Bio

As a structural geologist and microscopist, my research interests focus on understanding how the Earth deforms across all scales by characterizing the macro and microstructures recorded in the rocks. My work focuses on the interactions of deformation processes, geochemical controls and preservation potential to improve our understanding of the evolution of the system, whether that is a fault or fold or shear zones to economic deposits and gemstones. I am particularly interested in how various deformation processes interact and how fluids can facilitate these processes. I also focus on developing new ways to prepare and analyze samples to broaden our use of existing analytical capabilities and improve coincident data collection allowing the same area to be analyzed via multiple techniques to provide a greater understanding.

Current Role at Stanford

Director, Integrated Shared Laboratory Management

Education & Certifications

  • Masters of Earth Science, University of Liverpool, UK, Earth Science (2002)
  • PhD, University of Liverpool, UK, Structural Geology (2007)

Service, Volunteer and Community Work

  • Strategic initiatives Chair for the Microanalysis Society (MAS)

    The purpose of the Strategic Planning Committee (SPC) is to coordinate with MAS council to identify key objectives that best fulfill the mission of the society, and to create long-term plans and action items that will achieve these objectives.

    Location

    Wakefield, MA

Contact

  • Work
    halfpeny@stanford.edu
    University - Staff Department: Stanford Doerr School of Sustainability Position: Director, Integrated Shared Laboratory Management
    • 397 PANAMA MALL
    • STANFORD,  California  94305 

Additional Info

Professional Interests

Quartz Gemstones Color Controls: Integrating Hand Specimen, Geochemical, and Crystallographic Data for Source Determination. Using modern technologies such as portable, hand-held x-ray fluorescence devices with SEM based CL/BSE/EDS to determine the colour controls. Attempting to determine the “source” (where the sample was formed), by using ratios of the elements which contribute to the characteristic colour such as blue or rose, determined by non-destructive handheld XRF analysis to produce certification for “Ellensburg Blues”.

Coincident Data Collection: Preparation of Polished Resin Mounts for Coincident Data Collection from Multiple Analytical Techniques, Development of a Systematic workflow. One of the new aspects of this work was the incorporation of machine-readable, quick response (QR) codes into the resin mounts. Originally the aim was to place a single QR code in the back of the mounts but this would have blocked the transmitted light path. I came up with the idea of placing a collar around the edge of the mount therefore keeping the transmitted light path clear. The other advantage of the collar was that it contained an orientation line, allowing for easy coincident data collection from multiple analytical facilities.

Controls on Gold Mineralisation and Preservation: focusing on controlling mechanisms of ore generation across various scales and determine how these mechanisms interact to cause the formation of high-grade ore deposits. Understanding the fluid pathways which bring gold enriched fluids from their deep source to their point of deposition is essential for determining the differences in the mineralisation mechanisms which form low-grade versus high-grade ore deposits. Determining the links between macro- and microstructures utilizing combined EDS/EBSD analysis, combined with other geochemical techniques (microprobe, XRF, XRD) to understand the formation of ore systems and their evolution through time.

All Publications

  • Understanding the effect of microstructural texture on the anisotropic elastic properties of selective laser melted Ti-24Nb-4Zr-8Sn ACTA MATERIALIA Challis, V. J., Xu, X., Halfpenny, A., Cramer, A. D., Saunders, M., Roberts, A. P., Sercombe, T. B. 2023; 254

    View details for DOI 10.1016/j.actamat.2023.119021

    View details for Web of Science ID 001011012900001

  • Textural changes of graphitic carbon by tectonic and hydrothermal processes in an active plate boundary fault zone, Alpine Fault, New Zealand CHARACTERIZATION OF ORE-FORMING SYSTEMS FROM GEOLOGICAL, GEOCHEMICAL AND GEOPHYSICAL STUDIES Kirilova, M., Toy, V. G., Timms, N., Halfpenny, A., Menzies, C., Craw, D., Beyssac, O., Sutherland, R., Townend, J., Boulton, C., Carpenter, B. M., Cooper, A., Grieve, J., Little, T., Morales, L., Morgan, C., Mori, H., Sauer, K. M., Schleicher, A. M., Williams, J., Craw, L., Gessner, K., Blenkinsop, T. G., SorjonenWard, P. 2018; 453: 205-223

    View details for DOI 10.1144/SP453.13

    View details for Web of Science ID 000467834400009

  • Actively forming Kuroko-type volcanic-hosted massive sulfide (VHMS) mineralization at Iheya North, Okinawa Trough, Japan ORE GEOLOGY REVIEWS Yeats, C. J., Hollis, S. P., Halfpenny, A., Corona, J., LaFlamme, C., Southam, G., Fiorentini, M., Herrington, R. J., Spratt, J. 2017; 84: 20-41

    View details for DOI 10.1016/j.oregeorev.2016.12.014

    View details for Web of Science ID 000397361900002

  • Bedrock geology of DFDP-2B, central Alpine Fault, New Zealand NEW ZEALAND JOURNAL OF GEOLOGY AND GEOPHYSICS Toy, V., Sutherland, R., Townend, J., Allen, M. J., Becroft, L., Boles, A., Boulton, C., Carpenter, B., Cooper, A., Cox, S. C., Daube, C., Faulkner, D. R., Halfpenny, A., Kato, N., Keys, S., Kirilova, M., Kometani, Y., Little, T., Mariani, E., Melosh, B., Menzies, C. D., Morales, L., Morgan, C., Mori, H., Niemeijer, A., Norris, R., Prior, D., Sauer, K., Schleicher, A. M., Shigematsu, N., Teagle, D. H., Tobin, H., Valdez, R., Williams, J., Yeo, S., Baratin, L., Barth, N., Benson, A., Boese, C., Celerier, B., Chamberlain, C. J., Conze, R., Coussens, J., Craw, L., Doan, M., Eccles, J., Grieve, J., Grochowski, J., Gulley, A., Howarth, J., Jacobs, K., Janku-Capova, L., Jeppson, T., Langridge, R., Mallyon, D., Marx, R., Massiot, C., Mathewson, L., Moore, J., Nishikawa, O., Pooley, B., Pyne, A., Savage, M. K., Schmitt, D., Taylor-Offord, S., Upton, P., Weaver, K. C., Wiersberg, T., Zimmer, M., DFDP-2 Sci Team 2017; 60 (4): 497-518

    View details for DOI 10.1080/00288306.2017.1375533

    View details for Web of Science ID 000416802100014

  • The golden ark: arsenopyrite crystal plasticity and the retention of gold through high strain and metamorphism TERRA NOVA Fougerouse, D., Micklethwaite, S., Halfpenny, A., Reddy, S. M., Cliff, J. B., Martin, L. J., Kilburn, M., Guagliardo, P., Ulrich, S. 2016; 28 (3): 181-187

    View details for DOI 10.1111/ter.12206

    View details for Web of Science ID 000376003900004

  • Gold remobilisation and formation of high grade ore shoots driven by dissolution-reprecipitation replacement and Ni substitution into auriferous arsenopyrite GEOCHIMICA ET COSMOCHIMICA ACTA Fougerouse, D., Micklethwaite, S., Tomkins, A. G., Mei, Y., Kilburn, M., Guagliardo, P., Fisher, L. A., Halfpenny, A., Gee, M., Paterson, D., Howard, D. L. 2016; 178: 143-159

    View details for DOI 10.1016/j.gca.2016.01.040

    View details for Web of Science ID 000371332900009

  • Characterization of Mason Gully (H5): The second recovered fall from the Desert Fireball Network METEORITICS & PLANETARY SCIENCE Dyl, K. A., Benedix, G. K., Bland, P. A., Friedrich, J. M., Spurny, P., Towner, M. C., O'Keefe, M., Howard, K., Greenwood, R., Macke, R. J., Britt, D. T., Halfpenny, A., Thostenson, J. O., Rudolph, R. A., Rivers, M. L., Bevan, A. R. 2016; 51 (3): 596-613

    View details for DOI 10.1111/maps.12605

    View details for Web of Science ID 000372556800009

  • Quantified, multi-scale X-ray fluorescence element mapping using the Maia detector array: application to mineral deposit studies MINERALIUM DEPOSITA Fisher, L. A., Fougerouse, D., Cleverley, J. S., Ryan, C. G., Micklethwaite, S., Halfpenny, A., Hough, R. M., Gee, M., Paterson, D., Howard, D. L., Spiers, K. 2015; 50 (6): 665-674

    View details for DOI 10.1007/s00126-014-0562-z

    View details for Web of Science ID 000358785700003

  • The structure of and origin of nodular chromite from the Troodos ophiolite, Cyprus, revealed using high-resolution X-ray computed tomography and electron backscatter diffraction LITHOS Prichard, H. M., Barnes, S. J., Godel, B., Reddy, S. M., Vukmanovic, Z., Halfpenny, A., Neary, C. R., Fisher, P. C. 2015; 218: 87-98

    View details for DOI 10.1016/j.lithos.2015.01.013

    View details for Web of Science ID 000353851400006

  • Microelectronic junctions in arsenian pyrite due to impurity and mixed sulfide heterogeneity AMERICAN MINERALOGIST Laird, J. S., MacRae, C. M., Halfpenny, A., Large, R., Ryan, C. G. 2015; 100 (1): 26-34

    View details for DOI 10.2138/am-2015-4648

    View details for Web of Science ID 000347436600006

  • Maia X-ray fluorescence imaging: Capturing detail in complex natural samplesF Ryan, C. G., Siddons, D. P., Kirkham, R., Li, Z. Y., de Jonge, M. D., Paterson, D. J., Kuczewski, A., Howard, D. L., Dunn, P. A., Falkenberg, G., Boesenberg, U., De Geronimo, G., Fisher, L. A., Halfpenny, A., Lintern, M. J., Lombi, E., Dyl, K. A., Jensen, M., Moorhead, G. F., Cleverley, J. S., Hough, R. M., Godel, B., Barnes, S. J., James, S. A., Spiers, K. M., Alfeld, M., Wellenreuther, G., Vukmanovic, Z., Borg, S., IOP IOP PUBLISHING LTD. 2014

    View details for DOI 10.1088/1742-6596/499/1/012002

    View details for Web of Science ID 000338041300002

  • LA-ICP-MS mapping of olivine from the Brahin and Brenham meteorites: Complex elemental distributions in the pallasite olivine precursor GEOCHIMICA ET COSMOCHIMICA ACTA McKibbin, S. J., O'Neill, H. C., Mallmann, G., Halfpenny, A. 2013; 119: 1-17

    View details for DOI 10.1016/j.gca.2013.05.031

    View details for Web of Science ID 000324036200001

  • Preparation of Samples with Both Hard and Soft Phases for Electron Backscatter Diffraction: Examples from Gold Mineralization Halfpenny, A., Hough, R. M., Verrall, M. CAMBRIDGE UNIV PRESS. 2013: 1007-1018

    Abstract

    Preparation of high-quality polished sample surfaces is an essential step in the collection of microanalytical data on the microstructures of minerals and alloys. Poorly prepared samples can yield insufficient or inconsistent results and, in the case of gold, potentially no data due to the "beilby" layer. Currently, preparation of ore samples is difficult as they commonly contain both hard and soft mineral phases. The aim of our research is to produce suitably polished sample surfaces, on all phases, for electron backscatter diffraction analysis. A combination of chemical-mechanical polishing (CMP) and broad ion-beam polishing (BIBP) was used to tackle the problem. Our results show that it is critical to perform CMP first, as it produces a suitable polish on the hard mineral phases but tends to introduce more damage to the soft mineral surfaces. BIBP is essential to produce a high-quality polish to the soft phases (gold). This is a highly efficient method of sample preparation and is important as it allows the complete quantification of ore textures and all constituent mineral phases, including soft alloys.

    View details for DOI 10.1017/S1431927613001499

    View details for Web of Science ID 000321764700028

    View details for PubMedID 23721665

  • Understanding gold mineralisation: linking chemical and structural changes Halfpenny, A., Fisher, L., Hough, R., Cleverley, J., Jonsson, E. SGU-SVERIGES GEOLOGISKA UNDERSOKNING-GEOLOGY SURVEY SWEDEN. 2013: 1255-1258

    View details for Web of Science ID 000337983900317

  • The structure of nodular chromite from the Troodos ophiolite, Cyprus, revealed using high-resolution X-ray computed tomography and EBSD Pritchard, H. M., Barnes, S. J., Godel, B., Halfpenny, A., Neary, C., Jonsson, E. SGU-SVERIGES GEOLOGISKA UNDERSOKNING-GEOLOGY SURVEY SWEDEN. 2013: 236-+

    View details for Web of Science ID 000337983900059

  • Crystallography of Natural and Synthetic Gold Alloy Microstructures Halfpenny, A., Hough, R., Nugus, M., Barnett, M. TRANS TECH PUBLICATIONS LTD. 2013: 477-480

    View details for DOI 10.4028/www.scientific.net/MSF.753.477

    View details for Web of Science ID 000320677500101

  • Electron backscatter diffraction analysis to determine the mechanisms that operated during dynamic recrystallisation of quartz-rich rocks JOURNAL OF STRUCTURAL GEOLOGY Halfpenny, A., Prior, D. J., Wheeler, J. 2012; 36: 2-15

    View details for DOI 10.1016/j.jsg.2012.01.001

    View details for Web of Science ID 000301630600002

  • Drilling constraints on lithospheric accretion and evolution at Atlantis Massif, Mid-Atlantic Ridge 30°N JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH Blackman, D. K., Ildefonse, B., John, B. E., Ohara, Y., Miller, D. J., Abe, N., Abratis, M., Andal, E. S., Andreani, M., Awaji, S., Beard, J. S., Brunelli, D., Charney, A. B., Christie, D. M., Collins, J., Delacour, A. G., Delius, H., Drouin, M., Einaudi, F., Escartin, J., Frost, B. R., Frueh-Green, G., Fryer, P. B., Gee, J. S., Godard, M., Grimes, C. B., Halfpenny, A., Hansen, H., Harris, A. C., Tamura, A., Hayman, N. W., Hellebrand, E., Hirose, T., Hirth, J. G., Ishimaru, S., Johnson, K. M., Karner, G. D., Linek, M., MacLeod, C. J., Maeda, J., Mason, O. U., McCaig, A. M., Michibayashi, K., Morris, A., Nakagawa, T., Nozaka, T., Rosner, M., Searle, R. C., Suhr, G., Tominaga, M., von der Handt, A., Yamasaki, T., Zhao, X. 2011; 116

    View details for DOI 10.1029/2010JB007931

    View details for Web of Science ID 000293086500001

  • Garnet re-equilibration by coupled dissolution-reprecipitation: evidence from textural, major element and oxygen isotope zoning of 'cloudy' garnet JOURNAL OF METAMORPHIC GEOLOGY Martin, L. J., Ballevre, M., Boulvais, P., Halfpenny, A., Vanderhaeghe, O., Duchene, S., Deloule, E. 2011; 29 (2): 213-231

    View details for DOI 10.1111/j.1525-1314.2010.00912.x

    View details for Web of Science ID 000286841000003

  • Slip-system and EBSD analysis on compressively deformed fine-grained polycrystalline olivine DEFORMATION MECHANISMS, RHEOLOGY AND TECTONICS: MICROSTRUCTURES, MECHANICS AND ANISOTROPY Farla, R. M., Gerald, J., Kokkonen, H., Halfpenny, A., Faul, U. H., Jackson, I., Prior, D. J., Rutter, E. H., Tatham, D. J. 2011; 360: 225-235

    View details for DOI 10.1144/SP360.13

    View details for Web of Science ID 000308561200014

  • Development and Evolution of Fracture-Controlled Flow Regimes and Gold Mineralisation, Porgera Gold Deposit, PNG Halfpenny, A., Cox, S. F., Williams, P. J. JAMES COOK UNIV. 2010: 815-817

    View details for Web of Science ID 000282993400267

  • Oceanic core complexes and crustal accretion at slow-spreading ridges GEOLOGY Ildefonse, B., Blackman, D. K., John, B. E., Ohara, Y., Miller, D. J., MacLeod, C. J., Integrated Ocean Drilling Program 2007; 35 (7): 623-626

    View details for DOI 10.1130/G23531A.1

    View details for Web of Science ID 000247895900012

  • Analysis of dynamic recrystallization and nucleation in a quartzite mylonite Halfpenny, A., Prior, D. J., Wheeler, J. ELSEVIER SCIENCE BV. 2006: 3-14

    View details for DOI 10.1016/j.tecto.2006.05.016

    View details for Web of Science ID 000242871300002

  • IODP Expeditions 304 & 305 Characterize the Lithology, Structure, and Alteration of an Oceanic Core Complex SCIENTIFIC DRILLING Ildefonse, B., Blackman, D., John, B. E., Ohara, Y., Miller, D., MacLeod, C. J., IODP Expeditions 304-305 Scientist 2006; 3: 4-11

    View details for DOI 10.2204/iodp.sd.3.01.2006

    View details for Web of Science ID 000212881300002

  • Using electron backscatter diffraction (EBSD) to measure misorientation between 'parent' and 'daughter' grains. Implications for recrystallisation and nucleation. Halfpenny, A., Prior, D. J., Wheeler, J., Bacroix, B., Driver, J. H., LeGall, R., Maurice, C., Penelle, R., Regle, H., Tabourot, L. TRANS TECH PUBLICATIONS LTD. 2004: 573-578

    View details for DOI 10.4028/www.scientific.net/MSF.467-470.573

    View details for Web of Science ID 000225119800091

  • Recrystallization and grain growth in rocks and minerals Prior, D. J., Bestmann, M., Halfpenny, A., Mariani, E., Piazolo, S., Tullis, J., Wheeler, J., Bacroix, B., Driver, J. H., LeGall, R., Maurice, C., Penelle, R., Regle, H., Tabourot, L. TRANS TECH PUBLICATIONS LTD. 2004: 545-550

    View details for DOI 10.4028/www.scientific.net/MSF.467-470.545

    View details for Web of Science ID 000225119800087

https://orcid.org/0000-0001-6560-3134