It seems the ‘Boring Billion’ – a period in Earth’s history between 1,850 million and 850 million years ago – wasn’t so boring after all.

Geologists have found that our planet’s crust was ‘hot and thin’ throughout the time period, measuring just 25 miles (40km) or less.

Today, the base of the Earth’s crust can reach as deep at 60 miles (100km) in large mountain ranges such as the Sierra Nevada and the Alps.

Furthermore, the crust was thin and was populated with low mountain ranges that were created by less gentle tectonic activity. 

The Boring Billion was always considered the most dull period in Earth’s past, due to the fact that not much happened to its climate or tectonic activity.

Tectonic plates smashing together has caused the formation of most of Earth's mountains - a process called 'orogenesis' - including the Himalayas (pictured). But during the Boring Billion, Earth populated by lower mountain ranges, created by more gentle tectonic activity

The formation of most of Earth’s mountains has been caused by tectonic plates colliding together – a process known as ‘orogenesis’, which includes the Himalayas (pictured). Earth was populated with lower mountain ranges created by gentler tectonic activity during the Boring Billillion.


The ‘boring billion’ refers to a time in which the Earth’s climate was very peaceful. 

It is believed that between 1,800 million and 800 millions years ago, very little had changed. 

Algae was the most advanced form life on Earth and its oxygen levels were lower than they are now. 

It is believed that there were no severe ice age or volcanic activity, which allowed the status quo to be preserved for about a billion years.    

The new study, led by Christopher J. Spencer, a geological scientist at Queen’s University in Kingston, Canada, challenges this idea.

‘Notably during the Boring Billion, oxygen levels were low and there is no evidence of glaciation,’ the team say in their paper, published in Geophysical Research Letters. 

“We propose that the thin crust observed at this time is due to high temperatures, which result in greater crustal flow, and thus lower mountain ranges. 

Earth’s lithosphere – its rocky, outermost shell – is formed of around 15 tectonic plates, each of different shapes and sizes.

You can detect powerful seismic activity along the tectonic plates’ borders, where the plates rub up against one another. 

This is when plate tectonics can cause natural disasters all over the globe, including earthquakes and tsunamis. 

But tectonic plates smashing together has caused the formation of most of Earth’s mountains – a process called ‘orogenesis’ – including the Himalayas.   

Map shows the tectonic plates of the lithosphere on Earth. Orogenesis is the process whereby tectonic plates converge and mountain systems are created

Map showing the tectonic plates in the lithosphere of Earth. Orogenesis refers to the process by which tectonic plates collide and mountain systems are formed.

The study authors explain that orogenesis caused significant thickening in the continental crust in the case of the Himalayas and the Andes. 

“Recent efforts to provide geochemical proxy for crustal thickness has allowed geologists track the thickness through geologic times.”

Previous knowledge that the Earth’s crust was thin during the Boring Billion has led some to believe that it was a period of ‘orogenic quiescence’ or dormancy.  

The authors of this paper claim that the geologic record is “rife” with ancient orogenic belts at this time, as evidenced in metamorphic andigneous rock. 

They state that metamorphic rocks, in particular, have higher than normal pressure and temperature ratios, which indicates unusually hot crust. 

Earth has three layers: the crust (made of solid rocks and minerals), the mantle and the core. Today, under large mountain ranges, such as the Alps or the Sierra Nevada, the base of the Earth's crust can be as deep as 60 miles (100km)

The Earth’s three layers are the crust (made from solid rocks and minerals), mantle, and core. The Earth’s crust can reach as deep today as 60 miles (100km), depending on how high the mountain ranges are, such as the Sierra Nevada and the Alps. 

This created a style of plate tectonics much like ‘a waltz on a slippery dancefloor’, the Guardian reports – rather than the violent dodgem-car style we see today. 

Understanding more about the Boring Billion – which occurred in the the mid-Proterozoic era – may shed more light on how contemporary tectonic plates became so powerful. 

The Boring Billion was when algae was the most advanced form of life on Earth. However, oxygen levels were much lower than they are now. 

But despite its boring reputation, a study in 2017 found that the origin of photosynthesis in plants dated to 1.25 billion years ago during the period.

This era may have been the catalyst for the development of more complex life forms, which culminated in the Cambrian Explosion 541 million years ago. 

The Cambrian Explosion saw an explosion of new animal phyla. This may have been due to a steep increase in oxygen, which included arthropods with legs. 


Research continues to help determine when different stages of life first appeared on Earth. This is a more than 4.5 billion year old.

It’s believed that simple cells are what gave rise to life 3.8 billion year ago.

Multicellular life began in multicellular form 2.1 billion year ago.

800 million to 600,000,000 years ago were the first animals to appear, including the first arthropods.

475 million year ago, the first plants were born on land.

400 years ago, seeds and insects appeared.

360 million years ago, amphibians evolved, and reptiles developed 300 million years later. Dinosaurs followed soon after.

200 million years ago, the first mammals appeared.

Birds began to evolve 150 million years ago.

130 million years ago was the date of the birth of flowers.

60 million years ago, primates first arrived on Earth.

2.5 million years ago, the Homo genus (including humans and our predecessors) was created. This led to the development of anatomically modern humans 200,000 year ago.