How to Quantify Heavy Mineral Fertility From Point‐Counting Data

Journal of Geophysical Research Earth Surface, vol. 129

Abstract

Abstract Heavy minerals (HM) are widely used in provenance studies, for example, for reconstructing source areas and quantifying sediment budgets. Source rock mineral fertility influences the composition and concentration of HM in sediments. The resulting bias is of particular interest when interpreting single‐grain data such as detrital age distributions. However, the quantification of fertility is complex and there are no robust data for most HM, which prevents the routine implementation of fertility in many studies. In this study, we test whether mineral fertility can be assessed by quantifying mineral concentrations in detrital samples through point counting and quantitative evaluation of minerals by scanning electron microscopy (QEMSCAN). The challenge is to transform the resulting area percentage into mass percentage, which is a prerequisite for comparing those data with grain size or geochemical data. We suggest overcoming this problem by recording grain‐size and shape metrics of minerals using image analysis, and applying several transformation steps. We test our method by (a) using a series of detrital grain mixtures of known density and mass, and (b) applying it to a natural sediment from the European Alps. Our results agree with existing methods developed for apatite and zircon, that is, the quantification of fertility through geochemistry (with P2O5 and Zr concentrations as proxies for apatite and zircon) and the separation of pure apatite and zircon concentrates using additional separation steps. The advantage of our method is its applicability to all HM (not only apatite and zircon) and the redundancy of additional separation steps, which might create bias.

Authors 7

1. Laura Stütenbecker corresponding

   University of Münster

   Affiliation as printed

   University of Münster Institute of Geology and Palaeontology Münster Germany

2. A. Djahansouzi

   Technische Universität Darmstadt

   Affiliation as printed

   Technical University of Darmstadt Institute of Applied Geosciences Darmstadt Germany

   Technical University of Darmstadt, Institute of Applied Geosciences, Darmstadt, Germany

3. Christoph Glotzbach

   University of Tübingen

   Affiliation as printed

   Department of Geosciences University of Tübingen Tübingen Germany

4. Sarah Falkowski

   University of Tübingen · University of Glasgow

   Affiliation as printed

   Department of Geosciences University of Tübingen Tübingen Germany

   University of Glasgow School of Geographical & Earth Sciences Glasgow Scotland UK

   University of Glasgow, School of Geographical & Earth Sciences, Glasgow, Scotland, UK

5. Tim Adolffs Aachen Institute of Applied Mineralogy and Economic Geology

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen University Institute of Applied Mineralogy and Economic Geology Aachen Germany

   RWTH Aachen University, Institute of Applied Mineralogy and Economic Geology, Aachen, Germany

6. Sven Sindern Aachen Institute of Applied Mineralogy and Economic Geology

   RWTH Aachen University

   Affiliation as printed

   RWTH Aachen University Institute of Applied Mineralogy and Economic Geology Aachen Germany

   RWTH Aachen University, Institute of Applied Mineralogy and Economic Geology, Aachen, Germany

7. Matthias Hinderer

   Technische Universität Darmstadt

   Affiliation as printed

   Technical University of Darmstadt Institute of Applied Geosciences Darmstadt Germany

   Technical University of Darmstadt, Institute of Applied Geosciences, Darmstadt, Germany