CORDIS - EU research results

The magnitude and effect of a Cambrian large igneous province in Australia: a link between volcanism and mass extinction?

Final Activity Report Summary - A CAMBRIAN LIP (The magnitude and effect of a Cambrian large igneous province in Australia: a link between volcanism and mass extinction?)

This project concerned the possible link between a Cambrian mass extinction and an episode of massive volcanism. When the huge volcanic eruptions occurred, gases and particles were injected into the atmosphere with potentially devastating effects for the life forms that were then present on Earth.

The volcanism studied here coincided with a mass extinction, which occurred around 510 million years ago. This type of massive volcanism occurred several times during the history of Earth, many times coinciding with dramatic environmental change. These types of eruptions formed vast landscapes made up of basaltic lava called large igneous provinces (LIPs). Here, the Cambrian Kalkarindji LIP in Australia was investigated. One part of the project concerned revising the extent of this LIP in order to better estimate the size of the eruptions. This research resulted in a much larger size estimate for the Kalkarindji LIP, which was therefore defined to cover an area ten times the size of Great Britain.

Another part of the project dealt with the mixing of gases that erupted into the atmosphere. During magma evolution and eruption fluids and gases, e.g. carbon dioxide, are exsolved and transported to the atmosphere, where they affect climate. This project showed that one of the environmental effects of the Kalkarindji eruptions was global marine anoxia, i.e. low oxygen levels, possibly caused by global warming from the release of vast amounts of green house gases. One way of estimating the amount of volatiles released during the eruptions was to look at tiny bubbles of solidified magma (glass) in crystals in the volcanic rocks that were formed during the eruptions. The results of the studies indicated huge amounts of sulphur injected into the atmosphere during one eruptive event.

Another line of research involved determining what type of eruptions occurred, since highly explosive eruptions had the capabilities of injecting gases, ashes and aerosols into the stratosphere, where the they might affect climate more dramatically than in the troposphere. One of the results of this project was that important explosive eruptions occurred towards the end of the Kalkarindji volcanic activity.