Carbon in primitive meteorites

The colony meteorite

This PhD project will study primitive carbonaceous chondrite meteorites to examine the relationship between organic matter, nanodiamonds and minerals in protoplanetary dust.

This project is funded for three and a half years as an STFC studentship.

Apply for this project

Read the eligibility criteria and application guidance below, then send your application to postgradoffice@nhm.ac.uk

Application deadline: Wednesday 28 February 2018.

Primitive carbonaceous chondrite meteorites provide a detailed record of the geological processes and events that have shaped our solar system over the last 4.5 billion years. Carbonaceous chondrites are dominated by a fine-grained matrix of amorphous and crystalline silicates, oxides, sulphides and metal that have remained largely unaltered since the time they were accreted into an asteroid. The matrix also contains ~5 wt.% carbon in a wide variety of forms such as nanodiamonds, carbonates and organic materials including soluble molecules, unstructured, kerogen-like insoluble organic matter, and carbonaceous nanoglobules.

The abundance and diversity of the organic materials present within carbonaceous chondrites has led to suggestions that they may have seeded the early Earth, and potentially the other rocky inner solar system planets, with prebiotic molecules that went on to play a crucial role in formation of life.

icegrain-interstellar-two-column

A cartoon diagram from astrochem.org describing the relationship between interstellar dust and primitive organic matter prior to accretion on an asteroid

Astronomical observations of young star systems and interstellar space find organic and elemental carbon associated with dust. In the cold, outer regions of the early solar system amorphous and crystalline silicates likely acted as nucleation sites for the formation and processing of organic materials. Nanodiamonds on the other hand are thought to predate the Sun’s formation and additionally carry information related to the interstellar space and the solar nebul

The mineralogy and chemistry of the fine grained matrix that preserves these primitive carbonaceous materials varies across meteorite groups of carbonaceous chondrites, and in doing so provides a broad record of the chemical and physical processes that were active during accretion and early parent body processing. However, the spatial and textural relationship between organic matter, nanodiamonds and host matrix minerals in these carbonaceous chondrites are poorly understood.

The complex and heterogeneous nature of the organics, and the submicron grain size (≤1 μm) of the matrix minerals, means that imaging techniques with nanometre scale resolution are essential for studying them.

Consequently, in this project a suite of state-of-the-art imaging techniques with be utilised such that in-situ chemical, spectroscopic and diffraction information from the same samples can be combined. By correlating all these analyses the individual grain properties and the inter-grain relationships between the organic matter, nanodiamonds and minerals can be understood.

colony-meteorite-two-column

An elemental X-ray map of the CO3.0 carbonaceous chondrite Colony collected on a scanning electron microscope by Enrica Bonato of the Planetary Materials Group at the Natural History Museum.
Millimetre sized chondrules, calcium aluminium rich inclusions (CAIs) and silicate fragments are bound together by a very fine grained matrix of amorphous and crystalline minerals and carbonaceous materials.  Blue = Si; green = Mg; yellow = Ca; white = Al; red = Fe.

This project is particularly timely with respect to the ongoing 'sample return' space missions of the North American and Japanese space agencies (NASA and JAXA). NASA’s OSIRIS REx and JAXA’s Hyabusa 2 missions will study the carbon rich asteroids Bennu and Ryugu respectively, and both aim to return physical samples of the asteroid surfaces back to Earth.

The student will become integrated into the Planetary Materials Group at the Natural History Museum and the Centre for Research in Earth Sciences (CRES) at the University of Plymouth, and have the opportunity to study meteorites from one of the finest meteorite collections in the world at the Natural History Museum. The student will benefit from STFC-led training opportunities throughout the studentship, and also from an award-winning researcher development programme at the University of Plymouth.

Electron microscopy & spectroscopic analysis, including scanning and transmission electron microscopy (SEM and TEM), focused ion beam scanning electron microscopy (FIB-SEM), infrared, Raman and fluorescence spectroscopy, and thermal analysis will be performed in house, at both the Museum’s Image and Analysis Laboratories and the University of Plymouth’s Electron Microscopy Centre (PEMC), alongside the School of Geography, Earth & Environmental Science’s research facilities .

Micro- and nano-scale X-ray and infrared microscopy will be undertaken at international synchrotron facilities such as the UK’s Diamond Light Source, using X-ray nanoprobes, scanning transmission X-ray microscopy (STXM) and near-field / micro FTIR microscopy.

We seek an enthusiastic person for this project with a strong background in the physical sciences or planetary sciences or geology, and with an interest in applying analytical mineralogy to a planetary science context.

Suggested reading

Pizzarello S., Cooper G.W., Flynn G.J. (2002) The Nature and Distribution of the Organic Material in Carbonaceous Chondrites and Interplanetary Dust Particles. In: Meteorites and the Early Solar System II (Editors: D. S. Lauretta and H. Y. McSween) pp. 625-651.

Kebukawa Y., Zolensky M.E., Kilcoyne A.L.D., Raham Z., Jenniskens P., Cody G.D. (2014) Diamond xenolith and matrix organic matter in the Sutter’s Mill meteorite measured by C-XANES. Meteoritics and Planetary Science 49 (11) pp. 2095-2103.

Martins Z. (2011) Organic chemistry of carbonaceous meteorites. Elements 7(1) pp. 35-40.

Relevant issues of Elements Magazine:

Eligibility

This project is funded for three and a half years as an STFC studentship, which will cover all fees and a student stipend if you are from the UK, or from the EU and meet residency requirements (settled status, or 3 years full-time residency in the UK). For full details on what is covered by the studentship please see the STFC guidance.

For informal enquiries or further information, please contact Dr Paul Schofield.

How to apply

Deadline: Wednesday 28 February 2018

Please send the following documents to Anna Hutson at the Postgraduate Office

  • Curriculum vitae
  • Covering letter outlining your interest in the PhD project, relevant skills training, experience and qualifications, and a statement of how this PhD project fits your career development plans.
  • Transcripts of undergraduate and master's degree results.
  • Two academic references including (if applicable) master's project supervisor.

Interview date: March 2018

Start date: October 2018

Further Information

For informal enquiries or further information, please contact Dr Paul Schofield.

Supervisors

The Natural History Museum

Paul Schofield

Ashley King

Sara Russell

University of Plymouth

Natasha Stephen

Funded by 

Submit your application