Dr Geoff Lloyd
Reader: Microgeodynamics
Telephone number:
+44(0) 113 34
35209
Email address: eargel@leeds.ac.uk
Room: 9.153
Biography
I am Reader in Microgeodynamics in the Institute of Geophysics and Tectonics. I gained my first degree in 1975 (Nottingham), M.Phil. in 1979 (Nottingham) and Ph.D. in 1984 (Birmingham). I have acted as Secretary of the Tectonic Studies Group of the UK and Ireland and sat on the Electron Microscopy Committee of the Royal Microscopical Society.
Research Interests
I am a structural geologist with particular interest in microstructural evolution and deformation processes, although I have interest also in the regional geology of SW England, NW Scotland, the western Alps and the NW Himalaya. My early research career focussed on the formation of boudinage and related features, including their usage in strain analysis, and particularly the recognition, measurement, interpretation and significance of crystal lattice preferred orientation (LPO) development in rocks and analogue materials (i.e. metals and ceramics) using electron channelling in the scanning electron microscope. My interest in the latter has continued throughout my career to the present and today involves use of SEM electron backscattered diffraction (EBSD) to characterise the orientation and misorientation characteristics of minerals, rocks, metals and ceramics, from which various petrophysical properties can be derived. My current research therefore involves using petrofabric-derived seismic properties to explain and interpret seismic data in terms of large scale geodynamic processes in both the crust and mantle. I am a founder-member of the LEMAS (Leeds Electron Microscopy and Spectroscopy) Centre, in collaboration with the Institute of Materials Research at Leeds, which provides electron microscopy services to meet both internal and external demands.
Teaching Interests
I teach at all undergraduate levels within the School. Obviously, my main teaching involves structural geology but I teach also computing and statistics as well as mineralogy and petrology. I act currently as the Earth Sciences undergraduate field work convenor, organising all of the undergraduate field and project modules, as well as leading the Level 1 field class to Pembroke and supervising specific final year mapping projects (SW England, NW Scotland). I am engaged currently in developing electronic mapping resources for undergraduate teaching, in collaboration with the School Librarian (Clare Gordon). In addition, I act as the convenor for the School Kennedy Library and University Library representative for Earth Sciences.
Publications
- Lloyd GE; Butler RHW; Casey M; Tatham DJ; Mainprice D (2011) Constraints on the seismic properties of the middle and lower continental crust., In: Prior DJ; Rutter EH; Tatham DJ (Ed) Deformation Mechanisms, Rheology and Tectonics: Microstructures, Mechanics and Anisotropy, Geological Society, London, Special Publication, The Geological Society of London, pp.7-32. doi: 10.1144/SP360.2
- Morales LFG; Mainprice D; Lloyd GE; Law RD (2011) Crystal fabric development and slip systems in a quartz mylonite: an approach via transmission electron microscopy and viscoplastic self-consistent modelling, In: Prior DJ; Rutter EH; Tatham DJ (Ed) Deformation Mechanisms, Rheology and Tectonics: Microstructures, Mechanics and Anisotropy, Geological Society London, Special Publications, 360, The Geological Society of London, pp.151-174. doi: 10.1144/SP360.9
- Morales LFG; Casey M; Lloyd GE; Williams DM (2011) Kinematic and temporal relationships between parallel fold hinge lines and stretching lineations: A microstructural and crystallographic preferred orientation approach, TECTONOPHYSICS, 503, pp.207-221. doi: 10.1016/j.tecto.2011.03.003
- Díaz-Azpiroz M; Lloyd GE; Fernández C (2011) Deformation mechanisms of plagioclase and seismic anisotropy of the Acebuches metabasites (SW Iberian massif), In: Prior DJ; Rutter EH; Tatham DJ (Ed) 360, pp.79-95.
- Lloyd GE; Halliday JM; Butler RWH; Casey M; Kendall JM; Wookey J; Mainprice D (2011) From crystal to crustal: petrofabric derived seismic modelling of regional tectonics., In: Prior DJ; Rutter EH; Tatham DJ (Ed) Deformation Mechanisms, Rheology and Tectonics: Microstructures, Mechanics and Anisotropy, Geological Society London, Special Publications, 360, The Geological Society of London, pp.49-78. doi: 10.1144/SP360.4
- Thigpen JR; Law RD; Lloyd GE; Brown SJ; Cook B (2010) Deformation temperatures, vorticity of flow, and strain symmetry in the Loch Eriboll region, NW Scotland: Implications for the kinematic and structural evolution of the northernmost Moine thrust zone, In: Law; D R; Butler; H R; Holdsworth; R; Krabendam; M; Strachan; R (Ed) Continental Tectonics and Mountain Building: The Legacy of Peach and Horne, Geological Society, London, Special Publication, 335, The Geological Society of London, pp.623-662. doi: 10.1144/SP335.26
- Lloyd GE; Law RD; Mainprice DH (2010) Predicting seismic properties from three-dimensional microstructures - a new look at an old quartzite., In: Law; D R; Butler; H R; Holdsworth; R; Krabendam; M; Strachan; R (Ed) Continental Tectonics and Mountain Building: The Legacy of Peach and Horne, Geological Society, London, Special Publication, 335, The Geological Society of London, pp.603-622. doi: 10.1144/SP335.25
- Prasannakumar V; Lloyd GE (2010) Application of SEM-EBSD to Regional Scale Shear Zone Analysis: A Case Study of the Bhavani Shear Zone, South India, JOURNAL OF THE GEOLOGICAL SOCIETY OF INDIA, 75, pp.183-201. doi: 10.1007/s12594-010-0007-y
- Law RD; Mainprice DH; Casey M; Lloyd GE; Knipe RJ; Cook B; Thigpen JR (2010) Moine thrust zone mylonites at the Stack of Glencoul: I - microstructures, strain and influence of recrystallization on quartz crystal fabric development., In: Law; D R; Butler; H R; Holdsworth; R; Krabendam; M; Strachan; R (Ed) Continental Tectonics and Mountain Building: The Legacy of Peach and Horne, Geological Society, London, Special Publication, 335, The Geological Society of London, pp.543-577. doi: 10.1144/SP335.21
- Diaz Azpiroz M; Lloyd GE (2010) The influence of plagioclase LPO on P-wave anisotropy and seismic reflectivity of metabasites from the lower continental crust, Geogaceta, 48, .
- Thigpen JR; Law RD; Lloyd GE; Brown SJ (2010) Deformation temperatures, vorticity of flow, and strain in the Moine thrust zone and Moine nappe: Reassessing the tectonic evolution of the Scandian foreland-hinterland transition zone, JOURNAL OF STRUCTURAL GEOLOGY, 32, pp.920-940. doi: 10.1016/j.jsg.2010.05.001
- Lloyd GE; Butler RWH; Casey M; Mainprice D (2009) Mica, deformation fabrics and the seismic properties of the continental crust, EARTH AND PLANETARY SCIENCE LETTERS, 288, pp.320-328. doi: 10.1016/j.epsl.2009.09.035
- Wenk H; Barton N; Bortolotti M; Vogel SC; Voltolini M; Lloyd GE; Gonzalez GB (2009) Dauphin, twinning and texture memory in polycrystalline quartz. Part 3: texture memory during phase transformation, PHYSICS AND CHEMISTRY OF MINERALS, 36, pp.567-583. doi: 10.1007/s00269-009-0302-6
- Pollok K; Lloyd GE; Austrheim H; Putnis A (2008) Complex replacement patterns in garnets from Bergen Arcs eclogites: A combined EBSD and analytical TEM study, CHEMIE DER ERDE-GEOCHEMISTRY, 68, pp.177-191. doi: 10.1016/j.chemer.2007.12.002
- Tatham DJ; Lloyd GE; Butler RWH; Casey M (2008) Amphibole and lower crustal seismic properties, EARTH AND PLANETARY SCIENCE LETTERS, 267, pp.118-128. doi: 10.1016/j.epst.2007.11.042
- Jiang Q; Mullins J; Toman J; Hase TPA; Cantwell BJ; Lloyd GE; Basu A; Brinkman AW (2008) Hetero-Epitaxial Crystal Growth of CdTe on GaAs Substrates, Journal of Crystal Growth, 310, pp.1653-1656. doi: 10.1016/j.jcrysgro.2007.11.171
- McCaig A; Covey-Crump SJ; Ben Ismail W; Lloyd GE (2007) Fast diffusion along mobile grain boundaries in calcite, CONTRIBUTIONS TO MINERALOGY AND PETROLOGY, 153, pp.159-175. doi: 10.1007/s00410-006-0138-8
- Diaz Aspiroz M; Lloyd GE; Fernandez C (2007) Development of lattice preferred orientation in clinoamphiboles deformed under low-pressure metamorphic conditions. A SEM/EBSD study of metabasites from the Aracena metamorphic belt (SW Spain), JOURNAL OF STRUCTURAL GEOLOGY, 29, pp.629-645. doi: 10.1016/j.jsg.2006.10.010
- Azpiroz M; Lloyd GE (2007) Lattice preferred orientation and seismic fabric of metabasites deformed under medium-to-high temperature conditions from the Aracena metamorphic belt (SW Spain), Geophysical Research Abstracts, 9, pp.pp.06603.
- Prasannakumar V; Lloyd GE (2007) Development of crystallographic lattice preferred orientation and seismic properties in Bhavani shear zone, Southern India, JOURNAL OF THE GEOLOGICAL SOCIETY OF INDIA, 70, pp.282-296.
- Kendall J; Fisher QJ; Crump SC; Maddock J; Carter A; Hall SA; Wookey J; Valcke SLA; Casey M; Lloyd G; Ismail WB (2007) Seismic anisotropy as an indicator of reservoir quality in siliciclastic rocks, pp.123-136.
- Jefferies SP; Holdsworth RE; Wibberley CAJ; Shimamoto T; Spiers CJ; Niemeijer AR; Lloyd GE (2006) The nature and importance of phyllonite development in crustal-scale fault cores: an example from the Median Tectonic Line, Japan, JOURNAL OF STRUCTURAL GEOLOGY, 28, pp.220-235. doi: 10.1016/j.jsg.2005.10.008
- Jefferies SP; Holdsworth RE; Shimamoto T; Takagi H; Lloyd GE (2006) The formation and significance of foliated cataclasite and gouge in the cores of crustal-scale fault cores: examples from the Median Tectonic Line, Japan, Journal of Geophysical Research, 111 B12303, . doi: 10.1029/2005JB004205
- Jefferies SP; Holdsworth RE; Shimamoto T; Takagi H; Lloyd GE; Spiers CJ (2006) Origin and mechanical significance of foliated cataclastic rocks in the cores of crustal-scale faults: Examples from the Median Tectonic Line, Japan, JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH, 111, . doi: 10.1029/2005JB004205
- Valcke SLA; Casey M; Lloyd GE; Kendall J; Fisher QJ (2006) Lattice preferred orientation and seismic anisotropy in sedimentary rocks, GEOPHYSICAL JOURNAL INTERNATIONAL, 166, pp.652-666. doi: 10.1111/j.1365-246X.2006.02987.x
- Lloyd GE; Kendall JM (2005) Petrofabric-derived seismic properties of a mylonitic quartz simple shear zone: implications for seismic reflection profiling, 240, pp.75-94. doi: 10.1144/GSL.SP.2005.240.01.07
- Lloyd GE (2004) Microstructural evolution in a mylonitic quartz simple shear zone: the significant roles of dauphine twinning and misorientation, 224, pp.39-61. doi: 10.1144/GSL.SP.2004.224.01.04
- Wendt AS; Bayuk IO; Covey-Crump SJ; Wirth R; Lloyd GE (2003) An experimental and numerical study of the microstructural parameters contributing to the seismic anisotropy of rocks, JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH, 108, . doi: 10.1029/2002JB001915
- Lloyd GE; Chinnery N (2003) The Bude Formation, SW England: a reply to the comments by J. Treagus, JOURNAL OF STRUCTURAL GEOLOGY, 25, pp.2161-2163. doi: 10.1016/S0191-8141(03)00048-8
- Lloyd GE; Condliffe E (2003) 'Strain Reversal': a Windows (TM) program to determine extensional strain from rigid-brittle layers or inclusions, JOURNAL OF STRUCTURAL GEOLOGY, 25, pp.1141-1145. doi: 10.1016/S0191-8141(02)00056-1
- Butler RWH; Casey M; Lloyd GE; Bond CE; McDade P; Shipton Z; Jones R (2002) Vertical stretching and crustal thickening at Nanga Parbat, Pakistan Himalaya: A model for distributed continental deformation during mountain building, TECTONICS, 21, . doi: 10.1029/2001TC901022
- Lloyd GE; Chinnery N (2002) The Bude Formation, SW England - a three-dimensional, intra-formational Variscan imbricate stack?, JOURNAL OF STRUCTURAL GEOLOGY, 24, pp.1259-1280. doi: 10.1016/S0191-8141(01)00130-4
- Poole I; Lloyd GE (2000) Alternative SEM techniques for observing pyritised fossil material, REVIEW OF PALAEOBOTANY AND PALYNOLOGY, 112, pp.287-295. doi: 10.1016/S0034-6667(00)00047-6
- Calvert C; Brydson RMD; Lloyd GE; Banks DA (2000) Electron Energy-Loss Spectroscopy in the TEM and its applications within the geosciences, Geochemistry Group of the Mineralogical and Geological Societies, Research in Progress Meeting, .
- Leiss B; Ullemeyer K; Weber K; Brokmeier HG; Bunge HJ; Drury M; Faul U; Fueten F; Frischbutter A; Klein H; Kuhs W; Launeau P; Lloyd GE; Prior DJ; Scheffzuk C; Weiss T; Walther K; Wenk HR (2000) Recent developments and goals in texture research of geological materials, Journal of Structural Geology, 22, pp.1531-1540.
- Lloyd GE (2000) Grain boundary contact effects during faulting of quartzite: an SEM/EBSD analysis, Journal of Structural Geology, 22, pp.1675-1693. doi: 10.1016/S0191-8141(00)00069-9
- Lloyd GE (1998) Microstructural variations in a cataclastic quartz fault rock, In: Snoke; W A; Tullis; J; Todd; R V (Ed) Fault-related rocks: a photographic atlas, Princeton University Press, pp.48-49.
- Lloyd GE (1998) Microstructural development in a quartzo-feldspathic mylonite shear zones, In: Snoke; W A; Tullis; J; Todd; R V (Ed) Fault-related rocks: a photographic atlas, Princeton University Press, pp.274-275.
- Lloyd GE; Whalley JS (1997) Simple shear modification of chevron folds: implications for facing interpretation, strain analysis and deformation history, In: Sengupta S (Ed) Evolution of geologic structures from micro to macro scales, Kluwer Academic Publishers, pp.373-396.
- Agar SM; Lloyd GE (1997) Deformation of Fe-Ti oxides in gabbroic shear zones from the MARK area, Proceedings of the Ocean Drilling Program. Scientific Results, 153, pp.123-141.
- Lloyd GE; Farmer AB; Mainprice D (1997) Misorientation analysis and the formation and orientation of subgrain and grain boundaries, Tectonophysics, 279, pp.55-78. doi: 10.1016/S0040-1951(97)00115-7
- Butler RWH; Holdsworth RE; Lloyd GE (1997) The role of basement reactivation in continental deformation, Journal of the Geological Society, 154, pp.69-71.
- Imber J; Holdsworth RE; Butler CA; Lloyd GE (1997) Fault-zone weakening processes along the reactivated Outer Hebrides Fault Zone, Scotland, Journal of the Geological Society, 154, pp.105-109.
- Yardley BWD; Condliffe E; Lloyd GE; Harris DHM (1996) Polyphase garnets from western Ireland: two-phase intergrowths in the grossular-almandine series, European Journal of Mineralogy, 8, pp.383-392.