Hunting Fertilizer to Find Hints of Early Life

Justin Drummond and Mariana de Souza Carvalho, students of Pufahl and co-supervisor Claudio Porto, in the field looking at economic phosphorite. CREDIT: Peir Pufahl/Acadia University View full size image

In Brazil, a search for fertilizer fodder is also turning into a hunt for ancient life.

Scientists at Nova Scotia-based Acadia University are working with MbAC Fertilizer Corp. to help the Brazilian company find and analyze phosphate deposits — the basis for fertilizer — in a small mining town in central Brazil.

At the same time, the project researchers seek to understand how the tiny plants that deposited the phosphorous helped drive ocean evolution, particularly in the period from 700 million to 740 million years ago — just as multicellular life began evolving on Earth.

"It's kind of like turning a book on its side so you've got the pages horizontal. What we do, and what I train my students to do, is to learn the language. To interpret the rocks," said Peir Pufahl, a chemical and economic sedimentologist at Acadia.

"Mind you, 80 percent of our pages are ripped out and missing," he told OurAmazingPlanet. "We get to piece together the story using the layers of sediment we see accumulated in these ancient oceans."

MbAC and the Acadia researchers together examine aerial maps of the Campos Belos region, looking for rock outcrops, then travel to the sites to perform their work. Many of these sites have never been probed with modern tools, providing a bit of frontier research for the Acadia scientists.

Tidal environments

In a typical day, Pufahl and his students visit the site and examine the layers of rocks in the field. By day's end, they leave the area — often with a long cylinder of rock that they extracted using a special tool. They then perform chemical analyses on how the so-called phosphorous cycle changed over time. [Images: Mining for Signs of Early Life]

Phosphorous typically washes into the water from land deposits, then is eaten by algae. In turn, bigger animals eat the algae.

When those bigger animals die, their bodies sink to the seafloor, and the phosphorous is released into the sand as the animals decay, leaving deposits behind. Over eons, some of these once-underwater areas become dry land.

The scientists have completed only one field season of research, so their investigations have not yet produced any journal papers. But so far, the researchers have figured out the phosphate deposits arose in some sort of tidal flat.

"That's the first step to understand these deposits and the environments in which the phosphate is recycling," Pufahl said.

Pufahl aims to examine the global glaciations and melts that were occurring just before multicellular organisms arose, to see how these sudden climate changes affected the evolution of life.

Finding fodder

Pufahl's working relationship with MbAC arose through serendipity. Four years ago, at the request of the Society of Economic Geologists, he gave a talk on phosphorous in Brazil, where he met company representatives.

Brazil is seeking "mineral independence" in the next 20 years, meaning the country would no longer need to import these life essentials from other nations, Pufahl said. With a population of 200 million people to feed, phosphorous is important because it will let Brazil increase its fertilizer production, leading to more food for its residents.

MbAC assists with funding Pufahl's project, and provides research money for one of his students.

The company and the researchers expect to continue collaborations for another 1 to 2 field seasons, which typically last about a month during Brazil's fall or winter (the Northern Hemisphere's spring and summer.)

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