Search for: All records

Explosive volcanic eruptions generate electrical discharges, a phenomenon termed volcanic lightning (VL). VL is increasingly well-investigated and monitored for modern eruptions, however volcanism has been active since Earth’s origin. Thus, investigating VL under different atmospheric conditions is relevant for studies of early atmospheric chemistry and potential prebiotic reactions. We developed an experimental setup to investigate VL in varying atmospheres. We present the first experiments of laboratory discharges in particle-laden jets in varying atmospheric conditions. The new experimental setup is a mobile fragmentation bomb erupting into a gas-tight particle collector tank. This setup enables the testing of different atmospheric conditions, changes in the carrier gas of the jet, changes in the pressure within the tank, monitoring of the jet behaviour, and sampling of the atmosphere together with the decompressed solid materials. We find that the number and magnitude of near-vent electrical discharge events are similar in CO2-CO and air atmospheres. 

Abstract Mackinawite has unique structural properties and reactivities when compared to other iron sulfides. Herein we provide evidence for the mackinawite‐supported reduction of KCN into various reduced compounds under primordial conditions. We proposed a reaction mechanism based on the nucleophilic attack by the deprotonated mackinawite ‐SH surface groups at the carbon atom of HCN. The initial binding of the substrate and the subsequent reduction events are supported by DFT calculations and further experiments using other substrates, such as KSCN, KOCN and CS₂. Until now, conversion of CN⁻into CH₄and NH₃has been limited to nitrogenase cofactors or molecular Fe‐CN complexes. Our study provides evidence for mackinawite‐supported cleavage of the C−N bond under ambient conditions, which opens new avenues for investigation of other substrates for mackinawite‐supported reactions while shedding light on the relevance of this type of reaction to the origin of life on Earth.