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This is geology, B. 
I'm all of us. 

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Trampled, a former 
astrophysicists and Museum 

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director with an endless 
curiosity about the geology of 

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our extraordinary Planet, most 
rocks, have a history stretching

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back, tens, hundreds, or even 
thousands of millions of years, 

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During that time, some rocks 
have just sat there and been 

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largely ignored. 
While others have been subjected

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to enormous pressure and or 
temperature changes, knowing 

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what has happened to Iraq. 
During its lifetime gives us, 

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crucial insight into how 
geological processes work such 

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as how mountains form or how 
economically valuable mineral 

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resources originated. 
But how can we find out what 

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sort of History? 
A rock has been subjected to 

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Claire Warren is a senior 
lecturer in the school of 

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environment as an ecosystem 
Sciences at the open University,

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how workers helped us, 
understand how and when deeply 

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buried rocks, preserve a record 
of that burial and subsequent 

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Journey up to the surface. 
Armed with This Record. 

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She determines the processes and
mechanisms. 

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That Barry transform and bring 
rocks up to the surface. 

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Claire Warren. 
Welcome to geology, B. 

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Thanks very much for inviting me
Oliver. 

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It's great to be here today. 
The planet is covered with 

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rocks. 
So how do you decide which 

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rocks? 
Might tell you something 

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interesting about the geological
questions. 

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You're addressing There are 
three broad rock types that we 

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find on Earth. 
Igneous ones that have 

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crystallized from molten rock, 
sedimentary, rocks and 

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metamorphic rocks. 
And it's these latter ones that 

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have been subjected to high 
pressures and high temperatures 

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that tell us about how Mountain 
belts formed in the past, and 

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it's that process of mountain 
building that I am particularly 

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interested in, and particularly 
ones that form, where two 

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continents Collide, so I presume
to get the Rocks, you're 

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interested in, you have to go to
Mountain, Yes. 

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But they can be vast. 
Yes they are huge and it's 

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difficult. 
Sometimes to figure out which 

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parts of the mountain belt to go
to to find rocks of interest and

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different parts of mountain 
belts that we find can tell us 

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different parts of the history. 
So some parts tell us about the 

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early history of formation. 
Some parts tell us about the 

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later parts of formation so we 
have a rough idea of where to go

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to but then once we're there 
sometimes you've just got to 

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start exploring and see what you
find. 

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And when you're up there, are 
they Rocks. 

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Just lying around and say that 
looks interesting. 

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I'll grab that one. 
Or How does it go? 

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It really depends on where 
you're going. 

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So, some places now are 
protected in law their 

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geological Heritage sites. 
Of course, you can't sample from

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there and we always operate on a
leave, no Trace kind of basis. 

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So, when you take the geological
Hammer, you don't want to leave 

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evidence where you've collected 
samples from. 

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But otherwise pretty much apart 
from local laws about collecting

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things, you can go and take 
samples where you want to. 

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I mean, obviously, there's 
practical, Cooties when you're 

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working in modern Mountain belts
because sometimes the altitudes 

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really high. 
So there's not much oxygen in 

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the air. 
Sometimes there isn't much 

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exposure so you can't see many 
rocks for the taking and 

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sometimes where there's been 
glacial action. 

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For example, it's actually 
really hard to sample at all 

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because there's no nice sharp 
edges that you can hit off with 

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your Hammer. 
But generally you can go and 

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take what you want. 
So when you find a rock, you'd 

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like to focus on do you start by
just having a good look at it? 

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Where you Actually find it in 
the field. 

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Yeah, we start from a really 
broad scale, so sometimes you 

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might take a pair of binoculars 
out and have a scan of what's in

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the distance and you look for 
different colors and you look 

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for different textures. 
And you might look for the way 

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that rocks have folded or sit 
next to each other. 

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And then once you've identified 
an area of Interest, that's 

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where you start getting up 
closer and having a look at how 

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the Rocks fit together on the 
outcrop scale. 

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So on the sort of couple of 
meters scale and then once 

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you've done that, do find that 
it's pretty clear. 

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Which rocks you really want to 
hone in. 

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On our they ones that flash in 
sparkling covers or does it take

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a bit of Hit and Miss to get 
rocks? 

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That are really going to tell 
you the story or after. 

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Well that's a really interesting
question because obviously our 

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eyes are nearly always drawn to 
the most beautiful rocks and 

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those are the ones which will 
end up on our mantelpiece or on 

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the office equivalent of a 
mantelpiece but actually it's 

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quite often. 
It's the dull-looking works next

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to the pretty rocks that 
actually yield the best 

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scientific information. 
So there's one part for example,

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in Norway one Particular place 
in Western Norway, where 

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everybody gets taken to on these
geotourism holidays. 

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And a lot of people have got a 
lump of this beautiful green, 

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and red rock sitting on their 
desks, but it's actually the 

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sort of rather Dulla finer grain
to the black looking Rock. 

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Next to it, that yields the 
minerals that tell us about the 

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pressure temperature and time 
history and give us much more 

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information about how that 
mountain belt formed. 

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So in often, you don't actually 
know which are the best rocks 

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until you get back and start 
analyzing them in the lab. 

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But I presume you, whip out your
hand lens. 

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All the We'll just say I've seen
have Pam lens hanging around 

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their necks. 
Yeah, so we can tell quite a lot

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by just looking at a hand 
sample. 

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We can for example identify the 
different minerals that are in 

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the Rock and how they fit 
together. 

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So it might tell us something 
about roughly whether this rock 

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formed, 500 Degrees, which is 
fairly cool for a metamorphic 

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rock or 800 Degrees which is 
quite hot and whether they've 

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been faulted or whether they've 
been sheared out like toffee but

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until you actually take the rock
back to the lab and start 

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looking. 
At the chemistry of the 

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different minerals. 
There's only so much that you 

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can tell with the hand lens, 
okay? 

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So you've whacked off your 
samples with a hammer, and 

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you've put them in your bag, 
you've got home. 

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And now, you really want to try 
and uncover this history, that 

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tells us what The Rock is been 
through. 

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So what's the next step? 
So I guess the next step then is

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to make a thin section. 
So these are thin slices of rock

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that are about 30 microns thick 
about stickers, your hair and 

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when you cut rocks that thinly, 
you can actually start to see 

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Through them. 
So first thing we do is look at 

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the Rocks, under a microscope, 
which often confirms what we've 

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seen in hand lens. 
But it's much clearer to see 

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which different types of 
minerals. 

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There are, we might Identify 
some that are too fine grain to 

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be seen with a hand lens, and 
then once we've identified what 

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types of minerals are in the 
Rock, we then take those thin 

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sections to higher powered 
equipment. 

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So there's for example, an 
electron microprobe where we can

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measure chemistry of the 
minerals specifically the the 

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major element things like 
Silicon and iron and aluminium 

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things that make up quite a lot 
of the composition of the Rock. 

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And it also helps us to identify
which elements are in the 

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different minerals. 
We can then also take that 

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specific section of the rock to 
a mass spectrometer and that'll 

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tell us much finer detail about 
the elements that are in really 

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tiny concentrations in the rock.
Or for example, if we want to 

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know the age of the rock, we 
need to start looking at 

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Isotopes so ways and different 
elements behave, but have 

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different masses and you need 
really high resolution. 

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And if the mass spectrometer to 
be able to tell those apart, and

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once you've got all that 
information, we should be able 

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to, with a following wind, tell 
the pressure of the rock the 

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temperature of the Rock and 
hopefully the age of the rock as

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well. 
So the complete history of Iraq,

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if only you can get it, then 
would be the history of the 

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temperature and the pressure, 
the pressure telling us the rock

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depth over all the time since 
the rock was first conceived was

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a twinkle in In the eye of the 
magma, it came out of something 

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like that. 
Yeah. 

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So if you think about a rock a 
bit like a tree, the tree rings 

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on a tree can tell you time from
when the tree was just a sapling

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all the way through until it was
a stately, huge tree, 400 years 

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later and a rock behaves, a 
little bit like that as well. 

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So if we imagine, you know, our 
nice beach sand, for example, on

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the edge of a nice coast and 
then the ocean disappears and 

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that bit of Coast collides with 
the next bit of continent, Bit 

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of sand on our beach will 
eventually get buried, and will 

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turn into a new different rock 
type and growing different 

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minerals. 
But all of that takes millions 

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of years and so we need to look 
to see when the tape recorder 

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starts to see when that rock 
starts being buried, how deep it

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gets at what time it gets to its
highest debts in its highest 

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temperature and then its Journey
back towards the surface. 

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So the best rocks in my eyes are
the ones that record that 

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longest period of time and tell 
us what the pressure and 

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temperature. 
ER, and time was doing over 

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millions of years. 
Well, let's start with how you 

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can figure out pressures and 
temperatures that The Rock has 

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been subjected to. 
So these are recorded mainly by 

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the minerals that make up the 
bulk of The Rock, and there are 

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different ways that you can 
record, pressure, and 

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temperature sometimes. 
It's by the way, that magnesium 

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and iron, for example, swap 
between two different minerals. 

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So if you know, the magnesium 
and iron concentration of one 

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mineral and another mineral and 
you That they grew together at 

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the same time, you can calculate
the pressure and temperature 

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that those correct there are 
other newer techniques and more 

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high-powered techniques where 
you need to. 

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Look at Trace element 
concentration of titanium in a 

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particular mineral that might 
also tell you pressure and 

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temperature. 
So it's basically by chemistry 

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and by assuming the magical 
status of equilibrium and that's

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of course always the difficult 
bit. 

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But if we make a bunch of 
assumptions and do some 

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calculations and we know the 
chemistry then pressures and 

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temperatures usually fall out of
that. 

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That appear to make sense. 
Are there any particular 

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minerals that are particularly 
useful for determining pressure 

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and temperature? 
So the best ones for the rocks 

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that I work in our minerals 
called Garnet, which is a nice, 

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big bright, red ones, and 
minerals, like biotite. 

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That's the shiny Brown Mica that
you quite often. 

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See twinkling in rocks. 
So, those are two really good 

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ones, because they record 
pressure and temperature really 

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well. 
Other minerals. 

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There's a mineral called rutile,
which is most commonly used for 

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making the white color, Your 
toothpaste. 

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That's a really really good 
pressure. 

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Temperature indicator minerals 
as well. 

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So the detailed compositions of 
Telltale minerals such as garnet

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and biotite occurring in a 
particular, Rock depend in ways 

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unique to each mineral on what 
the temperature and pressure was

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while they were crystallizing 
from the Melt. 

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For example, it turns out that 
one, especially sensitive 

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indicator of the temperature, 
which these minerals 

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crystallized is the relationship
between the iron to magnesium 

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ratio in the garnet. 
And the iron to magnesium ratio 

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in the biotite. 
So, if you use these very 

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sensitive instruments, you have 
to measure the concentrations of

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iron and magnesium in these two 
minerals. 

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You can get at the temperature. 
That's right. 

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And Garnet, grows over a long 
period of time as well. 

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So, it's a, particularly good 
mineral for recording pressures 

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and temperatures, because it 
will called different values in 

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its core compared to an its Rim.
So, comparing back. 

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Of a tree rings. 
For example, Ghana is a 

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particular good recorder of 
pressures and temperatures 

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because it does grow over such a
long period of time. 

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Let's talk about the time 
Dimension. 

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Then how do you figure out the 
time at, which various things 

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happen to a rock? 
So we record or measure 

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geological time using 
radioactive decay. 

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And there are some elements 
which Decay for example, uranium

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or Decatur lead. 
And there are some minerals in a

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rock, which will concentrate 
uranium and exclude lead when 

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they start crystallizing. 
So there's a couple of good 

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minerals. 
Zircon is one another's 

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monocyte. 
They will have these fantastic 

231
00:11:46,000 --> 00:11:47,000
names. 
Minerals. 

232
00:11:47,200 --> 00:11:51,400
And these are particularly good 
geological clocks and because 

233
00:11:51,400 --> 00:11:54,900
again, they grow over long 
periods of time and they form 

234
00:11:54,900 --> 00:11:57,500
these different shells of 
different composition at 

235
00:11:57,500 --> 00:11:59,700
different times. 
We can actually start using 

236
00:11:59,700 --> 00:12:03,400
those as the tape recorder. 
The problem with those minerals 

237
00:12:03,400 --> 00:12:05,800
is that they don't record 
pressure and temperature. 

238
00:12:06,200 --> 00:12:09,200
So we then try to link our 
pressure temperature, minerals 

239
00:12:09,200 --> 00:12:12,200
like, Garnet, with the age 
information that are 

240
00:12:12,200 --> 00:12:15,200
chronometer, our clock minerals 
record. 

241
00:12:15,500 --> 00:12:18,900
How do you get this? 
This radiometric information out

242
00:12:18,900 --> 00:12:21,500
of a rock. 
So, that's where we have to go 

243
00:12:21,500 --> 00:12:24,400
to our mass spectrometers. 
And what we do is we have these 

244
00:12:24,400 --> 00:12:27,400
thin sections, over these rocks.
And we find the minerals, the 

245
00:12:27,400 --> 00:12:30,500
clock, minerals in our rock 
using, for example, the electron

246
00:12:30,500 --> 00:12:33,100
microprobe. 
And then we use a laser with a 

247
00:12:33,100 --> 00:12:37,100
spot size of about 10 microns. 
So that's about a third of the 

248
00:12:37,100 --> 00:12:41,200
size of your hair just to laser 
tiny little spots all the way 

249
00:12:41,200 --> 00:12:44,400
across these minerals. 
And then we collect the 

250
00:12:44,400 --> 00:12:46,100
chemistry information from those
minerals. 

251
00:12:46,100 --> 00:12:47,500
So how much Rhenium. 
It's got in it. 

252
00:12:47,500 --> 00:12:50,100
How much lead it's got in it and
the Isotopes of those two 

253
00:12:50,100 --> 00:12:53,200
elements as well as some of the 
other elements as well like to 

254
00:12:53,200 --> 00:12:55,400
taenia more The Rare Earth 
elements. 

255
00:12:55,400 --> 00:12:58,500
They've also got some weird and 
wonderful names and we collect 

256
00:12:58,500 --> 00:13:00,400
all that information spot by 
spot. 

257
00:13:00,900 --> 00:13:05,800
And these grains have probably 
about 100 to 200 microns big. 

258
00:13:05,800 --> 00:13:08,800
So so tiny tiny. 
We put a whole row of spots on 

259
00:13:08,800 --> 00:13:11,800
these grains and then we collect
all that age information. 

260
00:13:12,200 --> 00:13:15,900
So it is chemistry magic. 
Really much better than I ever 

261
00:13:15,900 --> 00:13:16,900
did at school. 
Cool. 

262
00:13:17,600 --> 00:13:21,900
So if I can spell this out a 
little more, you start off with 

263
00:13:21,900 --> 00:13:26,300
a mineral such as Zircon, which 
has a certain amount of uranium 

264
00:13:26,300 --> 00:13:32,400
trapped inside it and it decays 
to a particular isotope of lead.

265
00:13:33,300 --> 00:13:37,800
And then when you put the Zircon
into the mass, spectrometer you 

266
00:13:37,800 --> 00:13:41,300
measure how much of the lead 
Decay product, there is compared

267
00:13:41,300 --> 00:13:45,400
to the uranium and since you 
know, the half-life of the Decay

268
00:13:45,400 --> 00:13:50,500
process You can tell how long 
ago, the Zircon crystallized and

269
00:13:50,500 --> 00:13:54,500
trapped the uranium inside it, 
starting the radiometric clock. 

270
00:13:54,600 --> 00:13:57,100
Yeah, that's right. 
And the first people to carry 

271
00:13:57,100 --> 00:13:59,100
out age dating of rocks like 
this would measure all the 

272
00:13:59,100 --> 00:14:02,100
uranium and all the lead in the 
whole Rock and of course, they 

273
00:14:02,100 --> 00:14:04,900
didn't have mass spectrometers. 
Then that's about 150 years ago.

274
00:14:05,200 --> 00:14:08,300
So it's very complicated and 
very time-consuming to get one 

275
00:14:08,300 --> 00:14:10,300
age. 
And now we can measure these 

276
00:14:10,300 --> 00:14:13,700
tiny portions of these tiny 
minerals and measure hundreds of

277
00:14:13,700 --> 00:14:17,200
these minerals in a day and get 
much more accurate and precise 

278
00:14:17,200 --> 00:14:20,500
information out. 
So, the idea that we can use 

279
00:14:20,500 --> 00:14:23,000
radioactive decay, has been 
around for a long time, but the 

280
00:14:23,000 --> 00:14:25,700
techniques that we now use to do
that, give an amount of 

281
00:14:25,708 --> 00:14:29,100
information that the scientists 
hundred years ago, they would 

282
00:14:29,100 --> 00:14:34,600
have blown their heads, Okay. 
So now using these radioactive 

283
00:14:34,600 --> 00:14:38,200
methods, you can get the 
crystallization age of a 

284
00:14:38,200 --> 00:14:39,900
particular Crystal, when it 
forms. 

285
00:14:39,900 --> 00:14:42,500
So does that then tell us the 
age of the rock that it's 

286
00:14:42,500 --> 00:14:45,400
sitting in? 
It can do but metamorphic rock 

287
00:14:45,400 --> 00:14:48,900
to a little bit complicated 
because they have changed their 

288
00:14:48,900 --> 00:14:52,600
form from one type of rock to 
another type of rock and it's 

289
00:14:52,600 --> 00:14:56,400
the change that I'm particularly
interested in, but some of the 

290
00:14:56,400 --> 00:14:59,400
minerals in The Rock will still 
record the age of the original 

291
00:14:59,400 --> 00:15:00,600
Rock. 
For example. 

292
00:15:00,800 --> 00:15:03,400
It came out of a volcano 
originally or crystallized. 

293
00:15:03,400 --> 00:15:06,200
There's a large Granite body 
underground, and then it got 

294
00:15:06,200 --> 00:15:10,300
metamorphose later. 
So what we then need to do is to

295
00:15:10,300 --> 00:15:14,200
try to unravel, which of the 
ages relate to different parts 

296
00:15:14,400 --> 00:15:17,600
of the process that we're 
interested in and that's where 

297
00:15:17,600 --> 00:15:21,200
all these tools of linking 
pressure and temperature and age

298
00:15:21,200 --> 00:15:24,200
using these geochemical 
fingerprinting tools comes into 

299
00:15:24,200 --> 00:15:26,800
play. 
So it really is like a detective

300
00:15:26,800 --> 00:15:30,200
story like a forensic science 
story trying to link little 

301
00:15:30,400 --> 00:15:32,100
tent. 
It has bits of evidence from one

302
00:15:32,100 --> 00:15:35,900
mineral and try to patch that in
to when that other mineral was 

303
00:15:35,900 --> 00:15:38,700
growing. 
So nature doesn't make it easy 

304
00:15:38,700 --> 00:15:41,400
for us. 
There isn't anyone mineral whose

305
00:15:41,400 --> 00:15:46,500
tree rings will record both the 
age from the amount of uranium 

306
00:15:46,500 --> 00:15:51,500
lead and the composition saved? 
Like Darla to tell us the 

307
00:15:51,500 --> 00:15:53,300
temperature and pressure at the 
time, we've got to 

308
00:15:53,300 --> 00:15:55,800
cross-correlate different kinds 
of minerals. 

309
00:15:55,800 --> 00:15:59,000
That's right. 
And we can also use the way that

310
00:15:59,000 --> 00:16:00,700
different minerals sit 
alongside. 

311
00:16:00,800 --> 00:16:03,600
Solid each other. 
So for example, when Garnet 

312
00:16:03,600 --> 00:16:07,200
grows it will engulf other 
minerals that are in the Rock at

313
00:16:07,200 --> 00:16:10,200
the time that it's growing 
because if it comes across 

314
00:16:10,200 --> 00:16:13,200
something that it doesn't want 
to make part of its crystal 

315
00:16:13,200 --> 00:16:15,000
structure, it will just grow 
around it. 

316
00:16:15,300 --> 00:16:18,900
So Garnet might contain 
different inclusions of 

317
00:16:19,100 --> 00:16:22,100
monocytes in the core and 
different conclusions of 

318
00:16:22,100 --> 00:16:25,000
monocyte in the rim. 
And so those different 

319
00:16:25,000 --> 00:16:29,300
inclusions can then tell us how 
long that Garnet took to grow. 

320
00:16:29,400 --> 00:16:33,300
So there's these different Ways 
and mechanisms of linking, the 

321
00:16:33,300 --> 00:16:36,700
garnet, and the monocyte or the 
garnet, and the Zircon together,

322
00:16:36,700 --> 00:16:40,300
just by the way that they're 
growing, so let's say, by 

323
00:16:40,300 --> 00:16:43,600
applying this whole battery of 
techniques that you've managed 

324
00:16:43,600 --> 00:16:46,500
to glean enough information. 
To tell you what The Rock has 

325
00:16:46,500 --> 00:16:48,600
been through. 
Since it was formed, can you 

326
00:16:48,608 --> 00:16:51,100
give us an example of a rock? 
You've done this for. 

327
00:16:51,400 --> 00:16:54,100
So I think some of the most 
interesting examples of worked 

328
00:16:54,100 --> 00:16:55,900
on recently. 
Come from the Himalayas, I 

329
00:16:55,900 --> 00:16:58,600
actually went to Bhutan and the 
Eastern side of the Himalayas 

330
00:16:58,600 --> 00:17:01,200
and went all the way up to the 
northwest corner of And so, 

331
00:17:01,200 --> 00:17:04,400
we're camping at altitudes of 
about 4,000 meters or so. 

332
00:17:04,800 --> 00:17:07,900
So this is a proper hardcore, 
mountainous field, geology. 

333
00:17:08,000 --> 00:17:13,200
But we're trying to unravel how 
the Himalayas formed so which 

334
00:17:13,200 --> 00:17:18,400
rocks were colliding between 
India and Asia and when and what

335
00:17:18,400 --> 00:17:21,200
then happened to them as they 
got buried and brought back up 

336
00:17:21,200 --> 00:17:23,300
to the surface because obviously
the rocks that were surfaced 

337
00:17:23,300 --> 00:17:27,400
today were buried at depth 10, 
20, 30 million years ago. 

338
00:17:28,500 --> 00:17:33,000
So we found this one place with 
two specific samples that I was 

339
00:17:33,000 --> 00:17:36,500
looking at one, was a beautiful 
green and red rocks at high 

340
00:17:36,500 --> 00:17:39,200
pressure and metamorphic rock 
that told us something about the

341
00:17:39,200 --> 00:17:42,400
very depth of the Himalayas and 
then other rocks, which are 

342
00:17:42,400 --> 00:17:46,800
nearby, which were metamorphose 
that much shallower levels and 

343
00:17:46,800 --> 00:17:49,900
we were trying to figure out how
these two different rock types 

344
00:17:49,900 --> 00:17:54,400
fit together so where they just 
recording different parts of the

345
00:17:54,400 --> 00:17:58,900
story but had had the same 
history or did, they have a 

346
00:17:58,908 --> 00:18:03,100
different history and then Place
together somehow in the vast 

347
00:18:03,100 --> 00:18:05,300
washing machine that was 
underground. 

348
00:18:05,900 --> 00:18:08,900
So one of the Rocks told us a 
lot about the early parts of the

349
00:18:08,900 --> 00:18:11,300
Himalayan history. 
So India, and Asia collided 

350
00:18:11,300 --> 00:18:15,100
about 50 million years ago and 
the metamorphic processes that 

351
00:18:15,100 --> 00:18:18,300
heat up rocks and squash rocks. 
Start getting recorded in the 

352
00:18:18,300 --> 00:18:20,600
Himalayas about 35 million years
ago. 

353
00:18:21,200 --> 00:18:23,700
And these older, these 35 
million are rocks, are quite 

354
00:18:23,700 --> 00:18:26,800
rare in the Himalayas, because 
most of the time, those haven't 

355
00:18:26,800 --> 00:18:29,500
come up to the surface yet, 
actually, it's the younger rocks

356
00:18:29,500 --> 00:18:32,200
which were metamorphose that A 
lower level which are now at the

357
00:18:32,200 --> 00:18:34,000
surface. 
So we found this one, rock that 

358
00:18:34,008 --> 00:18:37,500
told us a lot about this early 
history and then this deep 

359
00:18:37,500 --> 00:18:39,600
high-pressure Rock was much 
younger than that. 

360
00:18:39,600 --> 00:18:43,100
And so that was also then a bit 
of a puzzle, how you get a young

361
00:18:43,100 --> 00:18:47,900
deep rock suddenly, a kilometer 
away from a shallower called 

362
00:18:47,900 --> 00:18:51,400
Iraq, but by pulling all these 
different pieces of the 

363
00:18:51,400 --> 00:18:55,100
geochemistry and the field 
relationships and the mineral 

364
00:18:55,100 --> 00:18:58,300
relationships and all of that 
together, it tells us a lot 

365
00:18:58,300 --> 00:19:02,400
about that washing machine. 
Process of how India and Asia 

366
00:19:02,400 --> 00:19:06,500
finally collided. 
So yeah, it's a fascinating 

367
00:19:06,500 --> 00:19:10,300
story which we only managed to 
unravel back in the lab from two

368
00:19:10,300 --> 00:19:12,600
rocks. 
That we happened to manage to 

369
00:19:12,600 --> 00:19:16,500
get to 4,000 meters altitude on 
a day when we actually had 

370
00:19:16,500 --> 00:19:19,600
enough strength and oxygen to 
wield a hammer to take these two

371
00:19:19,600 --> 00:19:24,500
bits, a home with us. 
So this washing machine process,

372
00:19:24,500 --> 00:19:29,200
you're uncovering is the 
somewhat chaotic burial, partial

373
00:19:29,200 --> 00:19:32,500
melting and uplift of the Indian
Rocks, caught up in the 

374
00:19:32,500 --> 00:19:36,900
collision with Asia, is this 
process specific to them earlier

375
00:19:37,500 --> 00:19:40,700
details of how the rocks are now
sitting together in the 

376
00:19:40,700 --> 00:19:43,700
Himalayas is quite specific to 
the Himalayas but what we're 

377
00:19:43,700 --> 00:19:48,700
finding is that the processes 
that operate as two continents 

378
00:19:48,700 --> 00:19:54,300
Collide, and which bits of rock,
tend to ride over each other, 

379
00:19:54,400 --> 00:19:57,300
and start melting and start 
getting mangled around. 

380
00:19:57,500 --> 00:20:00,600
That is actually been happening 
for billions of years. 

381
00:20:00,900 --> 00:20:04,000
And some of the oldest mountain 
belts that we have evidence for 

382
00:20:04,200 --> 00:20:07,800
on Earth today, so about 2 
billion years old actually 

383
00:20:07,800 --> 00:20:10,700
formed in much the same way as 
the Himalayas, the youngest 

384
00:20:10,700 --> 00:20:13,200
Mountain belt of these 
Continental Collision types 

385
00:20:13,600 --> 00:20:16,800
forming today. 
But what's unusual is that 

386
00:20:16,800 --> 00:20:20,200
Himalayas tend to only expose 
the rocks at the very surface 

387
00:20:20,200 --> 00:20:24,100
today, so the higher levels of 
the mountain belt and over time,

388
00:20:24,100 --> 00:20:27,100
those will erode and we'll start
then looking at the deepest 

389
00:20:27,100 --> 00:20:30,500
levels and so the older the 
mountain belt is the deeper you 

390
00:20:31,100 --> 00:20:34,800
Look down into the structure. 
And so, what's great about these

391
00:20:34,800 --> 00:20:37,300
rocks that we've been finding in
the northwest of the Himalayas, 

392
00:20:37,300 --> 00:20:39,700
is that they're showing us 
evidence from some of the deep 

393
00:20:39,700 --> 00:20:43,400
roots of the Himalayas at the 
surface today and that gives us 

394
00:20:43,400 --> 00:20:47,300
a tie point that we can link the
really old mountain belts with 

395
00:20:47,300 --> 00:20:50,300
this young Mountain belt and say
hey look the processes and the 

396
00:20:50,300 --> 00:20:53,400
roots of these Mountain belts 
were actually very very similar 

397
00:20:53,400 --> 00:20:56,100
in the past to the present day. 
So there's been no major 

398
00:20:56,100 --> 00:20:59,700
differences in the way that 
plate tectonics operates for 2 

399
00:20:59,700 --> 00:21:02,500
billion years. 
In this particular circumstance 

400
00:21:02,500 --> 00:21:05,200
and that's quite interesting. 
Is there a particular ancient 

401
00:21:05,200 --> 00:21:08,900
mountain range that you compare 
them allows with to come to this

402
00:21:08,900 --> 00:21:12,200
conclusion? 
So I haven't particularly been 

403
00:21:12,200 --> 00:21:15,400
to this mountain range of the 
called the trance Hudson origin 

404
00:21:15,400 --> 00:21:17,600
and it's in Canada. 
And that's about eighteen 

405
00:21:17,600 --> 00:21:20,800
hundred million years old, but 
other workers have worked there.

406
00:21:20,900 --> 00:21:25,400
And the kinds of metamorphic map
that they are producing a very, 

407
00:21:25,400 --> 00:21:27,100
very similar to the Himalayan 
ones. 

408
00:21:27,100 --> 00:21:28,600
When you look at them in a broad
scale. 

409
00:21:28,600 --> 00:21:32,300
So the types of rocks that we 
see, The rates and time scales 

410
00:21:32,300 --> 00:21:35,300
of the processes that operate in
those Mountain belts, and this 

411
00:21:35,300 --> 00:21:39,100
General pattern are very, very 
similar plate tectonics. 

412
00:21:39,100 --> 00:21:41,000
Has been around for most of the 
history of the earth. 

413
00:21:41,000 --> 00:21:42,400
It would seem. 
Yeah. 

414
00:21:42,400 --> 00:21:45,500
Some of the bits of plate. 
Tectonics appear to be much 

415
00:21:45,500 --> 00:21:49,400
younger, but the way that 
continents Collide appears to 

416
00:21:49,400 --> 00:21:52,600
have gone back at least half of 
the age of the Earth. 

417
00:21:53,200 --> 00:21:57,000
Are there any new tools? 
Emerging now that might help us 

418
00:21:57,000 --> 00:22:00,200
elucidate even more about the 
Rocks history than we can today.

419
00:22:00,800 --> 00:22:05,000
Well, what we're finding is that
the more and more we look and 

420
00:22:05,000 --> 00:22:08,700
the finer and finer detail that 
we look at the more and more we 

421
00:22:08,700 --> 00:22:10,700
find. 
So there's a particularly 

422
00:22:10,700 --> 00:22:15,000
interesting instrument called 
the atom probe which allows you 

423
00:22:15,000 --> 00:22:18,400
to take tiny tiny bits of 
minerals. 

424
00:22:18,400 --> 00:22:20,900
So 50 nanometers. 
And we were talking about 

425
00:22:20,900 --> 00:22:26,200
microns before so much, much 
smaller and peel off atom by 

426
00:22:26,200 --> 00:22:31,600
atom, the structure of that 
mineral and all Those atoms then

427
00:22:31,600 --> 00:22:35,100
fly off into a detector and how 
they hit the detector. 

428
00:22:35,100 --> 00:22:39,300
You can then use to unravel 
where that Adam was in the 

429
00:22:39,300 --> 00:22:41,800
structure originally. 
So it's a very, very high 

430
00:22:41,800 --> 00:22:45,000
powered Mass spectrometer. 
And so, you can actually see, 

431
00:22:45,000 --> 00:22:49,600
for example, where the lead is 
sitting in a Zircon, and we're 

432
00:22:49,600 --> 00:22:52,700
probably the original uranium 
was sitting as well and whether 

433
00:22:52,700 --> 00:22:55,700
that led has moved. 
So you can actually match the 

434
00:22:55,700 --> 00:22:58,600
original element that decayed 
into the new element that 

435
00:22:58,608 --> 00:23:02,600
decayed atom by atom by atom. 
And that is just phenomenal. 

436
00:23:03,700 --> 00:23:05,500
Claire Warren, thank you very 
much. 

437
00:23:05,800 --> 00:23:09,500
It's been an absolute pleasure, 
thank you for more about geology

438
00:23:09,500 --> 00:23:12,500
b, as well as pictures and 
diagrams that illustrate. 

439
00:23:12,500 --> 00:23:16,100
This podcast, you can go to 
geology B.com