University of Edinburgh Featured PhD Programmes
Norwich Research Park Featured PhD Programmes
Norwich Research Park Featured PhD Programmes
University College London Featured PhD Programmes
University of Bristol Featured PhD Programmes

(STFC DTP) Xenon isotopes and the chronology of the solar system


Project Description

Xenon isotopic signatures in extraterrestrial material that dates back to the early solar system record radioactive decay of now-extinct radioisotopes (244Pu and 129I), affording a means of dating processes that occurred as they formed or as they were processed on planetesimals. In the more recent past (last ~100 Myr), they have been modified by the products of cosmic ray interaction with the rock-forming elements Ba, La, Ce and Nd. These spallation interactions allow us to determine transit times between a meteorite’s parent body and the Earth, and examine the burial depth of samples returned from the regoliths of planetary bodies. At Manchester we run the world’s most sensitive instrument for xenon isotope analysis and have demonstrated in a preliminary study that we can extract this range of information from samples as small as 2 mg. In this project you will build on this development and apply it to achondritic meteorite samples, igneous material from the early solar system. As part of the study we aim…:
• To determine closure ages to xenon loss using the decay of 129I.
• To understand the geochemical behaviour of plutonium in these samples and established whether chronological information can be extracted from Pu/U or Pu/Nd ratios.
• To calibrate the 126Xe/131Xe ratio from barium spallation as an indicator of burial depth in the regolith.
• To develop protocols for using 126Xe/Ba ratios as measures of cosmic ray exposure age by analysing neutron-irradiated samples and cross-comparing with data from the 81Kr-Kr scheme.
• To examining the consistency of Ba/REE ratios in these igneous samples.
• To determine transit times from Vesta to the Earth and understand the frequency of impacts on the parent body.

Suggested skills needed. The project would suit a student interested in the evolution of the solar system who is keen to develop skills at the forefront of sample analysis and data reduction for geochemistry. A background in geoscience, physics or chemistry at undergraduate level is required.

References

Gilmour, J. D. (2018) “An Irrational Approach to Isotopic Analysis”. Available online at https://www.researchgate.net/publication/327387060_An_irrational_approach_to_isotopic_analysis/stats
Gilmour, J. D. & Crowther, S. A. (2017) The I-Xe chronometer and its constraints on the accretion and evolution of planetesimals. Geochemical Journal 51 Special Issue: SI 69-80
Claydon J. L., Crowther S. A., Fernandes V. A. and Gilmour J. D. (2015) Noble gases and halogens in Graves Nunataks 06129: the complex thermal history of a felsic asteroid crust. , Geochimica et Cosmochimica Acta. 159 177-189.
Strashnov I., Bland P. A., Spurný P., Towner M. C. and Gilmour J. D. (2013) Times of impacts that deliver samples of Vesta to Earth derived from Ultrasensitive 81Kr-Kr Cosmic Ray Exposure Age Analysis of Eucrites. Geochimica et Cosmochimica Acta 106 71-83.
Crowther S. A., Mohapatra R. K., Turner G., Blagburn D. J., Kehm K., and Gilmour J. D. 2008. Characteristics and Applications of RELAX, an Ultrasensitive Resonance Ionization Mass Spectrometer for Xenon. Journal of Analytical Atomic Spectrometry 23, 938-947.

Related Subjects

How good is research at The University of Manchester in Earth Systems and Environmental Sciences?

FTE Category A staff submitted: 42.13

Research output data provided by the Research Excellence Framework (REF)

Click here to see the results for all UK universities

Email Now

Insert previous message below for editing? 
You haven’t included a message. Providing a specific message means universities will take your enquiry more seriously and helps them provide the information you need.
Why not add a message here
* required field
Send a copy to me for my own records.

Your enquiry has been emailed successfully





FindAPhD. Copyright 2005-2019
All rights reserved.