MeltSheet thermal model for R

In Kenny et al. (2021, EPSL) we investigated the cooling timescale of the Morokweng impact melt sheet, South Africa. We compared high precision U-Pb zircon ages to a model of conductive cooling of the melt sheet and found that U-Pb zircon ages from the upper part of the melt sheet are consistent with conductive cooling within 30 kyr of the impact. The U-Pb zircon age from the lower part of the melt sheet is insufficiently explained by the conductive cooling alone and likely indicates melt-present conditions in the impact structure to ~65 kyr after impact. Additionally, we scaled the thermal model up to model the larger Chicxulub impact melt sheet and found melt sheet solidification timescales of ~100-150 kyr with melt-present conditions for ~300 kyr.

The R code provided here can be used to replicate our thermal models, or it can be modified for other impact melt sheets. MeltSheet.R runs the Morokweng impact melt sheet model, and MeltSheet_Chicxulub.R runs the Chicxulub impact melt sheet model.