Details of Award
NERC Reference : NE/X01732X/1
Determining the origin and evolutionary history of volatiles on Earth
Fellowship Award
- Fellow:
- Dr M Broadley, The University of Manchester, Earth Atmospheric and Env Sciences
- Grant held at:
- The University of Manchester, Earth Atmospheric and Env Sciences
- Science Area:
- Atmospheric
- Earth
- Terrestrial
- Overall Classification:
- Unknown
- ENRIs:
- Global Change
- Science Topics:
- Geochemistry
- Mantle composition
- Subduction
- Mantle & Core Processes
- Noble gases
- Plate tectonics
- Volcanic Processes
- Mantle plumes
- Planetary Atmospheres
- Abstract:
- With its surface covered in liquid water, the Earth stands out amongst the other planets of the solar system as the only known haven capable of supporting life. But what makes the Earth so unique? And where did its life-supporting oceans and atmosphere originate? These are the fundamental questions that drive my scientific research. When Earth formed 4.5 billion years ago, the solar system was a very different, chaotic, place. The Earth grew from repeated collisions between kilometre-sized asteroids. These impacts would have generated huge amounts of energy that would have ejected the oceans and atmosphere in to space, leaving it dry and barren of the ingredients essential for life. So how the Earth became the volatile-rich planet we know today remains a mystery. To understand how volatile elements arrived on Earth we need to looks for clues in their composition that could point us to their origin. However, the Earth's active geology and biology has wiped out any potential fingerprints that may have existed on the Earth's surface. Fortunately, deep inside the Earth's mantle there are regions that have remained isolated from the surface for billions of years, and still retain the information needed to solve the mysterious origin of Earth's volatiles. I therefore plan to analyse the composition of volatiles trapped in volcanic rocks and ancient diamonds erupted from deep within the Earth. This research will shed new light on, how and when, volatiles arrived on Earth, and evaluate how geological processes redistributed these volatiles throughout Earth's history. More specifically it will enable three central questions concerning the Earth's volatile cycle to be addressed 1) What is the origin of volatiles trapped within the mantle, and did Earth acquire volatiles from multiple different sources? Noble gases are inert volatile elements that show resolvable isotopic and elemental differences between different accretionary sources (solar, chondritic, cometary, etc.) making them key tools for understanding the origin of volatiles on Earth. By analysing noble gas isotopes within basaltic glasses I will attempt to reveal the origin of volatiles in Earth's mantle and provide a better understanding on the where exactly in the solar system did the Earth's volatiles originate. 2) When did volatiles first started being recycled to the mantle, and how has the process of subduction modified the mantle volatile budget through time? The Earth's surface environment and climate is modulated by the movement of volatiles such as water, carbon and nitrogen between the atmosphere and the mantle. The main process through which volatiles are introduced to the mantle is through subduction. This process is unique to the Earth and may have been key in preventing the runaway greenhouse conditions that affected our neighbouring planet Venus. However despite the important role volatile subduction plays in controlling the habitability of the Earth it is not currently well understood when this return flux of volatiles to the mantle commenced. In this project I will analyse volatiles in ancient diamonds to search for signs of ancient subduction and determine when and to what extent volatiles started being returned to the mantle. 3) Does subduction heterogeneously recycle different volatiles in to the mantle? From mass balance calculations at volcanic arcs it is known that at least some volatiles survive the subduction process and make it in to the mantle. However, how these volatiles are then distributed throughout the mantle is less well known. By combining the analysis of halogens and nitrogen with the heavy noble gases, which have an easily identifiable subducted signature I will determine to what extent halogens and nitrogen in the mantle have a recycled origin, and provide an insight into the mantle dynamics that control their distribution throughout the mantle.
- NERC Reference:
- NE/X01732X/1
- Grant Stage:
- Awaiting Event/Action
- Scheme:
- Research Fellowship
- Grant Status:
- Active
- Programme:
- IRF
This fellowship award has a total value of £780,159
FDAB - Financial Details (Award breakdown by headings)
| DI - Other Costs | Indirect - Indirect Costs | DI - Staff | DA - Estate Costs | DI - T&S | DA - Other Directly Allocated |
|---|---|---|---|---|---|
| £97,435 | £235,660 | £266,409 | £72,832 | £8,572 | £99,251 |
If you need further help, please read the user guide.