Stromatolites: What are they and what would I do with one?
- A stromatolite is the oldest thing in the world. So could be the most important fossil you will or can ever collect.
- You may like facts and learning or need answers for homework so here goes all about Stromatolites:
- As colonies of simple bacteria, Stromatolites were the first forms of life on the Earth! So they are amazing!!
- And they’re very pretty.
- Most fossils you will come across are only millions of years old. Dinosaurs roamed the earth between 230 and 65 million years ago. But most fossil stromatolites are billions of years old. Yep, Billions!! The world’s oldest Stromatolite is the Strelly Pool Stromatolite from Pilbara in Western Australia and its 3.5 billion years old! To put that in context, Earth is only 4.5 billion years old. People like us have been around for a mere 500,000 years.
Strelly Pool Stromatolite, Pilbara Western Australia. 3.5 billion years old.
- The word stromatolite is derived from the Greek words στρώμα / strōma (meaning mattress/strata) and λίθος / lithos (rock). So the literal translation is mattress rock or layered rock.
- A lot of rocks can be layered of course so the term Stromatolite is almost always reserved for a layered rock composed of microbial mats. Microbial mats are multi-layered sheets of bacteria that form in shallow waters that trap and cement sediment together. This continues layer upon layer and eventually they are preserved in rock.
- The progressive adding of layers, coupled with subtle environment changes at the time, has caused them to be known as ‘picture stone’ or ‘landscape stone’ because they can look like a landscape. Cotham Marble found near Bristol, England from 205 million years ago is a very good example.
- In a sliced surface such as the picture above you are looking at a cross section view. The picture below is what stromatolites look like in 3D (with or without the cinema specs!):
- Stromatolites are found around the world with an impressive amount of variation. Check out these two. The first is from from Crytozoon Colony, Chocolay Hills, Northern Michigan, USA. It is a mere 2.2 to 2.4 billion years old.
- The Stromatolite below is from the district of Cochabamba, Bolivia, South America. It is an incredible 2.3 billion years old:
- Stromatolites peaked in the fossil record at 1.25 billion years. They probably dwindled because they were destroyed by grazing organisms before they could become fossils. Before this decline Stromatolites containing photosynthetic bacteria (cyanobacteria) were crucial in giving the Earth an oxygenated atmosphere. So more complex life could follow on from them.
- Click to see our ‘Slice of Life’ Stromatolite‘ or to find more about caring for collections?
- Think you can’t sneak another stone in? Here’s our blog on creative ways to add lovely stones to your decor . The oldest things on our amazing planet disguised as something very new.
- Here’s a YouTube Video on Stromatolites, in case we’ve left you wanting more….