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Mr Lawrence Carter



PhD Project: Exsolution depth and migration pathways of mineralising fluids in porphyry deposit-forming magmatic systems

Porphyry copper deposits provide around 75% of the world's copper and are an important source of gold and other metals [1]. One aspect of porphyry deposit models that is poorly understood is whether the mineralising fluids from which they form are derived from: (i) high-level copper-rich porphyry magmatic stocks, (ii) feeder chambers at mid-upper crustal levels, (iii) a lower crustal magma reservoir, or (iv) a combination of these, possibly with a transcrustal magma-mush zone [2]. The high level porphyry stock is often assumed to be the fluid source as it is invariably mineralised and can usually be temporally and texturally linked to the mineralisation. However, it is unlikely that enough fluid could be derived from such a limited magma volume. It seems probable that much of the fluid comes from a deeper source, possibly 5 to 15 km, although how fluids are transported from such depths is poorly understood. 

The aim of my PhD is to define the nature and timing mineralising fluid exsolution and migration in Cu porphyry-forming magmatic systems. This is important because it is now generally recognised, through extensive global surface mapping, that the majority of exposed surface porphyry systems and their related deposits have been found. This is prompting research into new exploration tools for deposits too deep to be identified using remote sensing techniques, covered in barren or weakly altered rocks, or which may require expensive geophysical and drilling methods.

The deposits chosen as case studies are in the Yerington District, Nevada, USA, where due to tectonic tilting there is the rare opportunity to study well exposed sections through porphyry systems up to palaeo-depths of ~6km [3].  This study will be amongst the first to determine in detail the depths of fluid exsolution, and therefore the sources of mineralising fluids within the district whilst also assessing the mechanisms by which fluids migrate from depth in sufficient volume and time scale to generate economic porphyry deposits. This study is also reassessing temporal relations in the district through a combined zircon LA-ICP-MS trace element and high precision zircon CA-ID-TIMS U-Pb geochronological study.  It is hoped that this approach will inform models for porphyry deposit formation and lead to the development of new exploration tools for blind deposits and as such aid in their discovery.

This project is funded through the NERC GW4+ initiative with additional support from the Natural History Museum (NHM) and British Geological Survey (BGS). I am supervised by Prof Ben Williamson (CSM) and co-supervised by Dr Robin Armstrong (NHM) and Dr Simon Tapster (BGS). Prof Kathy Cashman (Bristol) and Dr Robin Shail (CSM) are additional supervisors. I am also part of the Ore Deposits and Critical Metals Research Group at CSM.


Media Cove‚Äčrage

"Understanding how porphyry-type copper deposits are formed may lead to new resources – study"  -

"Pioneering study gives new insight into formation of copper deposits" - Exeter news article

"Insights into the 'missing link' of how copper ore deposits form" - BGS research highlight



Journal Articles

Carter, L.C., Williamson, B.J., Tapster, S.R., Costa, C., Grime, G.W. & Rollinson, G.K. (2021) Crystal mush dykes as conduits for mineralising fluids in the Yerington porphyry copper district, Nevada. Communications Earth & Environment 2, 59.


Conference Presentations

Carter, L.C., Tapster, S.R.,  Williamson, B.J., Buret, Y. (2020) The porphyry fertility switch – detail from the Yerington District, Nevada. MDSG annual meeting (Online).

Carter, L.C., Williamson, B.J, Tapster, S.R., Costa, C. and Grime, G.W. (2020) Crystal mush dykes as the source and conduit for porphyry deposit forming fluids. SEG Student Showcase (Online).

Carter, L.C., Williamson, B.J, Tapster, S.R., Costa, C. and Grime, G.W. (2020) Total-IBA Detailing Mineralising Fluid Migration & Exsolution to form Porphyry Copper Deposits. 17th International Conference on Nuclear Microprobe Technology and Applications (ICNMTA) (Online).

Carter, L.C., Williamson, B.J., Armstrong, R.N., Tapster, S. and Buret, Y. (2020). Yerington District, Nevada: New porphyry system petrogeochronology. MDSG annual meeting, NHM, London. 

Carter, L.C., Williamson, B.J., Armstrong, R.N. and Tapster, S. (2020). Exsolution and migration of mineralising fluids in porphyry magmatic systems - Evidence from the Yerington District, Nevada. MDSG annual meeting, NHM, London.

Carter, L.C., Williamson, B.J., Armstrong, R.N. and Tapster, S. (2019). Mineralising fluid exsolution and migration in porphyry systems - New perspectives from the Yerington District, Nevada. SEG 2019 Santiago, South American Metallogeny: Sierra to Craton. [SEG award for best student presentation]

Carter, L.C., Williamson, B.J., Armstrong, R.N. and Tapster, S. (2019). The nature of fluid exsolution and migration in porphyry systems - evidence from the Yerington District, Nevada. Proceedings of the 15th SGA Biennial Meeting, Glasgow, Scotland, pp. 973-976.

Carter, L.C., Williamson, B.J., Armstrong, R.N. and Tapster, S. (2019). New perspectives into the timing and nature of fluid exsolution and migration in Cu porphyry-forming magmatic systems – evidence from the Yerington District, Nevada. Geophysical Research Abstracts, Vol. 21, EGU2019-13169.

Carter, L.C., Williamson, B.J., Armstrong, R.N. and Tapster, S. (2019). Exsolution depth and migration pathways of mineralising fluids in porphyry systems – examples from the Yerington District, Nevada. Applied Earth Science, Vol. 128:2, 42. DOI: 10.1080/25726838.2019.1601354 [RioTinto award for best PhD student presentation]


Additional Grants Secured

  • UK National Ion Beam Centre 'Pump-Primer' grant. Total Ion Beam Analysis (IBA) study. £6,496. 

  • Society of Economic Geologists (SEG) Student Travel Grant for SEG Santiago 2019. US$1,260.

  • SelFrag Ag. Sample preparation support in kind for CA-ID-TIMS study. 

  • NERC NIGL Isotope Geosciences Facilities. CA-ID-TIMS study. £85,000 in kind.

  • Society of Economic Geologists (SEG) Student Research Grant - Hugh McKinstry Fund. US$4,500.


Professional History

  • 2019 - present: LC Geoscience Ltd - Consultant Geologist.

  • 2017 - present: CC Geoscience Ltd - Consultant Geologist to the oil & gas and mining industries.

  • 2017: BP - Operations Geologist, Schiehallion Field. 

  • 2016 - 2017: BP - Wellsite Geologist, North Sea and West of Shetland.

  • 2015 - 2016: BP - Production & Well Planning Geologist, Clair Field.

  • 2015: IMERYS - Geotechnical Engineer, UK Kaolin Platform

  • 2013: BP - Intern Exploration Geologist, Namibian Exploration.

  • 2012: IMERYS - Intern Production Geologist, UK Kaolin Platform.


Academic Qualifications

  • MSc Mining Engineering (Distinction), 2015 (Camborne School of Mines). Sponsored by SRK Consulting Ltd. Working with IMERYS, for my dissertation I performed a geotechnical assessment of current excavations and the proposed life of mine excavation design for Melbur Pit, and recommendations therein.

  • BSc (Hons) Applied Geology (1st Class), 2014 (Camborne School of Mines). Working with BP, my dissertation investigated the conjugate margin of the South Atlantic - implications on petroleum systems therein.


Honours and Awards

  • SEG best student poster presentation - SEG conference, Santiago, 2019

  • RioTinto best PhD student presentation - MDSG conference, Falmouth, 2019

  • University of Exeter Dean's Commendations; 2013, 2014, 2015 - In recognition of outstanding academic performance.

  • CSMA's John Brook & John Trounson Prizes, 2015 - Awarded for best performance in management modules and best overall performance amongst the MSc cohort.

  • Excellence in Cornwall Postgraduate Scholarship, and further support from SRK Consulting Ltd for my MSc degree.

  • Richard Pearce Gold Medal, 2014 - awarded for best overall performance in cohort.

  • Martyn Nicholas Costello Memorial Prize, 2013 - For best overall academic result (2nd year Geology)

  • Mineralogical Society Student Award, 2013 - Best aggregate mark in mineralogical modules.

  • CSM Trust's Highest Achiever Award, 2012.

  • CSM Undergraduate Scholarship, 2011.



  • Camborne School of Mines Association.

  • Member of Society of Economic Geologists (SEG).

  • Member of Society for Geology Applied to Mineral Deposits (SGA). 

  • Member of the Mineral Deposits Study Group.

  • Member of the Mineralogical Society of Great Britain. 


[1] Sillitoe, R. H., 2010. Porphyry copper systems. Economic Geology, 105: 3-41.

[2] Cashman, K. V., Stephen, R. J. and Blundy, J. D., 2017. Vertically extensive and unstable magma systems: A unified view of igenous processes. Science, 355: 1280.

[3] Dilles, J. H., Einaudi, M. T., Proffett, J. and Barton, M. D., 2000. Overview of the Yerington porphyry copper district: Magmatic to non-magmatic sources of hydrothermal fluids, their flow paths, alteration effects on rocks, and Cu-Mo-Fe-Au Ores. SEG guidebook vol. 32.