Hostname: page-component-8448b6f56d-c4f8m Total loading time: 0 Render date: 2024-04-25T04:38:46.821Z Has data issue: false hasContentIssue false
  • English
  • Français

Comparison of K-Ar Ages of Diagenetic Illite-Smectite to the Age of a Chemical Remanent Magnetization (CRM): An Example from the Isle of Skye, Scotland

Published online by Cambridge University Press:  01 January 2024

W. Crawford Elliott ,
Ankan Basu ,
J. Marion Wampler ,
R. Douglas Elmore  and
Georg H. Grathoff
W. Crawford Elliott*
Affiliation:
Department of Geology, Georgia State University, PO Box 4105, Atlanta, GA 30302-4105, USA
Ankan Basu*
Affiliation:
Department of Geology, Georgia State University, PO Box 4105, Atlanta, GA 30302-4105, USA
J. Marion Wampler
Affiliation:
School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30332, USA
R. Douglas Elmore
Affiliation:
School of Geology and Geophysics, Oklahoma University, Norman, OK 73019, USA
Georg H. Grathoff
Affiliation:
Department of Geology, Portland State University, Portland, OR 97207, USA
*
*E-mail address of corresponding author: geowce@langate.gsu.edu
†Current address: Department of Geosciences, Virginia Polytechnic Institute and State University, Blacksburg, VA, USA
Get access Rights & Permissions [Opens in a new window]

Abstract

The clay fractions of Jurassic marls in the Great Estuarine Group in southern Isle of Skye are composed of mixed-layered illite-smectite (I-S) with large percentages (>85%) of illite layers, kaolinite, and generally smaller amounts of chlorite. These marls have not been buried to the depths normally required to convert smectite to illite-rich I-S, so it is possible that the conversion was in response to heat and hydrothermal fluids from nearby early Tertiary igneous activity ∼55 Ma ago. The large percentages of illite layers in I-S, the Środoń intensity ratios, and the Kübler index values appear to be consistent with the formation of diagenetic I-S as a result of relatively brief heating caused by igneous activity. The Jurassic rocks in southern Skye contain a secondary chemical remanent magnetization (CRM) that resides in magnetite and formed at approximately the same time as the Tertiary igneous rocks on Skye. K-Ar age values for I-S based on illite age analysis have been determined to test the hypothesis that the CRM was acquired coincidently with the smectite-to-illite conversion. However, linear extrapolation of K-Ar age vs. percentage of 2M1 polytype (detrital illite) from one marl (EL-6) yields an estimate for the age of diagenetic illite of 106 Ma, which is close to the measured age of the finest subfraction (108 Ma). These estimated and measured age values, however, could be substantially greater than the true age of the diagenetic illite in I-S because of the presence of detrital 1Md illite that was recycled from early Paleozoic shales and whose abundance relative to the diagenetic I-S may have been enhanced because the diagenetic fluid had a low K/Na ratio, limiting the amount of diagenetic illite formed. Nevertheless, most of the illite in the Elgol marls (80% or more in the finest fractions) must be diagenetic and probably formed in response to the early Tertiary magmatism.

Keywords

IlliteIsle of SkyeK-ArScotlandPaleomagnetism
Type
Research Article
Information
Clays and Clay Minerals , Volume 54 , Issue 3 , June 2006 , pp. 314 - 323
Copyright
Copyright © 2006, The Clay Minerals Society

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

Altaner, S.P., (1989) Calculation of K diffusional rates in bentonite beds Geochimica et Cosmochimica Acta 53 923–931 10.1016/0016-7037(89)90037-9.CrossRefGoogle Scholar
Andrews, J.E., (1987) Jurassic clay mineral assemblages and their post-depositional alteration: Upper Great Estuarine Group, Scotland Geological Magazine 124 261–271 10.1017/S0016756800016289.CrossRefGoogle Scholar
Banerjee, S. Elmore, R.D. and Engel, M.H., (1997) Chemical remagnetization and burial diagenesis of organic matter: Testing the hypothesis in the Pennsylvanian Beiden Formation, Colorado Journal of Geophysical Research 102 24825–24842 10.1029/97JB01893.CrossRefGoogle Scholar
Basu, A., (2004) A Comparison of K-Ar Ages of Illite to the Age of Chemical Remnant Magnetization Atlanta, USA Georgia State University 107 pp.Google Scholar
Bechtel, A. Elliott, W.C. Wampler, J.M. and Oszczepalski, S., (1999) Clay mineralogy, crystallinity, and K-Ar ages of illites within the Polish Zechstein Basin: Implications for the age of Kupferschiefer mineralization Economic Geology 94 261–272 10.2113/gsecongeo.94.2.261.CrossRefGoogle Scholar
Blumstein, A.M. Elmore, R.D. and Engel, M.H., (2004) Paleomagnetic dating of burial diagenesis in Mississippian carbonates, Utah Journal of Geophysical Research 109 B4 10.1029/2003JB002698 B04101.CrossRefGoogle Scholar
Boles, J.R. and Franks, S.G., (1979) Clay diagenesis in Wilcox sandstones of Southwest Texas: Implications of smectite diagenesis on sandstone cementation Journal of Sedimentary Petrology 49 55–70.Google Scholar
Brindley, G.W. and Brown, G., (1961) Kaolin, serpentine, and kindred minerals The X-ray Identification and Crystal Structures of Clay Minerals 2 London Mineralogical Society 51–131.Google Scholar
Burst, J.F., (1969) Diagenesis of Gulf Coast clayey sediments and its possible relation to petroleum migration American Association of Petroleum Geologists Bulletin 53 73–93.Google Scholar
Clauer, N. Środoń, J. Franců, J. and Śucha, V., (1997) K-Ar dating of illite fundamental particles separated from illite-smectite Clay Minerals 32 181–196 10.1180/claymin.1997.032.2.02.CrossRefGoogle Scholar
Dagley, P. Musset, A.E. and Skelhorn, R.R., (1990) Magnetic polarity stratigraphy of the Tertiary igneous rocks of Skye, Scotland Geophysical Journal International 101 395–409 10.1111/j.1365-246X.1990.tb06577.x.CrossRefGoogle Scholar
Eberl, D.D. and Velde, B., (1989) Beyond the Kübler Index Clay Minerals 24 571–577 10.1180/claymin.1989.024.4.01.CrossRefGoogle Scholar
Eberl, D.D. Srodon, J. Lee, M. Nadeau, P.H. and Northrop, H.R., (1987) Sericite from the Silverton caldera, Colorado: Correlation among structure, composition, origin, and particle thickness American Mineralogist 72 914–934.Google Scholar
Elliott, W.C. and Matisoff, G., (1996) Evaluation of kinetic models for the smectite to illite transformation Clays and Clay Minerals 44 77–87 10.1346/CCMN.1996.0440107.CrossRefGoogle Scholar
Elmore, R.D. London, D. Bagley, D. Fruit, D. and Gao, G., (1993) Remagnetization by basinal fluids: Testing the hypothesis in the Viola Limestone, southern Oklahoma Journal of Geophysical Research 98 6237–6254 10.1029/92JB02577.CrossRefGoogle Scholar
Elmore, R.D. Kelley, J. Evans, M. and Lewchuk, M.T., (2001) Remagnetization and orogenic fluids: Testing the hypothesis in the central Appalachians Geophysical Journal International 144 568–576 10.1111/j.1365-246X.2001.00349.x.CrossRefGoogle Scholar
Emeleus, C.H. and Craig, G.Y., (1991) Tertiary igneous activity Geology of Scotland 3 London Geological Society 455–502.Google Scholar
Gill, J.D. Elmore, R.D. and Engel, M.H., (2002) Chemical remagnetization and clay diagenesis: Testing the hypothesis in the Cretaceous sedimentary rocks of northwestern Montana Physics and Chemistry of the Earth 27 1131–1139 10.1016/S1474-7065(02)00108-0.CrossRefGoogle Scholar
Grathoff, G.H., (1996) Illite in the lower Paleozoic of the Illinois basin. Origin, age, and polytype quantification Urbana-Champaign, USA University of Illinois PhD dissertation.Google Scholar
Grathoff, G.H. and Moore, D.M., (1996) Illite polytype quantification using WILDFIRE© calculated X-ray diffraction patterns Clays and Clay Minerals 44 835–842 10.1346/CCMN.1996.0440615.CrossRefGoogle Scholar
Grathoff, G.H. and Moore, D.M., (2002) Characterization of the Waukesha illite: A mixed-polytype illite in the Clay Mineral Society repository American Mineralogist 87 1557–1563 10.2138/am-2002-11-1205.CrossRefGoogle Scholar
Hallam, A. and Craig, G.Y., (1991) Jurassic, Cretaceous and Tertiary sediments Geology of Scotland 3 London Geological Society 439–453.Google Scholar
Hoffman, J. and Hower, J. (1979) Clay mineral assemblages as low grade metamorphic geothermometers: Application to the thrust faulted disturbed belt of Montana, U.S.A. Pp. 55–79 in: Aspects of Diagenesis (Scholle, P.A. and Schluger, P.R., editors). Special Publication 26, Society of Economic Paleontologists and Mineralogists.CrossRefGoogle Scholar
Hower, J. (1981) X-ray diffraction identification of mixed-layer clay minerals. Pp. 39–59 in: Clays and the Resource Geologist (Longstaffe, F.J., editor). Short Course, 7, Mineralogical Association of Canada.Google Scholar
Hower, J. and Mowatt, T.C., (1966) The mineralogy of illites and mixed-layer illite/montmorillonites American Mineralogist 51 825–854.Google Scholar
Hower, J. Hurley, P.M. Pinson, W.H. and Fairburn, H.W., (1963) The dependence of K-Ar age on the mineralogy of various particle size ranges in a shale Geochimica et Cosmochimica Acta 27 405–410 10.1016/0016-7037(63)90080-2.CrossRefGoogle Scholar
Hudson, J.D. Andrews, J.E. and Marshall, J.D., (1987) The diagenesis of the Great Estuarine Group, Middle Jurassic, Inner Hebrides, Scotland Diagenesis of Sedimentary Sequences London Geological Society 259–276.Google Scholar
Hurley, P.M. Hunt, J.M. Pinson, W.H. and Fairbairn, H.W., (1963) K-Ar age values on the clay fractions in dated shales Geochimica et Cosmochimica Acta 21 279–284 10.1016/0016-7037(63)90031-0.CrossRefGoogle Scholar
Jackson, M.L., (1979) Soil Chemical Analysis — Advanced Course Madison, Wisconsin Published by the Author 895 pp.Google Scholar
Katz, B. Elmore, R.D. Engel, M.H. Cogoini, M. and Ferry, S., (2000) Associations between burial diagenesis of smectite, chemical remagnetization, and magnetite authigenesis in the Vocontian Trough, SE France Journal of Geophysical Research 105 851–868 10.1029/1999JB900309.CrossRefGoogle Scholar
Kübler, B., (1964) Les argiles, indicateurs de metamorphisme Revue de l’Institut Francais du Petrole 19 1093–1112.Google Scholar
Kübler, B., (1967) La crystallinite de l’illite et les zones tout a fait superieures du metamorphisme Etages Tectoniques Switzerland Institute of Geology, Neuchatel University 105–122.Google Scholar
Kübler, B., (1968) Evaluation quantitative du metamorphisme par la cristallinite de l’illite: Etat des progres realises ces dernieres annees Centre de Recherches de Pau (Societe Nationale des Petroles d’Aquitaine) Bulletin 2 385–397.Google Scholar
McCabe, C. and Elmore, R.D., (1989) The occurrence and origin of late Paleozoic remagnetization in the sedimentary rocks of North America Review of Geophysics 27 471–494 10.1029/RG027i004p00471.CrossRefGoogle Scholar
Moore, D.M. Reynolds, R.C. Jr., (1997) X-ray diffraction and the Identification and Analysis of Clay Minerals Oxford, UK Oxford University Press 378 pp.Google Scholar
Odin, G.S. 35 collaborators,Odin, G.S., (1982) Interlaboratory standards for dating purposes Numerical Dating in Stratigraphy New York John Wiley & Sons 123–150 1040 pp.Google Scholar
Pevear, D.R., (1999) Illite and hydrocarbon exploration Proceedings of the National Academy of Sciences 96 3440–3446 10.1073/pnas.96.7.3440.CrossRefGoogle ScholarPubMed
Pollastro, R.M., (1993) Considerations and applications of the illite/smectite geothermometer in hydrocarbon-bearing rocks of Miocene to Mississippian age Clays and Clay Minerals 41 119–133 10.1346/CCMN.1993.0410202.CrossRefGoogle Scholar
Pytte, A.M., (1982) The kinetics of the smectite to illite reaction in contact metamorphic shales Hanover, New Hampshire, USA Dartmouth College 78 pp.Google Scholar
Richey, J.E., MacGregor, A.G. and Anderson, F.W., (1961) Tertiary igneous rocks: Introduction and plateau lavas The Tertiary Volcanic Districts of Scotland 3rd Nottingham, UK British Geological Survey 41–54.Google Scholar
Środoń, J., (1984) X-ray powder diffraction identification of illitic materials Clays and Clay Minerals 32 337–349 10.1346/CCMN.1984.0320501.CrossRefGoogle Scholar
Środoń, J., (1999) Extracting K-Ar ages from shales: a theoretical test Clay Minerals 33 375–378 10.1180/000985599546163.CrossRefGoogle Scholar
Środoń, J., (2000) Reply to discussion of ‘Extracting K-Ar ages from shales: a theoretical test’ Clay Minerals 35 605–608 10.1180/000985500546927.CrossRefGoogle Scholar
Woods, S.D. Elmore, R.D. and Engel, M.H., (2002) Paleomagnetic dating of the smectite-to-illite conversion: Testing the hypothesis in Jurassic sedimentary rocks, Skye, Scotland Journal of Geophysical Research 107 B5 10.1029/2000JB000053.CrossRefGoogle Scholar
Ylagan, R.F. Pevear, D.R. and Vrolijk, P.J., (2000) Discussion of ‘Extracting K-Ar ages from shales: a theoretical test’ Clay Minerals 35 599–604 10.1180/000985500546918.CrossRefGoogle Scholar