Preprints
https://doi.org/10.5194/gchron-2020-19
https://doi.org/10.5194/gchron-2020-19

  26 Jun 2020

26 Jun 2020

Review status: a revised version of this preprint was accepted for the journal GChron and is expected to appear here in due course.

Towards in-situ U–Pb dating of dolomites

Bar Elisha1,3, Perach Nuriel1, Andrew Kylander-Clark2, and Ram Weinberger1 Bar Elisha et al.
  • 1Geological Survey of Israel, Jerusalem, Israel
  • 2Department of Earth Sciences, University of California, Santa Barbara, CA, USA
  • 3Department of Natural Sciences, The Open University of Israel

Abstract. Recent U–Pb dating by laser ablation ICP-MS has demonstrated that reasonable precision (3–10 % 2σ) can be achieved for high-resolution dating of texturally distinct calcite phases. Absolute dating of dolomite, for which biostratigraphy and traditional dating techniques are very limited, remains challenging but may resolve many fundamental questions related to the timing of mineral-rock formation by syngenetic, diagenesis, hydrothermal, and epigenetic processes. In this study we explore the possibility of dating dolomitic rocks via recent LA-ICP-MS dating techniques developed for calcite. The in-situ U–Pb dating was tested on a wide range of dolomite rocks of various origins (i.e., syngenetic, early diagenetic and epigenetic) from the Cambrian to Pliocene age – all of which from well-constrained stratigraphic sections in Israel. We present in-situ U–Pb results of dolomitic rock samples, together with imaging techniques and chemical characterizations. We show that dolomite dating is highly sensitive to textural differences and highlight parameters such as crater morphology and roughness, calcite zoning and impurities that may affect the interpretation of the resulted ages. Textural examination indicates zonation and mixing of different phases at the sub-millimeter scale (< 1 µm), and thus Tera-Wasserburg ages may represent mixing dates of early diagenesis and some later epigenetic dolomitization event(s). We conclude that age mixing at the sub-millimeter scale is a major problem in dolomite dating that need to be further studied and note the necessity of matrix-matched standards for accurate dating.

Bar Elisha et al.

 
Status: closed
Status: closed
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
Printer-friendly Version - Printer-friendly version Supplement - Supplement
 
Status: closed
Status: closed
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
Printer-friendly Version - Printer-friendly version Supplement - Supplement

Bar Elisha et al.

Viewed

Total article views: 962 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
642 283 37 962 37 36 39
  • HTML: 642
  • PDF: 283
  • XML: 37
  • Total: 962
  • Supplement: 37
  • BibTeX: 36
  • EndNote: 39
Views and downloads (calculated since 26 Jun 2020)
Cumulative views and downloads (calculated since 26 Jun 2020)

Viewed (geographical distribution)

Total article views: 849 (including HTML, PDF, and XML) Thereof 847 with geography defined and 2 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 

Cited

Latest update: 05 May 2021