What Is a Stone Mattress?

What Is a Stone Mattress?

This article relates to Stone Mattress

A "stone mattress" in the titular tale of this short story collection serves as a painful reminder of past events. It is also Margaret Atwood's nickname for fascinating geological formations called stromatolites.

Stromatolites (from the Greek 'stroma' = mattress/layer and 'lithos' = stone) are most easily described as living fossils. Blue-green algae, a type of cyanobacteria, trap the sediment around it with its sticky coating. The algae absorb both carbon dioxide and calcium dissolved in water, which then react to form calcium carbonate, which provides a limestone scaffolding for further expansion. This is a hugely lengthy process (it can take a stromatolite 100 years to grow just 5 cm) that eventually results in rock-like structures with forms varying widely dependent on their specific location.

Since stromatolites are one of the most ancient organisms with fossilized examples dating back 3.5 billion years, geologists can use cross-sections of fossilized examples to record the history of the planet much in the same way that dendrochronologists study the growth rings of timber. It is, in fact, highly likely that these mysterious monoliths are at least partly responsible for the rest of the life on planet Earth. By producing oxygen in quantities as a by-product of photosynthesis, the change they induced in the atmosphere played a large part in the development of eukaryotic cells. i.e. cells with a nucleus and the foundations of life as we know it.

The best example of living stromatolites are found at Shark Bay and Lake Thetis in Western Australia. The stromatolites can be found in parts of the lake that are particularly high in saline, an environment in which none of the stromatolites predators or competitors can survive, leaving the algae formations free to grow. The conservation of these strange structures is essential, not only for the information they can reveal regarding a murky and mysterious period in the history of the planet but also for the lessons they can teach us about the dramatic changes in our own environment as they are put at risk by the quality of our waters. Maintaining their current environment and decreasing any potential disruption by man or other organisms will help us retain these fascinating structures for future generations, structures that reflect the tough, multilayered, rather long-in-the tooth nature of Atwood's protagonists and their lives.

Picture of stromatolite in Shark Bay, Australia from australiascoralcoast.com

Filed under Nature and the Environment

This "beyond the book article" relates to Stone Mattress. It originally ran in November 2014 and has been updated for the June 2015 paperback edition. Go to magazine.