Details of Award
NERC Reference : NE/C000854/1
Defining the role of atmospheric sulphur in the Permo-Triassic terrestrial extinction.
Grant Award
- Principal Investigator:
- Professor S Bottrell, University of Leeds, School of Earth and Environment
- Co-Investigator:
- Professor P Wignall, University of Leeds, School of Earth and Environment
- Co-Investigator:
- Dr RJ Newton, University of Leeds, School of Earth and Environment
- Grant held at:
- University of Leeds, School of Earth and Environment
- Science Area:
- Terrestrial
- Freshwater
- Earth
- Atmospheric
- Overall Classification:
- Earth
- ENRIs:
- Global Change
- Biodiversity
- Science Topics:
- Land - Atmosphere Interactions
- Land - Ocean Interactions
- Palaeoenvironments
- Climate & Climate Change
- Abstract:
- Around 250 million years ago a huge number of animal and plant species living on the land and in the sea became extinct. This event is known as the Permo-Triassic mass extinction and was the greatest calamity that ever befell life on this planet. A wide range of theories have been put forward to explain this event and many of these have focussed on the way life went extinct in the oceans. This has left a significant gap in our understanding of how the extinction in the oceans and on land were linked. Two events in particular are thought to have contributed to this colossal loss of life on earth. Both may have involved the release of large amounts of damaging, sulphur- containing gases . It is well known that an unusually large outpouring of volcanic rock, called the Siberian Traps occurred at almost exactly the same time as the extinction. Volcanic eruptions such as this are often accompanied by the release of large volumes of gases, particularly sulphur dioxide. The other well-documented event that coincides with the extinction is the loss of dissolved oxygen from the ocean. It is bacteria that cause this decrease in oxygen as they use it to decompose organic matter and when the oxygen supply in the water runs out other types of bacteria take over and begin to use sulphate for the same purpose. A by product of these 'sulphate-reducing bacteria' is hydrogen sulphide, the smelly gas also produced in rotten eggs. Our recent research at Leeds University has shown that the amount of oxygen in the worlds oceans dropped drastically just before the mass extinction whilst the amount of hydrogen sulphide rose dramatically. This was converted back to sulphate during a big 'mixing event' that coincides with the extinction in the oceans. This huge mixing of the oceans may have released hydrogen sulphide to the atmosphere. Both sulphur dioxide and hydrogen sulphide can produce harmful effects on plants and animals, either indirectly, through the acidification of terrestrial environments as they are removed from the atmosphere by rain water, or directly, because they poisonous. The aim of this project is to try and find out how much sulphur was in the atmosphere during the extinction event, where it came from, and what effect it had on the animals and plants. The mud at the bottom of freshwater lakes tends to store sulphur removed from the atmosphere by rain. As the mud slowly accumulates it forms a record of atmospheric sulphur through time. We intend to measure the concentrations of sulphur from a series of lake muds of the right age that have been collected from NW China. This will let us see how much sulphur was around, prior to and during the mass extinction event. We will also measure its stable isotopic composition as this can distinguish between sulphur from volcanic or bacterial (oceanic) sources. When compared to the fossil record of plants and animals also present in these lake muds, this information should help us to decide exactly what impact the volcanism and oceanic mixing had on the terrestrial environment 250 million years ago.
- NERC Reference:
- NE/C000854/1
- Grant Stage:
- Completed
- Scheme:
- Small Grants Pre FEC
- Grant Status:
- Closed
- Programme:
- Small Grants
This grant award has a total value of £27,924
FDAB - Financial Details (Award breakdown by headings)
| Total - Staff | Total - T&S | Total - Other Costs | Total - Indirect Costs |
|---|---|---|---|
| £14,321 | £1,663 | £5,352 | £6,588 |
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