Details of Award
NERC Reference : NE/C517909/1
Temporal Constraints on Environmental and Biological Change in Earth History
Fellowship Award
- Fellow:
- Dr D Condon, British Geological Survey, NERC BGS - Keyworth
- Grant held at:
- British Geological Survey, NERC BGS - Keyworth
- Science Area:
- Earth
- Overall Classification:
- Earth
- ENRIs:
- Pollution and Waste
- Biodiversity
- Science Topics:
- Tectonic Processes
- Properties Of Earth Materials
- Palaeoenvironments
- Climate & Climate Change
- Abstract:
- In order to understand the linkages between major events in Earth History, such as meteorite impacts and periods of extreme climate change, and biological developments (for example, mass-extinctions), geologist have to collect data from different places. Integrating such data requires knowledge of the absolute age of the different rock successions in order to determine if, for example, the rock horizon preserving evidence of a large meteorite impact is the same age as a layer in which the change in fossil assemblages shows evidence for a major extinction event. If they are the same age, it would be strong evidence to support ideas that the meteorite impact caused the extinction. This project aims to investigate periods of Earth history where there appears to be a connection between dramatic changes in fossil assemblages (indicating major evolutionary developments) associated with fluctuations in the global climate from greenhouse to icehouse (characterised by extensive ice sheets) periods. The older of these periods occurred around 800 to 540 million years ago, and is called the Neoproterozoic. At least three glaciations occurred during this period with evidence for sea-ice at the equator during at least one of them. Interestingly, following the last glaciation the oldest known fossils of large organisms appear in the rock record. In the subsequent 50 million years there is a dramatic increase in the richness (diversity) of the fossils types. It is this broad coincidence of extreme climatic events followed by a remarkable period of biological invention that has led people to suggest that the two are related. Some people have suggested that the extreme glaciations might have acted as a series of 'environmental filters' on microscopic organisms which already existed, stimulating evolution and development in the aftermath of these events. Other people have suggested the opposite, that biological evolution was the result of internal (genetic) changes, and this in turn influenced global climate. These are two end-member' scenarios, it is most likely much more complex than this. A major obstacle to our understanding of this remarkable period of Earth history is that the pieces of evidence are now distributed across the planet. Very rarely do rocks recording both climatic and biological events occur in the same section making it difficult to asses their temporal relationship and ideas about their interrelationship. This problem hinders our understanding of the glacial periods themselves, we don't know how many there were, how long they lasted for, or what caused them. We need a better understanding of the absolute age of the various successions recording these events, and this should allow us to integrate evidence from different outcrops, different continents, and test/develop ideas about the relationship(s) between global environmental change and early animal evolution. This is just one example where apparent linkages between global environmental change and biological development suggest they are linked, and each time, a robust understanding of the temporal relationships IS required in order to fully understand the situation. In order to determine the age of fossils, or rocks recording a period of glaciation, it is necessary to date volcanic rocks that occur with them. Volcanic rocks commonly contain radioactive uranium-bearing minerals, which over time decays to another element, lead. By measuring the amounts of each element, we can calculate the age of the rock. If we are lucky enough and the volcanic rock directly overlies a fossil (this is the case with the oldest megascopic fossils which occur in Newfoundland) then the age of the volcanic rock is the same as the fossil itself. The aim of this Fellowship is to develop a strategic approach to obtaining age constraints and application to the problems outlined above.
- NERC Reference:
- NE/C517909/1
- Grant Stage:
- Completed
- Scheme:
- Postdoctoral Fellow
- Grant Status:
- Closed
- Programme:
- Postdoctoral Fellowship
This fellowship award has a total value of £143,025
FDAB - Financial Details (Award breakdown by headings)
| Total - T&S | Total - Staff | Total - Other Costs |
|---|---|---|
| £7,250 | £107,274 | £28,500 |
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