VOLCANOLOGY & MAGMATISM
MAGMATIC CRYSTAL RECORDS IN TIME, SPACE, AND PROCESS, CAUSATIVELY LINKED WITH VOLCANIC UNREST
Pankhurst MJ, Morgan DJ, Thordarson T, Loughlin S. (2018) Earth and Planetary Science Letters
This paper uses patterns of information in crystal chemistry to reconstruct the pathway of the magma that started the 2010 eruption of Eyjafjallajökull, Iceland, that closed European airspace. It is a detailed, causative, match with geophysical monitoring, and proves that proxy monitoring records at volcanoes is possible.
MONITORING THE MAGMAS FUELLING VOLCANIC ERUPTION IN NEAR-REAL-TIME USING X-RAY MICRO-COMPUTED TOMOGRAPHY
Pankhurst MJ, Dobson KJ, Morgan DJ, Loughlin S, Thordarson T, Lee PD, Courtois L (2014) Journal of Petrology
This paper demonstrates how large databases of mineral chemistry can be measured within an hour of sample receipt. It is tuned for use in volcanic eruptions, to monitor the processes occurring deep inside the plumbing system.
GEODYNAMICS OF RAPID VOLUMINOUS FELSIC MAGMATISM THROUGH TIME.
Pankhurst MJ, Schaefer BF, Betts PG (2011) Lithos
Rapid voluminous felsic magmatism and its geodynamic settings are reviewed. Two end-member types are identified. The first is high temperature, high fluorine magmas derived from assimilation-fractional crystallisation from a mafic parent as part of plume-head arrival underneath a continent. These have been produced in a regular manner since 2.45 Ga. The other is driven by extension during continental rifting or back-arc evolution, and is exclusive to Phanerozoic silicic large igneous province.
THE PETROGENESIS OF MAGMATIC SYSTEMS: USING IGNEOUS TEXTURES TO UNDERSTAND MAGMATIC PROCESSES
Jerram D, Dobson K, Morgan DJ, Pankhurst MJ. (2018) In Burchardt S. (ed) Volcanic and Igneous Plumbing Systems Elsevier
This book chapter summarises the state of the art in 2D and 3D textural analysis of igneous rocks to elucidate magmatic processes.
THE SOURCE OF A-TYPE MAGMAS IN TWO CONTRASTING SETTINGS: U–PB, LU–HF AND RE–OS ISOTOPIC CONSTRAINTS
Pankhurst MJ B.F. Schaefer, S.P. Turner, T. Argles, C.E. Wade (2013) Chemical Geology
Understanding the production of high-silica magmas is the key to understanding the evolution of the Earth's crust, and its concentration of metals into ore bodies. In this paper specialised isotopic techniques were used to discriminate between mantle sources, and link them to their tectonic environment.
A MESOPROTEROZOIC CONTINENTAL FLOOD RHYOLITE PROVINCE, THE GAWLER RANGES, AUSTRALIA: THE END MEMBER EXAMPLE OF THE LARGE IGNEOUS PROVINCE CLAN
Pankhurst MJ, Schaefer BF, Betts PG, Phillips N, Hand M (2011) Solid Earth
Normally, rhyolite magmas are sticky, and explode. Normally, large igneous provinces are basaltic, which flow easily. In the Mesoproterozoic of Australia, however, a large igneous province of runny rhyolite was formed, and this paper explains that the high temperature and high halogen content of those magmas acted to lower viscosity such that they behaved like basalts.
VOLCÁN DE COLIMA DOME COLLAPSE OF JULY, 2015 AND ASSOCIATED PYROCLASTIC DENSITY CURRENTS
Reyes-Dávila GA, Arámbula-Mendoza R, Espinasa-Pereña R, Pankhurst MJ, +18 (2016) Journal of Volcanology and Geothermal Research
Describes the pyroclastic density currents from Volcan de Colima and offers a mechanistic model of dome collapse triggered by boiling over.
CONTRASTING SR AND ND ISOTOPIC BEHAVIOUR DURING MAGMA MINGLING; NEW INSIGHTS FROM THE MANNUM A-TYPE GRANITE.
Pankhurst MJ, Vernon RH, Turner SP, Schaefer BF, Foden J (2011) Lithos
Magma-mixing is a classic paradigm in igneous petrology, and is often used to explain textural and chemical observations. In this paper, a curious de-coupling between Sr and Nd isotope system behavior is explored using a range of in-situ methods. We suggest the isotopic data can be explained by efficient growth and dissolution of feldspar during repeated mixing cycles, the "catch and release" mode of isotopic equilibration.
THE HALOGEN BUDGET OF BOLIVIAN MAFIC SHOSHONITES
Pankhurst MJ, Jimenez N, Schaefer BF, Turner SP (2012) Revista Boliviana de Geociencias
This paper contributes to a memorial edition dedicated to the career of Bertrand Heuschmidt. It describes the geochemistry and halogen geochemistry of some primitive shoshonites from Bolivia.
CLIMATE SCIENCE
ATMOSPHERIC K-FELDSPAR AS A POTENTIAL CLIMATE MODULATING AGENT THROUGH GEOLOGIC TIME
Pankhurst MJ. et al. (2021) Journal of the Geological Society
The size of a meteorite impact does not correlate with the timing or intensity of mass extinctions. What does correlate, strongly, timing of K-feldspar rich ejecta layers (which act a source of mineral dust for sometimes 100's kyr) and mass extinctions. Here my co-authors and I develop a new hypothesis that offers a solution to the long standing conundrums about impacts, volcanism and the evolution of life.
ATMOSPHERIC K-FELDSPAR AS A POTENTIAL CLIMATE MODULATING AGENT THROUGH GEOLOGIC TIME
Pankhurst MJ. (2017) Geology
Recent research has identified the one mineral which is critical in the Earths' atmosphere, due to its extraordinary ice-nucleation properties, and its affects on the microphysics and behaviour of cloud. In this paper, I reviewed K-feldspars' availability to the atmosphere through all of geologic time.
METEORITE IMPACT USED TO EVALUATE GLOBAL ALKALI FELDSPAR AVAILABILITY TO THE ATMOSPHERE SINCE 600 MA
Coldwell B, Pankhurst MJ. (2019) Journal of the Geological Society
For the majority of the past ~600 Ma, K-feldspar availability to the atmosphere has been low, and well-buffered. In this paper we looked to the only possible mechanism which could have changed that availability: major meteorite impact, and estimated global availability using the geology of target rocks, impact calculations and tectonic reconstructions. This paper won the Journal of the Geological Society's Early Career Award for 2019.
METHOD ADVANCES
NON-DESTRUCTIVE THREE-DIMENSIONAL CRYSTALLOGRAPHIC ORIENTATION ANALYSIS OF OLIVINE USING LABORATORY DIFFRACTION CONTRAST TOMOGRAPHY
Pankhurst MJ, Gueninchault N, Andrew M, Hill E. (2019) Mineralogical Magazine
This is the first paper to describe the non-destructive, 3D measurement of crystallographic orientation inside a silicate mineral. There are numerous applications for this technology, one of which is volcanology and igneous petrology.
ENABLING THREE-DIMENSIONAL DENSITOMETRIC MEASUREMENTS USING LABORATORY SOURCE X-RAY MICRO-COMPUTED TOMOGRAPHY
Pankhurst MJ, Fowler R, Courtois L, Nonni S, Zuddas F, Atwood RC, Davis GR, Lee PD (2018) SoftwareX
X-ray micro-imaging was not initially designed to provide quantitative and reproducible 3D images. In this paper we built a bolt-on set of known materials of known thickness, which we scanned and used to define the X-ray beam shape (flux and energy). With this known, we could then scan unknown materials and correct for imaging artefacts, as well as using the intensity data as a quantitative measure of density.
HIGH-ENERGY, HIGH-RESOLUTION, FLY-SCAN X-RAY PHASE TOMOGRAPHY
Wang H, Atwood RC, Pankhurst MJ, Kashyap Y, Cai B, Zhou T, Lee PD. (2019) Scientific Reports
This paper describes the application of a novel X-ray imaging technique, that allows researchers to observe different optical properties of the materials, and may lead to lowering X-ray dosages in clinical settings.
QUANTITATIVE MEASUREMENT OF OLIVINE COMPOSITION IN THREE DIMENSIONS USING X-RAY MICRO-COMPUTED TOMOGRAPHY
Pankhurst MJ, Vo NT, Butcher, AR, Long H, Wang H, Nonni S, Harvey J, Guðfinnsson G, Fowler R, Atwood R, Walshaw R, Lee PD. (2018) American Mineralogist
This paper builds upon Pankhurst et al. (2014: Journal of Petrology) and Pankhurst et al. (2018 SoftwareX), to achieve the first quantitative measurement of olivine chemistry in 3D, using a laboratory source of X-rays. Using this technique, volcano observatories can rapidly build large datasets of olivine chemistry from the rock record, and during live eruptions.
X-RAY PHASE CONTRAST IMAGING WITH ENGINEERED POROUS MATERIALS OVER 50 KEV
Wang H, Cai B, Pankhurst MJ, Zhou T, Kashyap Y, Atwood R, Le Gall N, Lee P, Drakopoulos M, Sawhney K. (2018) Journal of Synchrotron Radiation
Phase-contrast X-ray imaging is a powerful tool in understanding the 2D and 3D structures of materials and tissues, but traditional techniques have inherent limitations due to the imaging setup. In this paper, we used a different approach to creating a 'speckle', and with this limitation removed, successfully used phase-contrast imaging at high energies, which in turn allows imaging of dense materials, like volcanic rocks.
MAJOR ELEMENT CHEMICAL HETEROGENEITY IN GEO2 OLIVINE MICROBEAM REFERENCE MATERIAL: A SPATIAL APPROACH TO QUANTIFYING HETEROGENEITY IN PRIMARY REFERENCE MATERIALS
Pankhurst MJ, Walshaw R, Morgan DJ. (2017) Geostandards and Geoanalytical Research
As petrologists require larger databases of crystal chemistry, micro-analytical techniques have to get faster and more efficient. This, in turn, places pressure on the use of standard reference materials, which have to be analysed over and over again and are generally very small. In this paper, we describe how a large chip of non-homogeneous mineral can be used as reference material, by first mapping its chemistry using "gold standard" point analysis wavelength dispersive techniques. In principle, the idea could be applied to any reference material used as a micro-beam standard.
OTHER GEOSCIENCE
PROVENANCE OF THE EARLY MESOPROTEROZOIC RADIUM CREEK GROUP IN THE NORTHERN MOUNT PAINTER INLIER: CORRELATING ISOTOPIC SIGNATURES TO INFORM TECTONIC RECONSTRUCTIONS
Armit RJ, Betts PG, Schaefer BF, Pankhurst MJ, Giles D (2014) Precambrian Research
This paper describes the use of mineral scale isotopic data to track the sources of sediments in packages of (very!) old rock. The use of in-situ U-Pb and Hf isotopic data allows us to 'see-through' many stages of later tectonism, and conclude that the Mt. Painter Provence was connected to both the North and South Australian Cratons at ~1595 Ma, providing an important piece of the tectonic reconstruction puzzle.
MESOPROTEROZOIC PLUME-MODIFED OROGENESIS IN EASTERN PRECAMBRIAN AUSTRALIA
Betts PG, Giles D, Foden J, Schaefer, BF, Mark G, Pankhurst MJ, Forbes CJ, Williams HA, Chalmers NC, Hills Q (2009) Tectonics
This paper describes the interaction of a mantle plume with an active tectonic margin. A novel tectono-magmatic model is used to explain what first appears to be two sets of contradictory evidence for two different tectonic settings.