Catherine Mottram on Dating Deformation Events
Transcript
Note, transcripts are not fully edited for grammar or spelling.
Oliver Strimpel
This is Geology Bites with Oliver Strimpel. In earlier Geology Bites episodes, we talked about dating rocks by finding the ages of certain minerals found within them. We can do this for minerals that trap elements that undergo radioactive decay. The mineral zircon is the gold standard for such radiometric dating as it can often trap a significant amount of radioactive uranium, and its crystals are very durable. But there are many geological events that are not amenable to zircon dating. Catherine Mottram has focused her research on radiometric dating methods that do not rely on zircon. She has successfully developed methods based on calcite and other minerals that enable processes occurring at relatively low temperatures and pressures to be dated. Using these methods, she has helped unravel the deformation history of rocks as far afield as the far north of the Yukon in Canada and cast light on how minerals such as gold can collect along large-scale faults. Catherine Mottram is an Associate Professor of Geology at the University of Portsmouth. Catherine Mottram, welcome to Geology Bites.
Catherine Mottram
Thank you very much for inviting me to talk to you today. I'm very pleased to be here.
Oliver Strimpel
Why are some geological processes not amenable to zircon dating?
Catherine Mottram
If we start with where zircon crystallizes… so zircon is crystallizing typically in igneous rocks from melts at high temperatures. So, we're looking at usually over about 800 degrees C, where we've got melt crystallizing and recording that high temperature process. So, zircons are minerals that kind of lock-in — they're the geological clocks that lock in the timing of crystallization of igneous processes. But, of course, in our planet, in our crust, we have a huge diversity of different processes happening, and a lot of them revolve around fluid flow in the crust. So that might be during metamorphic processes. It might be during lower temperature processes, especially in sedimentary rocks along faults during deformation. And a lot of that fluid flow and deformation happens at much lower temperatures than 800 degrees C. So we can use a whole spectrum of different minerals. So some of these are other accessory phases such as monazite, appetite, titanite, allanite, epidote, garnet. You know, we've got a whole host of friends that we can use to help us to tie dates to different points in the temperature path, going from our very highest temperature zircon, down to pretty much the lowest temperature for tracking crystallization of processes, which is calcite. And this is sticking within the geochronology world. I don't know if you've ever had anybody talk about thermochronology, which is tracking even sort of lower temperature processes — thinking about landscape and mountain evolution uplift, that kind of thing. So we really have a huge arsenal of tools now that we can tie to very, very low temperatures processes through time.
Oliver Strimpel
You mentioned a whole lot of minerals just then. Are these minerals that occur quite commonly like zircon actually does, or are they rather rare finds and you just have to pick and choose the one that happens to be in the rock you want to date?
Catherine Mottram
What minerals crystallize in a rock is very much depending on the chemistry of the rocks. It's just like baking. You have to put in the raw ingredients to get the cake at the end. So, zircon commonly crystallizes in felsic igneous rocks and some metamorphic rocks, and some conditions, and the other minerals like monazite readily crystallizes and felsic igneous rocks and also a whole range of different metamorphic rocks, as well. Titanites tend to form in rocks like calc-silicates, metamorphosed marbles and carbonates, as well as some more mafic metaigneous rocks. And then appetite is pretty much everywhere. Minerals like rutile, you know, these minerals commonly form in the crust. And calcite really is everywhere. It's one of the minerals that pretty much any geologist should be able to identify. It's one of the most common minerals that we have in the crust, and calcite crystallizes during a huge range of processes. Everything from in the igneous rocks, and we think about things like carbonatites, which, of course are really important for mineralization of rare earth element deposits, as well as in sedimentary rocks in basins during diagenesis; in fossils, in veins during hydrothermal fluid flow processes. And also in faults, as slickenfibres. So, calcite really forms in a huge, huge range of tectonic environments, and in a lot of environments in the upper crust.
Oliver Strimpel
Some of those processes you just mentioned are actually pretty low temperature. Could it be that you could have calcite coexisting with fossils and a sedimentary rock?
Catherine Mottram
Yes, absolutely. So, you commonly find calcite as an early diagenetic alteration of fossils. So that might either be altering original oregonite that some fossils are made. Or it could be in filling a void space. So quite a lot of fossils have a space in the middle, you know, like an ammonite. It had a soft bodied creature in there. And that ammonite, the soft body, eventually dies and maybe will be removed from the fossil. And then we'll get calcite forming in that void. So we actually did a little case study looking at a fossil turtle from the Isle of Wight. So, this was quite a small turtle, maybe about 5 centimeters in diameter. And it had fallen out of the cliff… because, if anyone has been to the Isle of Wight, which is on the South Coast of the UK, you'll see there's very, very crumbly rocks. And people who are into fossils and dinosaurs love it because there's all sorts of dinosaur bones falling out of the cliffs all the time. So, this turtle had fallen out of the cliff, and they weren't sure how old it was… where it had come from in the stratigraphy… It was actually quite cool, because they'd never really seen a turtle like that in the part of the stratigraphy that they thought it had come from. But, unfortunately, they had no way of telling, because it had fallen out — until they brought it to me, because there was calcite in the middle of this turtle. So we were able to extract the calcite, and we were able to date it, and it yielded an age which was actually exactly what they thought it was going to be. So it proved that it had come from the past of the stratigraphy, that they had assumed it come from. Yeah. So that really helps them to work out where it had come from and what the environment was like during the Cretaceous, when it was swimming around in the seas, which had now become the rocks in the Isle of Wight.
Oliver Strimpel
That's fantastic. I didn't know you could have such a direct comparison between stratigraphic dating methods and radiometric dating methods. In fact, the geological timeline, it's an ongoing major project to make those two timescales, the stratigraphic one, of course, being much older, sync up with the radiometric one. So this is a perfect example where you can really do that.
Catherine Mottram
Yeah, absolutely. Calcite dating has a huge potential for providing absolute timing constraints to the stratigraphic record. Most of the stratigraphic record is very well constrained based on lots and lots of different proxies include different isotopes, fossils — these golden spikes as they call them. But, if we have absolute dating methods to be able to improve how we understand the timing of the geological time scale, it's very, very helpful. So, the calcite dating we did and the turtle from the Isle of Wight was actually the first absolute age for the Wessex Formation, which is part of the Cretaceous stratigraphy on the Isle of Wight. So, it's really useful for all of the paleontologists working there, `cause it provided some absolute numbers for how old their fossils are.
Oliver Strimpel
Coming back to that rather long list of minerals you reeled off a few minutes ago, do they all work in the same sort of way as zircon, with the uranium lead clock, or I should say — two clocks that are trapped within the crystal, and then you look at the ratio of the daughter nuclides to the parent nuclides to get the closure age. Is it the same basic idea?
Catherine Mottram
Yes, all radiometric dating methods work in roughly the same way, in that we're interested in the ratio of the parent isotope to the daughter isotope. So, with all of these examples, we're looking at uranium, which decays the lead over time. The main difference between all of these minerals is something called the closure temperature. So, you might have visited the idea of closure temperature on this podcast before. Essentially, this is the temperature at which the time starts ticking in a geochronometer. So with a mineral like zircon, it has a very high closure temperature —very similar to the crystallization temperature of that same mineral, so, say, roughly, around 800, 900 degrees C in some felsic igneous rocks. So for zircon, when we date zircon, we know that we're preserving that high closure temperature, essentially dating the crystallization event. With other minerals, such as titanite and appetite, they have much lower closure temperatures, so we're looking more on the order of 400, 500 degrees C, and higher or lower depending on the mineral. So that means that when we're at temperatures higher than the closure temperature, uranium or lead can diffuse in and out of the crystal freely. After we've gone through the closure temperature, the edges of the mineral become like a massive great big wall with barbed wire on the edge, and everything gets trapped inside the mineral. And that's when the clock starts ticking. And so, we're recording a slightly lower temperature process. However, the concept of closure temperature is not actually that well understood. And, with some minerals, we don't fully understand exactly what the closure temperature is – or, the closure temperature might be dependent on the size of the crystal; on the circumstances that the crystal has been through… you know, if it's been through a lot. If it's been deformed…That might have an influence on what their record of the isotopes which are recorded in that crystal. And, with calcite, we know that the closure temperature must be low temperature, so something on the order of say 100 to 300 degrees. But we don't actually know that well, and there's a lot of work we need to do to be able to understand exactly what the closure temperature is for uranium and lead in calcite. It's a bit of a work in progress.
Oliver Strimpel
Let me see if I understand this. So, you're looking at minerals that do not close until you reach a lower temperature, say, if our melt is cooling or if there's some heating going on in a metamorphic process. So, for example, you could have a zircon that was made in the Paleozoic and then in the Mesozoic, a whole bunch of metamorphic activity would take place. But the zircon would essentially ignore it because none of that got to its closure temperature. Is that the kind of situation that we're talking about?
Catherine Mottram
Yes, that is correct. So, mostly zircon records the original events that happened to it. So that might be crystallizing in a granitic melt… unless that zircon reaches high temperatures again. So either it gets re-melted, or sometimes, during high temperature metamorphic events, also have gone above the solidus. So, they've started to melt. Zircon can start to record a second event. So, we do usually see evidence for a couple of events in a zircon. For instance, in the Himalayan orogeny, they might record an older core, and then they might have a Himalayan rim on them. However, they're not very sensitive. They're very basic kind of minerals. They largely can exist in the crust without recording different events. Whereas monazite is a much more sensitive mineral, so it is a much more reactive in a whole range of geological situations, especially during metamorphism. So, if there's reactions happening, metamorphic fluids around, even, to lower temperature, hydrothermal processes monazite will get excited and start to dissolve and re-precipitate on itself. So monazite is really a great friend to us as a geochronologist, because it has the power to record a lot more events than zircon. And with minerals like calcite, we can see the same thing. So, you might think that calcite dissolves and recrystallizes very, very easily. You know you could just pass any fluid through a rock and the calcite would all disappear. But we've actually found that isn't true. For a lot of veins, the calcite can record multiple generations of vein growth, so multiple layers of calcite which are formed in different fluids through geological time, which actually could be millions of years separating these different events. So minerals such as monazite, calcite, and other phases that are reactive in hydrothermal fluids are very helpful for us for understanding the longevity and complexity of fluid flow processes in the crust.
Oliver Strimpel
So, you've talked about veins, and you've talked about structures that occur along faults like slickensides. Are you generally, with these lower temperature minerals, dating these secondary structures that occur after the bulk rock is formed, or are you also recording the bulk rock age itself?
Catherine Mottram
It depends on what the bulk rock is. So, if we're just looking at calcite dating now, if the bulk crop is a limestone, for instance, we might be able to date the timing of diagenesis in that host rock. So, for instance, I'm currently working on a project looking at the North Anatolian Fault. So, we're looking at the Greek islands and where the North Anatolian fault, which is a plate boundary, comes through the Greek islands through the Aegean. And there, a lot of the host rocks are carbonates. So, we're actually able to date those carbonates using uranium lead carbonate dating to tell us the age of the host rock itself. And then we can look at the strike slip slickenfibres. So, these are new carbonates, typically calcite which have crystallized during deformation. So, as that rock has deformed, as we've got these planes of weaknesses pulling apart, we have development of the calcite crystals. And we can use uranium lead dating to tell exactly where that faulting happened. So, we can date both the original diagenesis, or maybe even metamorphism. Or we could use other tools like monazite to tell us what the host rock was if we were looking at a non-carbonate. And then on top of that, we can date the timing of deformation, which is much later.
Oliver Strimpel
If I'm not mistaken, the North Anatolian fault is the fault along which at least some of the movement occurred when that devastating earthquake occurred in Turkey and Syria earlier this year. Are you in part using these methods to actually date active faults?
Catherine Mottram
Yes. So, the earthquake earlier in 2023 in Turkey and Syria happened on the South Anatolian Fault, which is part of the same system that we are looking at the North Anatolian Fault. So yes, theoretically we can use fault dating methods to directly date seismically active structures and look essentially at Paleo slip or, very simplified, a Paleo earthquake happening on a fault. Now, with the North Anatolian Fault, some of the slip is happening right now. We have the same thing in the Himalaya. We're also working on projects looking at structures like the main boundary thrust and the main frontal thrust, which both merge into the main Himalayan thrust, which is also the structure that has caused devastating earthquakes in the Himalaya, like the 2015 Gorkha earthquake in Nepal. We can look at faulting and slickenfibres and veins associated with faults on these structures to try and look at geological time periods where slip has happened. So, we're not necessarily looking at very recent movement, because depending on the dating method, we can only record certain periods of time. So, with uranium lead dating, we are limited to really looking at millions of years. It's very difficult to date processes that even happened a couple of millions of years in the very recent past. So, we need to be looking at periods of time which are longer. So, the North Anatolian Fault project, I've got a lovely age of about four million years for one of the fault structures that we've looked at. If we want to reveal the much more recent past that is easier to link to those seismic hazards that are happening right now, we need to use other methods. So, we can use a method called Uranium Series dating, which is looking at intermediate products in the uranium to lead decay chain, which records shorter periods of time in the order of hundreds of thousands of years, which is more useful for looking at past slip on seismically active faults.
Oliver Strimpel
Do you also actually look at the deformation of the crystals that you're dating to try and get a different, if you like, a sort of mechanical handle on what's happened to them?
Catherine Mottram
Yes. The challenge with all geochronology and trying to date deformation processes, whether that's in the ductile crust, where we've got metamorphic reactions happening, fluids moving around, and ductile deformation, or whether it's in the brittle crust, where we've got fluids moving around during much, much lower temperature brittle processes, is linking the deformation to the age. So, actually understanding what the age means. So, being able to look at deformation within the crystals is helpful to be able to link the date to the process. Say for calcite, we might look at things like deformation twinning or twining within the calcite. We ideally want to date calcite that is syntectonic, so it's forming things like slickenfibres which we can, without doubt, link to a faulting process. Looking at the ductile crust, we have many different studies looking at actual deformation of the geological clocks themselves. So, zircon, monazite, titanite…. Can we actually look at the crystal structure of these minerals to see if it's been deformed, and then by looking at very, very tiny, so usually micron-scale or even nanometer-scale features, even using very fancy pieces of kit, like an atom probe, where we can look down to an atomic scale of deformation, can we use that to link the zircon age, the monazite age to an actual process like faulting, or a meteorite impact, or whatever that kind of dynamic event that has happened to that mineral?
Oliver Strimpel
You said a minute ago that all these minerals used the same basic concept as zircon. Namely, they trapped uranium within their lattice, and then you're looking at the ratio of the daughter nuclides to the parent nuclides. But, I understand that calcite dating is much, much harder than zircon dating, which is why there are not many people who do it at all, and you're one of the very few who persevere with it. Why is calcite so much harder than zircon to date?
Catherine Mottram
Yes, calcite is a challenge. Calcite only naturally incorporates a very small amount of uranium into its crystal structure, and, depending on the age, that very small amount of uranium decays to an even smaller amount of the daughter's lead isotopes. So, it's analytically extremely challenging to measure both the uranium and crucially, the radiogenic lead in a carbonate. And then we also have a second challenge and that is because carbonate loves lead. So, it commonly doesn't have much uranium and it absolutely loves lead in its crystal structure. So, when we look at the lead isotopes, some of them are radiogenic, like 206 lead and 207 lead. But some of the lead isotopes are not radiogenic, and we call them common lead. So, 204 is a typical non-radiogenic lead isotope. And this common lead readily gets incorporated into the carbonate crystal structure. So, when we have not much uranium, not much radiogenic lead, and then loads of extra lead, which we're not really interested in for geochronology, it can swamp our radiogenic signal (that excess common lead) and it can cause analytical problems. And it does mean that calcite dating is a lot harder than some other methods for dating. But there's a reason we persevere, and that's because we can date fossils for the first time. We can date sediments for the first time. We can date low-temperature fluid flow processes for the first time. And, it's really through amazing advances in mass spectrometry, that mean we can date calcite in situ.
Oliver Strimpel
So, with these advanced mass spectrometers, are you able to detect much, much smaller amounts of lead than you were before, and how do you weed out all the common lead that is confusing the signal?
Catherine Mottram
We can now measure uranium even at a sub-ppm. So typically, we've got less than one parts per million uranium in a calcite crystal. And then your radiogenic lead's gonna be even less than that.
Oliver Strimpel
How does that compare to zircon, for example?
Catherine Mottram
So in zircon you'll get hundreds of ppm uranium in most zircons. A lot of the work done recently is in situ.
Oliver Strimpel
Could you explain what you mean by in situ dating as opposed to whatever was done before?
Catherine Mottram
Yes, in situ dating is leaving the mineral that we're interested in dating in the rock, so we are cutting it into a thin slice of rock which is polished, and we can put that into a laser, and we can ablate the mineral we're interested in dating in situ. And this is brilliant because it keeps all the wonderful context of that mineral. So, if we're looking at, for instance, a monazite, we can look at the interaction with the fabric forming minerals such as micas. We can think about how the chemistry of the monazite changes and how we can link that to other minerals within the thin section. And that can help us to understand the process that we are dating. The same with calcite. We want to understand here if this is the slickenfibre, how is that slickenfibre grown? Are there differences in the age across a slickenfibre set? Or we can see veins that have cracked open multiple times. And, as well as that, we've got complexity in the chemistry and the structure of minerals, so, being able to keep analyzing it in situ, in the context, then we can really capture that process really well. We can link the age to the process.
Oliver Strimpel
Let's talk a bit more about some of the specific applications of these geological chronometers. As you said, in many locations we see calcite veining in rocks, and I recall a particular occasion when I was in the far north of India in the Zanskar Valley among some intensely folded rocks, and we came across lots of white calcite veins. And some of these veins were clearly tension gashes that must have grown while the folding was taking place, and others crosscut the folds and must have grown after the folding event. The geologists I was with got very excited about the prospect of dating both types of veins, so as to address a long-standing question, which was: did this folding occur in the Late Cretaceous, before India collided with Asia, while an ophiolite was being abducted nearby, or later in the Paleocene or Eocene, during the collision itself? And, in fact, they sent the samples to you to try and date them.
Catherine Mottram
Yes, they did. And unfortunately those samples from the Himalayas contained very low uranium and high common lead. So that meant that the common lead signal completely swamped the radiogenic signal, and I wasn't able to date them. And the reason for that is still an open question. Is it that the calcite didn't ever incorporate enough uranium into it to be an effective geological clock? Or is it that the calcite was deformed or heated up during the Himalayan orogeny, and that meant it lost all its uranium? Because, actually, quite a lot of large-scale mountain belts, not that much calcite dating has been done. There's increasing studies in places like the pre-Alps, the Jura, the Pyrenees, looking at relatively low-temperature deformation processes, but the Himalaya are an obvious place to do calcite dating, and there's only been a few successful studies. And those studies were very challenging analytically to achieve. But we need more people to work on carbonates to actually address some of these fundamental questions of: where has all the uranium gone or why didn't we have any uranium in the first place?
Oliver Strimpel
You recently returned from a summer in the far north of Canada. What we were looking at there?
Catherine Mottram
We have been working with mineral exploration companies looking at carbonate dating as a tool for understanding the timing of faulting and fluid flow in ore deposits. Large-scale strike-slip faults commonly are associated with ore deposits, particularly in Canada. So, in the Canadian Cordillera, we have large number of strike-slip faults, some of which have been imaged using geophysics to go all the way into the mantle. Some of these are tectonically active still and seismically active. And some of them have spatially controlled the distribution of particularly copper and gold ore deposits in the Yukon. So, we went there because we were interested in: could we use carbonate as a tool to date faults? And, how important is faulting and lower temperature fluid flow in ore deposits? Most of the deposits I've been looking at in the Yukon and British Columbia are porphyry deposits. So, you might have heard of porphyries in South America. Here, typically, we have subduction zone; we have melting of the upper mantle, lower crust; we have those melts rising into magmatic bodies that form underneath volcanoes, and then in the shallow crust we have interaction of these magnetic bodies that are enriched in metals with the crust around them. We have loads and loads of fluid flow happening, so, expulsion of magnetic fluids; we have mixing with the meteoric waters; and we have deposition of ore. And, actually, in lots of porphyries, faults are very important for making space in the crust for controlling how the fluids move around. So we were able to try and date the fluids and the faults.
Oliver Strimpel
So, with your work in the Yukon and British Columbia, were you able to help unravel the history of faulting and hydrothermal fluid flow there?
Catherine Mottram
Our Yukon work has been really interesting because we've been able to directly date timing of faulting, which happened during the Cretaceous, into the Eocene. So, during this time in the Yukon, we are essentially in a kind of modern-day South American setting where we had active subduction, volcanoes — we had strike-slip faulting happening at the same time. And all of the faults are making space for the emplacement of igneous rocks which also were causing mineralization in a porphyry deposit. So our fault-dating showed when the fault had been active throughout this period, and it overlapped exactly with when all the igneous rocks were coming in. We were looking at a porphyry deposit, so there was actually quite good dating done using zircon, and also, one thing I haven't talked about today is, we can use other methods — other isotope methods, to date other minerals. So, rhenium-osmium is a system we can use to date an economic mineral — so, molybdenite. And in the deposit we were working on, there was molybdenite, rhenium, osmium ages of about 75 million years. So I think I've tried to date over 100 samples from this deposit, and about 50 of them have been successful. And we were able to show that carbonate within the system shows that fluid flow (so this is magmatic fluid coming out the granite mixing with meteoric waters) happened at exactly the same time, at 75 million years ago, which is what we would expect in a porphyry deposit. So we've got this high-temperature processes precipitating carbonate and economic minerals at this time. But, crucially, what our carbonate dating showed was that these hydrothermal fluid flow processes outlasted the magmatic system by actually tens of millions of years. So we can show that faulting and fluid flow in the system carried on. So we've got at least another five million years where there's associations with other economic minerals, so we've got these fluids moving around copper and gold, helping to concentrate them in the crust. And then we have another tens of millions of years. So, overall, over 40 million years of fluid flow happening in this deposit. This is pretty novel because nobody had looked at the longevity of a hydrothermal system in a porphyry deposit, because it wasn't possible before; because the tools that we use were capturing the higher-temperature processes and not these lower-temperature fluid flow processes.
Oliver Strimpel
Does the hydrothermal fluid flow itself sort of lubricate or somehow catalyze the movement along the faults?
Catherine Mottram
Yeah. For sure there is a feedback between fluid flow and faulting. So, normally in the cross what happens is we get buildup of fluid pressure and that can then reduce the effective stress that is needed to make a fault move. So, we could absolutely see this pulsing of fluids and the interaction between, you know, magmatic fluids, probably building up pressure, and then letting off steam during earthquakes; during faulting events; during hydrothermal brecciation events. And showing that this cycle of fluid buildup, and then faulting, probably happened over and over and over again in the system. And the implications of this are interesting for multiple reasons. So one is thinking about ore deposits and how does metal get concentrated, moved around, reconcentrated. And, if we've got all of these fluid flow processes it might be making our deposit more enriched in metal and making it a more economically viable deposit. But also, it's showing us these fundamental structural geology processes of how the fluids and faults interact — which could also be problematic from an ore deposit point of view, because if you've got these faults forming it's chopping up your metal, it's making it more difficult to mine. It's very interesting for both an academic point of view and also from an ore deposit point of view.
Oliver Strimpel
What was it like working in the remote north of Canada?
Catherine Mottram
We're working in very remote places. One of the deposits I've been working in, we can actually drive, although it's a three-hour drive down the dirt road. The reason we work with mineral exploration companies is because they have drilled huge amounts of drill core across some of the structures that we are interested in. And in the Yukon, exposure can be a challenge, because there's boreal forest pretty much on everything. So, we're working with the drill core because it was the only way that we could see some of these structures. I've also worked in the high mountains in the northern part of British Columbia, which is just absolutely, epically beautiful — being very lucky to get to go and flying helicopters and work on some of the recently glaciated rocks, so, 100% exposure (very different from the boreal forest locations I've worked in in the Yukon) where we can actually see the interactions between the faults, the igneous rocks, and the mineralization at the surface.
Oliver Strimpel
And you're saying these exploration companies get their equipment right up to the top of these mountains and start prospecting up there?
Catherine Mottram
Yes. So, in the Yukon and all of British Columbia, there's a very healthy mineral exploration community. We were working with small companies, so, Triumph Gold and Core Assets. These are very small junior exploration companies, but they are running very ambitious projects. So, Core Assets are working up in these very remote mountains. They have to helicopter everything in, including their drill rigs, all their drillers every day, all their geologists who are looking out in the fields, and then they're flying the core out of the field every day for the geologists to log back in the camp. So it's logistically very challenging work from a sort of adventurous point of view. It's pretty thrilling being up on these knife-edge ridges where they're drilling. And it's really interesting thinking about all of the challenges and considerations when doing exploration in these places: the environmental implications, the social and societal implications of working in areas where native people live. So it's been really interesting for me as a British geologist working in Canada, learning about the First Nations, about how we need to be working with the First Nations to protect their lands, but also provide opportunities for them, for mineral exploration potentially, and the environmental implications of drilling next to huge glaciers. It's been really very eye-opening for me as an academic geologist.
Oliver Strimpel
Catherine Mottram, thank you very much.
Catherine Mottram
Thank you. I really enjoyed chatting to you about my research.
Oliver Strimpel
To see pictures and illustrations that support this podcast, go to geologybites.com, where you'll also find transcripts and a subject matter index of all the episodes. There you can also give me feedback which I welcome, as well as sign up to get my emails about new episodes.