Photo of Angela

Dr. Angela Halfpenny

Ph.D., 2007, Liverpool University, UK

Murdock Laboratory Manager
Department of Geological Sciences
Central Washington University
Ellensburg, WA, 98926-7418
Office: 338 Discovery Hall
Tel: 509-963-2826
Mobile: 509-607-9748
angela.halfpenny@cwu.edu


Murdock Research Laboratory

The Murdoch Research Laboratory, housed in the Department of Geological Sciences, hosts multiple state-of-the-art instruments and expertise in a range of analytical techniques. The facilities are open to researchers for collaborative or non-collaborative access and for commercial access. The expert academic, technical and professional staff support the facility users from initial contact and project development, through to sample preparation, instrument training, data processing and interpretation for publication.

The laboratory contains a variety of techniques designed to collect high resolution images or measure the elemental concentrations or isotopes or crystallography of a wide range of samples. The techniques available can be split into two sampling categories: (1) instruments which can analyse Solid Samples and (2) instruments which can analyse Liquid Samples (although some instruments can measure both and more). Please see the Murdock Research Laboratory (MRL) website for more information: http://www.geology.cwu.edu/murdocklab

Teaching

I teach labs for a variety of courses which involve the analytical instruments in MRL and help with field classes. Courses I have been involved with include:

  • Chemistry 383: Physical Chemistry
  • Geology 346: Mineralogy
  • Geology 388: Field Trip - Big Island Hawaii
  • Geology 475/575: Petrography and Petrogenesis
  • Geology 493: Field Methods in Environmental Geology
  • Geology 502: Regional Field Geology of the Pacific Northwest

Research

As a structural geologist and microscopist, my research interests focus on understanding how the Earth deforms across all scales by characterising 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 analyse samples to broaden our use of existing analytical capabilities and improve coincident data collection allowing the same area to be analysed via multiple techniques to provide a greater understanding. Below are highlights from some of my current research projects and collaborations:

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. Working with commercial jewelry providers Carl Carlson and Robert Langford 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. (with Kelly Merigot, Curtin University, Australia).

Elemental and Mineralogical Characterisation of Light Absorbing Particles (LAP): Combining Reflected Light Optical Petrology, Hyperspectral Imaging Microscope Spectroscopy (HIMS) and Scanning Electron Microscope (SEM), Energy Dispersive Spectroscopy (EDS) to Identify the Abundance and Type of LAP in the snow and ice samples. Light absorbing particulate (LAP) include black carbon, mineral dust and organic matter. When deposited on snow and glacier surfaces LAP reduce snow albedo and accelerate melt. While geochemical techniques allow for the relative abundances of LAP to be determined, characterisation of the optical properties of LAP are needed to partition the contribution of the different classes of LAP to albedo reductions. (with Susan Kaspari, Melanie Swick and Riley Blanchard, CWU, USA).

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 (with Stephen Cox, ANU, Australia and Robert Hough, Chris Ryan, CSIRO, Australia).

Angela at Mt St Helens

Selected Publications

  • Kirilova, M., Halfpenny, A., et al., 2018. Textural changes of graphitic carbon by tectonic and hydrothermal processes in an active plate boundary fault zone, Alpine Fault, New Zealand. Geological Society, London, Special Publications 'Advances in the Characterization of Ore-Forming Systems from Geological, Geochemical and Geophysical data', 453, 13. DOI: 10.1144/SP453.13
  • Toy, V.G., Halfpenny, A., et al., 2017. Bedrock geology of DFDP-2B, central Alpine Fault, New Zealand, New Zealand. Journal of Geology and Geophysics, 60 (4), 497-518. DOI: 10.1080/00288306.2017.1375533
  • Stewart, J., Kerr, G., Prior, D., Halfpenny, A., Pearce, M., Hough, R., Craw, D., 2017. Low temperature recrystallisation of alluvial gold in paleoplacer deposits. Ore Geology Reviews, 88, 43-56. DOI: 10.1016/j.oregeorev.2017.04.020
  • Yeats, C.J., Hollis, S.P., Halfpenny, A., Corona, J.C., Laflamme, C., Southam, G., Fiorentini, M., Herrington, R.J., and Spratt, J., 2017. Actively forming Kuroko-type volcanic hosted massive sulfide (VHMS) mineralization at Iheya North, Okinawa Trough, Japan. Ore Geology Reviews, 84, 20-41. DOI: 10.1016/j.oregeorev.2016.12.014
  • Fougerouse, D., Micklethwaite, S., Halfpenny, A., Reddy, S., Cliff, J.B., Martin, L.A.J., Kilburn, M., Guagliardo, P., and Ulrich, S., 2016. The golden ark: Arsenopyrite crystal plasticity and the retention of gold through high strain metamorphism. Terra Nova, 28, 181-187. DOI: 10.1111/ter.12206
  • Dyl, K., Benedix, G., Bland, P.A., Friedrich, J.M., Spurný, P., Towner, M.C., 'Keefe, M. C., Howard, K., Greenwood, R., Macke, R.J., Britt, D.T., Halfpenny, A., Thostenson, T., Rudolph, R.A., Rivers, M.L., and Bevan, A.W., 2016. Charaterization of Mason Gully (H5): The second recovered fall from the Desert Fireball Network. Meteoritics & Planetary Science, 51 (3), 596-613. DOI: 10.1111/maps.12605
  • Fougerouse, D., Micklethwaite, S., Tomkins, A.G., Mei, Y., Guagliardo, P., Fisher, L.A., Halfpenny, A., Gee, M., Paterson, D., Howard, D.L., 2016. Gold remobilisation and formation of high grade ore shoots driven by dissolution-reprecipitation replacement and Ni substitution into auriferous arsenopyrite. Geochimca et Cosmochimica Acta, 178, 143-159. DOI: 10.1016/j.gca.2016.01.040
  • Pritchard, H.M., Barnes, S.J., Godel, B., Reddy, S.M., Vukmanovic, Z., Halfpenny, A., Neary, C.R., and Fisher, P.C., 2015. The structure and origin of nodular chromite from the Troodos ophiolite, Cyprus, revealed using high-resolution X-ray computed tomography and electron backscatter diffraction. Lithos, 218-219, 87-98. DOI: 10.1016/j.lithos.2015.01.013
  • Laird, J.S., MacRae, C.M., Halfpenny, A., Large, R., and Ryan, C.G., 2015. Microelectronic junctions in arsenian pyrite due to impurity and mixed sulfide heterogeneity. American Mineralogist, 100, 26-34. DOI: 10.2138/am-2015-4648
  • Fisher, L.A., Fougerouse, D., Cleverley, J., Ryan, C.G., Micklethwaite, S., Halfpenny, A., Hough, R., Gee, M., Paterson, D.J., Howard. D.L., and Spiers, K., 2014. Quantified, multi-scale X-ray fluorescence element mapping using the Maia detector array: application to mineral deposit studies. Mineralium Deposita, 50, 6, 665-674. DOI: 10.1007/s00126-014-0562-z
  • Ryan, C.G., Halfpenny, A., et al., 2014. Maia X-ray fluorescence imaging: Capturing detail in complex natural samples. Journal of Physics: Conference Series, 499, 1, 1-12. DOI: 10.1088/1742-6596/499/1/012002
  • Mckibbin, S.J., O'Neill, H.St.C., Mallman, G. and Halfpenny, A., 2013. LA-ICP-MS mapping of olivine from the Brahin and Brenham meteorites: Complex elemental distributions in the pallasite olivine precursor. Geochimica et Cosmochimica Acta, 119, 1-17. DOI: 10.1016/j.gca.2013.05.031
  • Halfpenny, A., Hough, R.M. and Verrall, M., 2013. Preparation of samples with both hard and soft phases for electron backscatter diffraction: Examples from gold mineralization. Microscopy and Microanalysis, 19, 4, 1007-1018. DOI: 10.1017/S1431927613001499
  • Halfpenny, A., Prior, D.J. and Wheeler, J., 2012. Electron backscatter diffraction analysis to determine the mechanisms that operated during dynamic recrystallization of quartz-rich rocks. Journal of Structural Geology, 36, 2-15. DOI: 10.1016/j.jsg.2012.01.001
  • Farla, R.J.M., Fitz Gerald, J.D., Kokkonen, H., Halfpenny, A., Faul, U.H. and Jackson, I., 2011. Slip system and EBSD analysis on compressively deformed synthetic sol-gel and San Carlos olivine aggregates. Geological Society, London, Special Publications, 360, 225-235. DOI: 10.1144/SP360.13
  • Blackman, D. K., Halfpenny, A., et al., 2011. Drilling constraints on lithospheric accretion and evolution at Atlantis Massif, Mid-Atlantic Ridge 30°N. Journal of Geophysical Research, 116, B07103. DOI: 10.1029/2010JB007931
  • Martin, L.A.J., Ballèvre, M., Boulvais, P., Halfpenny, A., Vanderhaeghe, O., Duchêne, S. and Deloule, E., 2011. Garnet re-equilibration by coupled dissolution-reprecipitation: Evidence from major element and oxygen isotope zoning of 'cloudy' garnet. Journal of Metamorphic Geology, 29(2), 213-231. DOI: 10.1111/j.1525-1314.2010.00912.x
  • Halfpenny, A., 2010. Some important practical issues for collection and manipulation of electron backscatter diffraction (EBSD) data from rocks and minerals. In: (Eds.) Marnie A. Forster, John D. Fitz Gerald, and Gordon S. Lister, The Science of Microstructure, Journal of the Virtual Explorer, Electronic Edition, ISSN 1441-8142, volume 35, paper 5. DOI: 10.3809/jvirtex.2011.00272
  • Ildefonse, B., Halfpenny, A., et al., 2007. Oceanic core complexes and crustal accretion at slow-spreading ridges. Geology, 35, 623-626. DOI: 10.1130/G23531A.1
  • Halfpenny, A., Prior, D.J. and Wheeler, J., 2006. Analysis of dynamic recrystallisation and nucleation in a quartzite mylonite. Tectonophysics, 427, 3-14. DOI: 10.1016/j.tecto.2006.05.016