Professor Kliti Grice
|Position||Professor of OSIG|
|Faculty||Faculty of Science & Engineering|
|School||School of Science|
|Department||Dept of Chemistry|
|Phone||+618 9266 2474|
|Fax||+618 9266 2300|
Professor Kliti Grice Grice is an internationally renowned organic geochemist who creatively combines geological information with data on molecular fossils and their stable carbon and hydrogen isotopic compositions to reconstruct details of microbial, fungal and floral inhabitants of ancient aquatic environments. She is especially well known for identifying a geological and environmental basis for the largest mass extinction in Earth’s history, which happened at the end of the Permian Period, about 252 million years ago.
Grice’s research over the years has integrated molecular and isotopic information on plant and algal physiology, microbial ecology, food-webs, organic chemistry, petroleum geochemistry and geology with our planet's history. In particular, she has shown how some of the major biological extinction events of the geological past can be traced to factors intrinsic to the Earth system, as opposed to external factors such as asteroid impacts. Analyses of the natural variation in stable isotopes of lipids present in controlled growth experiments from extant plants, algae and grazing organisms carried out by Grice have provided new insights into how these systems function across paleoecological to modern timescales and across a wide range of spatial scales.
Grice’s outstanding research reputation has also attracted many national and international PhD and postdoctoral scholars to the wonders of Earth science. She provides training and mentorship to students coming from a wide array of scientific disciplines, including chemistry, biology, geology and environmental science. In addition, the training of research students at the PhD and Masters level, as well as early career researchers, is the prime focus of the world-class organic and isotope geochemistry centre that she has established at Curtin University.
Anoxygenic Photosynthesis in Ancient Seas Grice’s first major scientific breakthrough, in 1995, involved measurements and interpretations of the stable carbon isotopic compositions of maleimides (small, polar, nitrogen-containing molecules) in sedimentary organic matter. She identified these compounds, which are derived uniquely from the chlorophylls of oxygenic photosynthetic organisms (e.g., cyanobacteria and algae) and bacteriochlorophylls of anoxygenic photosynthetic organisms (e.g., green sulfur bacteria, the Chlorobi), obtained from highly anoxic sedimentary deposits by their mass spectra and isotopic compositions.
Chlorobi can play a significant role in the sulfur cycle at the chemocline of stratified lakes and ocean basins such as the Black Sea. They are strict anaerobes, utilising hydrogen sulfide during photosynthesis to fix CO2 via the reversed tricarboxylic acid cycle, resulting in a 13C enrichment of lipids that renders them distinct from the lipids of other phytoplankton. Thus, the combination of chemical structures and stable isotopic compositions allowed her to unambiguously identify which maleimides originated from the Chlorobi. Grice also discovered an array of diagenetic alteration products from the secondary pigments (carotenoids) of the Chlorobi. Notably, her research inspired others to investigate the nitrogen isotopic compositions of maleimides, thus leading to a new tool for studying the marine nitrogen cycle in ancient oceans.
Grice’s multidisciplinary research approach has provided the best direct molecular and isotopic evidence for the role of anoxygenic photosynthesis in ancient seas in accounting for biogeochemical changes that occur during oceanic anoxic events and the deposition of rocks offering significant petroleum potential. Research led by Grice suggests that about 252 million years ago, a climate-related biogeochemical ‘event’ jolted the world so profoundly that atmospheric O2 levels became low concomitantly with the rise of toxic concentrations of CO2 and H2S. The Earth’s thermostat went awry and the ocean circulation became sluggish leading to the extinction of as much as 90% of marine and 75% of terrestrial eukaryotic species. Unlike a later extinction that wiped out the dinosaurs, the event that ended the Palaeozoic Era, 252 million years ago, appears not to have been triggered by the impact of a meteorite but, rather, by the climatic effects associated with the aggregation of the ancient supercontinent Pangea.
In reaching this conclusion, Grice first showed that Chlorobi were abundant organisms in the upper part of the water-column of the Late Permian seas at several widely-spaced locations, including Australia and China, thereby implying that the hydrogen sulfide, on which they depend, must have been prevalent as well. Release of sulfide into the atmosphere, therefore, probably also played a critical role in the extinction on land. Grice subsequently identified Chlorobi-derived biomarkers globally, using a novel multidisciplinary approach (biomarker data, fossil data, palynology, sulfur isotopes and compound specific carbon and hydrogen isotopes. More recently, she proposed that the collapse of the marine and terrestrial ecosystems led to high amounts of recycled 13C-depleted CO2 in the earliest Triassic oceans and atmosphere, thus explaining the world-wide carbon isotope excursion. In a 380 million year old concretion from the Canning Basin, WA, fossilised soft tissue from a crustacean we have revealed biomarkers & stable isotopes from Chlorobi and sulfate reducing bacteria.
The adjacent matrix only contained evidence of sulfate reducing bacteria that lived at the sediment/water interface and were involved in the formation of the carbonate concretion in a closed system. H2S in the paleowater column played a pivotal role in the preservation of the organism. Biodegradation of Petroleum by Subsurface Microbes In 1998, Grice expanded her research interests into petroleum geochemistry and petroleum biodegradation. She was the first to investigate the susceptibility of biphenyls and alkylbiphenyls to bacterial degradation, and later established that diamondoids (cage-shaped carbon skeletons) are also broken down. This research has enabled petroleum explorers to better understand subsurface processes, thus reducing exploration risk.
This research has implications for the petroleum industry because these processes reduce the quality of the oils. Isotopic Fractionation in Present-day Organisms Compound-specific isotope measurements of biomarkers are increasingly important for palaeoclimate reconstructions. In order to accurately interpret the stable carbon and hydrogen isotopic patterns found in sedimentary lipids, a fundamental understanding of the isotopic fractionations that occur in diverse living systems is essential. In 1998 Grice performed seminal zooplankton herbivory studies based on stable carbon isotopes. The stable carbon isotopic compositions of cholesterol, generally the dominant sterol of copepods, retain the signature of their dietary precursor sterols. The carbon isotopic composition of cholesterol in the faecal pellets released from copepods is identical to that of the sterols in the diet, indicating that no significant carbon isotopic fractionation effects occur when the copepod modifies algal precursor sterols to cholesterol.
This and other research on the isotopic composition of faecal pellets demonstrated that carbon isotopic compositions of sedimentary steroids may serve as conservative tracers of the algal community on which zooplankton feed. This study provided the basis for the identification of a 380 million year old invertebrate fossil in a carbonate nodule as a crustacean based on the stable carbon isotopic composition and abundance of cholestane within the fossil nucleus. Other carbon isotopic studies carried out on Nicotiana tabacum leaf wax by Grice have provided a qualitative phytochemical explanation of the observed δ13C differences among n-alkane, iso-alkane and anteiso-alkane and a physiological explanation for the observed δ13C shifts when environmental conditions of growth change.
Grice and co-workers have also proposed a new biosynthetic pathway leading to even carbon numbered n-alkane biosynthesis in plant was and sediments that also accounts for the previously enigmatic ‘saw-tooth’ that is evident in the isotopic patterns of fossil hydrocarbons. H-Isotopic Exchange in Fossil Hydrocarbons Grice’s research has also extended to the technically challenging task of determining the hydrogen isotopic composition of individual biomolecules. She was the first to show that, with increasing burial temperatures, isoprenoidal lipids become enriched in deuterium whereas the acetogenic lipids generally remain constant. A more rapid enrichment of deuterium in isoprenoids relative to alkanes with increasing temperature identifies a hydrogen exchange process that has been elegantly described by Grice.
Further, the hydrogen isotopic differentials between the isoprenoidal and n-alkyl compound classes correlate well with vitrinite reflectance values, indicating that hydrogen isotope compositions are useful for measuring thermal history over a wider range than are most conventional parameters. Many of Grice’s research achievements have been underpinned by the development of state-of-the-art analytical technology and protocols to support the high-resolution characterisation of the molecular and stable isotopic compositions of environmentally significant organic compounds. Her superb analytical skills and expertise have been broadly applied to elucidate the origins and preservation pathways of numerous natural and synthetic substances found in sedimentary environments, with implications for forensics, the provenance of food, carbon cycling, impact of humans on the environment as well as air. For example, Grice and her team have been able to use the carbon and hydrogen compositions of atmospheric volatile organic compounds (VOCs) for establishing their sources: forest fires, diesel fuels or industrial emissions.
These are exceedingly difficult measurements which were achieved using thermal desorption in combination with compound-specific isotope analysis. Grice and team have also demonstrated the improved separation of higher plant biomarkers in crude oils and a learning set of rock extracts (from the Arctic) of the Tertiary using comprehensive two-dimensional gas chromatography (GC x GC) coupled to a time-of-flight mass spectrometer (TOF). Higher plant biomarkers have great potential for high resolution molecular chronostratigraphy of the Tertiary (including Cenozoic), thus, stimulating significant interest in the study of angiosperm derived biomarker distribution in geological samples of unknown age. However, they occur in various compound classes with an array of isomers that are challenging to separate and identify. GC x GC TOF provides an extra dimension in assessing the composition of the so-called ‘Unresolved complex mixture’ for oils that have been heavily degraded by microbial communities, unravelling a wealth of important new molecular information. Significantly, use of the above analytical technologies for exploration purposes will alleviate the time & expense of drilling for source-rocks for oil-source correlation to determine the age of the oil.Back to top
Memberships, Awards and Training
MEMBERSHIPS OF LEARNED SOCIETIES, RESEARCH ALLIANCES AND RESEARCH COMMITTEES
2012- American Geophysical Union, Patterson award commitee.
2011-current CSIRO Cluster Leader of Minerals Down-under collaboration cluster fund, Australia.
2010-current Scientific Advisory Committee Sinopec Petroleum Exploration Research, WUXI, China Member of the Geological Society of Australia Fellow of the Royal Australian Chemical Institute
2010-current Chair of the ‘Best Paper Award’ Committee of the Organic Geochemistry Division, Geological Society of America (GSA) 2009–current Committee member of the European Association of Organic Geochemistry (EAOG) International Pieter Scheck Award
2009–2012 ARC College of Experts (Discovery Project and Linkage Project grants: Physics, Chemistry and Earth Sciences)
2009- current Executive member of the Australia and New Zealand Mass Spectrometry Society
2009-current Member of the Research and Development Committee of the Department of Chemistry, Curtin University
2008–2010 Board of the University Research and Development Committee, Curtin University
2008–2010 Board of the Research and Development Committee of the Faculty of Science and Engineering, Curtin University
2008–current International Geoscience Program 572 (Project Leader): Restoration of Marine Ecosystems following the Permian-Triassic Mass Extinction
2008–current Member, American Association of Petroleum Geologists
2007–current Member, Geological Society of America (GSA)
2007–2009 Member ‘Best Paper Award’ Committee of the Organic Geochemistry Division, GSA
2007–current Committee member of the EAOG Travel Awards
2007 Appointed ARC College of Experts – Linkage Infrastructure grants
1998–current Member, Petroleum Exploration Society of Australia
1998–current Member, Royal Australian Chemical Institute
1998–current Australasian Research Management Society, WA Chapter
1994–current Member, European Association of Organic Geochemistry AWARDS
2012 RACI Environmental medal to be presented in Dec 2012 and medallist lecture
2011 Award for the highest RPI 2010 Division for Science and Engineering
2010 VC Award for Excellence & Innovation at Curtin University, Finalist award
2010 Award for highest research performance index in Curtin University and in Faculty.
2009 Faculty Senior Researcher of the Year Award for Science, Curtin University
2008 Australian Research Council (ARC) QEII Fellowship (II)
2007 Faculty Researcher of the Year Award for Science (under 40), Curtin University
2002 The Premier’s Inaugural Science Award for Early Career Achievement in Science, Western Australia
2002 JG Russell Award, Australian Academy of Science for QEII research
2002 Dean’s Medallion for Emerging Research Effort, Division of Engineering and Science, Curtin University
2002 ARC QEII fellowship (I)
2001 International Pieter Schenck Award presented by the European Association of Organic Geochemistry for outstanding contributions in Organic Geochemistry Student and Staff Awards
Please see http://wa-oigc.curtin.edu.au/research/awards.cfm
Conference organization Organising committee of 2011
International Permian and Carboniferous Conference, UWA, Perth WA
Organising Committee of 2011 ANZSMS conference,
2010 Convenor of Australian Isotope/Environmental and Hydrogeology conference at Curtin University,
2009 Gordon Research Conference joint session chair on biodegradation,
2008 Gordon Research Conference session chair on ‘Hot Topics’,
2008 Convenor of Australian Organic Geochemistry Conference,
2006 Session Organising Chair at the 16th Annual V.M. Goldschmidt Conference, Melbourne,
2006 Session Organising Chair at the American Chemical Society, Orlando,
2002 Associate editor Organic Geochemistry, 2007–present Geology, 2007–2010;
2012-present Journal reviewer Organic Geochemistry Environmental Science and Technology, Chemical Geology, Geology Geochimica et Cosmochimica Acta, Paleo3 Earth and Planetary Science Letters, Applied Geochemistry, Analytical Chemistry Journal of Chromatography, Rapid Communications in Mass Spectrometry, Science, Nature, Geoscience
Grant reviewer UK Natural Environment Research Council,
1998–present Australian Research Council – International and Oz reader,
2001–2009 USA National Science Foundation,
2007–present American Chemical Society – Petroleum research fund,
1998–present Dutch Research Foundation,
2002–present German Research Foundation,
2002–present Student supervision PhD student supervision
2011: Alexander Holman APA
2011: Anais Pages: ARC Discovery (Grice)/ CIRTS
2010: Ines Melendez: ARC QEII (Grice)/CIRTS
2009: Svenja Tulipani: Curtin University Targeted Scholarship/CIRTS
2009: Mojgan Ladjavardi: Curtin University/CIRTS
2008: Salem Aboglila: Curtin University – completed
2007: Christiane Eiserbeck: Curtin University/Chevron- completed
2006: Ercin Maslen: Curtin University/ CUPSA – completed
2006: Dawn White: Curtin University/CRC-WQT/CIRTS – in preparation
2006: Birgit Nabbefeld: Curtin University/ARC/ CIRTS – completed
2006: Christian Hallmann: Curtin University/ CIRTS – completed
2006: Christiane Vitzthum Von Eckstaedt: Curtin University/CRC-CARE – completed
2005: Luc Fusetti: Curtin University/ IFP/ Cotutelle – completed and VC commendation
2004: Tamara Pilgrim: Curtin University/UWA – completed
2003: Daniel Dawson: Curtin University-APA – completed Collaborating PhD student supervision
2012: Aileen Robert: University of Western Australia
2009: Anthony Hall: University of Adelaide- in progress
2006: Lyndsay Hays: MIT, US- completed
2004: Pia Atahan: University of Western Australia – completed
2002: Pauline Chau: University of Western Australia – completed Honours and Masters student supervision
1998–present: 2 Masters, 25 Honours, 4 French Internships, 3 Pakistan Internships and 2 BioGenius students.
Research fellows (mentor) Dr Ken Williford Dr Katherine Trinajstic Dr Pia Atahan Dr Tobias Ertefai Dr Caroline Jaraula Dr Youping Zhou Dr Robert Lockhart Dr Pierre Le Metayer Dr Jeffrey Dick Dr Martijn Woltering Dr Alison Blyth Dr Lyndon BerwickBack to top
Department of Chemistry Curtin University Kent Street, Bentley WA 6102
Tel +61 8 9266 2474;
Fax +61 8 9266 2300
Professor of Organic and Isotope Geochemistry, Curtin University – since December 2007
2008 – current Founding Director, Western Australian Organic and Isotope Geochemistry Centre (founding director);
Australian Research Council (ARC) QEII Fellow (II)
2007 Professor of Organic and Isotope Geochemistry, Curtin University
2003 Associate Professor of Organic and Isotope Geochemistry, Curtin University
2002–2007 ARC (QEII) Fellow (I), WA State Centre for Excellence in Applied Organic Geochemistry, Curtin University Leader of the Stable Isotope and Biogeochemistry Research Group
1998–2002 Senior Research Fellow, John de Laeter State Centre for Excellence in Mass Spectrometry, Curtin University
1995–1998 Research Fellow, Royal Netherlands Institute for Sea Research, Texel, The Netherlands EDUCATION
1995 Doctor of Philosophy (University of Bristol, UK)
1991 Bachelor of Science in Applied Chemistry (Honours), University of Kingston, London, UKBack to top
- Organic Geochemistry
- Stable isotopes
- Environmental Chemistry
- Mass Extinctions and Earth's History
- Petroleum Geochemistry
- Biomarkers/ Molecular Fossils Provenancing
- Analytical Chemistry
- Compound Specific Isotopes
- Biogeochemical Cycles Biochemistry
For research please see http://wa-oigc.curtin.edu.au/research/
For grants http://wa-oigc.curtin.edu.au/research/grants.cfmBack to top
- Organic Geochemistry
- Stable isotopes
- Environmental Chemistry
- Mass Extinctions and Earth's History
- Petroleum Geochemistry
- Biomarkers/ Molecular Fossils Provenancing
- Analytical Chemistry
- Compound Specific Isotopes
- Biogeochemical Cycles
94 international peer reviewed publications 6 book chapters 26 Plenary and Keynotes 200 conference abstracts Prof. Kliti Grice, # research led by Grice K.
1. #Grice, K., Kagi, R.I., and Alexander, R. 1999, Proceedings of 8th ISMAS Symposium on Mass Spectrometry, Compound Specific 13C/12C and D/H Isotopes for Geochemical Studies. Perfect Prints, Thane, India. pp. 235-244.
2. #Grice, K., (2001) δ13C as an indicator of paleoenvironments: A molecular approach in: ‘Application of stable isotope techniques to study biological processes and functioning ecosystems’ (edited by Unkovich M, Pate J, McNeill A and Gibbs J). (1): 247-281.
3. Courty M.A., Crisci A., Fedoroff M., Grice K., Greenwood P.F., Mermoux M., Smith D., and Thiemens M., 2008, Regional Manifestation of the Widespread Disruption of Soil-Landscapes by the 4 kyr BP Impact-Linked Dust Event Using Pedo-Sedimentary Micro-Fabrics, 211–36. S. Kapur et al. (eds), New Trends in Soil Micromorphology, 211 © Springer-Verlag Berlin Heidelberg 2008.
4. #Grice K., and Brocks J.J., 2011, Biomarkers (organic, compound specific isotopes)Encyclopaedia of Geobiology. (Editors Thiel and Reitner), pp.147-167; Springer. Encyclopedia of Earth Science Series.
5. Brocks J.J., and Grice K., 2011, Encyclopaedia of Geobiology. (Editors Thiel and Reitner), pp.167-182; Springer. Encyclopedia of Earth Science Series.
6. #Grice K., and Eiserbeck C., 2012, Biomarkers and the evolution of life. Invited Book Chapter – 2nd edition of the Treatise on Geochemistry. Under Review.
PEER REVIEWED PUBLICATIONS
7. #Grice K., Gibbison R., Atkinson J.E., Eckardt, C.B., Schwark, L., and Maxwell, J.R. 1996, 1H-pyrrole-2,5-diones (maleimides) as indicators of anoxygenic photosynthesis in palaeowater columns. Geochimica et Cosmochimica Acta 60, 3913-3924.
8. #Grice K., Schaeffer P., Schwark, L., and Maxwell, J.R. 1996, Molecular indicators of palaeoenvironmental conditions in an mmature Permian shale (Kupferschiefer, Lower Rhine Basin, N.W. Germany) from free and sulfide-bound lipids. Organic Geochemistry 25, 131-147.
9. #Grice K., Schaeffer P., Schwark, L., and Maxwell, J.R. 1997, Changes in palaeoenvironmental conditions during deposition of the Permian Kupferschiefer (Lower Rhine Basin, N.W. Germany) inferred from molecular and isotopic compositions of biomarker components. Organic Geochemistry 26, 677-690.
10. #Grice, K., Schouten S., Nissenbaum, A., Charach, J., and Sinninghe-Damsté, J.S. 1998, A remarkable paradox: freshwater algal (Botryococcus braunii) lipids in an ancient hypersaline euxinic ecosystem. Organic Geochemistry 28, 195-216.
11. #Grice, K., Schouten S., Nissenbaum, A., Charach, J., and Sinninghe-Damsté, J.S. 1998, Isotopically heavy carbon in the C21 to C25 regular isoprenoids in halite-rich deposits from the Sdom Formation, Dead Sea Basin, Israel. Organic Geochemistry 28, 349-359.
12. #Grice, K., Klein Breteler, W.C., Schouten S., Grossi, V., de Leeuw, J.W., and Sinninghe-Damsté, J.S. 1998, The effects of zooplankton herbivory on biomarker proxy records. Paleoceanography 13, 686-693.
13. Schouten, S., Klein Breteler, W.C., Blokker, P., Schogt, N., Rijpstra, W.I., Grice, K., Baas, M., and Sinninghe-Damsté, J.S. 1998, Biosynthetic effects on the stable carbon isotopic compositions of algal lipids: Implications for deciphering the carbon isotopic biomarker record. Geochimica et Cosmochimica Acta 62, 1397-1406.
14. #Grice, K., Schouten S., Peters, K.E., and Sinninghe-Damsté, J.S. 1998, Molecular isotopic characterisation of hydrocarbon biomarkers in Palaeocene-Eocene evaporitic lacustrine source rocks from the Jianghan Basin, China. Organic Geochemistry 29, 1397-1406.
15. Trolio, R., Grice, K., Fisher, S.J., Alexander, R., and Kagi, R.I. 1999, Alkylbiphenyls and alkyldiphenylmethanes as indicators of petroleum biodegradation. Organic Geochemistry 30, 1241-1253.
16. Gagnon, M.M., Grice, K., and Kagi, R.I. 1999, Biochemical and Chemical Parameters for Aquatic Ecosystem Health Assessments Adapted to the Australian Oil& Gas Industry. The Australian Petroleum Production & Exploration Association Limited. Perth, Western Australia 39(1), 584-599.
17. #Grice, K., Alexander, R., and Kagi, R.I., 2000, Diamondoid hydrocarbon ratios as indicators of biodegradation in Australian crude oils. Organic Geochemistry 31, 67-73.
18. Audino, M., Grice, K., Alexander, R., Boreham, C.J., and Kagi, R.I., 2001, An unusual distribution of monomethylalkanes in Botryococcus Braunii-rich sediments. Geochimica et Cosmochimica Acta 12, 1995-2006.
19. Audino, M., Grice, K., Alexander, R., Kagi, R.I., 2001, Macrocyclic alkanes: A new class of biomarker.Organic Geochemistry 32, 759-763.
20. Barber, C.J., Grice, K., Bastow, T.P., Alexander, R., and Kagi, R.I., 2001, The identification of crocetane in Australian crude oils. Organic Geochemistry 12, 943-947.
21. Barber, C.J., Bastow, T.P., Grice, K., Alexander, R., and Kagi, R.I. 2001, Analysis of crocetane in crude oils and sediments: novel stationary phases for use in GC-MS. Organic Geochemistry 32, 765-769.
22. #Grice, K., Audino, M., Alexander, R., Boreham, C.J., and Kagi, R.I., 2001, Distributions and stable carbon isotopic compositions of biomarkers in torbanites from different palaeogeographical locations. Organic Geochemistry 32, 195-2110.
23. Audino, M., Grice, K., Alexander, R., and Kagi, R.I., 2002, Macrocyclic alkanes in crude oils from the algaenan of Botryococcus braunii. Organic Geochemistry 33, 978-984.
24. #Grice, K., 2002 From Bristol to the antipodes: exploring diverse environments of the past and present. Organic Geochemistry. 33 403-406.
25. Klein Breteler, W.C., Grice, K., Kloosterhuis, R., Schouten, S., and Sinninghe- Damsté, J.S., 2002, Unravelling sources of stable carbon isotope signals in pelagic copepods, their faecal pellets and POC. Marine Ecology Progress Series 40, 195-204.
26. Audino, M., Grice, K., Alexander, R., and Kagi, R.I. 2002, Macrocyclic alkanes: Markers for the Freshwater Alga Botryococcus Braunii in the Gippsland Basin. Australian Petroleum Production and Exploration Association Limited 1, 67-71.
27. Krull, E.S., Skjemstad, J.O., Graetz, D., Grice, K., Dunning, W.J., Cook, G., and Parr, J.F., 2003, 13C-depleted charcoal from C4 grasses and the role of occluded carbon in phytoliths. Organic Geochemistry 34, 1337-1352.
28. #Grice, K., Schouten, S., Blokker, P., Derenne, S., Largeau, C., Nissenbaum, A., and Sinninghe-Damsté, J.S., 2003, Structural and isotopic analysis of kerogens in sediments rich in free sulfurised Botryococcus braunii biomarkers. Organic Geochemistry 34, 471-482.
29. Audino, M., Grice, K., Alexander, R., and Kagi, R.I., 2004, Macrocyclic alkanes in crude oils and sediment extracts: Enrichment using molecular sieves. Organic Geochemistry 35, 661-663.
30. Dawson, D., #Grice, K., Wang, S., Alexander, R., and Radke, J., 2004, Stable hydrogen isotopic composition of hydrocarbons in torbanites (Late Carboniferous to Late Permian) deposited under various climatic conditions. Organic Geochemistry 35, 189-197.
31. Pedentchouk, N., Freeman, K.H., Harris, N.B., Clifford, D.J., and Grice, K., 2004, Sources of alkylbenzenes in Lower Cretaceous lacustrine source rocks, West African rift basins. Organic Geochemistry 35, 33-45.
32. #Grice, K., Cao, C., Love, G.D., Bottcher, M.E., Twitchett, R.J., Grosjean, E., Summons, R.E., Turgeon, S., Dunning, W.J., and Jin, Y., 2005, Photic Zone Euxinia During the Permian-Triassic Superanoxic Event. Science 307,706-709.
33. Dawson, D., #Grice, K., and Alexander, R., 2005, Effect on maturation on the indigenous δD signatures of individual hydrocarbons in sediments and crude oils from the Perth Basin (Western Australia). Organic Geochemistry 36, 95-104.
34. #Grice, K., Twitchett, R.J., Alexander, R., Foster, C.B., and Looy, C., 2005, A potential biomarker for the Permian-Triassic ecological crisis. Earth and Planetary Science Letters 236, 315-321.
35. #Grice, K., Backhouse, J., Alexander, R., Marshall, N., and Logan, G.A., 2005, Correlating terrestrial signatures from biomarker distributions, δ13C, and palynology in fluvio-deltaic deposits from NW Australia (Triassic-Jurassic).Organic Geochemistry 36, 1347-1358.
36. Dawson, D., #Grice, K., and Alexander, R., 2005, Stable hydrogen isotope ratios of sediment maturity? Australian Petroleum Production and Exploration Association 1, 253-261.
37. #Grice, K., Summons, R.E., Grosjean, E., Twitchett, R.J., Dunning, W.J., Wang, S., Bottcher, M.E., 2005, Depositional conditions of the Northern onshore Perth basin (Basal Triassic). Australian Petroleum Production and Exploration Association Limited Australia 1, 263-273.
38. Greenwood, P.F., Croue, J., Pritchard, D., Grice, K., and Wade, A., 2005, The Impact of the 2003 Canberra Wildfire on the Natural Organic Matter in ACT Source Waters. Australian Water Association Inc. Brisbane.
39. Thomas, B.M., Willink, R.J., Grice, K., Twitchett, R.J., Purcell, R.R., Archbold, N.W., George, A.D., Tye, S., Alexander, R., Foster, C.B., and Barber, C.J., 2004, Unique marine Permian/Triassic boundary section from Western Australia. Australian Journal of Earth Sciences 51, 423-430.
40. Turner, N., Jones, M., #Grice, K., Dawson, D., Ioppolo-Armanios, M., and Fisher, S.J., 2006, δ13C of volatile organic compounds (VOCS) in Airborne Samples by thermal desorption-Gas Chromatography-Isotope-Ratio-Mass Spectrometry (TD-GC-IRMS). Atmospheric Environment 40, 3381-3388.
41. Courty, M.A., Deniaux, B., Crisci, A., Grice, K., Greenwood, P., Mermoux, M., Smith, D., and Thiemens, M., 2006, Thermal processes of the 4 kyr BP oceanic impact based on carbon and mineral phase association in melt products. Meteorites and Planetary Science 41 A41-A41.
42. Greenwood, P.F., Croué, J-P, Boyd, L., Berwick, L., Busetti, L., Grice, K., and Habarou, H., 2006, Molecular and isotopic characterisation of the organic foulant of an RO membrane. Proceedings, Enviro06 Convention, paper e6398 (CD ROM) pp 1-8.
43. #Grice, K., Nabbefeld, B., and Maslen, E., 2007, Source and Significance of Selected Polycyclic Aromatic Hydrocarbons in Sediments (Hovea-3 well, Perth Basin, Western Australia) Spanning the Permian-Triassic Boundary. Organic Geochemistry 38, 1795-1803.
44. Gessler, A., Keitel, C., Kodama, N., Weston, C., Winters, T., Keith, H., Grice, K., Leuning, R., and Farquhar, G.D. 2007, δ13C of organic matter transported from the leaves to the roots in Eucalyptus delegatensis - short-term variations and relation to respired CO2. Functional Plant Biology 34 692-706.
45. Fenton, S., #Grice, K., Twitchett, R.T., Bottcher, M., Looy, C.V., and Nabbefeld, B., 2007, Changes in Biomarker Abundances and Sulfur Isotopes of Pyrite across the Permian-Triassic (P/Tr) Schuchert Dal Section (East Greenland). Earth and Planetary Science Letters 262 230-23.
46. Dawson, D., #Grice, K., Edwards, D.S., and Alexander, R., 2007, The effect of source and maturity on the stable isotopic compositions of individual hydrocarbons in sediments and crude oils from the Vulcan Sub-basin, Timor Sea, Northern Australia. Organic Geochemistry 38, 1015-1038.
47. Atahan, P., Grice, K., and Dodson, J., 2007, Human influence on Holocene environmental change in the Yangtze River delta: a combined biomarker, δ13C, 14C, pollen and charcoal approach. The Holocene 17, 507-515.
48. Summons R.E., Katherine H. Freeman K.H., Grice K., Pancost R.D., 2008. Where would we be without the isotopes? Organic Geochemistry 39, 483-484.
49. Hallmann, C., Schwark, L., and #Grice, K., 2008, Community dynamics of anaerobic bacteria in deep petroleum reservoirs. Nature Geoscience 1, 588-591.
50. #Grice, K., Lu, H., Zhou, Y., Stuart Williams, H., and Farquhar, G.D., 2008, Biosynthetic and environmental effects on the stable carbon isotopic compositions of the anteiso- (3-methyl) and iso- (2-methyl) alkanes in tobacco leaves. Phytochemistry. 69, 2807-2814.
51. Nurhuda, A., Greenwood, P., #Grice, K., Watling, J., and van, Bronswick, B., 2008, Molecular fingerprinting of the oil-based component of adhesive tapes. International Journal of Forensic Science 53, 1130-1137.
52. Hallmann, C., van Aarssen, B.G.K., and Grice, K., 2008, Relative efficiency of free fatty acid butyl esterification: Choice of catalyst and derivatisation procedure. Journal of Chromatography A, 1198,14-20.
53. #Grice, K., De Mesmay, R., Wang, S., and de Glucina A., 2008, New 5A molecular sieving method for CSIA. Organic Geochemistry 39, 284-288.
54. Maslen, E., #Grice, K., Gale, J., Hallmann, C., and Horsfield, B., 2009, Crocetane: A potential marker of photic zone euxinia in thermally mature sediments and crude oils of Devonian age. Organic Geochemistry 49, 1-17.
55. Asif, M., Grice, K., and Fazeelat T., 2009, Assessment of petroleum biodegradation using stable hydrogen isotopes and polycyclic aromatic hydrocarbons Organic Geochemistry 40, 301-311.
56. #Grice, K., Lu, H., Atahan, P., Hallmann, C., Asif, M., Greenwood, P.F., Tulipani, S., Maslen, E., Williford. K.H., and Dodson, J., 2009, New insights into the origin of perlyene in geological samples Geochimica et Cosmochimica Acta 73, 6531-6543.
57. Lu., H., Chen, T., Grice, K., Greenwood, P.F., Peng, P., and Sheng, G., 2009, Distribution and significance of novel low molecular weight sterenes in an immature evaporitic sediment from the Jinxian Sag, North China, Organic Geochemistry 8, 902-911.
58. Fusetti L., Behar F., Bounaceur R., Marquaire P.M., Grice K., and Derenne S., 2010, New insights into secondary gas generation from oil thermal cracking. A Kinetic approach using 1,2,4-trimethylbenzene. I. A free-radical mechanism. Organic Geochemistry 41, 146–67.
59. Fusetti L., Behar F., Grice K., and Derenne S., 2010, New insights into secondary gas generation from oil thermal cracking. A kinetic approach using 1,2,4-trimethylbenzene. Part II: A lumped kinetic scheme. Organic Geochemistry 41, 168–76.
60. Fusetti L., Behar F., Grice K., and Derenne S., 2010, New insights into secondary gas generation from oil thermal cracking. A kinetic approach using 1,2,4-trimethylbenzene. Part III. Organic Geochemistry 41, 431–36.
61. Nabbefeld B., #Grice K., Schimmelmann A., Summons R.E., Troitzsch A., and Twitchett R.J., 2010, A comparison of thermal maturity parameters between freely extracted hydrocarbons (Bitumen I) and a second extract (Bitumen II) from within the kerogen matrix of Permian and Triassic sedimentary rocks. Organic Geochemistry 41, 78–87.
62. Nabbefeld B., #Grice K., Schimmelmann A., Sauer P.E., Böttcher M.E., and Twitchett R.J., 2010, Significance of δDkerogen, δ13Ckerogen and δ34Spyrite from several Permian/Triassic (P/Tr) sections. Earth and Planetary Science Letters 295, 21–9.
63. Nabbefeld B., #Grice K., Twitchett R.J., Summons R.E., Hays L., Böttcher M.E., and Asif, M., 2010, An integrated biomarker, isotopic and palaeoenvironmental study through the Late Permian event at Lusitaniadalen, Spitsbergen. Earth and Planetary Science Letters 291, 84–96.
64. Kuhn T.K., Krull E.S., Gleixner G., Bowater A., and Grice K., 2010, The occurrence of short-chain n-alkanes with an even-over-odd predominance in higher plants and soils. Organic Geochemistry 41, 88–95.
65. McKirdy D., Krull E., Mee A., Haynes D., Thorpe C., Webster L., Grice K., and Gell P., 2010, Natural and cultural eutrophication in the Coorong, South Australia. Organic Geochemistry 41, 96–110.
66. Asif M., Alexander R., Fazeelat T., and Grice K., 2010, Sedimentary processes for the geosynthesis of heterocyclic aromatic hydrocarbons and fluorenes by surface reactions. Organic Geochemistry 41, 522–30.
67. Pilgrim T.S., Grice K., and Watling J.R., 2010, Application of trace element and stable isotope signatures to the provenance establishment of tea (Camellia sinensis) samples. Journal of Food Science 118, 921–6.
68. Zhou Y., #Grice K., Stuart-Williams H., Farquhar G.D., Hocart C.H., Lu H., and Liu W., 2010, Biosynthetic origin of the saw-toothed profile in 13C and of n-alkanes and systematic isotopic differences between n-, iso- and anteiso-alkanes in leaf waxes of land plants. Phytochemistry 71, 388–403.
69. Hallmann, C., Grey K., Webster L., McKirdy D., and Grice K., 2010, Molecular signature of the Neoproterozoic Acraman impact event. Organic Geochemistry 41, 111–5.
70. Aboglila S., #Grice K., Trinajstic K., Dawson D., and Williford K.H., 2010, Use of biomarker distributions and compound specific isotopes of carbon and hydrogen to delineate hydrocarbon characteristics in the East Sirte Basin (Libya). Organic Geochemistry 41, 1249-1258.
71. Nabbefeld B., #Grice K., Summons R.E., and Hays L., 2010, Significance of polycyclic aromatic hydrocarbons (PAHs) in Permian/Triassic boundary sections. Applied Geochemistry 25, 1374-1382.
72. Williford K.H., #Grice K., Logan G.A., Chen J., and Huston D., 2011, New insights into the hydrothermal alteration of organic matter from the Paleoproterozoic McArthur River Pb/Zn/Ag ore deposit of northern Australia based on compound specific hydrogen and carbon isotopes. Earth and Planetary Science Letters 301, 382-392.
73. Muhammad A., Nazir N., Fazeelat T., Grice K., Nasir S., Saleem A., 2011, Applications of Polycyclic Aromatic Hydrocarbons to Assess the Source and Thermal maturity of the crude oils from Lower Indus Basin, Pakistan. Petroleum Science and Technology 29, 2234-2246.
74. Vitzthum von Eckstaedt C., #Grice K., Ioppolo-Armanios M., Chidlow G., and Jones M., 2011, Method development for analysing δD and δ13C of atmospheric VOCs by thermal desorption-compound specific isotope analysis. Journal of Chromatography A 37, 6511-6517.
75. Vitzthum von Eckstaedt C., #Grice K., Ioppolo-Armanios M., and Jones M., 2011, δ13C and δD of volatile organic compounds in an alumina industry stack emission. Atmospheric Environment 45, 5477-5483.
76. Atahan P., Dodson J., Li X., Zhou X., Hu S., Chen L., Bertuch F., Grice K., 2011, Early Neolithic diets at Baijia, Wei River Valley, China: Stable carbon and nitrogen isotope analysis of human and faunal remains. Journal of Archaeological Science. 38, 2811-2817.
77. Asif M., Fazeelat T., Grice K., 2011, Petroleum geochemistry of the Potwar Basin, Pakistan: 1 Oil-oil correlation using biomarkers, 13C and D. Organic Geochemistry. 42, 1226-1240.
78. Eiserbeck C., #Grice K., Reddy C., Nelson R., Curiale J., Raiteri P., 2011, Separation of 18α-, 18β-oleanane and lupane by comprehensive two-dimensional gas chromatography. Journal of Chromatography A. 1218, 5549-5553.
79. Zhou Y., #Grice K., Stuart-Williams H., and Farquhar G.D., 2011, Temperature effect on leaf deuterium enrichment and isotopic fractionation during leaf lipid biosynthesis: results from controlled growth of C3 and C4 land plants, Phytochemistry 72, 207-213.
80. Maslen E., #Grice K., Dawson D., Le Metayer P., and Edwards D., 2011, Stable carbon isotopic compositions of individual aromatic hydrocarbons as source and age indicators in oil from Western Australian Basins. Organic Geochemistry 41, 387-398.
81. Aboglila S., #Grice K., Trinajstic K., Snape C., Williford K.H., 2011, The significance of 24-norcholestanes, 4-methylsteranes and dinosterane in oils and source-rocks from East Sirte Basin (Libya), Applied Geochemistry.26, 1694-1705.
82. Hays L., Grice K., Foster C.B. and Summons R.E., 2012, Biomarker and isotopic trends from a Permian-Triassic sedimentary section at Kap-Stosch, Greenland. Organic Geochemistry. 43, 67–82.
83. Maslen, E., #Grice, K., Dawson, D., Wang, S., and Horsfield, B., 2012, Stable hydrogen isotopes for assessing thermal history of sediments through geological time Thermal history analysis of sedimentary basins: methods and applications. Sedimentary Geology of Mars, SEPM Special Publication No 11, Society of Sedimentary Geology.
84. Eiserbeck C., Nelson R., #Grice K., Curiale J., Reddy C., 2012, Comparison of GC-MS, GC-MRM-MS, and GCxGC to characterise higher plant biomarkers in Tertiary oils and rock extracts. Geochimica et Cosmochimica Acta. 787, 299-322.
85. Alexander, R., Berwick, L.J., Nasir, S., Fazeelat, T., Grice, K., 2012. Markers for secondary reactions of migrated crude oil on carbonaceous surfaces. Organic Geochemistry, 49, 30-35.
86. Vitzthum von Eckstaedt C., #Grice K., Ioppolo-Armanios M., Kelly D., and Jones M. 2012, Compound specific carbon and hydrogen stable isotope analyses of volatile organic compounds in various emissions of combustion processes Chemosphere. In Press.
87. Melendez, I., #Grice, K., Trinajstic, K., Ladjavardi, M., Greenwood, P.F., Thompson, K. 2012 Biomarkers reveal the role of photic zone euxinia in exceptional fossil preservation: An organic geochemical perspective. Geology In Press.
88. Kelly, D., Zerihun, A., Singh, D.P., Vitzthum von Eckstaedt, C., Gibberd, M., Grice, K., and Downey, M. 2012 Exposure of grapes to smoke of vegetation with varying lignin composition and accretion of lignin-derived putative smoke taint compounds in wine. Food Chemistry, 135, 787-798.
89. Metcalfe, I., Nicoll, R.S., Willink, R.J., Ladjavadi, M., Grice, K., 2012 Early Triassic (Induan-Olenekian) global anoxia, stable carbon isotope excursions and environmental perturbations: New data from Western Australian. Gondwana Research, In Press.
90. Holman A., #Grice K., Jaraula C.M.B., Schimmelmann A., Brocks J.J, 2012 Efficiency of extraction of the Paleoproterozoic 'Here's Your Chance' Pb/Zn/Ag ore deposit and implications for the study of Bitumen II. Organic Geochemistry. 52, 81-87.
91. Berke MA, Johnson TC, Werne JP, Grice K, Schouten S, Sinninghe Damsté JS 2012, Seasonal insolation contrast forcing climate response in the Lake Victoria basin, East Africa Quaternary Science Research. In Review.
92. Le Métayer P., Maslen E., #Grice K., Dawson D., Fusetti L., Chow K., Cacetta L., van Aarssen CB., 2012 Stable carbon isotopic of individual aromatic hydrocarbons in petroleum: origin and formation of low molecular weight aromatic hydrocarbons. Geochimica et Cosmochimica Acta. Accepted subject to changes.
93. Review Article. Greenwood, P., Brocks, J.J., Grice, K., Schwark, L., Jaraula, C.M., Dick, J.D., Evans, K.A., 2012 Organic Geochemistry and Mineralogy. I. Characterisation of Organic Matter Associated with Metal Deposits. Ore Geology Reviews. In Pressres.
94. Van Kranendonk, M.J., Schopf, W.J., Grice, K. Walter, M.R., Pages, A., Kudryavtsev, A.B., Gallardo, V.A., Espinoz, C., Melendez, I., Lepland, A. 2012 A 2.3 Ga sulfuretum at the rise of atmospheric oxygen: microfossil and organic geochemical evidence from the Turee Creek Group, Western Australia. Nature. in Review.
Invited & Keynotes
1. 2012 Grice K. An overview of organic and isotope biomarker geochemistry in paleoclimate, mass extinction and petroleum research. Invited China University of Petroleum, Beijing.
2. 2012 Grice K., Eiserbeck C., Maslen E., and Curiale, J. The age of oil and source-rock intervals associated with several major geological events. Invited Sinopec, WUXI.
3. 2012 Grice K., Jaraula C., Williford K., Melendez I., Tulipani S., Nabbefeld B., Summons R.E., Bottcher M., Woltering M. and Twitchett R.J., Consistent changes in biomarkers (microbes and flora) and stable isotopes across several major extinction events of our planet. 34th International Geological Congress to be held in Brisbane, Australia, 5 – 10 August 2012. Keynote lecture.
4. 2011 K. Grice Exploring mass extinction events and their association with global warming events from muliproxy biomarker and isotopic approaches. (Invited) Stanford University. 9th December.
5. 2011 A. Pagès, K. Grice, R. Lockhart, P. Greenwood, M. van Kranendonk (2011) Biomarkers of sulfate reducing bacteria from a variety of different aged samples including a modern microbial mat. (Invited) Stanford University. 9th December.
6. 2011 I. Melendez, K. Grice, K. Trinajstic, K. Thompson, M. Ladjaverdi, P. Greenwood (2011) Biomarkers and stable isotopes of euxinia and their role in fossil preservation. (Invited) Stanford University. 9th December.
7. 2011 K. Grice Invited Talk Exploring mass extinction events and their association with global warming events from muliproxy biomarker and isotopic approaches (Invited) AGU Fall Meeting, 5th-9th December at the Moscone Convention Center, San Francisco, California.
8. 2011 K. Grice Invited Talk dD of biomarkers in relation to modern plants and mass extinction events. Hydrogen isotopes as environmental indicators. Le Stadium, Loire Valley, Insitute for Advanced Studies. CNRS, Orleans Campus, France, 15th-16th September.
9. 2011 K. Grice, B. Nabbefeld, R. Twitchett, L. Hays, K. Williford, A. Holman, R. Summons, J. McElwain, M. Bottcher. Exploring mass extinction events (Triassic/Jurassic and Permian/Triassic): association with global warming events. 18th-23rd September, Interlaken, Switzerland. Plenary Presentation.
10. 2011 K. Trinajstic Invited keynote The advancement of early vertebrate palaeontology through new discovery and the use of new technologies.13th Conference on Australasian Vertebrate Evolution Palaeontology and Systematics Perth 2011.
11. 2011 K. Grice Invited keynote Exploring mass extinction events (Triassic/Jurassic & Permian/Triassic): Association with global warming events. 13th Conference on Australasian Vertebrate Evolution Palaeontology and Systematics Perth 2011.
12. 2011 K. Grice Invited keynote Exploring mass extinction events: Association with global warming events 11th Australasian Environmental Isotope Conference & 3rd Australasian Hydrogeology Research Conference 12-14 July Cairns, Queensland.
13. 2010 K. Grice Invited presentation Southern Cross University What can you learn from an organic and isotopic geochemist (biomarkers, isotopes, mass extinctions and petroleum formation), 19th November 2010.
14. 2010 K. Grice Invited presentation Chemistry and Resources Precinct What can you learn from an organic and isotopic geochemist, Petroleum Seminar series 15th September 2010.
15. 2010 K. Grice ANSTO, Sydney Exploring mass extinction – Using molecules & stable isotopes (carbon and hydrogen) rather than fossils. Invited Presentation 27th August.
16. 2010 K. Grice UNSW, Sydney Exploring mass extinction – Using molecules & stable isotopes (carbon and hydrogen) rather than fossils. Invited Presentation 27th August. Grice K., Nabbefeld B., Twitchett R., Summons R.E, Hays L., Williford K., McElwain J., Le Metayer P., Bottcher M., Schimmelmann A. (2010). Linking global climate change to mass extinctions of the geological record and petroleum exploration. The 5th International Symposium on Novel Carbon Resource Sciences will be held on 22 and 23 April 2010 in Curtin University, Perth, Australia. Invited Lecture.
17. Grice K., Nabbefeld B., Twitchett R., Summons R.E, Hays L., Williford K., McElwain J., Le Metayer P., Bottcher M., Schimmelmann A. (2010). Biomarker distributions & isotopic signals associated with the Permian/Triassic & Triassic/Jurassic mass extinction events: A global perspective. Australian Earth Science Conference. June 2010, Canberra. Invited Keynote.
18. Maslen E, Grice K, Gale J, Horsfield B 2008 Crocetane a marker for Photic-zone euxinia in Devonian source rocks and crude oils. European Geophysical Union Conference, Vienna April 2008. Invited Presentation.
19. Grice K, Lu Hong, Atahan P, Hallmann C, James E, Greenwood P Dodson J. 2008 Perylene: A new molecular marker for lignin degradation and its significance in tracking the evolution of vascular plants. Australian Earth Science Conference, Perth, July 2008. Keynote lecture.
20. Hallmann C, Schwark L, Grice K. 2008 Microbial population dynamics in deep oil reservoirs – Insights from microbial membrane lipids. Gordon research conference invited lecture. www.grc.org/programs.aspx
21. Grice K, Nabbefeld B, Maslen E, Summons RE, Hays L, Twitchett RJ, Turgeon S, Algeo T, Boettcher ME 2007, Significance of Biomarkers for Permian/Trassic and Frasnian/Famennian Mass Extinctions, August 2007. Goldschmidt Conference, Cologne Germany Keynote
22. Nabbefeld B, Grice K, Twitchett R, Summons R, Turgeon S, Schimmelmann A, Fenton S, Böttcher ME, Hays L. 2007 Global and local changes in abundances and δD and δ13C of biomarkers across the Permian-Triassic boundary. International Meeting of Organic Geochemistry (IMOG), Abstracts. Plenary lecture.
23. Grice K. 2006 Biomarker distributions and their stable isotopes: Searching for clues to the cause of the end-Permian mass extinction event. International Keynote Speaker at the 9th Australasian Environmental Isotope Conference and 2nd Australasian Hydrogeology Research Conference, Adelaide, South Australia. Keynote lecture.13 December 2006.
24. Grice K, Twitchett R, Foster C, R. Summons RE, Grosjean E, Krull E, Barber C, Alexander R, Greenwood P and Logan G. 2004 Biomarker distributions and their stable isotopes in marine Permian/Triassic sections from around the globe: Searching for clues to the cause of the end-Permian mass extinction event. Australian Organic Geochemistry conference, Blue Mountains, Sydney. Keynote lecture.
25. Grice K. 2003 Extinction events in the geological past-causes and effects. July 31st. Invited Presentation at Australian Academy of Science: Australian Frontiers of Science 2003.
26. Grice K, Schouten S, Wong S Chin, Stuart-Williams H and Farquhar G. 2003 D/H isotopes of water, lipids and carbohydrates from modern plants grown under controlled conditions. 21st International Meeting on Organic Geochemistry, held in Krakow, Poland 8-12 September. Plenary lecture. & 200 Conference abstract presentations/ posters & many reports to industryBack to top Back to directory