Every zircon deserves a date: selection bias in detrital geochronology

Abstract Detrital zircon geochronology can help address stratigraphic- to lithospheric-scale geological questions. The approach is reliant on statistically robust, representative age distributions that fingerprint source areas. However, there a range of biases may influence any detrital signature. Despite being fundamental and controllable bias, handpicking grains has received surprisingly little attention. Here, we show significant differences in between bulk-mounted handpicked fractions from an unconsolidated heavy mineral sand deposit. Although no size difference grains, are their aspect ratio, circularity colour, which indicate inadvertent preferential visual selection euhedral coloured grains. Grain colour comparisons dated bulk quantify bias. Bulk-mounting the preferred method avoid human-induced bias geochronology.