Constraining quartz precipitation mechanisms in the Precambrian
Using what we know from modern systems and the way that silicon behaves, we can understand how silicon was delivered to the ocean in the ancient past.
In modern systems, silicon (Si) is taken from the continental due to chemical weathering on land and leached during hydrothermal alteration of oceanic crust. This silica is then delivered to the ocean.
Today, organisms such as diatoms take the silicon out of the ocean and use it to make their cell walls. In the geologic record >2.5 billion years ago, organisms that used silicon likely did not exist yet. Instead, the silicon that was delivered to the ocean from chemical weathering of the continents and the alteration of ocean crust precipitated out of the ocean to form iron-silica deposits, or iron formation (IF). In the rock record, such Fe-Si deposits are often found associated other sedimentary rocks (sandstone, shale, carbonate, etc.) or stacked in between volcanogenic successions.
To decipher the role of silicon in the early ocean, I am interested in using geochemical and isotopic tools to determine sources and sinks of silicon and quantify quartz deposition mechanisms throughout the Precambrian.
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Collaborators (past and present): Dr. Christopher Fedo (UTK), Dr. Martin Whitehouse (NORDSIMS)
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