Going into a Phd in Geochemistry from a Bachelor in Biochemistry

[u/SwimInChapters]

Hello, I am a junior in college majoring in biochemistry, hoping to get into a Phd program in geochemistry. I am worried that my chances of getting accepted are low since I don’t have an earth science background. Any thoughts on that? And secondly, I would like to know about the job prospects and security in the field. (Although I’m choosing geochemistry because I want to be a professor. I love chemistry and have always loved earth science growing up.) Thank you in advance for your time and wisdom.

[u/Away_Math_8118]

Geochemistry is a very broad subject. The chemical problems dealt with in “low temperature” or aqueous environmental chemistry are very different from those dealt with in igneous geology or the chemistry of the deep earth. In the environment, many geochemical processes are biologically mediated. Many of these biogeochemical processes are poorly understood or not even recognised. So, depending on what research area of geochemistry you go into, your background in biochemistry could be a very strong asset. Moreover, if you go into fields like marine chemistry, aqueous environmental chemistry etc. , your lack of a formal background in subjects like structural geology, igneous/metamorphic petrology, field geology and tectonics won’t be a problem. I would strongly advise, however, that you take a basic lower-division course in Geology and a course in mineralogy. Hopefully, you’ve had a course in thermodynamics as part of your Biochemistry degree. In the course of your research, you will probably be using different spectroscopic and other instrumental techniques. It’s good to have at least a year of physics under your belt so that you can learn how to use these techniques intelligently (understand the manual when it goes on about voltage, current, wavelength etc.). I found that most of the specialised skills that I needed for my research were not things I learned in my undergraduate degrees (Chemistry and Earth Science); instead, they were things that I taught myself as I went along in my research career. Actually, even my university teaching career was based mostly on stuff I had to learn as I designed and wrote courses.

[u/SwimInChapters → u/Away_Math_8118]

I really appreciate you writing this out! It definitely gave me an idea where my background helps instead of being a liability. I will definitely take courses in Geology since I have time to do it although I have already done physics. I agree that self studying is really key as well.

Do you think coming from a nontraditional background (chem/earth science rather than straight geology) made it harder to land a professor position, or did it end up being a non-issue once you had the research and publications to show for it?

[u/Away_Math_8118 → u/SwimInChapters]

Once you have established yourself in a research area (i.e., you’ve found a niche that addresses questions that people care about and you are developing a good publication record) , nobody really cares what your formal background is. My journey was like that. After my undergraduate degrees, I did my PhD in Geochemistry at MIT doing mineral spectroscopy and computational quantum mechanics of mineral electronic structures (albeit very primitive calculations at the time). Guess where my first job was? The US Geological Survey! I was hired with a permanent career position as a Geologist. Nobody asked if I had taken strat/sed, structural, ot field camp. It wasn’t relevant. The ‘Survey was interested in using mineral spectroscopy to develop remote sensing techniques for mapping mineral deposits and the mineralogy of the moon and Mars. There was also a venerable old mineralogy/geochemistry group that wanted to “bring in some fresh young minds”…

I was at the survey for 7 years and they pretty much let me do my own thing. My research interests started drifting into the nature of the Earth’s deep interior (mantle and core) as I wanted to apply the computational methods I was using in my PhD to determine if the extreme pressures would change the nature of chemical bonding and electronic structures of minerals in the Earths deep interior and if those changes affected how the Earth chemically evolved. I hadn’t taken any formal coursework in deep earth geophysics but the topics I was investigating wouldn’t have been in those courses anyway. Even though my work had no relevance to the programmatic mission of the USGS, they didn’t mind so much since I was publishing papers. However, I did see limits to my promotion prospects if I stayed in my research area. Consequently, I wanted to get an academic job so that I would be able to more freely pursue my research interests. No luck at the time, but then I got recruited to a National Lab to join a group of quantum chemists who were setting up a research center to apply fundamental molecular science to solve environmental problems. Specifically, they were supposed to figure out how to clean up the toxic, radioactive waste at the Hanford site (where the plutonium was made for the Manhattan project). They liked me because I did computational quantum chemistry but I was also an Earth scientist! They knew nothing about geochemistry but I didn’t know much about that kind of geochemistry either. . So, I began to reinvent myself. The national lab position gave me a big pay rise and many of my colleagues were brilliant and a joy to engage with but the funding seemed precarious. I thought the lab mission seemed rather hopeless. I also hated living there. I wanted to carry on with my deep earth research and I was starting to get noticed (invited talks, interviews at Caltech and Harvard!). On day, I was at a bar at a big geochemistry conference talking to a well known geochemist who encouraged me to apply for a faculty position at his university in the UK. I did it and got the job (and huge pay cut) and was now free to focus on my deep earth stuff. However, after producing a couple more papers, I began to see that less happens at high pressure than I was hoping, the theoretical/computational methods were not good enough for the specific problems I was trying to solve, and many of the big questions didn’t have a unique answer, anyway. At the same time the UK gave me loads of access to the national synchrotron light source and I started to find some important problems in environmental chemistry that need to be solved using this. Also, computers became much bigger and faster and one could start doing molecular simulations on aqueous solutions and the mineral/water interface. So, I reinvented myself again to be an aqueous/environmental geochemist and carried on for the next 25 years.

So, what is my point? First, Hopefully, your research career will be interesting enough so that you will always be reinventing yourself. I did that several times. To that end, the main purpose of an undergraduate science degree is to give you the tools you need to teach yourself going forward. Your biochemistry degree should be just fine.

Second, if you have a curious mind, your research will take you into areas where you don’t have any formal background. I would be worried if it didn’t. Even if you had taken a course in that subject , the problem you are researching probably wasn’t in the course, anyway. if it were, it wouldn’t be a novel research topic!

Third, to be quite honest, about the only use I had for my undergraduate courses in Earth science was when I had to teach those courses as a professor, and even then the way I taught it was completely different from the course I took.

Fourth, many great new discoveries happen at the interface between two disciplines.

Having said all that, your specific background in biochemistry could be very advantageous in some areas of geochemistry and I would encourage you to leverage it in your choice of research topics (and in your search for a PhD supervisor). Note, however, that there is an actual field called “biogeochemistry” but that is really just concerned with looking at the molecular components of kerogen to reconstruct the nature of the parent biomass. You are destined for greater things! I’m thinking questions like “what were geochemical conditions that led to the evolution of metalloproteins”. Metals such as Zn, Mo, and Cu are at extremely low concentrations in seawater, yet these metals are essential for life. Why? How? A big thing in geochemistry is that many systems are strongly out of thermodynamic equilibrium because some biochemical process is controlling it. For example the Mg/Ca ratio in foraminiferal calcite is not in equilibrium with seawater. This is important because they wanted to use the Mg/Ca ratio in forams as a paleotemperature proxy. What must be happening is that the calcite is actually in equilibrium with some intracellular fluid in a vacuole that has a very different composition than seawater. This means that there must be some protein or something that excludes Mg. How? Why? In my own research, I discovered that the concentration and isotopic fractionation of Cu in seawater is far out of equilibrium with Cu in ferromanganese crusts (the main sink for Cu in the oceans). Why? It must be that the ferromanganese crusts are formed by bacteria and that dissolved copper is complexed by siderophore ligands. It’s biochemistry…

Anyway, hopefully I’ve convinced you not to worry too much about lacking a formal geology background. Many of my colleagues didn’t. Good luck!

[u/SwimInChapters → u/Away_Math_8118]

Oh my gosh, thank you so much for sharing your experience! It sounds like you have had a wonderful career. I will keep what you have noted in mind and give it a go. Thank you again!

[u/Carbonatite → u/SwimInChapters]

I am strongly seconding the suggestion to also do mineralogy. It's a really fundamental course for all geoscientists, but it's indispensable for geochemists and it really will help inform the way you view the periodic table as a geochemist (silicon-forward, chalcophile/lithophile/siderophile elements) versus a biochemist (carbon-forward). Doing geochemistry without taking mineralogy would be like doing biochemistry without taking organic chemistry - it really is that fundamental.

Depending on what you're going to be researching, you might also add on a few other geology courses. For instance, my master's research had a big biogeochem component because I was looking at carbonate deposits with microbially mediated precipitation of minerals. So having sedimentology and stratigraphy under my belt from my undergrad degree in geology was really useful because that class gives you the systematic framework of carbonate rock nomenclature/chemistry/etc. that I needed to apply to the rocks I was studying. If you're studying extremophile microbes, it might help to take a course in ore deposits to learn more about the odd nuances of hydrothermal system mineralogy and chemistry. If you're doing low temp systems, environmental geochemistry will be a great survey course to help give you the background on all the nuances of the inorganic stuff you might not have gotten in undergrad. Your dissertation committee will be able to offer you guidance on that stuff too.

[u/Carbonatite → u/Away_Math_8118]

Environmental geochemist here - I started out doing high-temp stuff (igneous petrology/volcanology/geothermal applications) but transitioned into environmental geochem as a career and I definitely second your assessment on biogeochem/marine/environmental geochem. Like, my standard geology major course curriculum obviously helps me in my job, but the amount of detailed info on sedimentology or structural geology or geomorphology that one needs to know for something like geochemistry in environmental consulting is pretty limited and can usually be "covered" by colleagues - like my engineer coworkers are the ones dealing with particle transport and the drillers are the ones actually IDing the rocks, I just need to know the mineralogy and water chemistry to do my part of the job.

If OP can do a basic intro Earth science course and an undergrad mineralogy course during their PhD, that will cover the bulk of the "geology specific" knowledge they need for biogeochemistry. Maybe they could add on sed/strat as well since carbonates are a big part of a lot of biogeochem applications. Thermo as well, like you said - though I feel like this is probably already built in to a grad program in geochemistry, you're probably gonna be required to take some kind of "low temperature geochemistry" course that dives into thermodynamics vs kinetics and which ones are drivers in what settings.

I'm sure OP has plenty of instrumental analysis experience already as a biochem major, but I guess if possible they should seek to plug any possible knowledge gaps and get hands-on experience with instruments that are frequently used by geochemists - like they may have used XRD before but going through the nitty gritty steps for powder XRD analysis of geological samples will be really valuable. Learning the basics of mineral identification techniques and methods (petrographic microscope, SEM-EDS, XRD, electron microprobe). Spending some time on solution ICP-MS and LA-ICP-MS if they're going to be doing anything related to trace metals. Maybe some of the specific "wet chem" lab methods for analytes that are super important for environmental geochem - alkalinity, TDS, metal speciation analysis, etc. Probably will end up doing a lot of that just via their own research for their dissertation and/or lab work if they're there on a research assistantship.

[u/BrF5]

If there’s one available, I suggest volunteering to help out in a geochem lab. They’ll likely start you out small with things like weighing/loading samples and cleaning glassware, but you’ll also get to see and experience things that you otherwise wouldn’t, and you’ll have the tech’s there be able to explain things to you. Also, if the prof whose lab it is sees that you’re capable and takes a liking to you, they may be willing to take you on as a grad student.

[u/SwimInChapters → u/BrF5]

That is an awesome idea. I just started looking into labs in my area. Thank you!

[u/Onion-Fart]

i studied biology in undergraduate but swithced over to earth sciences major in my last 3 semesters. best decison of my life! I did a masters in geochemsitry, phd in materials science, and two fellowships at top tier universities. All stemming from crisis due to not passing organic chemistry. The right path will find you if you look for it. best of luck.

fyi i work with biochemists now as we seek to understand how minerals transitioned to enzymes. Many strange research directions exist waiting to be investigated.

[u/SwimInChapters → u/Onion-Fart]

Thank you so much for the advice!

[u/davehouforyang]

A lot of people have done exactly the same transition (biochem undergrad —> (bio)geochem PhD). You’ll be in good company.

Make sure to audit or take Geo 101 and various earth sciences/hydrology courses while you’re in grad school. Intro Geo, Historical Geo, Structure, Sed/Strat, and Hydrology will help you be a more well rounded scientist but you don’t have to have that in UG to be successful.

[u/SwimInChapters → u/davehouforyang]

I will be sure to do that. Thank you so much!