Spontaneous development of concentric layering in a solidified siliceous dike, East Greenland

Journal Article (Journal Article)

A meter-wide rhyolitic dike near the eastern margin of the Skaergaard Intrusion developed fine concentric layering in a small section where a fault appears to have fractured the dike and enhanced its interaction with meteoric water. Layers two or three millimeters thick consist of quartz alternating with low-temperature albite and potassium feldspar around a core of radiating clots of the same minerals. The layering seems to have resulted from late-stage crystallization and "self-organization" during devitrification in a warm hydrous environment. The development of fine-scale layering can be modeled quantitatively using the model for competitive particle growth (CPG) of Ortoleva and co-workers. Owing to the small differences of surface energy of grains of differing sizes, large crystals tend to grow at the expense of smaller ones, and a repetitive pattern of layering develops from a small initial perturbation of grain size. The spacing of layers predicted by a numerical model using reasonable estimates for the physical parameters, such as diffusivity and the rate of cooling, is in good agreement with the observed geometry and dimensions. © 1990.

Full Text

Duke Authors

Cited Authors

  • McBirney, AR; White, CM; Boudreau, AE

Published Date

  • January 1, 1990

Published In

Volume / Issue

  • 29 / 1-4

Start / End Page

  • 321 - 330

International Standard Serial Number (ISSN)

  • 0012-8252

Digital Object Identifier (DOI)

  • 10.1016/0012-8252(90)90046-X

Citation Source

  • Scopus