The violent making of the Earth - exploring the birth and infancy of a terrestrial planet using isotope geochemistry

Lead Research Organisation: University of Manchester
Department Name: Earth Atmospheric and Env Sciences

Abstract

This project aims to estimate the chemical composition of the Earth, which will contribute to our understanding of how it was formed. Knowing the chemical composition of the Earth is a fundamental parameter to almost every model in natural science, such as climate, atmospheric, oceanographic or solid Earth research. When estimating the composition of the Earth, scientists are facing a dilemma. We only have access to the very top part of the solid Earth, also called crust, which makes up only 0.5% of its mass. The remaining 99.5% are represented by the Earth's mantle and core and are beyond our reach, often buried more than 100km below the surface. Estimating the chemical composition of the entire Earth is therefore a complex and daunting task, fraught with large uncertainties, but essential to questions such as the Earth's contents of precious metals and how the key ingredients to life, particularly carbon and water, were delivered to our planet.

The Earth grew by collisions with its neighbouring planetary bodies some 4.6 billion years ago. The energies involved in these violent impacts were sufficient to melt the entire growing planet causing dense molten iron to sink to the centre and to form the Earth's core. Together with the iron, this process also stripped all precious metals, like gold and platinum, from the mantle leaving it devoid of these elements. After about 100 million years, these planetary collisions ceased and gave way to low-energy impacts of smaller asteroids. It has been suggested that this late asteroid shower, also called 'late veneer', not only delivered most of the ingredients essential for life, but also replenished the precious metal content of the mantle.

Some of the asteroids escaped incorporation into planets and have been circling the Sun unharmed for nearly 4.6 billion years. They therefore represent remnants of the building blocks that formed the Earth. Fragments of such asteroids are still falling to Earth as meteorites. They hold important clues as to what the bulk composition of the Earth was, before it separated into a core, mantle, and crust.

Over the past 40 years, the view persisted that the Earth has, on average, a chemical composition similar to that of meteorites. However, recent research showed that the rocks on Earth show a relative enrichment in the isotope 142-neodymium compared to these extraterrestrial rocks. It is therefore possible, that the Earth also has a completely different chemical composition. If true, our current models for the formation and evolution of the Earth have to be fundamentally revised.

Here, I will follow a different and novel approach of exploring this question: If one would know the composition of the crust, core, and mantle, one could simply 're-constitute' them into the composition of the whole Earth. Rocks of the crust are accessible and we know their composition. Based on geophysical evidence we also know the size of the core and we can estimate that it consists of almost 100% iron. The vital information that is still missing, is the composition of the mantle! I have developed two new analytical methods that will allow me to answer exactly this question. I will use them to measure lavas that originated in the mantle and erupted on the seafloor. For the first time, it will be possible to estimate the composition of the mantle and to calculate the composition of the Earth. The result will tell me, what the composition of the Earth's building blocks was and, ultimately, allow me to explore how the Earth was formed. Yet, I can take these studies a step further. My measurements will also show, how the precious metal-rich 'late veneer' was stirred back into the mantle and to what degree alternative explanations, such as leaking of hot iron melt from the core into the mantle, are alternative explanations of why the precious metals are so surprisingly "abundant" today.

Planned Impact

The results of this study and the new methods that are to be applied will be of interest not only to academics but also to the general public, industry, and policy makers:

1) Press/Media/Museums/Science education/Lay scientific organisations/Wider public

The massive media attention that followed the publication of my most recent research on the early geological history of the Earth in the journal 'Nature' demonstrated that my research produces results, which are of interest to the wider public. There is a general public interest in natural sciences, as shown by the large number of popular scientific journals and TV programs in the UK and worldwide. The origin of our planet is a regular theme of such productions. Yet, we still know only very little about this crucial time of Earth's history and, accordingly, new scientific results on this topic are readily embraced by the media.
I anticipate that the new scientific results of the proposed project will contribute to creating an improved public awareness of the processes that play a role in how the Earth and the planets were formed. I know that the press, TV and radio media, as well as lay science organisations are keen on disseminating this information. Therefore, important immediate beneficiaries of the project will be news channels, radio programmes, newspapers, popular scientific journals, scientific TV programs, natural history museums, geography/geology education programs in schools, and lay geologists and meteoriticists associations.

2) Commercial private sector

Industry: Nanotechnology is a fast-growing commercial sector, with an estimated 3 to 4 new products being released to the market every week. The Ce method that I recently developed, and which will be used in this project, can also be applied to the isotopic tracing of engineered CeO2 nanoparticles, based on radiogenic differences in their isotopic composition. This application will be developed in collaboration with Dr Mark Rehkämper and may be of reat interest for this industry sector.

Mining companies: An immediate result of the study will be to what extent the resources of precious metals that we find today in ore deposits, are due to the addition of meteoritic material to the early Earth. As such, the outcomes of this study will be of wider interest to commercial companies dealing with the mining of precious ore resources.

3) Policy makers

With the increased concern about manmade climate change, it is essential to understand the natural response of Earth systems to rapid climate change in the past, in order to predict what might happen in the future. Such future scenarios, based on high-quality data and open scientific findings, are integral to policy decisions about climate change prevention and mitigation. One of the methods that I recently developed, and which will be used in this project, will be applied to improve palaeo-oceanographic and palaeo-climate models (in collaboration with Dr Tina van de Flierdt). This work will have an immediate impact for the climate research community and this will transmit later to policy makers.

Related Projects

Project Reference Relationship Related To Start End Award Value
NE/J018031/1 01/03/2013 28/02/2014 £517,943
NE/J018031/2 Transfer NE/J018031/1 01/03/2014 31/12/2016 £431,343
 
Description More than 4 billion years ago, the Earth was a barren planet shocked by cataclysmic impacts of giant meteors and disrupted by planetary-scale volcanic eruptions. However, contrary to the more recent geological past less than 500 million years ago, we know where little about the geological processes that operated in the Early Earth and that may have completely transformed our planet into the one we know today.

A ground breaking new technique has been developed that allows the high-precision measurement of tungsten (W) isotopes in geological samples. These analyses can be used to study the processes involved in the evolution of the Early Earth.

This is an on-going study and the findings are still in the early stages. However, the first results show that the Earth may have been struck by a giant meteoritic shower sometime before 3.8 billion years ago and that this meteoritic material became incorporated into the Earth's mantle over the following 1 billion years. The results will help us to understand if and how mantle convection operated at that time. They may also help us to understand if plate-tectonics have operated on the Early Earth and if not, when this process has started. The results also yielded insights into the origin of precious metals in the Earth's mantle and crust.
Exploitation Route Media: The findings of this project so far (origin of precious metals, evolution of the Early Earth) are highly topical and the media has been very interested in them. The outcomes of this study will therefore further the interest of the general public in Earth Sciences in particular and Natural Sciences in general.

Research: The outcomes of the study have opened a new venue in study early geological processes on Earth and other terrestrial planets. As such, they will help other researchers inside and outside the immediate scientific community in their research.

Technology: The methods and outcomes of this study may be used to understand how natural resources formed in the geological past.
Sectors Education,Environment,Culture, Heritage, Museums and Collections

 
Description The findings of this study help to address the question of the origin of precious metals in the Earth's crust and mantel. This is a highly popular topic and has been picked up by the media. The PI has given several interviews to news reporters and TV production companies, all interested in gaining insights into the processes and theories involved. As a result, the findings of this study have been used in various magazine and news articles as well as TV productions. The PI has provided information regarding the general context as well as more specific models about the origin of precious metals based on the findings of this project (see details in 'Common Outcomes'). He has also made an appearance in a TV production by a Japanese TV channel. Apart from this, the PI has given several public lectures, delivered professional presentations at conferences/universities and is currently in the process of publishing the first outcomes of this project in high-imapct peer-reviewed journals. The results may have opened a new window into Early Earth research. Although the findings are discussed within the scientific community there is general consensus that the results are highly topical and important for our understanding of early geological processes.
First Year Of Impact 2013
Sector Education,Culture, Heritage, Museums and Collections
Impact Types Cultural

 
Description Standard grant (NI) - Testing the 'wet versus dry' late veneer hypothesis
Amount £332,000 (GBP)
Funding ID NE/L004011/1 
Organisation Natural Environment Research Council 
Sector Public
Country United Kingdom
Start 09/2014 
End 09/2017
 
Title Mass-dependent Mo isotope analyses in geological samples 
Description Novel chromatographic technique for the highly-efficient isolation of Mo from geological samples for high-precision isotope analyses 
Type Of Material Technology assay or reagent 
Year Produced 2013 
Provided To Others? Yes  
Impact Kick-off of a wide range of possible future applications of this method to geological and planetary research questions. Publication of method in high-impact, peer-reviewed analytical journal (under review). 
 
Title Radiogenic W isotope measurements in geological samples 
Description Novel chromatographic technique for the highly-efficient isolation of W from geological samples for high-precision isotope analyses. 
Type Of Material Technology assay or reagent 
Year Produced 2013 
Provided To Others? Yes  
Impact Kick-off of a wide range of possible future applications of this method to geological and planetary research questions. 
 
Description Mo isotope systematics in the terrestrial mantle 
Organisation University of Bristol
Country United Kingdom 
Sector Academic/University 
PI Contribution Provided analytical data for key geological samples. Data interpretation.
Collaborator Contribution Provided key geological samples. Data interpretation.
Impact Publication of data in peer-reviewed journal.
Start Year 2013
 
Description Mo isotope systematics in the terrestrial mantle 
Organisation University of Montpellier
Country France 
Sector Academic/University 
PI Contribution Provided analytical data for key geological samples. Data interpretation.
Collaborator Contribution Provided key geological samples. Data interpretation.
Impact Publication of data in peer-reviewed journal.
Start Year 2013
 
Description W isotope systematics in the Archean terrestrial crust 
Organisation University of Bristol
Country United Kingdom 
Sector Academic/University 
PI Contribution Provided analytical data for key geological samples. Data interpretation. Produced scientific output in form of peer-reviewed journal contribution.
Collaborator Contribution Provided key geological samples. Provided meta-data for samples. Data interpretation.
Impact Peer-reviewed research paper (under review). Public lectures. Scientific contribution and advise to news-paper articles and TV productions.
Start Year 2012
 
Description W isotope systematics in the Archean terrestrial crust 
Organisation University of Colorado Boulder
Country United States 
Sector Academic/University 
PI Contribution Provided analytical data for key geological samples. Data interpretation. Produced scientific output in form of peer-reviewed journal contribution.
Collaborator Contribution Provided key geological samples. Provided meta-data for samples. Data interpretation.
Impact Peer-reviewed research paper (under review). Public lectures. Scientific contribution and advise to news-paper articles and TV productions.
Start Year 2012
 
Description Astronomical Society of Manchester - Public Lecture 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Constructive discussion amongst the audience attending the session.

Recognition of research carried out by the research group. Improved understanding of research carried out at the University of Manchester.
Year(s) Of Engagement Activity 2015
 
Description BBC News Magazine article 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact Scientific input/advise for a magazine article published on the BBC homepage on the 19/09/2013.

Feedback/questions from the general public via email.
Year(s) Of Engagement Activity 2013
URL http://www.bbc.co.uk/news/magazine-22904141
 
Description Bath Geological Society - Guest Lecture 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact Lecture given to members of the public with general interest in Earth Sciences.

Positive feedback from the members of the Society.
Year(s) Of Engagement Activity 2012
URL http://www.bathgeolsoc.org.uk
 
Description Feature contribution to TV programme "Cosmic Front NEXT", NHK Japan 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact Contribution (filmed interview) to Japanese TV programme "Cosmic Front NEXT".

To be broadcasted in December 2015.
Year(s) Of Engagement Activity 2015
URL http://www.nhk.or.jp/space/cfn/
 
Description Geologists' Association - Guest Lecture 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact Guest lecture given to members of the public.

Very positive feedback from members of the Society.
Year(s) Of Engagement Activity 2013
URL http://www.geologistsassociation.org.uk
 
Description Guest Speaker University of Cambridge 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Other academic audiences (collaborators, peers etc.)
Results and Impact Guest seminar speaker at the Department of Earth Sciences, Cambridge.

Positive feedback from students attending the seminar.
Year(s) Of Engagement Activity 2012
URL http://www.esc.cam.ac.uk
 
Description Guest Speaker at ETH Zürich 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Other academic audiences (collaborators, peers etc.)
Results and Impact Guest speaker at departmental seminar.

Positive feedback from peers and students that have attended.
Year(s) Of Engagement Activity 2014
URL http://www.erdw.ethz.ch/index_EN
 
Description Guest Speaker at University of Manchester 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Other academic audiences (collaborators, peers etc.)
Results and Impact Guest speaker at departmental seminar.

Positive feedback from peers and students attending the presentation.
Year(s) Of Engagement Activity 2013
URL http://www.seaes.manchester.ac.uk
 
Description Guest speaker at University of Bonn (Germany) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Talk engaged students in participating in my research field.

Audience asked several questions. Students contacted me several days afterwards concerning questions related to the general subject area.
Year(s) Of Engagement Activity 2015
 
Description Presentation IARC symposium 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Participants in your research and patient groups
Results and Impact University-internal symposium to further interdisciplinary research.

Sparking ideas for new research proposals.
Year(s) Of Engagement Activity 2013
 
Description Science Festival Event 2015 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Public outreach 'Science Festival Event' at the Manchester Museum comprising visual as well as practical examples of research carried out.

Visitors to the booth were very interested in the reattach topic asking follow-up questions as well as related questions. Possibility of having attracted pupils to take up Earth Science studies.
Year(s) Of Engagement Activity 2015
URL http://www.manchestersciencefestival.com/whatson/thehitchhikersguidetothesolarsystem
 
Description Science Uncovered Event 2015 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Public outreach 'Science Uncovered Event' at the Manchester Museum comprising visual as well as practical examples of research carried out.

Visitors to the booth were very interested in the reattach topic asking follow-up questions as well as related questions. Possibility of having attracted pupils to take up Earth Science studies.
Year(s) Of Engagement Activity 2015
URL http://events.manchester.ac.uk/event/event:hno-id8uglqd-6ffd2a/science-uncovered-manchester
 
Description Scientific Adviser - news article (Die Zeit) 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Media (as a channel to the public)
Results and Impact Scientific adviser to news article published in nationwide German newspaper.

Feedback from general public via email.
Year(s) Of Engagement Activity 2013
URL http://www.zeit.de/wissen/2013-10/gold-entstehung-geowissenschaft
 
Description Scientific Adviser - news article (Tagesspiegel) 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Media (as a channel to the public)
Results and Impact Scientific adviser to a newspaper article published in nationwide German newspaper.

Feedback from public via email.
Year(s) Of Engagement Activity 2013
URL http://www.tagesspiegel.de/wissen/edles-metall-die-spur-des-goldes/9007574.html
 
Description Scientific Adviser BBC World 'Really Cool Stuff' - TV 360production 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact Scientific advise for the production of a TV series.

Increased interest in Natural Sciences.
Year(s) Of Engagement Activity 2013
URL http://www.bbc.co.uk/mediacentre/worldwide/160513coolstuff
 
Description Scientific Adviser Nova (PBS) 'Treasures of the Earth' - TV Pioneer Productions 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact Scientific advise to production of TV series (PBS); filming commences in Feb 2015 with interviews/filming at the University of Manchester taking place shortly thereafter.

Furthers general interest in Natural Sciences.
Year(s) Of Engagement Activity 2014
URL http://www.pioneertv.com
 
Description Session organiser 2015 Goldschmidt Conference 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other academic audiences (collaborators, peers etc.)
Results and Impact Constructive discussion amongst the audience attending the session.

Initiation of further collaborations. International recognition of research carried out by the research group.
Year(s) Of Engagement Activity 2015
URL http://goldschmidt.info/2015/program/programViewThemes#session20b
 
Description Session organiser Goldschmidt Conference 2013 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other academic audiences (collaborators, peers etc.)
Results and Impact Organiser of session at international research conference.

Constructive discussion amongst the audience attending the session.
Year(s) Of Engagement Activity 2013
 
Description Session organiser at 2015 Goldschmidt conference 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other academic audiences (collaborators, peers etc.)
Results and Impact Constructive discussion amongst the audience attending the session.

Initiation of further collaborations. International recognition of research carried out by the research group.
Year(s) Of Engagement Activity 2015
URL http://goldschmidt.info/2015/program/programViewThemes#session20b