| Summary: | The Belcher Group Microbiota (BGM) are a collection of microbial organisms from the Paleoproterozoic (~2.0 to 1.8 Ga) Belcher Group from the Belcher Islands, Nunavut, Canada. The Belcher Group is exceptionally well-preserved, having avoided deep burial or strong deformation during the Trans-Hudson orogen. The 6-9 km thick Belcher Group includes a variety of shallow marine depositional environments, two distinct periods of volcanism, and a prograding submarine fan system. The rock types range from dolomitic carbonate platforms to flood and pillow basalts to granular iron formations to sandstones. The BGM are found primarily in chert-replaced stromatolitic layers in dolostones of the lower and middle Belcher Group, including the Kasegalik and McLeary formations, and show dominantly filamentous (i.e., segmented) and coccoid (i.e., spherical) morphologies. The Belcher Group was first studied over 100 years ago, with the focus initially on the iron formation rocks and stromatolitic dolostones. Research on the putative microfossils and the geological history of the Belcher Group became the focus of later studies during the 1960s through the 1980s. The BGM were first described by Hans Hofmann as a collection of benthic prokaryotic organisms consisting of up to 24 taxa with filamentous and coccoid morphologies. However, due to degradation and diagenesis effects, Hofmann determined that the 24 different taxa could be as few as 10 distinctive taxa. The taxa of the BGM are contemporaneous with the Gunflint Microbiota but share more similarities with the microbiota of the Bitter Springs Formation. The main objective of this thesis is to confirm the biogenicity of the BGM. Previous characterization of the BGM utilized transmitted light microscopy. This thesis further investigates the BGM by utilizing other methods including Raman spectroscopy, X-ray photoelectron spectroscopy, and both electron microprobe and scanning electron microscopy, in addition to petrography and field work. This work shows that the microbiota likely ...
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