Skip to main content

Research Repository

Advanced Search

Late diagenesis of illite-smectite in the Podhale Basin, southern Poland: Chemistry, morphology, and preferred orientation

Day-Stirrat, Ruarri J.; Aplin, Andrew C.; Kurtev, Kuncho D.; Schleicher, Anja M.; Brown, Andrew P.; Środoń, Jan

Late diagenesis of illite-smectite in the Podhale Basin, southern Poland: Chemistry, morphology, and preferred orientation Thumbnail


Authors

Ruarri J. Day-Stirrat

Kuncho D. Kurtev

Anja M. Schleicher

Andrew P. Brown

Jan Środoń



Abstract

Well-characterized samples from the Podhale Basin, southern Poland, formed the basis for exploring and illuminating subtle diagenetic changes to a mudstone toward the upper end of the diagenetic window, prior to metamorphism.Transmission electron microscopy (TEM) performed on dispersed grains and ion-beam thinned preparations, selected area diffraction patterns,and chemistry by TEM-EDS (energy dispersive spectra) augmented mineralogy and fabric data. The deepest samples show no change in their percent illite in illite-smectite (I-S), yet I-S–phase octahedral Fe3+ and Al3+ are statistically different between samples. A decrease in the Fe3+ concentration in the octahedral sheet correlates with an increase in I-S fabric intensity and apparent crystallinity. The D-statistic from the Kolmogorov-Smirnov test on TEM- EDS data describes statistical differences in the I-S chemistry. Previous work on these samples showed a significant increase in the preferred orientation of the I-S phase across the smectite to illite transition and a significant slowdown in the rate of development of preferred orientation beyond the termination of smectite illitization. Lattice fringe images describe an I-S morphology that coalesces into larger and tighter packets with increasing burial temperature and a decrease in I-S packet contact angle, yet some evidence for smectite collapse structures is retained. The deepest sample shows the thickest, most coherent I-S packets. We propose that the deepest samples in the Podhale Basin describe the precursor stage in phyllosilicate fabric preferred orientation increase from diagenesis into metamorphism, where continued evolution of crystallite packets and associated crystallinity create higher I-S fabric intensities as the structural formulae of I-S approach an end-member composition.

Citation

Day-Stirrat, R. J., Aplin, A. C., Kurtev, K. D., Schleicher, A. M., Brown, A. P., & Środoń, J. (2017). Late diagenesis of illite-smectite in the Podhale Basin, southern Poland: Chemistry, morphology, and preferred orientation. Geosphere, 13(6), 2137-2153. https://doi.org/10.1130/ges01516.1

Journal Article Type Article
Acceptance Date Aug 16, 2017
Online Publication Date Oct 5, 2017
Publication Date Oct 5, 2017
Deposit Date Oct 13, 2017
Publicly Available Date Mar 29, 2024
Journal Geosphere
Publisher Geological Society of America
Peer Reviewed Peer Reviewed
Volume 13
Issue 6
Pages 2137-2153
DOI https://doi.org/10.1130/ges01516.1

Files




You might also like



Downloadable Citations