A comparative analyses of microstructures from Late Jurassic diamictic units, near Helmsdale, northeast Scotland and a Pleistocene diamicton from near Milton, southern Ontario, Canada – a differential diagnostic method of sediment typing using micromorphology

John Menzies, C.A. Whiteman

Research output: Contribution to journalArticle

Abstract

Micromorphology is used to examine and compare a Late Jurassic diamictite from northeast Scotland with a Pleistocene diamict from southern Ontario, Canada in order to test if a statistical difference between diamicts can be recognized and used to separate differing types of diamicts/ diamictites. The diamictites from Scotland have been ascribed to various depositional agencies occurring in several distinctly differing terrestrial and marine palaeoenvironments. In contrast, the Pleistocene diamicton is regarded as a subglacial till. Both diamicts appear remarkably similar visually and contain many corresponding features such as macrostructures, and exotic and fractured subangular to subrounded clasts. Micromorphology is used to re-examine these diamicts/diamictites at the microscopic level to detect if the palaeoenvironments within which they were deposited can be ascertained. In this paper a quantitative assessment of microstructures using micromorphology is developed. Comparative statistical analyses of these diamicts, using micromorphological features, reveals that the Jurassic diamictites are non-glacigenic, non-terrestrial and most likely deposited within a marine environment as a result of subaquatic debris mass movement, while, in contrast, the Pleistocene diamicts were most likely subglacial tectomicts deposited beneath the active base of the Laurentide Ice Sheet.
Original languageEnglish
Pages (from-to)75-94
Number of pages20
JournalNetherlands Journal of Geosciences
Volume88
Issue number1
Publication statusPublished - 2009

Keywords

  • diamictites
  • diamictons
  • diamicts
  • till
  • micromorphology
  • Jurassic
  • conglomerates
  • Pleistocene
  • statistical analyses

Fingerprint Dive into the research topics of 'A comparative analyses of microstructures from Late Jurassic diamictic units, near Helmsdale, northeast Scotland and a Pleistocene diamicton from near Milton, southern Ontario, Canada – a differential diagnostic method of sediment typing using micromorphology'. Together they form a unique fingerprint.

  • Cite this