Images: See the Cave Where Bacteria Build Rocks

Microbes can make rocks

Tjuv-Ante’s Cave

(Image credit: Johannes Lundberg/Swedish Museum of Natural History)

In Sweden's Tjuv-Antes cave, researchers discovered that bacteria help build clusters of calcite rock that resemble popcorn and coral.

Entering the cave

Tjuv-Ante’s Cave

(Image credit: Johannes Lundberg/Swedish Museum of Natural History)

Researchers enter Tjuv-Ante’s Cave.

Dark dolerite

Tjuv-Ante’s Cave

(Image credit: Johannes Lundberg/Swedish Museum of Natural History)

Dripstones called coralloids coat the cave's ceiling. Dripstones are created by mineral-laden water seeping inside a cave.

Close inspection

Tjuv-Ante’s Cave

(Image credit: Johannes Lundberg/Swedish Museum of Natural History)

Researchers collected rocks and microbes for testing.

Cave popcorn

Tjuv-Ante’s Cave

(Image credit: Johannes Lundberg/Swedish Museum of Natural History)

The popcorn ceiling in Tjuv-Ante’s Cave.

Rock coral

Tjuv-Ante’s Cave

(Image credit: Johannes Lundberg/Swedish Museum of Natural History)

Fingers of coral-like calcite dangle from the cave ceiling.

Flowstone

Tjuv-Ante’s Cave

(Image credit: Johannes Lundberg/Swedish Museum of Natural History)

Water dripping into the cave in spring and summer spurs intense bacterial growth. The bacteria excrete calcium, which helps form the cave's calcite dripstones.

Collecting samples

Tjuv-Ante’s Cave

(Image credit: Johannes Lundberg/Swedish Museum of Natural History)

Sampling the microbes inside Tjuv-Ante’s Cave.

Cave interior

Tjuv-Ante’s Cave

(Image credit: Johannes Lundberg/Swedish Museum of Natural History)

Cave popcorn, a type of dripstone.

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Becky Oskin
Contributing Writer
Becky Oskin covers Earth science, climate change and space, as well as general science topics. Becky was a science reporter at Live Science and The Pasadena Star-News; she has freelanced for New Scientist and the American Institute of Physics. She earned a master's degree in geology from Caltech, a bachelor's degree from Washington State University, and a graduate certificate in science writing from the University of California, Santa Cruz.