(intriguing acapella music)
(rhythmic clapping)
- Good afternoon.
Good afternoon and welcome
to Science Sundays.
I'm your host, John Beacom.
Today we have a great event,
and I see it's been very popular,
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people still streaming in.
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So today our speaker is
Professor Robert Hazen
of the Carnegie Institution
in Washington, D.C.
He is both a distinguished
researcher with over 400
scientific publications
and a long list of awards,
he's also a distinguished educator
and expositor of science,
with over 25 books,
many of them intended for the public.
He's renowned for both
his scientific research
and his sharing it with the public,
which is a perfect fit
for Science Sundays,
so let's welcome Dr. Robert Hazen.
(audience applauds)
- Thank you John, and it's
such a pleasure to be here.
We live on a planet of
breathtaking beauty.
From the proximity of our solitary moon,
we see that blue marble, we
see the swirling white clouds.
And we know we live on a planet of change.
And so it's logical to ask,
has Earth always looked like this?
Has it changed, and if
it has changed, how,
by what process, what
were the stages of change?
What is the story of Earth?
Today I wanna explore that question.
I wanna do it from the perspective,
my unique perspective as a mineralogist.
And that may seem strange, we're looking
at an entire planet and
I'm talking about minerals,
crystals, and yet I will argue today
that those crystals, those minerals,
are the best preservers of our past.
They're robust, they last
for billions of years,
they carry hints about
what's happened in the past.
So today what I wanna
do is look at this idea,
the Earth has transformed
repeatedly over billions of years,
that life and rocks have co-evolved.
It's part of the same story.
And I also wanna emphasize the theme
that data-driven discovery
is gonna be a key
to understanding that great history,
the four and a half billion years.
Much of what I'm gonna tell you about
has been funded by the Sloan Foundation,
the Keck Foundation, the
Templeton Foundation,
and I invite you to go to our website,
dtdi.carnegiescience.edu to see many
of the images and some of the stories
that I'm gonna be describing
to you today in more detail.
I'm also thrilled that I'm now part
of a growing international network,
something like 67 different
institutions in 20 countries,
hundreds of researchers,
this is the network
of our growing Deep-Time Data
Infrastructure Initiative
where we're trying to
understand Earth history
through deep-time, through
four and a half billion years
by looking at a variety of data sources.
So that's where we're
gonna be focusing on today.
I wanna do three things, I wanted to look
at a field called mineral evolution,
it's been around for about 10 years
and it looks at the diversity
and the distribution
of minerals on Earth through
four and a half billion years.
I also wanna look at mineral ecology,
which looks at the
diversity and distribution
of minerals on Earth
today, which allows us
to predict some of those minerals,
where we might find new
deposits and so forth,
and finally, a really fascinating field,
sort of the social lives of minerals.
Mineral network analysis,
where we try to understand
the interrelationships of
many, many different kinds
of minerals as they exist together,
and this idea of network
analysis allows us to do that.
So we have several overarching
scientific goals here.
We really want to document
the history of Earth,
we wanna use minerals in order to do that.
We also wanna compare the evolution
of different planets and moons,
and we're extremely interested
in the co-evolution of life and minerals.
Now, all of these discoveries,
right from the beginning,
they rely on deep-time data resources.
So I wanna pay homage
to some of my colleagues
who have been spending
decades, often unheralded,
in trying to build data
resources that we use.
One of the most important for mineralogy
is called the RRUFF
database, rruff.info/ima,
and the RRUFF database has
lists of all the different
known mineral species,
about 4,500 of those.
You can search by
chemistry, you can search
by structure type, and
what we've been adding
is something called a
mineral evolution database
where we have information
on a mineral species,
a locality, and an age, and
we now have 185 thousand
different localities.
Now I'm gonna be using
this name mineral species
quite a bit during this talk.
This idea of mineral species,
it's not a very familiar idea,
you could talk about biological species,
but in mineralogy, it means
that it's naturally occurring,
it has an end-member idealized
composition like SiO2,
it has an idealized crystal structure,
it has an idealized
end-member composition,
and it has to be naturally occurring.
And so if you have a crystal that you find
just walking out in the woods
and it's new combination
of crystal structure and composition,
that is a new mineral species,
there're about 5,400 known species,
and I'll be talking about species
throughout tonight's talk.
Okay, so we now have also
the mindat.org database.
This is run in large part
by mineral collectors
around the world, and
they have over a million
mineral locality pairs,
so if you wanna know
where a particular mineral
occurs, this is where you go.
We also use EarthChem,
that's a huge amount
of geochemical data, the analyses of rocks
and other geological materials,
millions and millions of
analyses from around the world.
Kerstin Lehnert at Columbia works on that.
We have Macrostrat, which is the different
sedimentary columns of rocks,
that's another huge database.
Also the Paleobiodb, all the
fossil data that's out there,
so these are databases that
are tremendously valuable,
open access, available to everyone.
We even use the protein databank,
which has protein structures
through deep-time,
and you can look at protein structures
and see how they've
evolved, so all of these,
that's the raw material that we use.
So let's begin, let's
look at mineral evolution.
Mineral evolution, as
I said, it's the study
of the diversity and the
distribution of minerals
through deep-time.
How has mineralogy changed
on Earth's surface?
So the idea here is that
we study the difference
in the diversity, how many
different kinds of minerals,
but also the distributions,
the abundances of minerals,
the compositional ranges,
and that includes trace
and minor elements, not just
the idealized end-members,
and we also look at the
grain sizes and shapes.
As a mineral collector when I was young,
I loved the crystals
in the different forms
and the different colors,
something that professional
mineralogists have kind of abandoned
when they talk about minerals,
but we're coming back to it
because that's information.
If we wanna understand the
past, we need information.
So we look only at the shallow depths,
because these are places where
we're most likely to study
minerals on Earth, it's
what we're gonna be able
to see on other planets and moons,
and also very importantly, it's
where there's an interaction
with biology, and you'll see that biology
plays a huge role in the
evolution of minerals.
So the basic bottom line is that you get
new mineral species when
you have new combinations
of physical, chemical,
and biological processes.
I have to defend the use
of the word evolution.
I'm sure there's some people in here
that are trained in biology,
and sometimes biologists
are very offended, you can't
use the word evolution,
that's our word, it's not your word,
and I disagree, I disagree.
This idea of evolution
has changed over time,
it's been used in many,
many different fields.
We talk about the evolution of planets,
the evolution of meteorites,
the evolution of stars,
the evolution of galaxies,
"Evolution of the Igneous Rocks,"
so you can certainly talk
about change over time,
but it means something more than that.
There's an implication in evolution
that things get more
complex, more patterned,
more diverse, and that's
certainly true for minerals.
There's also an idea of congruency,
the idea that each step follows logically
from the step that came before,
so there's a sequence, it's
not just a random thing,
but it's not this.
(audience laughs)
And please just erase this from your mind,
it's not Darwinian evolution.
Mineralogy has its own
set of selection rules,
but it's not the same.
Okay, so to show you
how this was different,
this idea was introduced
in 2008, mineral evolution.
And this is a question
that we asked at that time,
and we looked in vain
through hundreds of years
of mineralogical literature.
What was the very first
crystal in the cosmos?
When and where did the first crystal form
after the Big Bang?
And it seems like such
an obvious question,
everybody asks about the origin.
If you're talking about a field,
you talk about what's the first,
what's the earliest, what's the,
and yet we couldn't find this answer.
So think about it, what was the
first crystal in the cosmos?
You know, think about the Big Bang,
13.8 billion years ago,
incredibly hot, incredibly dense,
there aren't even any atoms yet
so it couldn't have been
right at the beginning,
and then things expand,
they expand and cool,
they expand and cool, and
then you have the first atoms.
That took a while before
you got the first atoms,
and then it was mostly hydrogen and helium
which are gasses and
they don't form crystals,
so it's not then, so what happens next?
Well, you maybe have to
wait a 100 million years
til you form the first stars,
but stars are much too hot.
I mean, they're hydrogen and helium,
but stars start to make other elements,
and they make the heavier elements,
things, carbon and oxygen
and silicon and nitrogen,
the things that form minerals.
And so what we suspect is
that the very first minerals
occurred when those stars exploded.
So supernovas, imagine
what happens, the envelope
is now element rich, and
it expands and it cools,
and so you can get condensation.
And we think the very
first mineral was diamond.
And the reason is is because carbon
is an incredibly abundant
element in those early stars,
and it condenses at the highest
temperature, 4,400 Kelvin.
Now if you cool down a
little bit from there
to 4,000 Kelvin, still pretty hot,
you can make the stabler form, graphite,
and so we think these are the first two,
and indeed, there're about
a dozen in all minerals
that we think came in
this earliest period,
formed basically from stars.
Minerals formed around stars.
These are called the ur-minerals,
they're all very, very
high temperature minerals,
they all form from common elements,
and if you look them,
here are the 10 elements
that are most abundant
in those early minerals,
and so maybe the question
for mineral evolution
can be posed in a different way.
How do you go from 12
different mineral species
with 10 essential elements
to what we have today,
over 5,400 mineral species
with 72 essential elements?
That's the story of mineral evolution.
And we tell it in a series
of 10 different stages
of mineral evolution.
So here's the story,
you start with a nebula,
a nebula of dust and gas.
This is a vast expanse of space,
if you looked at our entire solar system,
it would be much smaller
than that red dot.
So there's thousands of star systems
that can form in a place like this,
and we were one of them once upon a time,
four and a half billion years ago.
And that early period of dust
and gas, most of it of course,
98% or more, went into the central sun,
and that's getting larger and larger
and the temperature and
the pressure is increasing
as the sun forms by gravity.
But the surrounding dust,
it's very hard to attract
these dust grains by
gravity, they're too small,
but they do stick together
by electrostatic forces.
In fact you have nebular dust bunnies,
and just, I mean it's just
like underneath your bed
where you haven't swept recently.
And what happens then is
the sun begins to ignite
and flashes of heat spread out.
And also nebular lightning can do this.
You take those dust
bunnies, you heat them up,
and they melt and they come down
to little tiny droplets called chondrules.
So the first stage in
mineral evolution then
is these most primitive meteorites
which contain the tiny
droplets that have been melted
and fused together and the
chondrites come together
and you form things that
are the size of a basketball
and then the size of this room,
then the size of the campus,
and then the size of the state of Ohio.
As you get larger and
larger, you start getting
other processes though, so
there's about 60 minerals
in these most primitive chondrites,
but when they come together and
start forming planetesimals,
there're new processes,
processes of heating,
processes of aqueous alteration,
impacts as large object hit each other
with very, very high velocities,
and so you now can make up
around 250 mineral species.
That's stage two, all
the different meteorites
that fall to Earth today contain
about this number of minerals.
And then stage three, that's
when you have a planet
like Earth, and in fact, all the planets
in our solar system, Mars
and Venus and Mercury,
they all get coded by this layer,
this outer layer of a black,
dense rock called basalt.
Now, if that basalt is wet,
you can have all sorts of minerals,
new kinds of ices, new kinds
of clay minerals and so forth.
If it's dry like Mercury and the moon,
we think we're maybe limited
to about 300 mineral species,
and we think that's the
end point of these worlds.
If you have something like Earth,
you can get up to 420 mineral species
pretty easily with these wet minerals,
hydroxides and ices, clays and so forth,
and we think that may be
the end point of Mars.
We're exploring Mars right
now with the Curiosity Rover,
we're looking at the mineralogy,
and everything we've found so far
fits very well into this
model of a stage-three planet
that hasn't gone very far.
Now Earth has other tricks in mind.
When you take a large planet like Earth
that's covered in basalt
and if that basalt is wet
and if it starts to melt from
the heat coming from below,
you generate an entirely new
kind of rock called granite.
And the thing about
granite is it concentrates
all sorts of rare elements
so you start making
new minerals, minerals of
things like boron and beryllium,
lithium, there's tantalum
and even caesium,
concentrations of extremely rare elements
in these things called pegmatites,
and that gets you up to about
a thousand mineral species.
So here we've gone from the 12 ur-minerals
to 60 to 250 to maybe 400,
now we're at a thousand,
and Earth has even one
more trick up its sleeve,
that's called plate
tectonics where as you take
slabs of Earth's crusts and upper mantel
and subduct them down
into the hot interior,
they begin to melt, and huge volumes
of Earth's crust and
upper mantle are affected.
Fluid rock interactions generate
all sorts of new
concentrations of elements.
They lead to new kinds of metal deposits,
hundreds of new sulfide
and sulfosalt minerals.
You get new high-pressure
suites of minerals
that are brought to the surface
by plate tectonic activities
as mountain building occurs.
And so these kinds of processes
we think can get you up
to 1,500 mineral species,
and we've now gone through
five of our 10 stages.
But think about this, we've
made about 1,500 mineral species
through purely physical
and chemical processes.
But we have more than
5,400 known on Earth today,
how can you possibly do it?
And the amazing answer,
the surprising answer,
is the reason is life.
What Earth does in terms
of making new minerals
is primarily a biological phenomenon,
that's an astonishing
statement, and it's true.
Now one of the things
that amuses me about this
is that there're many, many scenarios
for the origin of life
and virtually all of them
require in one way or another minerals.
Maybe sulfide minerals or
clay minerals or borates
or something else, and minerals
play all sorts of key roles.
They help to protect
molecules as molecules
go in a mineral surface
and get sort of protected
from the elements surrounded,
they can bound to the surface.
You get catalysts of
new kinds of molecules.
For example, the production of
ammonia, essential for life.
It happens on minerals' surfaces
through catalytic reactions.
You have different
selection and absorption
of molecules, concentrating
molecules on surfaces.
So minerals play all these roles
that are critical to the origin of life.
But by the same token it turns out
that further mineral
evolution depends on life.
This is what we mean by the co-evolution
of the geosphere and the
biosphere, of life and rocks.
Stage six, this is when
life has gotten established,
the earliest, most primitive
microbes actually eat rocks.
They take the chemical potential energy
of a rock in its surface,
and they use that energy
as their metabolic source.
So we have all sorts of rocks
that are being precipitated
in new ways, but we don't have
a lot of new mineral species.
We don't think there're
a lot of new minerals
that result of this.
By the way, these are the culprits,
they're called Archaea,
technical name chemolithotrophs.
They're microbes that eat rocks,
and there are lots and
lots of them on Earth today
and they do all sorts of
fascinating chemistry.
But what really was the game changer
was photosynthesis and
the production of oxygen.
(clears throat) Excuse me.
2.5 billion years ago, Earth turned red.
It turned red because these
photosynthetic microbes,
oxygen in the atmosphere rose gradually,
and as it did so, the
surface rusted, essentially,
and many, many different kinds
of minerals arise from this.
You can find the largest
iron deposits on Earth
from this age because the oceans,
which were previously rich in iron,
started getting oxygenated,
the rust came out of solution,
fell to the ocean floor and
made these huge deposits
of iron oxides.
And our hypothesis, about two-thirds
of all the mineral diversity on Earth
is the consequence of this oxygenation.
What it means is that most
of the beautiful minerals
that you see in museums would not occur
were it not for life.
The copper minerals, the
blue and green minerals,
I would say two-thirds of
those simply wouldn't form.
Roughly 90% of the uranium
minerals wouldn't have formed,
and same thing's true for manganese
and for nickel and iron and cobalt
and molybdenum, arsenic,
and you can go on and on
down the list, any of those minerals
that are sensitive to how much oxygen
there is in the atmosphere,
suddenly you have an explosion
of new species after that
great oxygenation event.
And so this is one of
our central hypotheses
that this represents the
single most important
diversification mechanism.
Occurred about two and a
half billion years ago,
and that's this punctuation event
in the evolution of minerals.
Stage eight is a period about
a billion years after that
in which the oceans gradually got
more oxygenated from the
surface exposed to the air,
deeper and deeper and deeper, until today
when the oceans are completely oxygenated
from top to bottom in most places.
Don't think there were
a lot of new species,
we estimate roughly 4,600.
There then was a period about
800 to 600 million years ago
when Earth went through a
convulsion of climate changes
from extreme ice box conditions
where it may have been covered with ice
from poles to the equator,
alternating with hot house events
where you had extreme warming.
Up and down and up and
down, and during periods
when ice was the dominant
phase on the surface,
that's the dominant mineral.
Ice is H2O in a particular
crystal structure,
so this is one of our
5,400 mineral species.
And then finally the stage 10,
this is the green Earth stage when life
moved to land, when
life learned how to make
its own shells and hard
parts out of minerals.
So one of the things that happens
about 400 million years ago
was the formation of roots
radically changing the
mineralogy of the land.
Root systems that we now see on Earth,
they're vast and they
create huge quantities
of clay minerals for
example, breaking rocks down
much more efficiently than ever before.
We also have all sorts of
biologically precipitated shells
and teeth and bones and other minerals
that have transformed
the surface of our globe
That's stage 10.
And that's the story of Earth.
And it's a nice story, it's
a story that feels good,
we see progression, we see things going
from a very early primitive stage to us.
And yet for me, even 10 years
ago when we introduced it,
it was strangely unsatisfying.
Because it's like a just-so story.
It's very qualitative, there's
no meat on these bones.
And we can talk about these--
and furthermore, we know that parts of it
are just simply wrong, I mean,
wrong in the sense that it's not stage one
and stage two and stage three,
stage three, making basalt,
that's going on today,
stage four, making granite,
that's going on today,
stage five, plate tectonics,
well that's still happening,
so this isn't like one after another,
it's like they're all kind of--
there's still microbes of
all sorts making minerals.
It gets much more confused,
the chronology is not just
a simple linear thing
here, and so how can we be
more quantitative, and
that's where data comes in.
That's where data-driven
discovery comes in so important.
So what I would like to do is talk now
about a quantitative, data-driven approach
to understanding the
diversity and distribution
of minerals, and by extension,
the evolution of our planet.
So we're gonna be looking
at these data resources,
and first I wanna look
at mineral evolution.
Now, the raw data for mineral evolution
is a mineral at a locality with an age.
And we've been building
these data resources,
as I mentioned, we have
185,000 data points now
for what are called the transition metals,
the things that are, like iron and nickel
and copper and cobalt
which are very abundant
and play a role in biology and so forth,
we have about 60,000 data.
And what we see when we look at a plot
that goes back four billion years,
this is modern times, going
back by billions of years,
this is the number in
each 50 million year bin,
how many mineral locality
do we have in that bin.
And what you see here
are a couple of things.
You see peaks, it's not
just smooth and continuous,
and you also see a change in the colors,
and those colors represent
how oxidized the surface was.
And we're gonna see it change,
these are the two first
order things that we see.
So the first change
has to do with we think
the Supercontinent Cycle.
Earth's continents have
shifted dramatically
over four billion years.
Sometimes they come together
and form mountain ranges,
sometimes they break apart
as they're doing today
in most parts of the world,
and these plate tectonic motions,
whenever you have a
mountain-building event,
whenever the plates come together
to form what's called a Supercontinent,
then you tend to have more
mineralization occurring,
both because mountains form minerals
and they also preserve minerals.
And so when you look at that
graph I just showed you,
here are these five stages where you have
Supercontinent Cycles where all
the continents have come together,
and in each billion-year interval,
the highest peak is always
underneath one of these episodes.
So the Supercontinent
Cycle clearly is reflected
in the mineral evolution of our planet.
Now the other thing that happens
has to do with the oxidation,
and one of the biggest sensors
of oxygen is manganese minerals.
Manganese minerals can
occur in a reduced form,
a less oxidized form in this 2+ state,
but in a more oxidized or
kind of a manganese rust
if you will with 4+ manganese.
Dan Hummer, my colleague at
Southern Illinois University,
has plotted all the manganese minerals
back through four billion years,
how many you see, but also the colors
indicate the manganese oxidation state,
and the most oxidized,
this purple ban band here
you see is much, much
stronger towards recent times.
So if we do this with lots
of different minerals,
we see an increase in oxidation state.
So this allows us then to look
at minerals in a new
way through deep-time.
We can do various kinds of nice imaging,
you can compare all of
these different metals,
iron, nickel, cobalt and so forth,
you can see how they are similar,
how they're different in some ways,
there's a vast amount of data represented
in a figure like this.
Indeed we can do this for
the entire periodic table.
Every one of these little boxes
is a different chemical element
with a high resolution map of the minerals
just containing that particular element.
So a huge amount of data
here that we're exploring now
and we're continuing to build.
So that's the mineral evolution story.
I think what you can see is
that the qualitative tale
that I told you at the beginning
is now being bolstered but also modified,
and we're seeing much
more quantitative detail
by using data.
A second way of thinking about minerals
is thinking about what's on Earth today,
what are the diversity and distribution
of minerals on our planet today?
And that's mineral ecology.
So what we once again do is
we employ these huge databases
that list minerals and their
localities across the globe.
To give away the punchline,
what we've discovered
is the distribution of minerals on Earth
is very much like the
distribution of words in a book.
What we call lexical statistics.
And what we find in a book
is that most of the words
you see are kind of
common, a, and, and the.
But there are many, many more rare words
that are used only once or twice
gathered throughout the volume,
and it's those rare words
that tells you the authorship,
that could tell you the genre of book.
So you have an unsigned manuscript,
you can analyze it looking
at these rare words.
So how are minerals distributed?
A few common minerals dominate,
but in fact it's the rare minerals
that tell us much, much more
about Earth's diversity,
and those rare minerals
follow what's called
a Large Number of Rare Event
frequency distribution.
Let me show you what that means.
On the horizontal scale
here, minerals that are known
from only one locality, one
locality only on all of earth,
and there's over a thousand minerals
that are known from one locality.
For exactly two localities,
there're about 600.
Three, four, five, the number decreases.
In black is the observed data,
in red is the model that we have,
this Large Number of Rare Event model.
And you can go and you can basically plot
all different kinds of
minerals in this way.
The neat thing about a model like this
is it allows you to make
an accumulation curve.
Accumulation curves have
been used in biology
for a long, long time.
Imagine going into a woods
you've never seen before
and you wanna know how
many different species
are in that woods.
Well you go to the first
tree and you write it down
in your notebook, that's
new for your list.
And the second bush and the second tree
and the second plant,
and third, fourth, fifth,
they may be new too, but eventually,
you're gonna come to
one you've seen before.
But then you're gonna
keep building your list.
Gradually as you look
at more and more plants,
you have fewer and fewer new things
to add to your list, and
that's an accumulation curve.
So you don't have to look
at every single plant
in a forest to extrapolate out
to tell you roughly how
much diversity there is.
We do the same thing with minerals.
By the way, you can do
this with genomes as well,
DNA counts.
So here's the mineral version of this.
This is the number of
mineral locality pairs data.
So quartz from Columbus,
Ohio, that's one point,
and we've got, you know,
over a million today of this.
And then the vertical scale
is how many different species
do we see, and when you start out,
you're finding new species rapidly.
But the more you look, the
fewer new species there are
and the more you're just seeing things
you've already found before
someplace else on earth.
Now when we first did this back in 2014,
that was the data point,
you can extrapolate it out,
and it turns out when you extrapolate it,
there are thousands of missing minerals.
Something over 4,000 missing minerals.
And using tricks, we can actually predict
which one of those minerals there are.
For example, we can say
how many of these minerals
contain the element sodium,
and when we do that,
well here's carbon, the
frequency spectrum for carbon.
What you find here is
that's the data as of 2016,
we did this analysis,
but you can extrapolate
into the future and there are
145 missing carbon minerals.
And then we can say how many
of those carbon minerals
have sodium, we can look up the known
sodium carbonate
minerals, we can then look
in other reference books and say well,
there're are these other
two sodium carbonates
that are extremely well-known
as synthetic phases,
they should occur in nature too
but nobody's ever described them,
so we predict that they're missing,
we go out and we look for them.
Here's Lake Natron and Ol Doinyo Lengai,
these are both carbonate-rich
volcanic zones in Tanzania.
And you can actually go and look,
and the reason those
minerals hadn't been found
is because they are all sort
of white crumbly powders,
they all look pretty much alike,
they're not big beautiful
crystals that you'd pick up,
and so you just have to find
the right speck of powder
and analyze it.
And I predict we're gonna
find that very soon.
And so we wrote this up,
we have this prediction
of the missing the minerals of carbon,
and we started a carbon mineral challenge
a few years ago just for fun.
This is part of something called
the Deep Carbon Observatory,
we're trying to understand
all the different properties and phases
of carbon on earth, and
we've predicted there's more
than 100 missing carbon minerals,
we should go out and find them,
and we started an international search.
The first one that was
found in this search
is actually one that we'd
predicted in our paper,
there's another one that we predicted.
We didn't predict every
new mineral though.
One of them, tinnunculite,
was not on our list.
It's an organic mineral, it's one that,
we did predict there to be eight
new organic minerals, but
we didn't predict this one,
and you may understand why when I read you
the description, little
hard to read there.
"Tinnunculite only
exists when the excrement
"of a falcon bakes in the hot gases
"of a coal fire."
(audience laughs)
Okay so, I admit we didn't predict that,
but that's one of the wonderful
things about mineralogy,
it turns out about 50% of
all the minerals discovered
are completely new crystal
structures to science,
they've never been synthesized
in any form anywhere.
So minerals are a wonderful
entry point to new materials.
That's tinnunculite, okay.
So in mineral ecology,
we can actually predict
for the very first time
the missing minerals.
And you know, it's interesting,
common minerals, the things
that make up the normal rocks,
they define an Earth-like planet.
And every Earth-like planet we think
are gonna have the same common minerals,
but it's the rare minerals that describe
the uniqueness of Earth,
and we can actually show
statistically that the
combination of minerals
we have on Earth probably is unmatched
on any other planet
anywhere in the cosmos.
The really rare ones in that combination.
And this is another
really fascinating idea
we're trying to explore,
this idea that the LNRE redistribution,
we don't see it on Mars, we
don't see it on the moon,
it appears this may be a biosignature.
So that's kind of cool, something
if we go to another planet
and find a LRNE
redistribution of minerals,
maybe that's giving us a hint.
Okay, and finally,
mineral network analysis.
You know, we're trying
to understand minerals
and their distribution
and their diversity,
how they coexist, what kind of
patterns they form in nature,
and one way you can do this is by looking
at many, many different
minerals at the same time
in what are called network analysis.
You've probably heard of network analysis
as used for social networks and analyzing
how people interact, well
minerals are very much the same.
So imagine this, each of these little dots
or nodes is a different mineral species,
two minerals that are
found together form a link,
and then you make a network.
So image here's a granite,
a common rock type,
you may have a granite kitchen countertop
that's been polished, then
you'll have several different
minerals in that, they coexist,
and so if you have a
network, here's a network
of all the minerals that are found
commonly in what are called igneous rocks,
37 different minerals, and the
subset here, this is granite.
And there's another subset up here,
that's a rock type called olivine basalt,
here's a rock type called
nepheline syenite and so forth,
all of the field of igneous petrology,
which you can spend a
year studying in college
and spend your whole life delving into,
it's all represented here by one diagram.
So that's the power of network diagrams,
there's so much information embedded here.
We can do this in a more elaborate way,
this is called a force-directed graph
where now we have 51 different minerals
that are found in igneous rocks.
Each circle represents a mineral,
each link is like a spring in this case,
and this spring is very tight
if the two minerals always occur together,
there's either no spring
or a very loose spring
if the minerals rarely occur together,
and you can actually look
at this whole diagram
and convey huge amounts of information.
So for example, the node size here
tells you whether it's a very
common or a rare mineral,
the spacing says how
much they occur together,
the colors give you something
about the mineral group
in this particular case,
and you can actually play
around with this and go online
to our website dtdi.carnegiescience
and you can download this and you can see
how each mineral is
connected to everything else.
This is 51 different minerals,
that means it's 50 dimensional
space we're exploring,
which is really hard to imagine,
but when you start playing around with it,
you start seeing trends.
We can do this for
different planets and moons,
we can do the networks, and what we find
is the planetary networks are different.
Earth's is distinct and it may
be a biosignature once again,
just the network geometries.
This is a network,
little more complicated,
with 243 copper-bearing minerals,
the most common minerals of copper,
in this case colored by composition,
so these are minerals that
are called sulfides in red,
we have minerals that
are oxides and carbonates
and so forth, like malachites
and azurites in blue,
these are what are
called sulfate minerals.
You see they segregate, and again,
this is the work of Shaunna Morrison,
you can look at a very common mineral
like chalcopyrite that's
connected to almost everything
in the diagram and the diagram
is very much controlled by that.
The same thing's true for
the very common mineral
malachite, that's that beautiful
green semi-precious stone
you may have seen
polished in various ways.
One thing that surprised me
was this green circle here
is native copper, and I would've thought
native copper would've been
in the more red zone here,
these sulfides, but
it's smack in the middle
of all the blue things,
they're much more connected to those.
So there're little things like
that you can start learning.
You can spend hours and hours and hours
studying this if you're a
copper mineral specialist,
that's something you might do.
Here's Dan Hummer's work on manganese,
I mentioned that before.
In this case, this's a
three-dimensional network
in which the manganese
minerals are colored,
and we learn new things,
these are all the known
manganese minerals and how
they're connected to each other.
Turns out there's this
little clump way up here,
mostly red, that means they're mostly
divalent manganese phosphates
that occur in pegmatites.
Here's another clump over
here, again mostly red,
these are high-pressure
metamorphic manganese minerals,
and then this thing here
which is technically called
a hairball,
(audience laughs)
which is all the other stuff,
and these are the near-surface
manganese minerals that
just kind of are a mess
if you know anything about manganese,
but some of us love them.
And you can make this into
a three-dimensional map,
you can rotate it, this is online again,
you can go and see this and you can look
at each individual node and
see what minerals are in there.
You can explore all the
different interconnectedness.
You can zoom in and look at
specific regions of this.
The amount of information
that's contained here
is just unimaginable.
This is hundreds of years of research
on manganese minerals
and how they co-occur,
all presented in a single graph.
But wait, there's more.
We can do bipartite
networks, bipartite networks
have two different kinds of nodes.
Here's one that might be familiar to you
in terms of the spread of disease,
a viral disease where
these might be airports
or hospitals and these are people,
men and women colored differently
and how they've traveled
to different places
and the virus spreads and it spreads
and you can imagine how that works.
We can do the same thing with minerals
where we have the mineral species
in colored circles,
like very common calcite
with a big circle, also colored red
for the commonest minerals.
Little less common is witherite,
a smaller circle a little more toward
the orange or yellow part of the spectrum,
and then the greens and
blues on the outside
are the extremely rare
minerals like kozoite.
So what you're seeing here
is we go from minerals,
the sizes and in this case the colors
also tell you whether they're
common or rare minerals,
and then in black this U-shaped
thing are all the localities
where those minerals occur, the regions.
Turns out that the two regions
where there're the most number
of carbon-based minerals
are the Kola Peninsula in Russia,
the La Poudre quarry in Quebec.
And something that's really amazing here,
look at the symmetry that
goes right down here.
Now, no one's ever seen a network diagram,
a bipartite diagram with this symmetry.
We've talked to lots of
people who do the mathematics
of networks and they're
utterly fascinated by this
'cause this seems to be something
embedded in the natural world,
something about the distribution
and diversity of minerals
which forms this beautiful
flowering of species,
the really common ones in the middle,
the rare ones on the
outside, this U shape.
And we wondered, well how about going
into higher dimensions,
so we can now do this
in three dimensions.
There's a three-dimensional
rendering of this,
in which case the gray
circles are the localities
and the colored circles here
are colored by structure type,
so it's a little bit different,
and you can rotate this, again,
you can zoom in and you
can see the properties,
and it turns out that
those gray localities
now form a kind of vase-like
structure, an inverted vase.
And you can see that even better
'cause we can do this with
virtual reality glasses,
you put on the glasses
and you can actually walk
into the network and manipulate it,
and you see in red are the localities,
and you see that vase-like structure,
and in blue are all the
minerals on the outside.
So we're now actually
using virtual reality
to explore the diversity and
distribution of minerals.
Ah, it's fun, it's really fun,
go to the website and try
this, dtdi.carnegiescience.edu.
But if you are like me,
you may be asking yourself,
wow, those are sort of cool,
they're kind of pretty,
maybe they'd be fun to play with.
Is there anything there?
Is there anything scientific here,
I mean, is this just a trick?
And you have to ask that question,
and for us, I think they're two answers
that give us a very strong feeling
that there is something real here,
there's something that's very compelling.
One is that these
networks have turned out,
embed information that we don't include
when we make the network,
and I'll show you what I mean in a second.
And the second is something
called affinity analysis
where we can actually make
predictions about what's missing.
Let me show you what I mean.
So here's that copper network diagram,
copper mineral network
diagram I showed you before.
Remember, it's very strongly
clustered by composition,
there's sulfides, here's
oxides, here's sulfates.
Well, what it's telling
us, the only information
that went into making this diagram
was which minerals coexist
with which minerals,
and then you set up a bunch of springs
and it comes to some kind
of equilibrium arrangement.
But there's a very, very
strong compositional axis
through this diagram, going
from very high activity
of oxygen down here to very
low activity of oxygen,
'cause these are things
that are gonna be reduced
or not rusted and these are things
that are increasingly
rusted as you go down here.
We didn't include that
compositional information
when we made the diagram,
but it's embedded in there anyway.
Here's the sulfur axis, very
low sulfur, very high sulfur.
Again, we didn't include that information,
but it's embedded in the diagram.
Even more intriguing has to do with time.
It turns out all of these diagrams
have a time axis embedded in them,
even though we didn't say anything
about the age or the minerals
when we made the network.
To give you an understanding of this,
let me talk about fossils for a change,
because fossils, you can sort of see
why there'd be a timeline
running through a network.
This is all the different
kinds of trilobites.
The genera of trilobites,
I love trilobites,
and when I look at this diagram,
they're colored according to
the eight different orders
of trilobites that occur.
There's the Olenoids,
there's the Ptychopariids,
that's the Asaphids, the Phacopids,
Lichids, Proetids, these things that,
and when you look at these,
if you've collected trilobites
like I have since I was--
in Ohio, I found my first trilobite,
in Cleveland, Ohio when
I was nine years old,
so this is really exciting.
When you look at this, that's a timeline.
From the very earliest,
the very late stage.
Indeed, we can animate this information
in a way that's very, very powerful
because it not only shows that evolution
but it shows the mass extinctions.
So if you look, it's very
hard to see up there,
525, 520, 550, that's how
many million years ago.
These are the different, for
each one million year period,
which trilobite genera coexist,
and there was a mass
extinction right there.
And so it changes gradually for a while,
it changes gradually, and we'll
see couple other big jumps,
and we're now at about
420, we're getting close
to another mass extinction,
wait for it, wait for it.
Sort of just sits there not doing much,
and then bang, there it goes, okay.
So this, you can see, this network diagram
was only built by knowing
the coexisting genera,
in this case though, with the ages.
So how does that relate to minerals?
Well, here's the same
diagram you just saw,
the bipartite diagram of carbon minerals
with the localities in black,
the minerals in colors,
but now they're colored by
the earliest known occurrence
of that mineral.
And you see how the hot colors
are down here concentrated,
as you go out, they get lighter
and lighter and lighter.
There is a time axis embedded in here,
even though there was no time information.
Well, this suggests to us that as we start
looking at these networks
and especially when we start
looking at higher dimensions,
not two dimensions or three,
but in 20 or 50 or 100 dimensions,
we'll start being able to see trends
within the data that
give us additional keys
about the evolution of minerals.
Alright, so that's one
reason I think these networks
really mean something,
they embed information.
A second reason is because
they're very closely related
to something called
market basket analysis,
or affinity analysis, which
is a way of predicting
that we've never used before.
Let me give you an example.
I went on Amazon a couple months ago,
and I wanted to buy a copy
of Jonathan Lunine's book
called Astrobiology.
There was only one used
copy, it was 300 bucks.
I decided it wasn't worth paying 300 bucks
for this, I could get it at the library,
but within one second, this is what I got.
"Your recently viewed items,"
"inspired by your rousing
history, we recommend,"
and so they recommended a group of books.
And I've no idea why they
picked some of those,
but they know, they have
this incredible algorithm
where they have hundreds
of millions of buyers,
they have billions of sales,
they know what you like,
they know what you don't like,
and they can put all
that information together
and use this, something
called affinity analysis
or market basket analysis
to predict what's missing.
So the same math applies to minerals,
we know which minerals like each other,
we know which minerals
don't like each other.
We can look at a locality
that has a certain number
of minerals and say, well
what's the missing mineral
at this locality?
Or here's one of my favorite minerals,
where do I go on Earth to find it
where it's never been found before?
So if you can find groups
of minerals at a locality,
you're more or less likely
to find other minerals.
It's the same thing as buying
books or any other product.
And mineral networks
reveal these associations.
The first test of this
was by Jolyon Ralph,
the person who runs the
Mindat organization.
He said I love the mineral wulfenite,
it's a beautiful mineral, it's rare,
I wanna find a new version.
He went to Mindat, he looked
at different localties,
and here's Cookes Peak,
Cookes Peak in New Mexico.
There was a list of minerals,
but it didn't include wulfenite,
and he said, there's
gotta be wulfenite there
based on my statistical analysis,
so he sent collectors out there,
and low and behold, they found wulfenite.
So this same technique could be applied
to finding the next big copper mine,
next cobalt mine, or
maybe some rare minerals
that we haven't ever found before,
but we can say this is where you go
to find that rare mineral.
This is the technique, and so big data
is gonna allow us to do that.
So my conclusions I
think are what I stated
as being, you know, the
analysis of visualization
mineral data through
deep-time, through space,
they reveal all sorts
of new aspects of Earth,
that Earth's transformed repeatedly
over four and a half billion years,
that life and rocks have co-evolved,
and we can predict for the very first time
the existence of minerals
and other natural objects.
This approach is about to transform
our understanding of Earth.
As I said at the beginning,
we live on a planet of change,
and many of those change
that are occurring these days
seem very rapid, they seem unsettling,
we're not really sure
what the future holds,
but I think if we're going
to understand that future
and be able to predict
it, one of the key things
is to be able to understand
the past as well.
So with that, I thank you very much.
I hope there might be a chance
to answer some questions.
Appreciate it very much.
(audience applauds)
- Thanks very much.
We'll take questions for Dr. Hazen,
and I usually like to start with anybody
who is not yet in college.
- Not yet in college, great.
- Anybody?
Okay, sometimes we have some takers.
Alright, just hands up.
Let's start with David
in the middle, go around.
- Could you explain the term
Large Numbers of Rare Events,
it sounds like an internal contradiction,
so I couldn't figure out what it means.
- Yes (laughs).
It means, if there's 5,400 species,
there may be a hundred of those
that account for 99.9% of
the volume of the crust,
but there may be three or four thousand
that are incredibly rare, that only occur
one or two or three places.
Many of those minerals are known
only by a few samples
that are microscopic,
where the entire world's
supply of a mineral species
would fit into a thimble, and so you have
a large number of those rare things
but a very small number of
extremely common things.
So that's a statistical distribution
which seems to be very
common to biological systems
and also to mineral systems on Earth,
but not to mineral systems on Mars.
- Sir, that corner, just yell it out.
- [Questioner 1] Could past
astroidal impacts events
have bearing on the time
and location of the network mineral?
- So astroid impacts
could have a huge impact--
I guess that's a--
(audience laughs)
on mineral distribution.
It's absolutely true.
It would need to be a very large impact
to cause a particular species
to go completely extinct.
We do think there have been
perhaps mineral extinction
events in the past, but most impacts,
even ones the size of the Chicxulub,
the dinosaur extinction
event that they talk about,
it really didn't affect the
global mineral distribution,
it didn't affect the global
microbial distribution,
it affected just big
animals like dinosaurs,
and it would affect us in
a similar, negative way.
So it takes a very, very large impact
like a moon-forming event to
disrupt the entire planet.
- Ma'am, go ahead.
- [Questioner 2] I would
think that mining companies
would be really keen on
this particular ability.
Are they funding further
research or how is that--
- Yeah that's--
- Please repeat the question.
- Yeah, so what're mining
companies and their interests.
We're meeting with a cobalt
mining company next week,
we had a workshop, a three-day workshop
at the Colorado School of Mines,
we had another workshop at
the US Geological Survey
to look at this.
There's an ironic problem here.
The only way this works
is if the data resources
are completely open, so if you wanna find,
you have a copper mining prospect,
it's 10 kilometers by 10 kilometers,
and you wanna find where on that property
should I drill to get the money.
Well you have to have all the data
on another hundred
similar mining prospects,
and then you'll have, you'll be able
to use machine-learning
techniques and so forth.
The trouble is all the mining companies
keep their data proprietary.
They'll say, I'll let you see that data
on our 10 kilometer square (laughs),
but you can't see anybody else's,
and so the mining companies are just,
they can't use this.
The one bright spot is Australia,
because in Australia,
all the mining companies,
all the land is public,
and every mining company
has to make any measurement
they make public.
So it is possible that Australia--
and there's a big data prospecting effort
going on now in Australia,
that may point the way
for other companies.
But right now in the United States,
everybody holds on to their data,
and so data science doesn't
work if you don't share data.
- Sir, go ahead.
- [Questioner 3] Can you
predict where petroleum
and natural gas are
located without drilling?
Will that be an--
- Please repeat the question.
- The question is can you predict
where petroleum and natural
gas are without drilling,
and we certainly think, once again,
given large data resources,
and the largest petroleum companies,
the resource companies have their own data
and they have their own data scientists,
so we're quite sure that Exxon and Shell
and other companies are doing this,
but they're not sharing that information,
so it's, it's tricky,
you know, you try to,
if you have enough prospects of your own,
you may be able to use machine learning
on the data you already have,
but the big companies as far as I know
are not sharing their data,
so that it's not something
for us to be able to do.
- I think there was a question over here.
Is that right?
Go ahead sir.
- [Questioner 4] What's the difference
between a dry planet and a wet planet?
- Ah, what's the difference
between a dry planet and a wet planet?
Water is an incredibly important agent
in mineral diversification.
There are literally thousands of minerals
that are either hydrated,
that have hydrogen
incorporated in some way,
that are alteration products.
You may have noticed I gave
a list of sodium minerals,
sodium carbonate minerals.
Well, those sodium carbonate minerals,
there's seven possibilities, six of them
have different amounts of water.
And it's, you know, how
wet or how dry it is,
you can imagine you
have a sodium-rich lake,
it evaporates, and as it evaporates,
you go through stages of dehydration.
And so much of the mineral diversity
that we're seeing in
these near-surface rocks
has to do with water.
If you don't have any
water, then all you have
is the dry minerals, and
that's a very limited list.
- Ma'am, go ahead.
- [Questioner 5] Will the
question of geo-engineering
affect distribution or diversity?
- Oh that's fascinating.
So geo-engineering itself,
there certainly are ways
that human activities could affect
the distribution, I
mean, some are as mundane
as we have mineral collections,
so we go to these places where there are
incredibly exotic and rare minerals
that are all concentrated in one place,
we mine them all out,
and then that locality
no longer has the minerals
and they're distributed
all over the Earth.
(audience laughs)
So for a mineral collector point of view,
that's one example.
But on a more global scale,
I think the kinds of changes
we do that could cause
big changes in mineralogy
have to do for example with changing
the global CO2 concentration
in the atmosphere
which can radically
affect the distribution
and the extent of carbonate
minerals on Earth.
- [Questioner 5] What about contrails,
like they modify climate with...
- Airplane transit.
- Airplane, oh contrails, yeah.
I'm not an expert on that, I don't,
certainly atmospheric changes
can have long-term changes
on the kinds of minerals
that are going to form
stably in terms of the relative ratios,
but to have entirely new minerals form
over large areas, I think we're not making
enough of a change to do that.
That's a different long-term problem.
- Let's take one or two
more last questions.
- [Questioner 6] You said
that the, for co-evolving,
it's obvious to me how
life affects the minerals,
you showed examples,
but do minerals affect
how life evolves also?
- Minerals can have a
profound effect on life,
because minerals provide habitats,
they provide ecosystems,
they provide nutrients.
So for example, we see
in the history of life,
the very earliest microbes,
the proteins that they used
for their metabolism where
dominated by the element iron,
'cause iron was abundantly
available in the oceans.
As the Earth's near-surface
environment changed,
it became much more
possible to use manganese,
and then much more possible to use copper,
and if you look at the
evolution of proteins,
we now have organisms
that use manganese-based--
for example, photosynthesis
is manganese based,
and then copper-based metabolisms
which are much more recent innovations,
and that's because this co-evolution,
as life changes the atmospheric condition,
it changes the geochemistry
which changes the mineralogy
which changes the
availability of the elements
you might use when you're
building your proteins.
So that's the kind of
feedbacks that we're seeing,
I think are really fascinating,
we're trying to study that feedback.
- Let's take one last question.
Sir.
- [Questioner 7] Thinking
about the location
and how you use the big data for it,
I don't know if this can be
done strictly at a distance
by something like spectral analysis,
but do you think with sufficient data,
this could be used for
predicting astroid findings
or something of that nature?
I was thinking, a lot of them are,
there're very large quantities of astroids
but not so much--
- Wow, that's fascinating.
So you'd have to have good reliable data.
What I've proposed is that
it's much more likely we could
use it for Mars because we
do have extremely good now
reflectance specter for
the surface of Mars,
down to pixel-size at
roughly 10 square meters.
So if you have something like that
and you have an anomaly,
you may be able to spot it.
They haven't really been doing that yet,
we've been trying to work with them
to say let's see if we can
look for anomalous pixels
and see if we can interpret them that way,
but to me, that is a very
good prospecting tool, yeah.
- Okay, so we're about
to thank Dr. Hazen again.
But wait, you have a
chance for the next hour
to join us at the reception
upstairs at the Traditions Room,
have a cookie, have a coffee,
and talk to Dr. Hazen.
Thanks very much for coming.
- Thank you.
(audience applauds)
(grand orchestral music)
