Document Type
Article
Publication Date
12-1-2001
Publication Title
Palaios
Abstract
This paper documents a difference in isotopic compositions between Upper Cambrian microbial and non-microbial micritic deposits and proposes implications for diagenesis of calcimicrobial deposits. The δ 18O values (-10.98 to -8.71; average -9.88‰ VPDB) of calcimicrite comprising shallow subtidal microbialites from the southern Appalachians are more negative than: (1) the calcimicrite from associated subtidal non-microbial deposits (-8.98 to -7.16; average -7.82), suggesting a different diagenetic history; and (2) estimates of Late Cambrian marine calcite values (-5 to -3 ‰), indicating postdepositional modifications. Early diagenetic calcification of microbial deposits promoted the formation of growth cavities and borings rimmed with marine fibrous and prismatic calcite cement. Some of the voids remained open and provided pathways for fluids during later diagenesis. The microbial deposits, therefore, experienced more pronounced diagenetic alteration than the less porous non-microbial micritic deposits. The δ 18O compositions provided invaluable insights into the influence of early lithification on the later diagenesis of microbialites and into the processes that can result in poor preservation of syndepositional marine isotope signatures in these deposits.
Volume
16
Issue
6
First Page
593
Last Page
600
DOI
10.1669/0883-1351(2001)016<0593:IOELOL>2.0.CO;2
ISSN
08831351
Rights
© 2002 SEPM
Recommended Citation
Glumac, B., "Influence of Early Lithification on Late Diagenesis of Microbialities: Insights from δ 18O Composition of Upper Cambrian Carbonate Deposits from the Southern Appalachians" (2001). Geosciences: Faculty Publications, Smith College, Northampton, MA.
https://scholarworks.smith.edu/geo_facpubs/161
Comments
Archived as published. Open access article.