I'm a PhD graduate of the Australian Centre for Astrobiology (ACA) at the University of New South Wales (UNSW), Sydney, Australia. I was awarded my PhD in Geology at the end of 2019 and am pursuing both national and international postdoctoral opportunities in Geobiology and Astrobiology.
Over the past 10 years, since I started studying in Earth Science, I've had the opportunity to explore many beautiful and interesting places. I love doing field work, but also being in the outdoors in general. Camping, hiking, caving and kayaking are some of my favourite activities.
I study ancient fossils, in the form of stromatolites (macroscopic structures built by communities of microorganisms) and microfossils (cellularly-preserved remains of microorganisms), to contribute to our understanding of the type and diversity of life present early on in Earth's history. My research so far has focused on ~2.3 billion-year-old fossiliferous rocks from the Turee Creek Group in the Hamersley Ranges of Western Australia.
I'm particularly interested in:
- microfossil metabolisms and how these may be related to habitat;
- how Precambrian microfossils became preserved;
- how biological information may be altered through time;
- how we better distinguish between physical artefacts and biological structures;
- how life may have changed as a result of the significant increase in atmospheric oxygen at ~2.4 Ga (a.k.a. the Great Oxidation Event, GOE);
- the apparent increase in microfossil complexity through time; and
- the timing of the emergence of eukaryotes.
Honours research (2013-2014)
My Honours research involved 4 weeks of remote field work, where I mapped the distribution of various Turee Creek Group units for ~15 km along strike and pieced together the lithostratigraphy. I documented several types of shallow-water stromatolites, including stratiform, domal and columnar (± branching) forms, which I used to reconstruct transgression-regression cycles (relative sea-level change). This work is detailed in my Honours thesis (Barlow, 2014) and a paper in the journal Geobiology (Barlow et al., 2016).
PhD research (2015-2019)
During my PhD, I investigated black chert units from the deeper-water portion of the same Turee Creek Group sequence. Inside the black cherts, I discovered there were numerous microfossil morphologies preserved. Based on cell shape and size, I divided these forms into 19 specific categories, or morphotypes.
Using field and petrographic observations, I determined that these morphotypes were actually distributed within four distinct microfossil communities, and that these communities could be tied into different habitats within the ancient ecosystem. I also inferred the possible metabolisms of the microfossils using in situ C and S isotopic analyses.
Two of the microfossil morphotypes are new to science - they have no known counterparts in either older or younger rocks. In addition, a number of forms I've documented are remarkably similar to (but ~400 million-years older than) microfossils described from the well-known ~1.9 Ga Gunflint Iron Formation in Canada.
Part of these findings are reported in a second paper in Geobiology (Barlow & Van Kranendonk, 2018), while the rest of my work is detailed in my PhD thesis (Barlow, 2019) and in papers in prep.
My research has shown that life immediately after the GOE was more complex and diverse than previously thought, highlighting the Turee Creek Group as a substantial new reference point in the sparse fossil record of the early Paleoproterozoic.
I've been generously supported over the years by my supervisor, Prof. Martin Van Kranendonk.