PhD Candidate, Gondwana Tectonics, Sheree Armistead @geoSheree: A Day in the GeoLife Series

Mt. Cook

Sheree Armistead at Mount Cook, New Zealand. ©2016 Sheree Armistead

NAME:  Sheree Armistead

CURRENT TITLE:  PhD Candidate, The University of Adelaide, Australia

AREA OF EXPERTISE:  Tectonic evolution of Gondwana in Madagascar and India; structural geology and geochronology

YEARS OF EXPERIENCE:  6 years experience (3 years undergrad, 1 year honors, 2 years geologist/geochronologist for Geoscience Australia, and currently undertaking PhD)

EDUCATION:  Currently a PhD candidate at the University of Adelaide, Australia

WEBSITE:   @geoSheree

What’s your job like?

My research is on how the supercontinent Gondwana formed around 850–500 million years ago. A key piece of this puzzle is Madagascar, which was right in the middle of the major collision zone that formed Gondwana at that time. This ancient zone is comparable to the modern day Himalayan collision zone. My research looks at how parts of Madagascar formed and their relationship to areas in both Africa and India.

I use a range of techniques to figure out the geology at this time including geochronology and structural geology. Structural geology involves taking a lot of measurements in the field, such as ‘strike and dip’ of bedding and foliations, and then trying to figure out the deformation history and how this relates to larger tectonic processes. For geochronology, I primarily use U-Pb dating of zircons. The tiny little zircon grains are super tough, so they record the age of when they crystallised in a magma – even if they have since been removed by weathering processes. The zircons might be in their original magmatic rock, or incorporated into later sedimentary rocks.

SHRIMP

Operating the SHRIMP at Geoscience Australia; this machine is used to find out the ages of zircons. ©2016 Sheree Armistead

What’s a typical day like?

There’s not really a typical day as a geologist. My work varies a lot between field work, lab work, analysing data and writing up results. I recently completed field work in India, so as an example, I’ll run through a typical day of field work.

Firstly, the group will work out the plan for the day, identifying specific areas we want to go and look for rocks that will help us answer the big geological questions for my project. Often we don’t know until we’re right there as to whether there will be a good outcrop, so there’s a lot of driving around looking for rocks! Indians love to drink tea, or as they call it ‘chai’. So there are lots of chai stops which we manage to find in even the most remote villages. Once we see some good outcropping rock, we stop. We record global position system (GPS) coordinates, take detailed notes about the rock types and then hammer off a sample. We stop at maybe five or so sites each day, depending on how far we need to drive. The evenings are usually quite relaxed; we briefly discuss the importance of the days’ activities in the context of the larger research questions and enjoy some delicious Indian food and beer.

India

Down time while on field work in India. Visiting a few outcrops on motorbikes. ©2016 Sheree Armistead

What’s fun?

Field work and travel is what I find most fun. Getting to visit new places for work is always exciting (although usually exhausting, too). Travel is usually for either field work or conferences. Conferences are a great opportunity to meet other geologists and to present your research to a large audience. It’s also a chance to see what other research is being done in your field.

What’s challenging?

Trying to get my head around a complex geological problem is always a challenge for me. So basically the start of any new project is challenging. There’s so much reading that needs to be done before you can even begin to understand some of the geological problems. There are also complex analytical procedures (such as U-Pb isotopic dating) that we need to understand to be able to make our interpretations.

What’s your advice to students?

My advice would be to seek out and take up as many opportunities as you can, such as joining geological society committees, undertaking relevant internships/vacation work, or getting involved in small research projects while an undergraduate. A lot of opportunities aren’t advertised, so ask around if there’s something specific you’re interested in. Not only do these opportunities open your mind and allow you to learn more, but they also lead to stronger networks and potential job opportunities.

Australia

Field work in the New England Orogen of eastern Australia, while I was a geologist at Geoscience Australia. ©2016 Sheree Armistead

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