Subscribe to our free daily newsletters
. Earth Science News .




Subscribe to our free daily newsletters



WOOD PILE
Rotting oaks lead to hazardous voids in Indiana's Mount Baldy sand dune
by Staff Writers
Baltimore MD (SPX) Nov 12, 2015


This is an example of a hole in Mount Baldy -- all that remains of a buried oak. Image courtesy Erin Argyilan. For a larger version of this image please go here.

Mount Baldy, a sand dune in Indiana Dunes National Lakeshore, may appear to be no more than an innocent pile of sand grains speckled with vegetation, but the rolling slopes hide narrow, deep holes, which are evidence of entombed oak trees.

No one knew the holes under Mount Baldy existed until a six-year-old boy fell into one in the summer of 2013 and was buried. Emergency responders successfully rescued the boy after three and a half hours (Read more in Smithsonian), but the accident left Indiana University Northwest coastal geologist Erin Argyilan, who was there at the time, struck by the concept that deep, stable holes could form and survive in loose sand.

The subsequent study by Argyilan and her co-authors, which will be presented at the Geological Society of America meeting on Tuesday in Baltimore, Maryland, concludes that the holes formed when trees, buried by wind-blown sands, rotted away. A cement formed by fungi-produced minerals and chemical weathering lines the walls of the hole and temporarily maintains the branching shape of the tree hollows.

"These are living systems. There is a real interaction between biologic and geologic properties," said Argyilan. "We have to look at these dunes with an interdisciplinary mindset or we will miss how the system works."

Scientists know Mount Baldy is on the move. Geologists estimate that winds shift the crescent-shaped dune, which reaches 38 meters (126 feet) above the south shore of Lake Michigan, roughly 1.0-1.2 meters (3-4 feet) inland a year, although the actual movement is highly variable. Blowing sands overwhelm and bury vegetation, buildings and parking lots on the dune's windward side, and the tree hollows are being exhumed on the hill's leeward slope.

To learn how Mount Baldy's holes formed, the team first had to find some holes. Park Service personnel spotted some, while the Indiana Geological Survey used ground-penetrating radar to search for others. Argyilan and her colleagues even found one or two using paintbrushes and trowels. At one point they even found a fungus-ridden oak limb that terminated in a tree-shaped hollow.

"At that point, I was sold that we had trees being buried and decomposition driven by fungus," said Argyilan. "But I did not know why the holes would stay open."

The scientists turned to scanning electron microscopy, which helps ascertain the surface texture and chemistry of minerals. Not only were the walls of the tunnels littered with hyphae, the equivalent of fungal roots, but they also were covered with a cementing mineral.

Fungi were likely living inside the trees prior to the plants' burial. Once the trees were entombed, the fungi decomposed the tree, and the long-lasting cement maintained the structural integrity of the hollow even after the tree had decomposed, according to the study.

The cement is a byproduct of the fungal decomposition process and the result of chemical weathering, but the scientists are still studying the precise biological and chemical pathways that form the cement.

"The next step is to examine how involved the fungi are in creating the cement," said Argyilan.

Since starting to explore Mount Baldy's holes, Argyilan has learned of similar holes in Oregon coast dunes and at two other locations along the Great Lakes. The Oregon dunes appear to have been caused by smaller trees compared to the oaks at Mount Baldy. "The oaks make significantly more hazardous holes," said Argyilan, "especially when you can't see them from the surface."

Scientists have identified eleven holes on Mount Baldy, but Argyilan suspects they will find more as the dune migrates, partially the result of human activity in the area. A local harbor blocks sands from reaching the dune, while historic mining and tourists have eroded the dune's sandy slopes. Erosion has also increased during winter; shrinking lake ice - a product of climate change - does not protect the dune from winter winds as it has in the past.

"What's happening at Mount Baldy is basically the perfect storm for destroying and reactivating [the movement of] a dune," said Argyilan. "Here, and in general, I think it is a real possibility that we will see more holes as more dunes are reactivated by human activity."

Investigating the Origin of Holes Appearing in the Mount Baldy Dune at the Indiana Dunes National Lakeshore


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only

.


Related Links
Geological Society of America
Forestry News - Global and Local News, Science and Application






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle

Previous Report
WOOD PILE
Treetop leaves of tall trees store extra water
Kobe, Japan (SPX) Nov 09, 2015
A research team led by Associate Professor Ishii Roaki and Doctoral Student Azuma Wakana from the Kobe University Graduate School of Agricultural Science has discovered that the water storage tissue that they recently found in the world's tallest tree, Sequoia sempervirens (coast redwood), is also found in Japan's tallest trees, Cryptomeria japonica (Japanese cedar). How do tall trees supp ... read more


WOOD PILE
Slovenia toughens border ahead of EU migrant summit

McMurdo extends search and rescue ecosystem with new comsat solution

McMurdo completes MEOSAR satellite ground station in New Zealand

Italy's painstaking bid to identify shipwrecked migrants

WOOD PILE
Space rains junk on Spain

Researchers find way to create wide variety of new holograms

Lowering the 'softening temperature' via electric field

The complexity of modeling

WOOD PILE
Shipping fears as Rhine falls to lowest level in 40 years

Jellyfish highly efficient swimmers

Wildfires may double erosion across western US watersheds by 2050

Rapidly acidifying waters pose major threat for Southern Ocean ecosystem

WOOD PILE
Helping the Saimaa ringed seal adapt to climate change

Mammal body-size responds to climate change in ancient Wyoming

Local destabilization can cause complete loss of West Antarctica's ice masses

Scientists have front row seat to Arctic warming

WOOD PILE
China's Singles Day sparks baby formula shortage in Australia

Kenya army involved in sugar smuggling racket: report

EU downplays cancer risk from weedkiller in win for Monsanto

Ground-level ozone reduces maize and soybean yields

WOOD PILE
At least 8 killed in Iran flash flooding: state TV

Cyclone killed 14 on Yemeni island, officials say

Fuego Volcano eruption subsides in Guatemala

Strong 6.9-magnitude quake hits Chile: USGS

WOOD PILE
GBissau releases ex-military chief charged over coup bid

Liberian teenager awarded kids peace prize

French anti-jihadist forces seize Mali arms stashes

German diplomat to lead UN Libya talks, ex-envoy heads to UAE

WOOD PILE
Early proto-porcelain from China likely made from local materials

Environment and climate helped shape varied evolution of human languages

Divisive religious beliefs humanity's biggest challenge: Grayling

Predicting the human genome using evolution




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News






The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement