Nav: Home

Ash from dinosaur-era volcanoes linked with shale oil, gas

March 13, 2018

Nutrient-rich ash from an enormous flare-up of volcanic eruptions toward the end of the dinosaurs' reign kicked off a chain of events that led to the formation of shale gas and oil fields from Texas to Montana.

That's the conclusion of a new study by Rice University geologists that appears this week in Nature Publishing's online journal Scientific Reports.

"One of the things about these shale deposits is they occur in certain periods in Earth's history, and one of those is the Cretaceous time, which is around the time of the dinosaurs," said study lead author Cin-Ty Lee, professor and chair of Rice's Department of Earth, Environmental and Planetary Sciences. "This was about 90 million to 100 million years ago, which is about the same time as a massive flare-up of arc volcanoes along what is today the Pacific rim of the Western United States."

Advances in horizontal drilling and hydraulic fracturing over the past 20 years led to a U.S. energy boom in "unconventionals," a category that includes the shale gas and "tight" oil found in shale fields like the Cretaceous Eagle Ford and Mowry and older ones like the Barnett and Bakken.

"These types of natural gas and oil are in tiny, tiny pores that range from a few millionths of a meter in diameter to a few thousandths of a meter," Lee said. "The deposits are in narrow bands that can only be accessed with horizontal drilling, and the oil and gas are locked in these little pockets and are only available with techniques like hydraulic fracturing."

Lee said that there have always been hints of a connection between ancient volcanic eruptions and unconventional shale hydrocarbons. During field trips out to West Texas, he and Rice students noticed hundreds of ash layers in exposed rock that dated to the Cretaceous period when much of western North America lay beneath a shallow ocean.

One of these trips happened in 2014 while Lee and Rice colleagues also were studying how a flare-up of Cretaceous-era arc volcanoes along the U.S. Pacific rim had impacted Earth's climate through enhanced volcanic production of carbon dioxide.

"We had seen ash layers before, but at this site we could see there were a lot of them, and that got us thinking," Lee said. Lee, graduate student Hehe Jiang and Rice undergraduates Elli Ronay, Jackson Stiles and Matthew Neal decided to investigate the ash beds in collaboration with Daniel Minisini, a colleague at Shell Oil who had been doing extensive work on quantifying the exact number of ash beds.

"It's almost continuous," Lee said. "There's an ash layer at least every 10,000 years."

Lee said the team determined that ash had come from hundreds of eruptions that spanned some 10 million years. The layers had been transported several hundred miles east of their volcanic source in California. The ash was deposited on the seafloor after being blown through plumes that rose miles into the atmosphere and drifted over the ocean. Lee and students analyzed samples of the ash beds in the geochemical facilities at Rice.

"Their chemical composition didn't look anything like it would have when they left the volcano," he said. "Most of the original phosphorus, iron and silica were missing."

That brought to mind the oceanic "dead zones" that often form today near the mouths of rivers. Overfertilization of farms pumps large volumes of phosphorus down these rivers. When that hits the ocean, phytoplankton gobble up the nutrients and multiply so quickly they draw all the available oxygen from the water, leaving a "dead" region void of fish and other organisms.

Lee suspected the Cretaceous ash plumes might have caused a similar effect. To nail down whether the ash could have supplied enough nutrients, Lee and his team used trace elements like zirconium and titanium to match ash layers to their volcanic sources. By comparing rock samples from those sources with the depleted ash, the team was able to calculate how much phosphorus, iron and silica were missing.

"Normally, you don't get any deposition of organic matter at the bottom of the water column because other living things will eat it before it sinks to the bottom," Lee said. "We found the amount of phosphorus entering the ocean from this volcanic ash was about 10 times more than all the phosphorus entering all the world's oceans today. That would have been enough to feed an oxygen-depleted dead zone where carbon could be exported all the way down to the sediment."

The combination of the ashfall and oceanic dead zone concentrated enough carbon to form hydrocarbons.

"To generate a hydrocarbon deposit of economic value, you have to concentrate it," Lee said. "In this case, it got concentrated because the ashes drove that biological productivity, and that's where the organic carbon got funneled in."

Lee said shale gas and tight oil deposits are not found in the ash layers but appear to be associated with them. Because the layers are so thin, they don't show up on seismic scans that energy companies use to look for unconventionals. The discovery that hundreds of closely spaced ash layers could be a tell-tale sign of unconventionals might allow industry geologists to look for bulk properties of ash layers that would show up on scans, Lee said.

"There also are implications for the nature of marine environments," he said. "Today, phosphorus is also a limiting nutrient for the oceans, but the input of the phosphorus and iron into the ocean from these volcanoes has major paleoenvironmental and ecological consequences."

While the published study looked specifically at the Cretaceous and North America, Lee said arc volcano flare-ups at other times and locations on Earth may also be responsible for other hydrocarbon-rich shale deposits.

"I suspect they could," he said. "The Vaca Muerta field in Argentina is the same age and was behind the same arc as what we were studying. The rock record gets more incomplete as you go further back in time, but in terms of other U.S. shales, the Marcellus in Pennsylvania was laid down more than 400 million years ago in the Ordovician, and it's also associated with ashes."
-end-
The research was funded by the National Science Foundation, the Guggenheim Foundation and the Geological Society of America.

A copy of the paper is available at: https://www.nature.com/articles/s41598-018-22576-3.pdf

High-resolution IMAGES are available for download at:

https://www.flickr.com/photos/gsfc/8805097469/in/album-72157633661168968/
CAPTION: The eruption of Alaska's Pavlof Volcano as seen from the International Space Station May 18, 2013. The volcano's ash cloud rose to 20,000 feet and extended over hundreds of miles of the northern Pacific Ocean. (Photo courtesy of NASA/ISS Crew Earth Observations experiment and Image Science and Analysis Laboratory, Johnson Space Center)

https://commons.wikimedia.org/wiki/File:Shale_natural_gas_map_of_United_States.jpeg
CAPTION: An enormous volcanic flare-up at the end of the dinosaurs' reign kicked off a chain of events that led to the formation of the U.S. shale oil and gas fields from Texas to Montana. Rice University geologists said older shale gas fields, like the Marcellus in Pennsylvania and Ohio, may have formed from similar volcanic flare-ups hundreds of millions of years earlier. (Photo courtesy of Wikimedia Commons)

https://www.flickr.com/photos/gsfc/6714667901
CAPTION: Oxygen-depleted "dead zones" often form in the northern Gulf of Mexico due to nutrient-rich runoff from the Mississippi and Atchafalaya rivers, which are seen here as tan and greenish-brown plumes visible from the International Space Station in 2012. Nutrient-rich volcanic ash may have fed similar dead zones that produced shale oil and gas fields from Texas to Montana. (Photo courtesy of NASA/GSFC/Aqua MODIS)

Related research from Rice:

Rice's Cin-Ty Lee wins Guggenheim Fellowship -- April 7, 2017

Oxygen atmosphere recipe = tectonics + continents + life -- May 16, 2016

Going deep to study long-term climate evolution -- Oct. 31, 2013

Volcano location could be greenhouse-icehouse key -- Feb. 6, 2013

Copper chains: Study reveals Earth's deep-seated hold on copper -- April 5, 2012

Rice researchers track zinc, iron in magma to see how oxygen travels inside planet -- Dec. 2, 2010

This release can be found online at news.rice.edu.

Follow Rice News and Media Relations via Twitter @RiceUNews

Located on a 300-acre forested campus in Houston, Rice University is consistently ranked among the nation's top 20 universities by U.S. News & World Report. Rice has highly respected schools of Architecture, Business, Continuing Studies, Engineering, Humanities, Music, Natural Sciences and Social Sciences and is home to the Baker Institute for Public Policy. With 3,879 undergraduates and 2,861 graduate students, Rice's undergraduate student-to-faculty ratio is 6-to-1. Its residential college system builds close-knit communities and lifelong friendships, just one reason why Rice is ranked No. 1 for quality of life and for lots of race/class interaction and No. 2 for happiest students by the Princeton Review. Rice is also rated as a best value among private universities by Kiplinger's Personal Finance. To read "What they're saying about Rice," go to http://tinyurl.com/RiceUniversityoverview.

Rice University

Related Phosphorus Articles:

Zinc's negative effects on mineral digestibility can be mitigated, study shows
Researchers at the University of Illinois have shown that a common strategy for reducing postweaning digestive problems in pigs may have negative effects on calcium and phosphorus digestibility, and are suggesting management practices to counteract the effects.
Iron deficiency restrains marine microbes
Iron is a critical nutrient in the ocean. Its importance for algae and the nitrogen cycle has already been investigated in detail.
A better way to manage phosphorus?
A new project proposes a restructured index to build on phosphorus management efforts in farm fields in New York state and beyond.
Nitrogen, phosphorus from fertilizers and pet waste polluting urban water
New research from the University of Minnesota points to lawn fertilizers and pet waste as the dominant sources of nitrogen and phosphorus pollutants in seven sub-watersheds of the Mississippi River in Saint Paul, Minn.
Study quantifies effect of 'legacy phosphorus' in reduced water quality
For decades, phosphorous has accumulated in Wisconsin soils. Though farmers have taken steps to reduce the quantity of the agricultural nutrient applied to and running off their fields, a new study from the University of Wisconsin-Madison reveals that a 'legacy' of abundant soil phosphorus in the Yahara watershed of Southern Wisconsin has a large, direct and long-lasting impact on water quality.
Increased water availability from climate change may release more nutrients into soil in Antarctica
As climate change continues to impact the Antarctic, glacier melt and permafrost thaw are likely to make more liquid water available to soil and aquatic ecosystems in the McMurdo Dry Valleys, potentially providing a more nutrient-rich environment for life, according to a Dartmouth study recently published in Antarctic Science.
UD's Jaisi wins NSF Career Award for research on phosphorus in soil
Much like criminal forensic scientists use fingerprints to identify guilty parties at crime scenes, the University of Delaware's Deb Jaisi utilizes isotopic fingerprinting technology to locate the sources of phosphorus compounds and studies the degraded products they leave behind in soil and water.
Wastewater research may help protect aquatic life
New wastewater system design guidelines developed at UBC can help municipal governments better protect aquatic life and save millions of dollars a year.
Safe fog
Safety combined with power and effectiveness is one of the most important targets in the development of pyrotechnic obscurants.
How your diet can influence your environmental impact
The impact of our dietary choices on the global phosphorus footprint shouldn't be neglected, shows a new study.

Related Phosphorus Reading:

Low Phosphorus Cookbook: MAIN COURSE – 80 + Low-Phosphorus Breakfast, Main Course, Dessert and Snacks Recipes (Proven recipes to treat renal problems)

Phosphorus, The Best Brain Food: The Neglected Mineral That Makes You Smarter

Phosphorus (Elements)
by Richard Beatty (Author)

The 13th Element: The Sordid Tale of Murder, Fire, and Phosphorus
by John Emsley (Author)

Phosphorus in Action: Biological Processes in Soil Phosphorus Cycling (Soil Biology)
by Else K. Bünemann (Editor), Astrid Oberson (Editor), Emmanuel Frossard (Editor)

Potassium and Phosphorus guide

Phosphorus: A Winterstrike Story (NewCon Press Novellas Set 3)

Phosphorus: An Element that could have been called Lucifer (SpringerBriefs in Environmental Science Book 9)
by Springer

Eating A Pre-Dialysis Kidney Diet - Sodium, Potassium, Phosphorus and Fluids: A Kidney Disease Solution (Renal Diet HQ IQ Pre Dialysis Living) (Volume 2)
by Mrs. Mathea Ford (Author)

Phosphorus Compounds: Advanced Tools in Catalysis and Material Sciences (Catalysis by Metal Complexes Book 37)
by Springer

Best Science Podcasts 2018

We have hand picked the best science podcasts for 2018. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Circular
We're told if the economy is growing, and if we keep producing, that's a good thing. But at what cost? This hour, TED speakers explore circular systems that regenerate and re-use what we already have. Guests include economist Kate Raworth, environmental activist Tristram Stuart, landscape architect Kate Orff, entrepreneur David Katz, and graphic designer Jessi Arrington.
Now Playing: Science for the People

#504 The Art of Logic
How can mathematics help us have better arguments? This week we spend the hour with "The Art of Logic in an Illogical World" author, mathematician Eugenia Cheng, as she makes her case that the logic of mathematics can combine with emotional resonance to allow us to have better debates and arguments. Along the way we learn a lot about rigorous logic using arguments you're probably having every day, while also learning a lot about our own underlying beliefs and assumptions.