Dolomite has been found inside 'reef building' algae.

(PhysOrg.com) -- The century-old mystery of a missing mineral in coral reefs has been solved by a team from The Australian National University.

The team, led by Dr. Bradley Opdyke of the Research School of Earth Sciences, has uncovered a hidden stash of the mineral dolomite in coral reefs around the globe, ending a search that has lasted over 100 years. The discovery was published in Novembers Biogeosciences.

For over a century scientists have puzzled over the dolomite problem  the mystery surrounding the abundance of dolomite in fossil reefs and its apparent absence from modern reefs, said Dr. Opdyke.

We have discovered that dolomite is in fact present in large quantities in modern coral reefs, but from an unexpected source.

The teams eureka moment came when they found large quantities of dolomite packed inside a reef builder species of red algae, Hydrolithon onkodes.

There was dolomite on the reefs all along, but it was hidden within these algae, said Dr. Opdyke.

This species of algae is found in abundance on reefs around the world. The algae work with coral to cement the reef structure to withstand the tremendous hydraulic pressure of waves.

This is the first discovery of dolomite associated with a living organism.

Student Marinda Nash and Dr. Uli Troitzsch made the surprise discovery while investigating the effects of climate change on red algae.

The discovery was completely serendipitous  we were working on an unrelated question at the time, said Dr. Opdyke. When we confirmed the finding I said to Marinda, This is going to be huge. It opens up a kaleidoscope of future research topics.

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Provided by Australian National University