, the Chilean salt flat, Salar de Atacama, provides "a unique case-study to investigate questions about sub-surface fluid flow on the margins" of the Central Andean Plateau and others like it where mountain building forces are still active, they point out.
A drainage area that is several times larger than the topographic catchment is more common than people think, Boutt notes. "You can't assume that the surface catchment and ground water catchment are the same, and it tends not to happen in humid areas. But in dry areas--his is the driest non-polar desert in the world--the difference can be extensive, as it is in this case. And, this water is very, very old," he adds. In such closed basins, high concentrations of mineral deposits, in particular lithium brine, represent an increasingly important resource in high global demand.
The researchers collected 300 samples of freshwater and brine to analyze how much sodium is entering the basin. Boutt says, "knowing something about how much sodium is there now can help us reconstruct how much water must have been coming in over the 7 to 10 million years as the Andes plateau uplift was taking place. The high elevation regions of the Andes are like wicks pulling water out of the atmosphere and putting it into the basin," he adds.
They also used satellite precipitation data to "backsolve" the brine's origins using sodium concentrations, oxygen and hydrogen isotopes, as the isotopic composition of water reflects the condensation temperature and precipitation rate over time. The main controls are source of the moisture and condensation temperature, and whether or not the water has experienced evaporation, Boutt notes.
Janet Lathrop | EurekAlert!
Solving the mystery of carbon on ocean floor
06.12.2019 | University of Delaware
Great Barrier Reef study shows how reef copes with rapid sea-level rise
05.12.2019 | University of Sydney
University of Texas and MIT researchers create virtual UAVs that can predict vehicle health, enable autonomous decision-making
In the not too distant future, we can expect to see our skies filled with unmanned aerial vehicles (UAVs) delivering packages, maybe even people, from location...
With ultracold chemistry, researchers get a first look at exactly what happens during a chemical reaction
The coldest chemical reaction in the known universe took place in what appears to be a chaotic mess of lasers. The appearance deceives: Deep within that...
Abnormal scarring is a serious threat resulting in non-healing chronic wounds or fibrosis. Scars form when fibroblasts, a type of cell of connective tissue, reach wounded skin and deposit plugs of extracellular matrix. Until today, the question about the exact anatomical origin of these fibroblasts has not been answered. In order to find potential ways of influencing the scarring process, the team of Dr. Yuval Rinkevich, Group Leader for Regenerative Biology at the Institute of Lung Biology and Disease at Helmholtz Zentrum München, aimed to finally find an answer. As it was already known that all scars derive from a fibroblast lineage expressing the Engrailed-1 gene - a lineage not only present in skin, but also in fascia - the researchers intentionally tried to understand whether or not fascia might be the origin of fibroblasts.
Fibroblasts kit - ready to heal wounds
Research from a leading international expert on the health of the Great Lakes suggests that the growing intensity and scale of pollution from plastics poses serious risks to human health and will continue to have profound consequences on the ecosystem.
In an article published this month in the Journal of Waste Resources and Recycling, Gail Krantzberg, a professor in the Booth School of Engineering Practice...
03.12.2019 | Event News
15.11.2019 | Event News
15.11.2019 | Event News
06.12.2019 | Earth Sciences
06.12.2019 | Life Sciences
06.12.2019 | Information Technology