Archean Carbonate Platforms in Canada

Did life help build Earth’s earliest carbonate platforms?

Archean (2.7 - 3.0 Ga) sedimentary deposits in Canada contain the earliest significant carbonate deposition on Earth, but are relatively understudied compared to other locations. Initial field surveys have revealed a series of shallow carbonate banks with stromatolites and carbonate fans, which provide excellent targets for understanding ancient metabolisms and ocean chemistry. Future research will provide detailed geochemical logs and petrographic studies.

Archean Barite Deposition in South Africa

How did oxidized sulfur deposits form in a low-oxygen world?

While sulfate deposits are typically rare before the Great Oxidation Event 2.4 Ga, several notable exceptions occur between 3.2 - 3.5 Ga. Initial studies of 3.2 Ga Fig Tree barites indicate a mixture of hydrothermal meteoric waters in shallow environments. Future research will examine previously unpublished barite locations in difficult terrain using classic sedimentology, aerial photomosaics, and laboratory geochemistry.

The Cambrian Oncoid Radiation

Why are oncoids prevalent in Cambrian carbonates?

While oncoids (laminated microbialite grains) occur through the geologic record, especially abundant oncoid beds occur in Cambrian deposits. The exact chronology and environmental significance of the Cambrian proliferation is unknown, but is potentially linked to global shifts in biology, geochemistry, and climate. Future research will include literature surveys, field sedimentology, and carbonate petrography.

The Catalog of Archean Life

Where is the next great discovery in Archean geobiology?

Archean deposits capable of preserving biosignatures are rare, and many locations have only received initial surveys, lying unstudied for decades. One of my long-term career goals is to develop a digital database of Archean locations and literature, in the spirit of the PaleoDB for Phanerozoic fossils, and previous compilations of Archean literature (Awramik et al., 1976, Hofmann 2000, Schopf 2006). Such a compendium will help future scientists easily compile large datasets of Archean geobiology, and select previously overlooked sites for further investigation.