Tiny tunnels inside garnets appear to be the result of boring microorganisms

August 8, 2018, Public Library of Science
Garnet crystal with distinct tubular structures. Credit: Ivarsson et al, 2018

Complex systems of microscopic tunnels found inside garnet crystals from Thailand are most likely the result of microorganisms making their homes inside these minerals, according to a study published August 8, 2018 in the open-access journal PLOS ONE by Magnus Ivarsson of the University of Southern Denmark and colleagues.

Endolithic organisms are those that live inside a substrate, be it , wood, bone, or some other material. Some microbes move into pre-existing cavities while others dig their own way in, but this behavior is unexpected in highly resistant minerals like garnet. In this study, Ivarsson and colleagues examined the structure and content of intricately branching tunnels inside garnet crystals from river sediments and soils in Thailand to determine whether they were formed by abiotic or biotic processes.

Chemical analysis of the tunnels found lingering organic compounds and filament-like structures reminiscent of bacteria and fungi, strongly suggesting that microbes once lived inside. Whether or not these organisms excavated the tunnels is less clear. The shape of the tunnels, examined under microscopy, doesn't completely rule out an abiotic origin, but certain features characteristic of endolithic lairs, such as anastomoses (connecting passages between adjacent tunnels) suggest the tunnels were at least partially formed by endolithic microbes.

Microphotograph of network of tubular structures originating at garnet surface. Credit: Ivarsson et al, 2018

These tunnels were originally noted because they "significantly decrease the quality and value of the garnets as gems," but this study has shown that they also represent a previously unrecognized habitat for endolithic organisms. In iron-poor sediments like those studied here, garnets represent a rare source of iron for iron-oxidizing , but confirming the identity of the tunnel-borers will require observations of live in a laboratory setting.

Ivarsson notes: "The reported system in garnets represents a new endolithic habitat in a hard silicate mineral otherwise known to be resistant to abrasion and chemical attack."

Explore further: Elon Musk presents underground LA tunnel project

More information: Ivarsson M, Skogby H, Phichaikamjornwut B, Bengtson S, Siljeström S, Ounchanum P, et al. (2018) Intricate tunnels in garnets from soils and river sediments in Thailand - Possible endolithic microborings. PLoS ONE 13(8): e0200351. doi.org/10.1371/journal.pone.0200351

Related Stories

Elon Musk presents underground LA tunnel project

May 18, 2018

Entrepreneur Elon Musk has given updated details of a project to build high-speed transport tunnels underneath Los Angeles in a bid to combat traffic and said he wanted to work with the city's subway operator.

New discovery: Microbes create dripstones

August 18, 2014

According to new research humble, microscopic organisms can create dripstones in caves. This illustrates how biological life can influence the formation of Earth's geology - and the same may be happening right now on other ...

High tunnels boost yield, along with plant-damaging insects

August 31, 2017

Growers of tomatoes, cucumbers and other vegetables can extend their growing season and increase yield by placing high tunnels over their cold-sensitive crops, but those tunnels don't provide the pest protection that has ...

Recommended for you

2018-2022 expected to be abnormally hot years

August 14, 2018

This summer's worldwide heatwave makes 2018 a particularly hot year. And the next few years will be similar, according to a study led by Florian Sévellec, a CNRS researcher at the Laboratory for Ocean Physics and Remote ...

10 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

abraxascarab
5 / 5 (8) Aug 08, 2018
Of course they are "Boring"... if they wanted to be popular, they'd be hanging out in diamonds or emeralds or some other mafic mineral like olivine. :)
TheGhostofOtto1923
4.2 / 5 (5) Aug 08, 2018
holy crap - and I thought that ash borers were tenacious. Lends more credence to panspermia.
delkin1
5 / 5 (5) Aug 09, 2018
Liked abraxascarab's pun on Boring endoliths. Thanks for the laugh! On a serious note...amazing that small living creatures can (slowly) drill through minerals. Got to admire their tenacity, and that of life, generally.
Thorium Boy
4.3 / 5 (6) Aug 09, 2018
Microbes eat gravestones and even lenses, under the right conditions. Remember the "Horta" the creature on Star Trek that bored through solid rock? Same thing.
rrwillsj
1 / 5 (2) Aug 10, 2018
Okay, I thought otto's panspermia fetish was ridiculous enough. But thumbtack boy bringing up comicbook fantasy;s truly achieves a new low of imbecility.

(TB, you forgot to mention the Star Trek episode with the rock-eating creature.)

otto, you are just going to have to try harder to reach such depths of stupidity in your fantasy league competition.

Go otto! We know you can do it!
Phyllis Harmonic
not rated yet Aug 10, 2018
(TB, you forgot to mention the Star Trek episode with the rock-eating creature.)


No he didn't:
TB: Remember the "Horta" the creature on Star Trek that bored through solid rock?


A lot of you guys seem to be more interested in pissing games and soap-boxing than actually contributing valuable commentary. Just an observation from a noobie, but it's annoying to have a comments section filled with endless screeds and juvenile name-calling.
Whart1984
not rated yet Aug 10, 2018
If you take a look thoroughly at the above picture, these microchannels could form in similar way, like similar tubes inside freezing ice, which is trapping bubbles at its slowly traveling surface.
IwinUlose
1 / 5 (1) Aug 10, 2018
A lot of you guys seem to be more interested in pissing games and soap-boxing than actually contributing valuable commentary. Just an observation from a noobie, but it's annoying to have a comments section filled with endless screeds and juvenile name-calling.


Welcome to the comments section! Most of the useful info stops at 'Journal reference:"
rrwillsj
3 / 5 (2) Aug 10, 2018
Yep, I blew it. Read "Star Trek". thought "Star Wars". Mea culpa. Mea culpa.

PH and IU, it has been my speculation that this site is to entice and entrap all us cranks, woo artists, stinky comedians and outright loons. To keep us off the "Real" science sites irritating the professionals.

That these comments are for the use of the Psych & Mental Health students to provide them with dissertation material.

Nevertheless, patronize the advertisers. They're the ones paying for this forum of futile foolishness.
granville583762
5 / 5 (1) Aug 11, 2018
Time to dig into Martian Regolith to uncover these garnets where Martian life has found the only safe place on mars to hide, not that it will help much when found, they bored into them billions of years a go.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.