Data and supporting information for: From source rock to cinnabar – how the giant mercury deposits in earth’s crust formed

The largest concentrations of Hg on Earth exist as giant deposits of cinnabar (HgS). How such enrichments of Hg formed, based on its known crustal abundance has never been fully resolved, nor has the source(s) of Hg been unequivocally established. Hg isotopes were used to elucidate crustal processes leading to the concentration of Hg during thermal maturation of Hg and organic matter enriched sediments and cinnabar formation. Mass dependent fractionation (MDF) of Hg isotopes shows remarkable enrichment of 202Hg in cinnabar relative to its upper mantle source. Two mechanisms contribute to this enrichment: one is the low temperature, early diagenetic loss of volatile 198Hg*(g)* to an extant gas phase; the other is oxidation during cinnabar deposition. Loss of 198Hg*(g)* results in 202Hg enrichment of Hg in residual organic matter in source sediments. Evidence for this significant loss of 198Hg*(g)* is observed as large depletions in the δ202Hg isotopic composition of proximal gas condensa..., , # Data and supporting information for: From source rock to cinnabar – how the giant mercury deposits in earth’s crust formed

Dataset DOI: [10.5061/dryad.2547d7x5j](https://doi.org/10.5061/dryad.2547d7x5j)

**This Data and Supporting Information file includes the following sections:**

**Mercury isotopes**: Includes a brief description of nomenclature used in reporting both mass dependent and mass independent mercury isotopic data, together with a detailed description of laboratory and analytical procedures used in sample preparation and analysis of mercury isotopic composition in natural mercury-bearing samples discussed in this study.

Table S1: MC-ICP-MS operating parameters and measurement conditions for isotope ratio measurements.

Supporting references.

**Hg isotope data for cinnabar from each deposit discussed in this study**

Hg isotope data for each deposit were compiled from previously published studies, and together with a short summary of the geological setting are given in...,