Precambrian impact structures and ejecta on earth: A review

Earth's early geological history, particularly the Precambrian era, holds critical clues about its impact record. A review of Precambrian impact structures and ejecta reveals that while intense bombardment likely occurred around 4.5 and 3.9 billion years ago, evidence for a 'late heavy bombardment' phase remains debated due to lunar rock biases and limited terrestrial records. The oldest confirmed terrestrial impact record includes spherule layers in South Africa and Australia (3.5–2.5 Ga) and large structures like Vredefort and Sudbury (~2 Ga). However, the Earth's incomplete rock record for this period makes the impact history challenging to reconstruct. Despite these gaps, recent discoveries suggest potential for further findings, underscoring the need for continued research into Earth's ancient impact events.

Koeberl, C., Schulz, T., & Huber, M. S. (2024). Precambrian impact structures and ejecta on earth: A review. Precambrian Research, 411, 107511. https://doi.org/10.1016/j.precamres.2024.107511