Welcome to series produced by the UF Thompson Earth Systems Institute's Scientists in
Every Florida School program and the
Community Scholars Initiative. Each
Friday at 3:00 p.m. for 30 minutes a
scientist will present on their area of
expertise followed by a
question-and-answer session. Scientist
in Every Florida School is a free
program housed within the Thompson Earth
Systems Institute at the University of
Florida. The SEFS program connects and
builds long-term partnerships between
teachers and scientists in order to
bring current scientific research and
big data into classrooms in Florida and
Beyond. The Community Scholars Initiative
is based at Valencia College in Orlando
Florida. Our goal is to connect, create
and elevate educational experiences in
the classroom and our community.
Supported by the Lake Nona community, we
facilitate programs in both Orange and
Osceola County Schools and work with
community leaders and businesses to
build out of school learning programs.
During the Covid-19 school closures, we
are happy to partner with SEFS to
continue engaging with our students,
teachers and parents in a digital
platform. Today we are joined by Dr.
Anthony Pivarunas. He is a
geoscientist who focuses on paleomagnetism,  numerical methods geochronology and
field geology. A lot of his research
involves the extraction of magnetic data
from rocks, information about the ancient
magnetic field on earth, the positioning
of continents and major earth history
events. He's currently a visiting
assistant professor at the University of
Florida. He received his Ph.D. at UF in 2019 and he
received his undergraduate degree in
geophysics from the State University of
New York College at Geneseo - I'm
hoping I pronounced that right- In 2015.
So as Tony tells you about his work,
please add your questions for him in
the chat box and one of our moderators will
ask your questions. We will also be
adding an email address to the chat box
there for Tony to identify a rock in your
collection so send us a photo. If you
have a rock you want to know what it i.
Without further ado, I will hand it over
to you.
Hi so I'm Tony and I'm a geologist/
geoscientist. I look at Earth and try to
study it so what exactly do I do?
What's kind of the specifics and if you
could switch the slide.
So
one thing I do is I use power drills to
to take little cores out of rocks like
this. So I have a bunch of them so I have
some old ones at home and so if the in
this video which I think Brian can start
now the so I'm in India here using a
modified chainsaw with a diamond tip
drill bit to to take out these little
plugs of rock. It's being videoed by my
old advisor now colleague Dr. Joe Mert
also at the University of Florida and
the person pumping the water to cool off
the rock because I take out these little
cores is a Scott Miller PhD candidate in
our group and so then you can see kind
of the yes you can see the little the
water coming out of the hole. It gets
really hot as the that spins around and
wears out the and you know the diamonds
are really hard so they enable us to
take these little chunks out and so uh
and then that's kind of what it looks
like after I'm done so we take some
so you can see these little holes so if
you're ever along the side of the road
maybe in the southwestern US or in some
area and you see these tiny little holes
like a little human woodpecker holes
that's probably some paleomagnetized
somewhere and so next slide and so you
know what one thing I get to do which I
really enjoy. In geology, I get to play
with friends outside and so these are
some of our colleagues in India. So a
lot of my work gets done in India and so
it couldn't really be done without Mynosh, Anoop and you see scott again
back here and then joe there. So
one thing I really like about geology is
kind of that opportunity to travel to
interesting places and look at
interesting questions about Earth
history. Next slide and so today
specifically one thing geologists do
among a number of different things so
geology isn't just look at you know some
people might think geology is looking
just just at rocks is kind of old dusty
rocks but geologists look at a number of
different aspects of the Earth. Geoscientists look at
water, they look at climate and
indeed rocks too and so we see some UF
students looking at rocks in Texas here
and those rocks are made up of different
minerals and so I've got a
couple of rocks and you guys probably
have some pictures of rocks to show me
but rocks are made up of different
minerals. So here we have in this very
nice illustration we have the different
forms of the mineral garnet. So you see
that minerals can have different color.
That the same mineral garnet can have
different colors depending on what
chemical elements are in it and so if
rocks are kind of the book that we want
to read to understand the history of the
Earth. The minerals are the pages in that
book that help that make you know make
it up and allow us to get information
out of it. Next slide and so this is a
map from the United States Geological
Survey. So this is a federal government
agency that examines geological
questions in the United States and so
what these different colors are is these
represent the different rocks that the
different bedrock that exists in all of
the different areas of the United States.
So you can see that up here in Florida
we have where we are in Florida you can
see there's these yellow rocks which if
you look at that scale on the side it
goes from old rocks to young rocks. So
Florida's all relatively young rocks and
these are young limestones and
sands and other terrestrial deposits but
you can see that the different
areas of the United States if you think
of the West as being very
mountainous. You can see these mountains
are made up of a variety of different
rocks throughout in the western US and
you can we could spend hours and hours
talk I could spend hours and hours
talking about this map but I think and
you can see the Appalachians
here that kind of twisty. The twisty
bands of color. Those are those the
Appalachian Mountains and then you can
see how the Mississippi River has cut
into the rocks here.
So looking at the rocks in the United States
and you can do this around the world too
it tells you about how land
changes and why the land why
continents look the way they do and I
just find that incredibly fascinating
and just answering questions
about why why the Earth is the way it is
is kind of really exciting to me and
I think I have one more slide and
this is just the and so geologists use a
I won't you know go into all of the
different names here but this is just
the the geologic time scale so this is
from you know 4.6 billion years at the
beginning of Earth's history all the way to
through the paleozoic mesozoic and now.
Florida those yellow rocks are rocks
from the Cenozoic. So
most of what you're seeing in Florida is at
the recent period of Earth history. So
Cenozoic means recent
life and so most of Florida where we are
is kind of more younger rocks and
that's about it. I'm
happy to be here and excited to take
your questions about geology. Tony, thank
you so much. Before we jump into the
questions and while our attendees are
writing their questions in the chat box
on the side there, we would love to
quiz you just a little bit. We're very
excited because some of our attendees
sent us rocks early in
the hopes that you would help them
identify which those are. So today we're
going to start with Stephanie who is in
third grade. She sent us four pictures
hoping that you would be able to tell
her what type of rock this is. Yeah, so a
Stephanie this rock looks like it's
you find these it's called a type of
rock called a concretion. So it's really
this kind of a compact layered
accumulation of matter of different
minerals that crisp that generally is
kind of cemented together inside of what
we call sedimentary rock so those
rocks are made up of little pieces of
other rocks that broke apart and then
get laid down and eventually squeezed
into usually you see them as you think
of them as we think of them as these big
flat sheets but inside those sedimentary
rocks we sometimes have these little
concretions. Some different areas where
some material accumulates thanks to
water flowing through it and things like
that and sometimes they form around
fossils too. So as if some organism if
the remains of some organism gets
squeezed into the rock different
microbial activity around it so little
critters trying to eat it are going to
form these kind of concretions as they as they dispose of that of that
creature. Perfect.
So moving on to Rafa. Rafa who is in
fifth grade asks what is this? So this
looks like to me it's I think it looks
kind of bluish and kind of or a grey.
Blue grayish. I think this might be a
chunk of chert. So that's a so you've
probably heard of quartz. You've seen big
quartz crystals. Well sometimes quartz forms as these
as these what we call crypto crystalline.
So these very little kind of crypto
crystalline masses that are very hard
and sometimes they were used to make
arrowheads or other tools. So a lot of
arrowheads are made of chert and
scraping tools and things like that so
yeah that's why I think that is Rafa.
Awesome. Emma who's in fourth grade asks
about this one. What do you think this is?
This is so that's really nice and we've got this little
this cube here. That looks kind of
strange to a form naturally but that
cube is actually a pyrite and so that's
an iron sulfide. So when you put iron and
sulfur together it forms these little
cubes and you might have may
have heard of pyrite called fool's gold
and so sometimes it forms these really
spectacular large cubes. At other times you
have to use a microscope or a hand lens
to see the cubes but sometimes it's
spectacular like this and it's probably
embedded in some type of in some type
of slightly altered rocks some type
of metamorphosed rock. Next we have Mary
who's an eighth grade is wondering what
do you think this is? So this one is
pretty interesting. So it's kind of got
that nice orangey. It's orange or yellow
color, orangey red color here and then
this yellowish here. It looks like it has
some conchoidal fracture. So it looks
like it kind of breaks apart and doesn't
have a really nice crystal form. So that
makes me think it could be something
like quartz or maybe you know some
other people are saying it might be
something like amber but I'd have to
know a little bit more about it but
it's a really pretty rock. Thanks. Next we have Jacob who's in
seventh grade is wondering what do you
think this one is and so this one I
think the giveaway with this one is this
very shiny and so it looks like
it's something that we'd call a mica
schist. So it's got these flat sheet like
minerals in it that we call Micahs. It
could be biotite or muscovite. Those are
some of the different names for the
minerals and so these
form when the rock gets squeezed and
heated up. So these new minerals form and
generally they form in these kind of
flat shiny sheets and then they make the
rock layered and I actually have an
example of a different mica schist here.
You can see how it's kind of catching
the light and it's shiny and so I
believe that's what that that is from
Jacob and Jennie who is
in ninth grade is curious what do you
think this one is and so I actually
believe I have rocks from the same at
least an area very similar. So that
purplish mineral that you can see at
some different areas is something called
lepidolite and that's a mica just like
that shiny earlier rock but it's a mica
the contains a lot of lithium and
so that's that purplish mineral is
lepidolite. This is probably i -- I've
been to a place with lepidolite called
the Harding pegmatite mine in New Mexico
and so in pegmatite you get a lot of
exotic minerals forming with large
crystals and they're generally very you
can find neat minerals like lepidolite in those pegmatite so I think
that's a pegmatite. Okay so now we're
gonna jump into our Q&A portion of it
and I'm really excited to see all of
these questions coming in. So today we
are going to start with Bruce and he
asks what part of the timescale do you
study? So I study the old part of the timescale. So all those colors
when you looked at the colors you didn't
probably see a lot of them in the map of
the United States because they're all
been all of the older acts have been
covered by younger rocks but where that
timescale was purple and reddish in the
and that's called the Proterozoic
and that lasted from 2.5 billion to
about 542 million years ago and so that
was  a very long time obviously
billions and billions of years. It's
almost hard to imagine that
that amount of time and so I studied be
how the and so in the Proterozoic the
big land masses that we now know the
continents that we now know like North
America all little puzzle pieces of them
all came together and so I try to study
how that puzzle all fit together in the
Proterozoic and how we have the
continents we know today because
everything was moving around until they
all smashed together into these larger
amalgamations.
So that's what makes the Proterozoic
are pretty fascinating to me. Although I
do study things at different periods of
geology time as well. A lot of my time is
spent there.
Nikhita asks what are the rocks you have
found before. So I found a lot of
different rocks depending on where I go.
So you saw in the United States there's
kind of you know all a number
of different colors so in each different
area you can you
can drive you know to the next town over
almost and find different types of rocks.
So I found some of the coolest rocks I
found as I found some  -- is for example I
found this one in Texas. So this is
called llanite and it's from lLlano
Texas. This is actually only found in llano Texas and you probably can't
see it well but there's that
what looks pretty dark. It's almost
bluish in the right light. That's
actually a bluish form of quartz which
it has very little bits of a of rutile
in it which is a mineral - a titanium dioxide
and that gives a bluish color and so
that's when the cooler rocks I found in
Texas and then for example here
from the Upper Peninsula of Michigan is
some copper ore actually. You should
might catch the light you can see some
of these these kind of copper colored
things this is copper ore from from
Michigan. The Upper Peninsula. So there's
some of the cool rocks I've found but
really there's just you know a lot of
the different types routes like
Granites, Basalts and you
know as I go across as I've been across
the in my travels I found really a lot
of different types of rocks. Alberto is
curious where do you think is the best
place to collect pretty rocks specimens?
So that's partly gonna depend on what you're
looking for. So if you're looking for
rocks like maybe those lepidolites and
things like that you're gonna want to go
to places with generally with some where
you can find igneous rocks if you want
to find pegmatite and many of those are
found in and a lot of those are found in
the western US. There's a lot of good
exposures of rocks out there but in
Florida for instance we have a lot of
interesting fossils. That's a cool
feature that we we find in Florida. So
you could go down to your creek and find
some some shark's teeth
instance or things like that or you find
if you look at really a lot of the
limestone boulders around you can see
different bivalves different mollusks so
the sea creatures from when Florida was
kind of covered by a shallow sea and it
was very much like the Bahamas are today.
So if you want fossils Florida's a great
place and you can find fossils in a
number of different places throughout
the United States. Mostly in sedimentary
rocks so if you're looking for ancient
life and fossils you want to look for
sedimentary rocks and but if you're
looking for more of the minerals and
kind of neatly colored large crystals
things of that nature you'd want to go
more towards the igneous rocks in the
United States which a lot of those you
can find in the in the western US
because that's been more geologically
active. More recently than the
eastern United States so it all depends.
Colon asks how do you know how old a rock
is? So there's a number of different ways
and so we saw that when I showed the geologic time
scale. So that's kind of a representation
of time and how it's been named and
subdivided by geologists over really
hundreds of years you know. Since it's
the culmination of a lot of work and so
that there's really two kind of things
to take away. One is you can date
things relatively where you can say okay
well  the rocks at the
bottom of these layers. There are the
bottom got laid down first and then they
got covered by subsequent rocks. That's
relative dating so you know the rocks at
the bottom our oldest and rocks the top
are the youngest and if you look at say
maybe some fossils throughout that
sequence you could tell that you could
tell how and then you go to somewhere
else you could say maybe how old
relatively the rocks are. Then the other
way of dating is absolute dating and so
the way that geologists do that is we
look at different minerals that are in
inside rocks so those minerals some of
them are radioactive so
they decay away too from some unstable
form like maybe uranium. So it's very energetic and it decays
away too and at the end it goes all the
way from uranium down to lead and so and
so looking at how much uranium has
decayed to lead for instance in the rock. So
looking at radioactive decay in rocks
allows us a absolute chronometer we can
give it you know this is rock is this
many hundreds of millions or
tens of millions or millions of years
old and so the two types of ways we tell
how rock stars we look at relative
relative dating and absolute dating. Joe
is curious what do you do with the
samples you take out of rocks from the
earlier slide when you are drilling? So
we take those samples so
this is actually a this is a
sample from some basalts so a very
iron-rich mafic rock. So this igneous
rock that squeezes in squeezes up out of
the mantle and this is from
Antarctica actually and so we take those
and we trim them so they look so
these nice standard size cylinders and
then what I do specifically is I measure the magnetic
field that these rocks recorded. So the
iron in these rocks like magnetite like
iron oxides. These iron oxides. They can
really remember what the Earth's
magnetic field was like as they formed.
So as they cool down they lock in the
Earth's magnetic field and so from the
arrangement of the Earth's magnetic
field then we can tell how where on the
surface of the earth that rock was and
so you can trace if you look at that
throughout time you can it up tracing
the path of that rock and the continent
it was on and so that's kind of that's a
lot of what my research is about and so
you can tell that it's important then
not only where the rock was but also
when it was there so that's where say
dating the rock and trying to figure out
when the absolute date of that rock
becomes important. So it's all kind of a
it's very interdisciplinary in trying to get
as much information out of these  rocks as possible. Claudia asks
can falls in rocks disappear in
volcanoes erupting? Can fossils disappear
in volcanoes erupting? Yes so I talked about you what we
want to find fossils in
sedimentary rocks and another key caveat
is another important thing is
that you don't want that sedimentary
rocks to have been cooked too much by
say a volcano erupting making them
really hot or squeezed too much by
getting rocks buried on top of them
because that can destroy fossils. Yeah so
if you have enough heat and pressure and
a volcano erupting would provide a lot
of heat you can you can
called metamorphose. You can change those rock and altered enough that you the
fossils become unrecognizable or really
absent. Emma asks how does a rock make a
cube shape like we saw earlier? So the mineral like that pyrite
so it's the arrangement of
the atoms of the iron and sulfur atoms
so how those bond to each other. They
bond to each other. They tend to bond to
each other in these cube shapes and so
what it really all comes down from the
very so it from the very very smallest
pieces of from these very very small
pieces of matter. From the atoms
themselves. They like to arrange
themselves in these cubes and then as
you get more and more of those cubes
forming it can turn into something that
we can actually see which is really
fascinating to me because you know you
can it's very hard to see. Well it's
impossible for us to just naturally look
at this rock and be like oh this is made up of
atoms like a lot of empty space. I can't
like poke my finger through it but the
way that they those atoms bond together
can create large enough things. Large
enough minerals for us to see that
cube shape. That way they bond
together with our eyes which is
one of the things which I found
fascinating about geology is being able
to... it's a discipline. It's a
the scientific field where you can a lot
of the times you can see
what you're interested in rather than it
being a little harder to see. Holly is
curious what's the best way to tell the
difference between a metamorphic rock
and an igneous rock?
so this is an igneous rock. This llanite
is an igneous rock and this
schist from New Mexico is a metamorphic
rock. So one of the ways you can say
igneous metamorphic and so one of the
ways you can see this
layering in the metamorphic rock.
So one of the ways you as things get
metamorphosed they tend to get layered.
As they get squeezed and heated and
squeezed and new minerals form so you
want to look at the minerals in the rock
are gonna tell you so a lot of these so
all these Mica's forming in sheets is
one of the ways I could tell this is a
metamorphic rock and then you can see
actually might be able to see these
these darker minerals. These kind of
elongate ones. Those are staurolites and
so that's another mineral that forms as
rocks get metamorphosed and then you look at this rock
and you see that there's really no
layering to it, right? It's just kind of
all these minerals grew as the rock
cooled and it didn't get squeezed or
heated afterwards. So that's one of the
ways you can tell the difference between
the igneous and a metamorphic rock. We
have time for just a few more questions.
Next we have Hannah who asks what type of rock is in geode? Is it a rock? I would
say it's a rock. I have a very
inclusive definition of rocks but so
yeah. So geodes are going to form in kind
of this -- they're going form in the
interior of  -- if you have this say some
open space and
as minerals precipitate in that open
space or some void in the rock and then
later you can crack it open. You find
like you know some very generally very
beautiful crystals because they have so
much space to grow and so the
geodes are generally in rocks so they're
more of that space where minerals have
grown and have precipitated out inside a
rock
so I'd say geodes are in rocks and yeah
they're rocks.
Samantha is wondering what
are some of the most important things
that people can learn from rocks? So I
think the one of the things that I find
fascinating about earth history is that
earth is -- we see-- we look at a map say on
the wall, we look at the arrangement of
continents, we go outside and we see how
warm it is, we you know and how warm
 and things and the climate
for instance and the thing is is that
these have all of these things even you
know the arrangement the continents has
drastically changed through all of Earth
history and so looking at different
rocks and putting together all that
knowledge we can gain from say where a
rock was. We can see that the Earth has
changed a lot. The the arrangement of
continents has changed a lot. The
continents all used to be together.
You've probably heard of Pangaea and the
supercontinent but Pangaea was only the
most recent supercontinent. There's been
others at different times throughout
Earth history and so rocks have moved
all over. The continents have moved all over. Earth's climate has changed drastically
at different times and so by looking at
rocks we can understand that Earth has
been a very different planet throughout
all of the billions of years
of its history and so getting at
that history seeing how things have
changed and how that and how we can
understand maybe the future of Earth
from the past and how we can understand
the presence of Earth from its past is
is really interesting to me so I think
 that's the interesting thing
which we can learn from rocks is that
they're the book of Earth's
history that we can crack open the pages
of in and read and we'll wrap up with
one final question from Rick. He asks
does pillow basalt form in freshwater
conditions? Yeah, so pillow basalt is that's
going to form so it's an
igneous rock so as that so as it's
squeezing out if it's if the basalt if this hot
lava squeezes out into water it
tends to form these structures called
pillows because they look geologists are
very descriptive and so since they look
somewhat like pillows you know it's
called pillow basalt. So you get all
these kind of lumps of rock all together
and so the important thing is that
the lavas squeezing out into
water. It doesn't necessarily matter if
it's fresh or saltwater. That's not going
to be the biggest thing on it. It's
mostly the fact that it's coming up
under water to begin with. So yeah in
rivers or lakes if some basalt squeezed
out into that under water there, you
could form a pillow basalts there.
Awesome, Tony. Thank you so much. Is there
anything you would like to say to our
attendees today before we wrap up? I
guess I just want to reiterate. Geology
is a big realm of science,
right? I look at rocks. I look
at the magnets in rocks. So I do
something very specific in geology but
there's a lot of different disciplines.
You know some people look at ancient
life. They look at fossils. Other people
look at maybe hydrogeology. You look at
water. Some people look at ancient
climates. There's a lot of different
things you can do in geology which is
why you know we're Earth's scientists,
right? We look at the earth geology is
the study of earth geo and so I just
want to kind of reiterate that there's a
lot of different things. I myself am
fascinated by rocks but there's a lot of
different avenues of geology and that I
just encourage you to find what science
is a great way of looking at it's a way
of looking at the world, right? It's the
process of asking questions and answering them and anyone
can do it and I kind of encourage all
all the people watching to to try to
apply that to their own life to you know
apply that scientific method ask
questions and try to systematically
answer them and thank you
for listening to me and coming online
and I really enjoyed all your questions
and yeah thanks for being
here. Thank you so much, Tony. At this
point I'm going to hand things over to
Stephanie
for some closing remarks. That was wonderful. Thank you so much. We want to thank
everyone for joining us on the call
today, particularly to learn about
geology and rocks and our special thanks
to Dr. Anthony Pivarunas from the University
of Florida for connecting with us today.
Once again, our Friday Q&A is with a
scientist take place weekly at 3:00
p.m. as part of a collaboration between
Scientist in Every Florida School and
the Community Scholars Initiative. You
can learn more about our guests as well
as each of our programs by visiting the
websites you see on your screen. You'll
find a recording of today's program on
the UF Thompson Earth System's youtube
channel along with great resources that
we've curated on the topic of geology
for you. Please be sure to register for
next Friday's QA where we will investigate a
beehive to learn more about bees. Thank
you and we'll see you soon.
Bye-bye.
you
