Hostname: page-component-78c5997874-m6dg7 Total loading time: 0 Render date: 2024-11-16T07:29:34.619Z Has data issue: false hasContentIssue false

Reply to discussion of “Extracting K-Ar ages from shales: a theoretical test”

Published online by Cambridge University Press:  09 July 2018

J . Środoń*
Affiliation:
Institute of Geological Sciences PAN, Senacka 1, 31-002 Kraków, Poland
*

Abstract

As plots of K-Ar ages vs. percentage of the detrital component of mineral mixtures containing a detrital and a diagenetic illite (or illite-smectite) have different curved shapes, the linear extrapolation method of extracting the end-member ages is not justified. The curvature depends on the difference in K2O contents; thus it can be minimized if the percentage of detrital illite is normalized to the sum of detrital illite plus illitic fraction of diagenetic illite-smectite.

Type
Reply
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

Drits, V., Środoń, J. & Eberl, D.D. (1997) XRD measurement of mean crystallite thickness of illite and illite/smectite: reappraisal of the Kubler index and the Scherrer equation. Clays Clay Miner. 45, 461 – 475.CrossRefGoogle Scholar
Eberl, D.D., Nüesch, R., Šucha, V. & Tsipursky, S. (1998) Measurement of fundamental illite particle thickness by X-ray diffraction using PVP-10 intercalation. Clays Clay Miner. 46, 89 – 97.CrossRefGoogle Scholar
Elsass, F., Środoń, J. & Robert, M. (1997) Illite-smectite alterat ion and accompa nying reactio ns in a Pennsylvanian underclay studied by TEM. Clays Clay Miner. 45, 390 – 403.CrossRefGoogle Scholar
Kotarba, M. & Środoń, J. (2000) Diagenetic evolution of crystallite thickness distribution of illitic material in Carpathian flysch shales studied by the Bertaut- Warren-Averbach XRD method (MudMaster computer program). Clay Miner. 35, 387 – 395.CrossRefGoogle Scholar
Pevear, D.R. (1992) Illite age analysis, a new tool for basin thermal history analysis. Pp. 1251 – 1254 in: Proc. 7th Int. Symp. Water-Rock Interactions (Kharaka, Y.K. & Maest, A.S., editors), Park City, Utah.Google Scholar
Środoń, J. (1999) Extracting K-Ar ages from shales: a theoretical test. Clay Miner. 34. 375 – 378.CrossRefGoogle Scholar
Środoń, J., Morgan, D.J., Eslinger, E.V., Eberl, D.D. & Karlinger, M.R. (1986) Chemistry of illite/smectite and end-member illite. Clays Clay Miner. 34, 368 – 378.CrossRefGoogle Scholar
Środoń, J., Elsass, F., McHardy, W.J. & Morgan, D.J. (1992) Chemistry of illite/smectite inferred from TEM measurements of fundamental particles. Clay Miner. 27, 137 – 158.CrossRefGoogle Scholar
Ylagan, R.F., Pevear, D.R. & Vrolijk, P.J. (2000) Discussion of ‘‘Extracting K-Ar ages from shales: a theoretical test’’. Clay Miner. 35, 599 – 604.CrossRefGoogle Scholar