ECONOMIC GEOLOGY AND MINERALOGY GROUP

 

LAURENCE N. WARR


Professor of Economic Geology - Geochemistry
Ernst-Moritz-Arndt Universität Greifswald
Institute for Geography and Geology
Friedrich-Ludwig-Jahn-Str. 17a
D-17487 Greifswald
Germany
Tel. ++49(0)3834 86 4578
E-mail: warr@uni-greifswald.de
Secretary: Tel. ++49(0)3834 86 4570
Publication record Google scholar and Researchgate

DFG-Gepris

Research interests
Reactivity of natural fine-particle based materials (clays, colloids and nanoparticles) and their application in understanding Earth processes, exploring economic clay deposits and addressing geotechnical and environmental problems.

Themes of research are:

Bentonites and the disposal of nuclear waste

Geopolymer "green" cements

Clay - bacteria interactions and the bioremediation of oil spills.

Underground storage of gases

The role of clays and other fine particles in fault zones

Frictional melt processes during earthquakes (pseudotachylytes)

Diagenesis and very low-grade metamorphism

 

Press releases
"Tiny clays curb big earthquakes"

Scientific American

Science Daily

Discovery Channel

UPI.com

USNews

Microbes rule the waves


 

Analytical methods

X-ray diffraction techniques including the development of wet-cells for the insitu monitoring of fine powder reactions in solutions

Electron microscope techniques, in particular the application of transmission electron microscopy and SEM-FIB microscopy

Radiogenic isotope (K-Ar and Ar-Ar) dating of phyllosilicate minerals

Clay mineral crystallinity as a measure of very low grade metamorphisms and development of calibration methods (the Crystallinity Index Standard).

Selection of collaborating researchers and industry

Bentonite and cements
GRS - Gesellschaft für Anlagen- und Reaktorsicherheit (society for reactor safety and waste disposal)
Roland Pusch. Technical University of Luleå.
Julia Perdrial. University of Arizona.

Geopolymer cements
MRG Mineralische Rohstoffmanagement GmbH

Bioremediation using clays
Ralph Portier. Louisiana State University
Frieder Schauer. Microbiology, University of Greifswald

Diagenesis and Petroleum Geology in north-east Germany
Central European Petroleum
Martin Meschede. Structural geology and tectonics, University of Greifswald

Carbon storage in north-east Germany
Karsten Obst. Geological Survey, LUNG, M.V.

Fault rock group
Anja Schleicher. University of Michigan.
Ben van der Pluijm. University of Michigan.

Rock mechanics group
Chris Marone. Penn State.
Demian Saffer. Penn State.

Current doctoral students
Nanjie Hu. Alkali activation of meta-illitic clays (geopolymers)
Jan Dietal- dehydroxylation of clays and geopolymer cements
Jasmaria Wojatschke
- clays in fault zones
Carolin Podlech - bentonite stability

Markus Peltz - Shale gas FIB-SEM

Past doctoral students
Julia Perdrial.
Anja Schleicher.
Kai Frings.
Fernando Ayllon.
Heiko Hofmann.


Clay-coated slickencrysts from a Palaeozoic fault, Jesensky Mountains, Czech

2nd edition of Geological history of Britain and Ireland (2012)
Read lastest review in the "Geological Journal"

 

     

Published papers

76. Pusch, R., Warr, L.N., Knutsson, S., Yang, T.(2017). Condensed summary of current R&D on cementitious sealants for deep boreholes with HLW. Engineering Geology, https://doi.org/10.1016/j.enggeo.2017.06.008.

75. Mittermayr, F., Baldermann, A., Baldermann, C., Grathoff, G., Klammer, D., Köhler, S. J., Leis, A., Warr, L.N., Dietzel, M. (2017). Environmental controls and reaction pathways of coupled de-dolomitization and thaumasite formation. Cement and Concrete Research, 95:282-293.

74. Baldermann, A., Dietzel, M., Mavromatis, V., Mittermayr, F., Warr, L.N., Wemmer, K. (2017). The role of Fe on the formation and diagenesis of interstratified glauconite-smectite and illite-smectite: A case study of Upper Cretaceous. Chemical Geology, 453, 21-34.

73. Dietel, J., Warr, L.N., Bertmer, M., Steudel, A., Grathoff, G.H., Emerrich, K. (2017). The importance of specific surface area in the geopolymerization of heated illitic clay. Applied Clay Science, 139, 99-107

72. Hu, N., Bernsmeier,D., Grathoff, G.H,, Warr, L.N. (2016). The influence of alkali activator type, curing temperature and gibbsite on the geopolymerization of an interstratified illite-smectite rich clay from Friedland. Applied Clay Science, http://dx.doi.org/10.1016/j.clay.2016.10.021.

71. Wojatschke, J., Scuderi, M.M, Warr, L.N, Carpenter, B.M, Saffer, D.S., Marone, C. (2016). Experimental constraints on the relationship between clay abundance, clay fabric, and frictional behavior for the Central Deforming Zone of the San Andreas Fault. Geochemistry, Geophysics, Geosystems, , 17,
doi:10.1002/2016GC006500.

70. Warr, L.N.,Friese, A., Schwarz, F., Schauer, F., Portier, R.J.,.Basirico, L.M., Olson, G.M (2016). Experimental study of clay-hydrocarbon interactions relevant to the biodegradation of the Deepwater Horizon oil from the Gulf of Mexico. Chemosphere, 161, 208-221. PDF copy.

69. Warr, L.N. & Cox, S.C. (2016). Correlating illite (Kübler) and chlorite (Árkai) “crystallinity” indices with metamorphic mineral zones of the South Island, New Zealand. Applied Clay Science, doi:10.1016/j.clay.2016.06.024

68. Mohammed, M.H., Pusch, R., Knutsson, S. & Warr, L.N. (2016). IHydrothermal alteration of clay and low pH concrete applicable to deep borehole disposal of high-level radioactive waste - a pilot study. Construction & Building Materials, 401, 1-8.

67. Warr, L.N., van der Pluijm, B.A., Hofmann, H. (2016). Constraining the alteration history of a Late Cretaceous Patagonian volcaniclastic bentonite-ash-mudstone sequence using 40K/40Ar and 40Ar/39Ar isotopes. International Journal of Earth Sciences. doi: 10.​1007/​s00531-016-1315-2.

66. Mohammed, M.H., Pusch, R., Warr, L.N., Kasbohm, J. & Knutsson, S. (2015). Interaction of clay and concrete relevant to the deep disposal of high-level radioactive waste. Applied Clay Science. Applied Clay Science, 118, 178–187.

65. Schlosser, J., Grathoff, G.H., Ostertag-Henning, C., Kaufhold, S. & Warr, L.N. (2015). Mineralogical changes in organic-rich Posidonia Shale during burial and experimental maturation. International Journal of Coal Petrology, 157, 74-83..

64. Baldermann, A., Warr, L.N., Lefofsky-Papst, I. & Mavromatis, V. (2015). Substantial iron sequestration during green-clay authigensis in modern deep-sea sediments. Nature-Geoscience,DOI: 10.1038/NGEO2542

63. Boles, A., van der Pluijm, B.A., Mulch, A., Mutlu, H., Tonguc, U. & Warr, L.N. (2015). Hydrogen and 40Ar/39Ar isotope evidence for multiple and protracted paleofluid flow events within the long-lived North Anatolian Keirogen (Turkey). Geochemistry, Geophysics, Geosystems (G-cubed). Wiley. DOI: 10.1002/2015GC005810

62. Dietel J., Steudel A, Warr, L.N. & Emmerich, K. (2015). Crystal chemistry of Na-rich rectorite from North Little Rock, Arkansas. Clay Minerals, 50, 297–306.

61. Warr, L.N.&& Ferreiro Mahlmann ,R.F. (2015). Recommendations for Kübler Index standardization. Clay Minerals, 50, 283–286.

60. Warr, L.N., Wojatschke, J., Carpenter, B.M., Marone, C. Schleicher, A.M., van der Pluijm, B.A. (2014). A " slice -and- view " (FIB-SEM) study of clay gouge from the SAFOD creeping section of the San Andreas Fault at ~2.7 km depth. Journal of Structural Geology, 69, 234-244.

59. Kaufhold, S., Reese, A., Schwiebacher, W., Dohrmann, R.a, Grathoff, G., Warr, L.N., Halisch, M., Müller, C., Schwarz-Schampera, U. & Ufer, K. (2014). Porosity and distribution of water in perlite from the island of Milos, Greece. SpringerPlus. 3(1):598. DOI: 10.1186/2193-1801-3-598.

58. Pusch, R., Warr, L.N., Grathoff, G., Purbakhtiar, A., Knutsson, S. & Ramqvist, G. (2014). A study on cement-poor concrete with talc for borehole sealing in rock hosting radioactive waste. Comunicações Geológicas, 100, 1, 89-98.

57. Warr, L.N., Friese, A., Schwarz, F., Schauer, F., Portier, R.J. & Basirico, L.M.. (2013). Bioremediating oil spills in nutrient poor ocean waters using fertilized clay mineral flakes: some experimental contraints. Biotechnical Research International, 2013, Article ID 704806, 9 pages.

56. Baldermann, A., Warr, L.N., Grathoff, G. & Dietzel, M. (2013). The rate and mechanism of deep sea glauconite formation at the Ivory coast-Ghana marginal ridge.Clays and Clay Minerals, 61, 258-276.

55. Pusch, R., Warr, L.N., Grathoff, G., Pourbakhtiar, A., Knutsson, S. & Mohammed, M.H. (2013). A talc-based cement-poor concrete for sealing boreholes in rock. Engineering, 5, 251-267. PDF copy.

54. Schleicher, A.J., van der Pluijm, B.A.. & Warr, L.N. (2012). Chlorite-smectite clay minerals and fault behavior: Evidence from the San Andreas Fault Obsertvatory at Depth. Insights, the EarthScope newsletter.

53. Frings, K. & Warr, L.N. (2012). Hydrothermally altered mudrock of the Ciñera-Matallana coal basin, Cantabrian Zone, northern Spain. European Journal of Mineralogy, 24 (6), 1017 - 1029. Abstract.

52. Schleicher, A.J., van der Pluijm, B. & Warr, L.N. (2012). Chlorite-smectite clay minerals and fault behavior: New evidence from the San Andreas Fault Observatory at Depth (SAFOD) core.Lithosphere, 4, 209-220.

51. Warr, L.N. (2012). The Variscan Orogeny: the welding of Pangea. In: Geological History of Britain and Ireland. (2nd Edition). (Eds. Woodcock, N. and Strachan, R.), Wiley, 274-298.

50. Perdial, J.N. & Warr, L.N. (2011). Hydration behavior of MX80 bentonite in a confined-volume system: Implications for backfill design. Clays and Clay Minerals, 59, 640-653.

49. Warr, L.N. & Grathoff, G. (2011). Geoscientific applications of particle detection and imaging techniques with special focus on the monitoring clay mineral reactions.In Handbook of Particle Detection (Editor C. Grupen). ISBN 978-3-642-13270-4. Springer.

48. Schleicher, A. M., van der Pluijm, B. A. & Warr, L.N. (2010). Nano-coatings of clay and creep of the San Andreas Fault at Parkfield, California. Geology, 38, 667-670. Abstract. See press release.

47. Barker, S.L.L., Palin, J.M., Sibson, R.H., Fitzgerald, J.D., Reddy, S., Warr, L.N. & van der Pluijm, B. A. (2010). Cretaceous age pseudotachlylyte in the Otago Schist, New Zealand. New Zealand Journal of Geology and Geophysics. Abstract.

46. Warr, L.N., Perdrial, J.N., Lett, M-C., Heinrich-Salmeron, A. & Khodja, M. (2009). Clay-enhanced bioremediation of marine oil spills. Applied Clay Science, 46, 337- 345. IF 2.005. Abstract.

45. Perdrial, J. N., Warr, L.N., Pedrial, N., Lett, M.C. & Elsass, F. (2009). Interaction between smectite and bacteria: implications for bentonite as backfill material in the disposal of nuclear waste. Chemical Geology, 264, 281-294. IF 3.531. Abstract.

44. Schleicher, A. M., Tourscher, S., van der Pluijm, B. A. & Warr, L.N. (2009). Constraints on mineralization, fluid-rock interaction, and mass transfer during faulting at 2–3 km depth from the SAFOD drill hole, Journal of Geophysical Research, 114, B04202, doi:10.1029/2008JB006092. IF 3.147. Abstract.

43. Schleicher, A., Warr, L.N. & van der Pluijm, B.A. (2009). On the origin of mixed-layered clay minerals from the San Andreas Fault at 2.5 - 3 km depth (SAFOD at Parkfield, California). Contributions to Mineralogy and Petrology, 157, 173-187. IF 3.853. Abstract.

42. Place, J., Geraud, Y., Diraisonson, M. & Warr, L.N. (2007). North-south relay structures and paleo-morphological reconstruction of the Xylocastro area (Corinth Gulf, Greece). Tectonophysics, 440, 121-139. IF 1.677. Abstract.

41. Warr, L.N. & Berger, J. (2007). Hydration of bentonite in natural waters: Application of "confined volume" wet-cell X-ray diffractometry. Physics and chemistry of the Earth, 32, 247-258. Abstract. IF 1.138. Abstract.

40. Warr, L.N., van der Pluijm; B. & Tourscher, S. (2007). The age and depth of exhumed friction melts along the Alpine Fault, New Zealand. Geology, 35, 603-606. Abstract. IF 3.89. Abstract.

39. Schleicher, A., van der Pluijm, Solum, J.G and Warr, L.N. (2006a). The origin and significance clay-coated fractures in rock fragments of the SAFOD borehole (Parkfield, California). Geophysical Research Letters, 33, doi:10.1029/2006GL026505. IF 2.602. Abstract.

38. Schleicher, A. Warr, L.N., Kober, B., Clauer N & Laverret (2006b). Episodic mineralization of hydrothermal illite in the Soultz-sous-forets granite (Upper Rhine Graben, France). Contributions to Mineralogy and Petrology, 152, 349–364. doi:10.1007/s00410-006-0110-7. IF 2.754. Abstract.

37. Schleicher, A. Warr, L.N., van der Pluijm, B. (2006). Fluid focusing and back-reactions in the uplifted shoulder of the Rhine rift system: a clay minerals study along the Schauenburg fault zone (Heidelberg, Germany). International Journal of Earth Sciences, 95, 19-33. IF 1.905. Abstract.

36. Marbach, T., Kober, B., Mangini, A., Warr, L.N. & Schleicher, A. (2005). Mobility of U-Th radionuclides connected with fault porosity: a case study of the Schauenburg Fault, Rhine Graben Shoulder, Germany. Physics and Chemistry of the Earth, 30, 1030-1037. IF 0.864. Abstract.

35. Warr, L.N. & van der Pluijm, B. (2005). Crystal fractionation in friction melts of seismic faults (Alpine Fault, New Zealand). Tectonophysics, 403, 111-124. IF 1.732. Abstract.

34. Hofmann, H., Bauer, A. & Warr, L.N. (2004). Behaviour of smectite in strong salt brines under conditions relevant to the disposal of low- to medium-grade nuclear waste. Clays and Clay Minerals, 52, 14-24. IF 1.116. Abstract.

33. De Wall, H. & Warr, L.N. (2004). Oblique magnetic fabric in siderite-bearing pelitic rocks of the Upper Carboniferous Culm Basin, SW England: an indicator for paleo fluid migration? In: Martin-Hernandez, F., Lüneburg, C., Aubourg, C. & Jackson, M. (eds.): Magnetic Fabric: Methods and Applications, Geological Society of London, Special publication, 238, 493-507. Abstract.

32. Frings, K., Lutz, R,. De Wall, H. and Warr, L.N. (2004). Coalification history of the Stephanian Ciñera-Matallana pull-apart basin, NW-Spain: Combining anisotropy of vitrinite reflectance and thermal modelling. International Journal of Earth Sciences, 93, 92-106. IF 1.147. Abstract.

31. Warr, L.N., Clauer, N. & Liewig, N. (2004). Predicting the diagenetic evolution of argillite repositoried based on the study of natural and experimental systems. In: Stability and Buffering Capacity of the Geosphere for Long-term isolation of radioactive waste. Applications to Argillaceous Media "Clay Club" Workshop Proceedings Braunschweig, Germany 9-11 December 2003, OECD Publishing, pages 83-87.

30. Warr, L.N. & Hofmann, H. (2003). In-situ monitoring of powder reactions in percolating solution by wet-cell X-ray diffraction techniques. Journal of Applied Crystallography, 36, 948-949. IF 2.324. Abstract.

29. Peacor, D. & Warr, L.N. (2003). Reply to comment on "Evaluation of X-ray diffraction methods for determining the crystal growth mechanisms of clay minerals in mudstones, shales and slates" Schweizerische Mineralogische und Petrographische Mitteilungen, 83/3, 359-363. IF 0.755.

28. Solum, J., van der Pluijm, B., Peacor, D. & Warr, L.N. (2003). Influence of phyllosilicate mineral assemblages, fabrics, and fluids on the behaviour of the Punchbowl fault, southern Californian. Journal of Geophysical Research, 108, B5, 2233 (10 pages). IF 2.839. Abstract.

27. Ayllon, F., Bakker, R. & Warr, L.N. (2003). Thermal decrepitation of low temperature quartz inclusions in a Stephanian pull-apart basin, Northern Spain. Geofluids, 3, 49-68. IF 1.55.

26. Warr, L.N. van der Pluijm, B., Peacor, D.R. & Hall, C. (2003). Frictional melt pulses during a ca. 1.1 Ma earthquake along the Alpine Fault, New Zealand. Earth and Planetary Science Letters, 209, 39-52. IF 3.499. Abstract.

25. Warr, L.N. & Peacor, D. (2002). Evaluation of X-ray diffraction methods for determining the crystal growth mechanisms of clay minerals in mudstones, shales and slate. Schweizerische Mineralogische und Petrographische Mitteilungen, 82/2, 187-202. IF 1.146. Abstract.

24. Warr, L.N. (2001). The Variscan Orogeny: the welding of Pangaea. In: Geological History of Britain and Ireland. (Eds. Woodcock, N. and Strachan, R.), Blackwell Science, 271-294.

23. Warr, L.N. & Cox, S. (2001). Clay mineral transformations and weakening mechanisms along the Alpine Fault, New Zealand. In: Holdsworth, R.E., Strachan, R.A., Magloughlin, J. & Knipe, R.J. (eds) The Nature and Tectonic Significance of Fault Zone Weakening. Geological Society London Special Publication, 186, 85-101. Abstract.

22. Schmitt, T., de Wall, H. & Warr, L.N. (2001). Enclave geometry and strain quantification in the Igoudrane granodiorite, Eastern Sahgro, Anti Atlas, Morocco. In: DE WALL, H. & GREILING, R.O. (eds.). Magmatic Evolution of a Neoproterozoic Island-Arc: Syn- to Post-Orogenic Igneous Activity in the Anti-Atlas (Morocco). International Cooperation Scientific Series, 45, 255-267.

21. Warr, L.N., Greiling, R.O., Rice, A.H.N., Abdeen, M.M., Sadek, M.F., Kamal el Din, G.M. and Osman, A.F. (1999). Low temperature metamorphism in the Hammamat Basins of the Eastern Desert of Egypt. In: De Wall, H. and Greiling, R.O. (eds.). Aspects of Pan-African Tectonics, 167-171.

20. Warr, L.N. & Nieto (1998). Crystallite thickness and defect density of phyllosilicates in low-temperature metamorphic pelites: A HRTEM and XRD study of clay mineral crystallinity index standards. The Canadian Mineralogist, 36, 1453-1474. Abstract.

19. Abdeen, M.M. & Warr, L.N. (1998). Late orogenic basin evolution, deformation and metamorphism in the Pan-African Basement, Wadi Queih, Eastern Desert of Egypt. In: NAIM, G.M. HUSSEIN, A.A., GREILING, R.O. & WARR, L.N. (eds.) International Cooperation Scientific Series, 42: 272 pp.

18. Warr, L.N., Greiling, R.O. & Zachrisson, E (1996). Thrust-related very low-grade metamorphism in the marginal part of an orogenic wedge, Scandinavian Caledonides. Tectonics, 15, 1213-1229. Abstract.

17. Geng, A., Warr, L.N. & Bechstät, T. (1996). Clay mineral crystallinity of diagenetic grade Middle Triassic Muschelkalk of the Rhine Graben, southwest Germany. XIIIth Conference on Clay Mineralogy and Petrology, Praha (1994). Acta Universitatis Carolinae Geologica, 38, 81-90.

16. Krumm, S., Kisch, H.J. & Warr, L.N. (1996). Interlaboratory study of the effects of sample preparation on illite crystallinity: a progress report. XIIIth Conference on Clay Mineralogy and Petrology, Praha (1994). Acta Universitatis Carolinae Geologica, 38, 263-270.

15. Warr, L.N. (1996). Standardized clay mineral crystallinity data from the very low-grade metamorphic facies of southern New Zealand. The European Journal of Mineralogy, 8, 115-127. Abstract.

14. Warr, L.N. (1995). A reconnaissance study of very low-grade metamorphism in south Devon. Proceeding of the Usshers Society, 8, 405-410. PDF.

13. Selwood, E.B., Thomas, J.M., Williams, B.J., Clayton, R.E., Durning, B., Smith, O. and Warr, L.N. (1994). The geology of the country around Trevose Head and Camelford. Memoir for 1:50 000 geological sheets 335 and 336 (England and Wales). British Geological Memoir, 149 pp.

12. Warr, L.N. and Greiling. R.O. (1994). Illite crystallinity data from the Caledonides of Västerbotten, north-central Sweden. Sveriges geol. unders., BRAP95047: 12 pp.

11. Warr, L.N. (1994). Illite and chlorite crystallinity data from the Djupdal-65, borehole 1, north-central Sweden.- Sveriges geol. unders., BRAP95048: 12 pp.

10. Warr, L.N. & Rice, A.H.N. (1994). Interlaboratory standardization and calibration of clay mineral crystallinity and crystallite size data. Journal of Metamorphic Geology, 12, 141-152. Abstract.

9. Osman, A.F., Greiling, R.O., Warr, L.N., Hilmy, M.E., Ragab, A.I., & EL Ramly, M.F. (1993). Distinction of different syn- and late orogenic sedimentary sequences by metamorphic grade and illite crystallinity (W. Zeidun, Central Eastern Desert, Egypt). In: THORWEIHE & SCHANDELMEIER (eds.) Geoscientific Research in Northeast Africa, Balkema, Rotterdam, 21-25.

8. Warr, L.N. (1993). Basin inversion and foreland basin development in the Rhenohercynian of south-west England. In: GAYER, R.A. & GREILING, R.O. (eds.). Rhenohercynian and Sub-Variscan Fold Belts. Earth Evolution Series, Vieweg,197-224.

7. Warr, L.N. & Hecht, C. (1993). A clay mineral crystallinity investigation of the Upper Carboniferous Culm Basin of southwest England. Proceedings of the Usshers Society, 8, 94-98. PDF.

6. Warr, L.N., Primmer, T.J. & Robinson, D. (1991). Variscanc very low-grade metamorphism in southwest England: a diastathermal and thrust-related origin. Journal of Metamorphic Geology, 9, 751-764. Abstract.

5. Hartley, A., & Warr, L.N. (1990). Upper Carboniferous foreland basin evolution in southwest Britain. Proceedings of the Ussher Society, 7, 212-216. PDF

4. Robinson, D., Warr, L.N. & Bevins, R.E. (1990). The illite crystallinity technique: a critical appraisal of its precision. Journal of Metamorphic Geology, 8, 333-344.

3. Warr, L.N. & Durning, B. (1990). Discussion on: A reappraisal of the facing confrontation: fold- or thrust-dominated tectonics? Journal of the Geological Society, London, 147, 408-410.

2. Warr, L.N. (1989). The structural evolution of the Davidstow Anticline and its relationship to the Southern Culm Overfold, north Cornwall. Proceedings of the Ussher Society, 7, 136-140. PDF

1. Warr, L.N. (1988). The deformational history of the area north-west of the Bodmin Moor granite, north Cornwall. Proceedings of the Ussher Society, 7, 67-72. PDF

 

Book contributions

Geological History of Britain and Ireland (Paperback)


The geology of the country around Trevose Head and Camelford

Magnetic fabric

 

Art Gallery

 

Selection of conference abstracts

74. Warr, L.N.(2017). On the availability of clay mineral "Crystallinity" Index Standards. XVI International Clay Conference, ICC, Granada. Talk abstract.

73. Schomberg, A.C., Wemmer, C., Grathoff, G., Warr, L.N.(2017). K-Ar age determinations on clay size fine fractions of CIS samples (Crystallinity Index Standard). XVI International Clay Conference, ICC, Granada. Talk abstract.

72. Baldermann, A., Warr, L.N., Letofsky-Papst I., Mavromatis, V. & Böttcher, M.E. (2014). The role of deep-water glauconitization on the marine iron cycle. MECC, Dresden. Talk abstract.

71 .Baldermann, A., Warr, L.N., Letofsky-Papst I., Mavromatis, V. & Böttcher, M.E. (2014). Iron sequestration in young deep-sea sediments. EGU. Talk abstract.

70. Dietel, J., Warr, L.N., Emmerich, K. & Bertmer, M. (2014). The role of metaclay surface area for binder material. MECC, Dresden. Talk abstract.

69. Warr, L.N. (2014). 20 years of the Crystallinity Index Standard- a progress reportl. MECC, Dresden. Talk abstract.

Warr, L.N., Wojatschke, J., Carpenter, B., Marone, C., Schleicher, A.J. & van der Pluijm, B.A. (2014). 3D microstructural and microchemical characteristics of SAFOD fault gouge: implications for understanding fault creep. Geophysical Research Abstracts, 15, EGU2013-12387. Talk abstract.

68. Nickel, C., Baldermann, A., Dietzel, M. & Grathoff, G. & Warr, L.N. (2013). Alteration at bentonite-cement interfaces - an experimental approach. Goldschmidt Conference 2013, Florence, Italy. Poster abstract.

67. Dietel, J., Emmerich, K., Grathoff, G.H. & Warr, L.N. (2012). Dehydroxylated illite/smectite as a precursor for geopolymer binders. Poster abstract. 6th Mid-European Clay Conference, Sept. 4-9, 2012 in Pruhonice, Czech Republic. Poster.

66. Warr, L.N. Using Clay to Bioremediate Oil Spills (2012). Revista de la sociedad española de mineralogía, Macla nº 16. junio 12. Abstract.

65. Warr, L.N., van der Pluijm, B. & Schleicher, A.M. (2010). The importance of the pseudotachylyte clast-matrix ratio in determining the mechanism, age and crustal depth of episodic coseismic faulting. Geophysical Research Abstracts, Vol. 12, EGU2010-8588. Abstract.

64. Lischka. M., Meschede, M. & Warr, L.N. (2009). Insights into the fine-grained fraction of serpentine mud from the Southern Chamorro seamount (ODP Leg 195): A combined XRD, RFA and TEM-EDS study. AGU Fall meeting San Francisco, USA. Poster abstract.

63. Schleicher, A. M., Ali, S., Stute, M., Torgersen, T., van der Pluijm, B. A. '& Warr,L. N. (2009) Mineral Reactions in Active Fault Strands of the SAFOD Borehole: Results from Mineralogical and U/Th Studies. AGU Fall meeting San Francisco, USA. Poster abstract.

62. Baioumy, H., Gilg, A., Hegner, E., Hölzl, S., Taubald, H., & Warr. L.N. (2009). Source and origin of sedimentary kaolin deposits in Egypt. Clay Minerals Society annual meeting, Billings, USA. Oral.

61. Warr, L.N., Hofmann, H. & Schleicher, A.J. (2009). A K-Ar study of the Lake Pelligrini bentonite (Malargüe Group), northern Patagonia: can the age of montmorillonite formation be dated? International clay conference, 14th meeting, Castellaneta Marina, Italy. Oral.

60. Schleicher A.M., Warr L.N. & van der Pluijm B.A. (2008). Mixed-layered clay minerals and their geological significance in the San Andreas Fault Observatory at depth drillhole (SAFOD) in Parkfield, California, extended abstract, DFG-colloquium, ICDP-IODP Hannover, Germany. Oral.

59. Warr L.N., Schleicher A.M. & van der Pluijm B.A. (2008). Thin film coatings and faulting: new insights from the SAFOD drillhole, Parkfield, California, EGU Vienna, Austria. Geophysical Research Abstracts, 10, EGU2008-A-10829. Oral.

58. Berger, J.N., Warr, L.N., Lett, M-C. & Perdrial, N. (2007). Effect of bacteria on the water storage and retention capacity of swelling clays. Geophysical Research Abstracts, 9, 04434. Oral.

57. Schleicher, A.M., van der Pluijm, B.A., Warr, L.N. & Tourscher, S. (2007). Do swelling clays influence the behavior of the San Andreas Fault? New results from the San Andreas Fault Observatory at Depth (SAFOD) drill hole. Geophysical Research Abstracts, 9, 07843. Poster.

56. Schleicher A.M., van der Pluijm B.A. & Warr L.N. (2007). Clay neomineralization and its role in a weak San Andreas Fault: new insights from the SAFOD drillhole in Parkfield, California, AGU San Francisco, USA. Oral.

55. Schleicher A.M., van der Pluijm B.A., Warr L.N. & de Wall H. (2007). Does the clay mineral hydration states influences the seismic behavior of the San Andreas Fault (SAFOD drill hole)? Extended abstract, DFG-colloquium ICDP-IODP, Potsdam, Germany. Oral.

54. van der Pluijm B.A., Schleicher A.M. & Warr L.N. (2007). The potential and role of mineral and rock transformations in the San Andreas Fault, GSA Denver, USA. Oral.

53. Warr, L.N., Berger, J., Lett, M-C. & Khodja, M. (2007). An experimental study of clay-bacterial interactions in Prestige oil. Geophysical Research Abstracts, 9, 11096. Poster.

52. Warr, L.N. & van der Pluijm, B. (2007). Dating young frictional melts of the Alpine Fault (New Zealand) by laser ablation 40Ar/39Ar step heating analysis. Geophysical Research Abstracts, 9, 09344. Poster.

51. Schleicher, A.M., van der Pluijm, B.A. & Warr, L.N. (2006). Alteration history of mudrock samples from the San Andreas Fault Observatory at Depth (SAFOD) drill hole: a TEM-XRD study. Eos Trans. AGU, 87 (52), Fall Meet. Suppl., Abstract T32C-02.

50. Tourscher, S., Schleicher, A.M., van der Pluijm, B.A. and Warr, L.N. (2006). Elemental Geochemistry of Samples From Fault Segments of the San Andreas Fault Observatory at Depth (SAFOD) Drill Hole. Eos Trans. AGU, 87 (52), Fall Meet. Suppl., Abstract T21C-0433.

49. Berger, J., Warr, L.N, Lett, M-C. and Pedrial, N. (2006). Monitoring the interaction of swelling clays and metal-reducing bacteria.. Geophysical Research Abstracts, 8, 09795.

48. Place, J., Geraud, Y., Diraison, M. and Warr, L.N. (2006). North-south relay structures in the Xylocastro area. (Corinth Gulf, Greece). Geophysical Research Abstracts, 8, 06846.

47. Warr, L.N. and Berger, J. (2006). Bentonite hydration in solution: application of confined volume wet-cell X-ray diffraction techniques. Geophysical Research Abstracts, 8, 09785.

46. Khodja, M., Canselier, J.P., Khodja-Saber, M., and Warr L.N. and Duplay, J. (2005). Enhancing filtration and inhibitive properties of Drilling Fluids. Formula. IV: Frontiers in Formulation, Science King's College London, United, Kingdom, 04 July 2005 - 07 July 2005, talk abstract.

45. Schleicher, A.M., Warr, L.N., Kober, B., Clauer N and Laverret, E (2005): Illite Crystal shapes and polytypes during episodic hydrothermal mineralization in the Soultz-Sous-Forest Granite, France. The Clay Minerals Society 42nd Annual meeting June 11-15, Burlington, Vermont, USA, talk abstract.

44. Tourscher, S., van der Pluijm, B.A. and Warr, L.N. (2005): Geochemistry and geochronology of pseudotachylytes of the Alpine Fault, New Zealand. Geological Society of America Abstracts with Programs, Vol. 37, No. 7, p. 464, oral presentation. Read abstract.

43. Warr, L.N., Berger, J. and Duplay, J. (2005): The swelling of smectite in percolating solution: behaviour in a confined volume system. The Clay Minerals Society 42nd Annual meeting June 11-15, Burlington, Vermont, USA, talk abstract.

42. Berger, J., Warr, L.N. and Duplay, J. (2005): Monitoring the hydration and stability of bentonite backfill under the influence of percolating solutions. International Meeting, March 14-18, Tours, France, Clays in Natural & Engineered Barriers for Radioactive Waste Confinement, P/1GE/12, poster abstract.

41. van der Pluijm, B.A., Schleicher, A.M., Solum, J.G., Toucher, S., Warr L.N. (2005): Phyllosilicate mineral assemblages, elemental compositions and microstructures from the SAFOD Main Hole; AGU San Francisco/USA, poster abstract.

40. Warr, L.N. (2004): In-situ monitoring of clay mineral reactions in solution using XRD wet-cell techniques. RST Joint Earth Sciences Meeting, Strasbourg. Talk abstract.

39. Warr, L.N., Clauer, N. and Liewig, N. (2005): Predicting the diagenetic evolution of argillite repositories: application of flow-through reaction cells. International Meeting, March 14-18, Tours, France, Clays in Natural & Engineered Barriers for Radioactive Waste Confinement, P/1GE/12, poster abstract.

38. Schleicher, A.M., Warr, L.N., Kober, B., Laverret, E and Clauer N. (2004). The nature of Mesozoic hydrothermal illites in the Soultz-Sous-Forêts granite, Upper Rhine graben. Reunion des Sciences de la Terre, Strasbourg, France, September, talk.

37. Schleicher, A.M., Warr, L.N., Kober, B., Laverret, E and Clauer N. (2004). Mesozoic illites in the hydrothermally altered granite basement of the EPS-1 drilling (Soultz-sous-Forets/France). The 32nd International Geological Congress (32IGC), Florence, Italy, poster.

36. Warr, L.N. (2004). In-situ monitoring of clay mineral reactions in solution using XRD wet-cell techniques. Reunion des Sciences de la Terre, Strasbourg, France, September, talk.

35. Schleicher*, A.M., Warr, L.N., Kober, B., Clauer N. and Laverret, E (2004). Mesozoic hydrothermal illites in the altered Soultz-Sous-Forets granite, France. Clay Minerals Society 41st Annual Meeting, Richland, Washington D.C. USA, June, poster (*received best student poster prise).

34. Warr, L.N. (2004). In-situ monitoring of solution – clay reactions by wet-cell X-ray diffraction (WC-XRD). Clay Minerals Society 41st Annual Meeting, Richland, Washington D.C. USA, June, talk.

33. Warr, L.N., Clauer, N. and Liewig, N. (2003). New experimental methods in studying the diagenetic evolution in argillite host rocks. In: Stability and buffering capacity of the geosphere for the long-term isolation of radioactive waste: application to argillaceous media. An IGSC "Geosphere Stability" Workshop, Germany 9-11 December 2003, extended abstract.

32. De Wall, H. and Warr, L.N. (2003). Influence of low temperature fluid-related Fe-carbonate formation on AMS fabrics (Culm Basin, SW England). Geophysical Research Abstracts, 5, 12393, EUG, talk.

31. Marbach T., Schleicher A., Mangini A., Kober B. and Warr L.N. (2003). Fluid/rock interaction of a faulted rhyolite-granite contact determined by Sr-Pb-Isotopes, Th/U-disequilibria and elemental distributions (Eastern Rhine Graben shoulder, SW-Germany). Geophysical Research Abstracts, 5, 5775, EUG, talk.

30. Schleicher, A.M., Warr, L.N., Peacor, D.R. and van der Pluijm, B.A. (2003). The formation of clay minerals in faulted granite of the Rhine rift system. Geophysical Research Abstracts, 5, 13235, EUG, poster.

29. Schleicher, A.M., Warr, L.N. and van der Pluijm, B.A. (2003): Textural development in granitic fault rocks of the Rhine Graben, western Europe: a XTG and HRTEM study. Geological Society of America, Abstract program, 192, Seattle, USA, talk.

28. Warr, L.N. and van der Pluijm, B.A. (2003). Compositional variations in frictional melts: a HRTEM study of glass-bearing pseudotachylytes (Alpine Fault, New Zealand). Geological Society of America, Abstract program, 185, Seattle, USA, talk.

27. Warr, L.N., van der Pluijm, B., Peacor, D.R. and Hall, C.M. (2003). Dating prehistoric earthquakes and their frictional melts along the Alpine Fault, New Zealand. Geophysical Research Abstracts, 5, 12973. poster.

26. Schleicher A.M., Warr L.N. and Peacor D.R. (2002). Low temperature mineral alteration in felsic rocks along the Schauenburg fault, eastern Rhine Graben shoulder, SW-Germany. The Clay Minerals Society 39th Annual Meeting, Boulder Colorado, USA, poster.

25. Warr, L.N., Hofmann, H. and Scheicher, A.M. (2002): Formation conditions of Cretaceous bentonite and associated volcanoclastic dykes, Lago Pellegrini, Neuquen, Argentina. The Clay Minerals Society 39th Annual Meeting, Boulder Colorado, USA, talk.

24. Marbach, T., Scheicher, A.M, Kober, B., Mangini, A. and Warr, L.N. (2001). Mineralogical alteration processes determined by Sr- Pb-Isotopes and U/Th-Radionuclides along a faulted rhyolite-granite contact, eastern Rhine Graben shoulder, SW-Germany. EUG XI, Strasbourg, France, poster.

23. Warr L.N. and Peacor, D. (2001). Can X-ray scattering domain-size really provide information about crystal growth mechanisms of clay minerals? EUG XI, Strasbourg, France, talk.

22. Frings, K. and Warr, L.N. (2001). Hydrothermal pyrophyllite in diagenetic grade mudstones and shales from the Cinera-Matallana coal basin of northern Spain. EUG XI. Strasbourg, France, poster.

21. Warr, L.N. (2000). Clay-rich fault rocks and fault zone weakening: a case study from the Alpine fault of New Zealand.- The nature and tectonic significance of fault zone weakening. Joint International Research Meeting at the Geological Society, Burlington House, London, poster.

20. Frings, K., Warr, L.N., de Wall, H., Bresser, G. and Walter, R. (1999). The kinetic influence on the crystallinity of clay minerals within the external Variscides of Europe. EUROCLAY 1999, poster.

19. De Wall, H., Errami, E., Greiling, R. O., Karl, A., Kober, B., Riegner, M., Schmitt, T. and Warr, L.N. (1999). Beziehung zwischen panafrikanischer Deformation und Platznahme von kalkalkalinen Intrusionen im Saghro Gebiet, Anti-Atlas, Marokko, Jahrestagung der Afrikagruppe Deutscher Geowissenschaftler (AdG, Würzburg, 25. - 26.6.1999), extended abstract.

18. Warr, L.N. and Cox, S.C. (1998). Charakteriserung von Mikrostrukturellen Veränderungen in den Otago Schiefern aus der Südinsel von Neuseeland durch kombinierte RDA/TEM Untersuchungen. Freiberger Forschungsheft, 471, 239-241. Extended abstract, talk.

17. Deckart, K., Clark, A.H., Warr, L.N., Farrar, E. and Archibald, D.A. (1998). Origin of highly-disturbed 40Ar-39Ar age spectra for Devonian and Carboniferous, diagenetic to very-low-grade metapelites of SW England). Geological Association of Canada meeting, talk.

16. De Wall, H., Warr, L.N., Kamal el-Din, G. M. and Greiling, R. O. (1998). Spätorogene Entwicklung an steilen Deformationszonen - pure shear oder simple shear? Panafrikanische Atalla Zone, Eastern Desert, Ägypten. Freiberger Forschungshefte, C471: 55-57, talk.

15. Warr, L.N. (1997). Microstructural trends in low temperature phyllosilicate assemblages: An X-ray diffraction approach. Terra Abstracts, 9. 577, talk.

14. De Wall, H. and Warr, L.N. (1996). Einfluß der Deformation auf die Inkolung in schwach metamorphen pelitischen Gesteinen - erste Ergebinisse von Vitrinitreflecktions-/AMS-Untersuchungen. TSK-6, Salzburg 96, Extended abstract, talk.

13. Warr, L.N. (1995). How does strain influence the phyllosilicate domain-size in very low-grade metamorphic pelites? TSG 95 abstract, talk.

12. De Wall, H. and Warr, L.N. (1995). The role of strain on organic maturation in very low-grade metamorphic pelites: Preliminary results of a vitrinite reflectance and AMS study. TSG 95, poster.

11. Warr, L.N. and Krumm, S. (1995). Clay mineral crystallinity size studies in very low-grade metamorphism: A comparison of methods. Terra Abstracts, talk.

10. Krumm, S., Kisch, H. and Warr, L.N. (1994). Very-low-grade-Metamorphose: uneinheitliche Definitionen und Korrelationsmoeglichkeiten-Erste Ergebnisse einer internationalen Laborvergleichsuntersuchung. Goettinger Arb. Geol. Paelont, 5: Symposium TSK, 76-78, Göttingen.

9. Warr, L.N., Greiling, R.O. and Zachrisson, E. (1994). The pattern of very low-grade thrust-related metamorphism in the foreland fold-and-thrust belt of the Scandinavian Caledonides. Nachrichten Deutsche Geologische Gesellschaft, 52, 145-146.

8. Warr, L.N. and Nieto, F. (1994). Phyllosilicate growth in a mudstone to slate transition from the Variscides of SW England: a XRD, SEM and HRTEM study. TSG, Leeds 1994, poster.

7. Warr, L.N., Rice, A.H.N., Greiling, R.O., Osman., A.F., Abdeen, M. and Sadek, M.F. (1994). Clay mineral crystallinity as a tool for comparing the very low-grade metamorphism of sedimentary basins: a case study from the Molasse (Hammamat) basins of Egypt. Basin Formation and inversion in Europe. Nachrichten Deutsch Geologische Gesellschaft, 52, 146, talk.

6. Kisch, H.J., Krumm, S. and Warr, L.N. (1993). Interlaboratory study of the effects of sample preparation on illite crystallinity. Terra Abstracts, 5, 417, talk.

5. Warr, L.N. (1993). A calibration approach to the standardization of XRD clay mineral crystallinity (domain) size data. Terra Abstracts, 5, 421, talk.

4. Greiling, R.O. and Warr, L.N. (1992). Interrelationships between polyphase thrusting and very low-grade metamorphism in the Caledonian Lower Allochthon (N Sweden) TSG poster.

3. Warr, L.N. (1991). Illite crystallinity vs crystallite size measurements: examples from the external Variscan fold- and thrust belt of Europe. Low temperature Metamorphic processes in contrasting geodynamic settings. IGCP 294. Auckland, NZ, talk.

2. Warr, L.N. and Rice, A.H.N. (1991). The Crystallinity Index Standard. Unpublished report written to accompany a set of interlaboratory rock standards, pp. 45.

1. Robinson, D., Warr, L.N. and Bevins, R.E. (1989). Illite crystallinity: an accurate or general indicator of very low grade metamorphism? Terra Abstracts, 1, 31.