Hostname: page-component-848d4c4894-v5vhk Total loading time: 0 Render date: 2024-07-01T18:11:05.367Z Has data issue: false hasContentIssue false
  • English
  • Français

Retarded illite crystallinity caused by stressinduced sub-grain boundaries in illite

Published online by Cambridge University Press:  09 July 2018

G. Giorgetti ,
I. Memmi  and
D. R. Peacor
G. Giorgetti*
Affiliation:
Department of Geological Sciences, The University of Siena, Via Laterina, 8, 53100 Siena, Italy Department of Geological Sciences, University of Michigan, Ann Arbor MI 48109-1063, USA
I. Memmi
Affiliation:
Department of Geological Sciences, The University of Siena, Via Laterina, 8, 53100 Siena, Italy
D. R. Peacor
Affiliation:
Department of Geological Sciences, University of Michigan, Ann Arbor MI 48109-1063, USA
*
*E-mail: giorgettig@unisi.it
Get access Rights & Permissions [Opens in a new window]

Abstract

An XRD-TEM study was carried out on low-grade metapelites (Transantarctic Mountains) to determine the cause of apparent inconsistences in grade as determined by IC and independent geologic relations. The illite crystallinity (IC) data indicate that the three units investigated (BT, RBT, MS) were affected by very low- (IC = 0.24°Δ2θ in BT) to low-grade metamorphism (0.19°Δ2θ in MS). In all three samples, mica crystals are of a size typical of the epizone, but the mean size increases from BT to RBT and MS, due to the increasing strain features from BT to MS. These results indicate that strain-induced reduction in crystal size was retained in BT samples (with anomalously high IC values). Microtextures in RBT and MS (with smaller IC) samples suggest a recovery of sub-grain boundaries. A decrease in crystal size may occur with increasing grade where strain rates are high relative to the rate of recrystallization.

Keywords

illite crystallinity (IC)stress-induced boundariesTEMAntarctica
Type
Research Article
Information
Clay Minerals , Volume 35 , Issue 4 , September 2000 , pp. 693 - 708
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2000

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Arkai, P., Merriman, R.J., Roberts, B., Peacor, D.R. & Toth, M. (1996) Crystallinity, crystallite size and lattice strain of illite-muscovite and chlorite: comparison of XRD and TEM data for diagenetic to epizonal pelites. Eur. J. Miner. 8, 1119–1137.CrossRefGoogle Scholar
Bell, I.A. & Wilson, C.J.L. (1981) Deformation of biotite and muscovite: TEM microstructures and deformation model. Tectonophysics, 78, 201–228.CrossRefGoogle Scholar
Bons, A.-J. (1988) Intracrystalline deformation and slaty cleavage development in very low-grade slates from the Central Pyrenees. Am. Miner. 74, 1113–1123.Google Scholar
Borg, S.G., Stump, E., Chappell, B.W., McCulloch, M.T., Wyborn, D., Armstrong, R.L. & Holloway, S.R. (1987) Granitoids of northern Victoria Land Antarctica: implication of chemical and isotopic variations to regional crustal structure and tectonics. Am. J. Sci. 287, 127–169.CrossRefGoogle Scholar
Buggisch, W. & Kleinschmidt, G. (1989) Recovery and recrystallization of quartz and “crystallinity” of illite in the Bowers and Robertson Bay Terranes (Northern Victoria Land, Antarctica ). Pp. 155–159.in: Geologic al Evolution of Antarct ica (Thomson, M.R.A., Crame, J.A. & Thomson, J.W., editors). Cambridge University Press, Cambridge, UK.Google Scholar
Capponi, G., Carosi, R., Meccheri, M. & Oggiano, G. (1994) Strain determination and tectonic evolution in the Millen Range area (northern Victoria Land, Antarctica). Terra Antarctica, 1, 63–66.Google Scholar
Capponi, G., Carosi, R., Meccheri, M. & Oggiano, G. (1995) Reply to comment on “Strain determination and tectonic evolution in the Millen Range area (northern Victoria Land, Antarctica)” by R.H. Findlay. Terra Antarctica, 2, 67–69.Google Scholar
Findlay, R.H. (1986) Structural geology of the Robertson Bay and Millen Terranes, Northern Victoria Land, Antarctica. Pp. 91–114.in. Geological Investigations in Northern Victoria Land (Stump, E., editor). American Geophysical Union, Antarctic Research Service, 46.CrossRefGoogle Scholar
Findlay, R.H. (1987) A review of the problems important for interpretation of the Cambro-Ordovician paleogeography of Northern Victoria Land (Antarctica), Tasmania and New Zealand. Pp. 67–76.in. Gondwana Six (McKenzie, G.D., editor). American Geophysical Union, Antarctic Research Service, 40.Google Scholar
Findlay, R.H. & Field, B.D. (1982) Preliminary report on the structural geology of the Robertson Bay Group, North Victoria Land, Antarctica. N. Z. Antarctic Records, 4.2, 15–19.Google Scholar
Franceschelli, M., Pandeli, E., Puxeddu, M., Porcu, R. & Fadda, S. (1994) Illite crystallinity in pelitic and marly rocks from the northern Apennines (southern Tuscany and Umbria, Italy). N. Jahrb. Min. Ab. 8, 367–384.Google Scholar
Frey, M. (1987) Very low-grade metamorphism of clastic sedimentary rocks. Pp. 9–58.in: Low Temperature Metamorphism (Frey, M., editor). Blackie & Son, Glasgow, UK.Google Scholar
Giorgetti, G. & Memmi, I. (1993) Variable muscovite composition: evidence for disequilibrium in very low-grade metapelites (Bowers and Robertson Bay Terranes, Northern Victoria Land, Antarctica). TERRA abstract, EUG VII, Strasbourg, suppl. to Terra Nova, 5, 417.Google Scholar
Giorgetti, G., Capponi, G., Meccheri, M. & Memmi, I. (1998) Further illite crystallinity data from Bowers Terrane, Millen Schists and Robertson Bay Terrane (northe rn Victor ia Land, Antarctica). Terra Antarctica, 5, 235–244.Google Scholar
Inoue, A., Velde, B., Meunier, A. & Touchard, G. (1988) Mechanism of illite formation during smectite-toillite conversion in a hydrothermal system. Am. Miner. 73, 1325–1334.Google Scholar
Jiang, W.-T., Peacor, D.R., Arkai, P., Toth, M. & Kim, J.W. (1997) TEM and XRD determination of crystallite size and lattice strain as a function of illite crystallinity in pelitic rocks. J. Metam. Geol. 15, 267–281.CrossRefGoogle Scholar
Kisch, H.J. (1987) Correlation between indicators of very low-grade metamorphism. Pp 227–300.in: Low Temperature Metamorphism (Frey, M., editor). Blackie & Son, Glasgow, UK.Google Scholar
Kisch, H.J. (1991) Illite crystallinity: recommendations on sample preparation, X-ray diffraction settings, and interlaboratory samples. J. Metam. Geol. 9, 665–670.CrossRefGoogle Scholar
Kleinschmidt, G., Mazzoli, C. & Sassi, F.P. (1991) The pressure character of the low-grade metapelites from Robertson Bay Terrane and Bowers Terrane, Northern Victoria Land (Antarctica). Mem. Soc. Geol. It. 46, 283–289.Google Scholar
Klug, H.P. & Alexander, L.E. (1974) X-ray Diffraction Procedures for Polycrystalline and Amorphous Material. Wiley Interscience, New York.Google Scholar
Kubler, B. (1967) La cristallinité de l’illite et les zones tout a` fait supérieures du métamorphisme. Colloque Etages Tectoniques, Baconniere, 105–122.Google Scholar
Kubler, B. (1968) Evaluation quantitative du métamorphisme par la cristallinité de l’illite. Bull. Centre Rech., Pau-SNPA, 2, 385–397.Google Scholar
Kubler, B. (1984) Les indicateurs des transformations physiques et chimiques dans la diagenèse, température et calorimétrie. Pp. 486–596.in. Thermométrie et Barométrie Géologiques (Lagache, M., editor). Societè Française Minereralogie et Cristallographie, 2, Paris.Google Scholar
Laird, M.G., Bradshaw, J.D. & Wodzicky, A. (1982) Stratigraphy of the Late Cambrian and Early Paleozoic Bowers Supergroup, Northern Victoria Land, Antarctica. Pp. 535–542.in: Antarctic Geosciences (Craddock, C., editor). University of Wisconsin Press, WI, USA.Google Scholar
Li, G., Peacor, D.R. & Buseck, P.R. (1999) Modification of illite-muscovite crystallite-size distributions by sample preparation for powder XRD analysis. Canad. Miner. 36, 1435–1451.Google Scholar
Li, G., Peacor, D.R., Merriman, R.J. & Roberts, B. (1994) The diagenetic to low-grade metamorphic evolution of matrix white micas in the system muscoviteparagonite in a mudrock from central Wales, United Kingdom. Clays Clay Miner. 42, 369–381.CrossRefGoogle Scholar
Meike, A. (1989) In situ deformation of micas: a highvoltage electron-microscope study. Am. Miner. 74, 780–796.Google Scholar
Merriman, R.J. & Frey, M. (1999) Patterns of very low grade metamorphism in metapelitic rocks. Pp. 61–107.in: Low-grade Metamorphism (Frey, M. & Robinson, D., editors). Blackwell Science Ltd, Oxford, UK.Google Scholar
Merriman, R.J. & Peacor, D.R. (1999) Very low-grade metapelites: mineralogy, microfabrics and measuring reaction progress. Pp. 10–60.in: Low-grade metamorphism (M. Frey & D. Robinson, editors). Blackwell Science Ltd, Oxford, UK.Google Scholar
Merriman, R.J. & Roberts, B. (1985) A survey of white mica crystallinity and polytypes in pelitic rocks of Snowdonia and Llyn, North Wales. Mineral. Mag. 49, 305–319.CrossRefGoogle Scholar
Merriman, R.J., Roberts, B. & Peacor, D.R. (1990) A transmission electron microscope study of white mica crystallite size distribution in a mudstone to slate transitional sequence, North Wales, UK. Contrib. Mineral. Pet. 106, 27–40.CrossRefGoogle Scholar
Merriman, R.J., Roberts, B., Peacor, D.R. & Hirons, S.R. (1995) Strain-related differences in the crystal growth of white mica and chlorite: a TEM and XRD study of the development of metapelitic microfabrics in the Southern Uplands thrust terrane, Scotland. J. Metam. Geol. 13, 559–576.CrossRefGoogle Scholar
Nieto, F. & Sánchez-Navas, A. (1994) A comparative XRD and TEM study of the physical meaning of the white mica crystallinity index. Eur. J. Miner. 6, 611–621.CrossRefGoogle Scholar
Tessensohn, F., Duphorn, K., Jordan, H., Kleinschmidt, G., Skinner, D.N.B., Vetter, U., Wright, T.O. & Wyborn, D. (1981) Geological comparison of basement units in North Victoria Land, Antarctica. Geol. Jarhb. B41, 31–88.Google Scholar
Warr, L.N. & Rice, A.H.N. (1994) Interlaboratory standardization and calibration of clay mineral crystallinity and crystallite size data. J. Metam. Geol. 12, 141–152.CrossRefGoogle Scholar
Wodzicki, A., Bradshaw, J.D. & Laird, M.G. (1982) Petrology of the Wilson and Robertson Bay Groups and Bowers Supergroup, Northern Victoria Land, Antarctica. Pp. 549–554.in: Antarctic Geosciences (Craddock, C., editor). University of Wisconsin Press, WI, USA.Google Scholar
Wright, T.O., Ross, R.J. & Repetski, J.E. (1984) Newly discovered youngest Cambrian or oldest Ordovician fossils from the Robertson Bay terrane (formerly Precambrian), northern Victoria Land, Antarctica. Geology, 12, 301–305.2.0.CO;2>CrossRefGoogle Scholar