Ickert et al., 2015

Chemical and Pb-isotope composition of phenocrysts from bentonites constrain the chronostratigraphy around the Cretaceous-Paleogene boundary in the Hell Creek region, Montana

Ryan B. Ickert, Sean R. Mulcahy, Courtney J. Sprain, Jessica F. Banaszak, Paul R. Renne

doi:10.1002/2015GC005898

Summary

This repository contains electron probe microanalysis (EPMA) data and median Pb isotopes and the necessary code to produce the compositional diagrams in Figures 4 and 5 of the manuscript.

Cite as:

Ickert, R. B., S. R. Mulcahy, C. J. Sprain, J. F. Banaszak, and P. R. Renne (2015), Chemical and Pb isotope composition of phenocrysts from bentonites constrains the chronostratigraphy around the Cretaceous-Paleogene boundary in the Hell Creek region, Montana, Geochem. Geophys. Geosyst., 16, 2743–2761, doi:10.1002/2015GC005898.

Code and data set archived on Zenodo:

Project Folders

• code: r scripts for generating plots

  • fsp-ternary.md: Plot ternary feldspar compositions in Figure 4
  • ttn-ternary.md: Plot ternary titanite compositions in Figure 4
  • mds-plot.md: Plot MDS diagram in Figure 5

• data: raw data used in analysis

  • feldspar.csv: feldspar weight% oxides and formulas
  • titanite.csv: titanite weight% oxides and formulas
  • mds-feldspar.csv: feldspar compositional data adjusted for mds
  • pb-feldspar.csv: median pb-isotope compositions

• figures: pdf plots from r scripts

  • fsp-ternary.pdf: Plot of ternary feldspar compositions in Figure 4
  • ttn-ternary.pdf: Plot of ternary titanite compositions in Figure 4
  • mds-plot.pdf: MDS diagram in Figure 5

R Packages

compositions van den Boogaart, K.G., Tolosana, R., and Bren, M., 2014, compositions: Compositional Data Analysis. R package version 1.40-1. http://CRAN.R-project.org/package=compositions

plyr Wickham, H., 2011, The Split-Apply-Combine Strategy for Data Analysis. Journal of Statistical Software, 40(1), 1-29.

robCompositions Templ ,M., Hron,K., and Filzmoser, P., 2011, robCompositions: an R-package for robust statistical analysis of compositional data. In V. Pawlowsky-Glahn and A. Buccianti, editors, Compositional Data Analysis. Theory and Applications, pp. 341-355, John Wiley & Sons, Chichester (UK)

RColorBrewer Neuwirth, E., 2014, RColorBrewer: ColorBrewer Palettes. R package version 1.1-2. http://CRAN.R-project.org/package=RColorBrewer

scales Wickham, H., 2015, scales: Scale Functions for Visualization. R package version 0.2.5. http://CRAN.R-project.org/package=scales

License

This work is licensed under a Creative Commons Attribution 3.0 Unported License.