Transcript Fossils - Campbell County Schools

How much do you know about
Paleontology?
JOURNAL # 1
What is a fossil?
(YOUR DEFINITION)
Geology:
Paleontology
& Geologic
Time
Created in 2008 by Tim F. Rowbotham
Geology
is the study of
the origin,
history, and
structure of the
earth.
Paleontology
is the study of
prehistoric life,
particularly
through fossil
remains.
Fossils
are the remains,
imprints, or
traces of
prehistoric
organisms.
Fossil Formation
Requires shelter
from scavengers,
decay, and
physical
destruction.
Fossil Formation
• Most commonly occurs
through quick burial by
sediment.
• Is more likely to occur with
hard parts such as bone,
shells, and teeth.
Types of
Fossils
Types of Fossils
• Permineralized
remains
• Carbon films
• Molds & Casts
• Original Remains
• Trace Fossils
Permineralized Remains
occur when parts
of the original
remains are
replaced by
minerals flowing
through ground
water.
This process is called petrification.
Permineralized Remains
Fossil turtle shell
Permineralized Remains
Fossil dimetrodon
Permineralized Remains
Petrified wood
Permineralized Remains
Baby protoceratops
Permineralized Remains
Whale fossil
Permineralized Remains
Fossil tyrannosaurus
Carbon Films
occur when
pressure from
layers of sediment
leaves only a thin
carbon residue.
Carbon Films
Beech leaf
Carbon Films
Ancient salamander
Carbon Films
Fossil fish
Molds & Casts
Formation of fossil shell molds
Molds
are hollow areas
left in sediment
that show the
shape of the
original organism.
Molds & Casts
External mold of shell
Molds & Casts
Internal mold of shell
Casts
are copies of the
shape of original
organism that form
from minerals
deposited into the
mold.
Molds & Casts
Cast of trilobite
Molds & Casts
Formation of fossil shell molds
Original Remains
including the soft
parts of the
organism are
sometimes found in
hardened tree
resin, frozen
ground, or tar pits.
Original Remains
Bee encased in amber
Original Remains
Scorpion in amber
Original Remains
Mammoth hair
Trace Fossils
provide evidence
of an organism’s
activity. They
include
footprints, trails,
burrows, and
excrement.
Trace Fossils
Dinosaur tracks
Trace Fossils
Fossil trails of climactichnites
Trace Fossils
Fossil burrows
Journal #2
List 3 types of fossils and give a
brief description of each.
READY YOUR REMOTES
How fossils form
VIDEOS
• How Fossils are Formed 2
• How Fossils are Formed 1
Fun Facts about Sue
Sue Wiki
Relative Age
is the age of a
rock or fossil
compared to the
ages of other
rocks or fossils.
Catastrophism
is the belief that the
earth’s geological
features were formed
rapidly as a result of
large catastrophes.
Catastrophes
that could cause
rapid geologic
change include
landslides, volcanic
eruptions, floods,
and earthquakes.
Uniformitarianism
is the idea that the
processes
occurring on earth
today are similar to
those that occurred
in the past.
Uniformitarianism
basically says
“The present is
the key to the
past.”
Uniformitarianism
is the idea that
geological
features formed
slowly over long
periods of time.
Catastrophism vs.
Uniformitarianism
Geologic
Features
Age of the
earth
Uniformitarianism
Catastrophism
Form slowly over
time
Form rapidly
due to major
forces & events
Billions of years
Thousands of
years
Catastrophism & a
Young Earth
Where would dinosaurs fit
in?
DRAGONS or DINOSAURS VIDEO
(FULL VIDEO 1:24)
3:09 – ?
Principle of Superposition
as sedimentary
rocks form, they
are deposited on
older rock layers.
Principle of Superposition
in undisturbed
layers, the oldest
is on the bottom
and higher layers
are younger.
Principle of Superposition
Oldest layer is on bottom (1)
Principle of Superposition
The Grand Canyon
Principle of Superposition
The Grand Canyon
Principle of Superposition
Younger Layers of Rock
Older Layers of Rock
The Grand Canyon
Extrusions
are igneous
rocks layers
that form on the
surface when
lava hardens.
Extrusions
are always
younger than
the layers over
which they form.
Extrusion
Kubu Rock – Botswana, Africa
Intrusions
are igneous
rocks that form
when magma
pushes up into
rock layers.
Intrusions
are always
younger than
the rock layers
they invade.
Intrusion
Devil’s Tower, WY
Intrusions & Extrusions
Journal #3
Draw the following geologic cross-section:
1.) 2 layers of sedimentary rock form.
2.) An extrusion forms on top of the two layers.
3.) A 3rd layer of sedimentary rock forms.
4.) An intrusion cuts through the all the rock
layers, but not to the surface.
5.) A 4th layer of sedimentary rock forms.
Faults
are breaks in the
earth’s crust. A
fault is always
younger than
the rock it cuts
through.
Faults
Faults
Shoshone Fault, CA
Folds
occur when
rock layers are
compressed
together and
bend or curve.
Folds
Guadalajara, Spain
Folds
Mojave Desert, CA
Folds
• South Wales, Australia
Journal #4
Draw the following geologic cross-section:
1.) 2 layers of sedimentary rock form.
2.) The 2 layers of rock are folded.
3.) A 3rd sedimentary layer forms.
4.) A fault cuts through all the layers, shifting some
rock up.
5.) A 4th sedimentary layer forms.
6.) An intrusion cuts all the way to the surface
forming an extrusion.
Unconformities
are gaps in the
rock sequence
(caused by the
erosion of rock
layers).
Angular Unconformity
occur when rock
layers are tilted or
uplifted, and then
worn down by
erosion and
weathering.
Sediments are then deposited
on top of these eroded layers.
Angular Unconformity
Angular Unconformity
Angular Unconformity
Angular Unconformity
Grand Canyon
Angular Unconformity
Siccar Point, Scotland
Angular Unconformity
Combs Quarry, Yorkshire, England
Disconformities
are gaps created
when erosion
occurs on an
overlying rock
layer.
Disconformity
Disconformity
Disconformity
Nonconformity
are formed when
sedimentary rock
overlays igneous
or metamorphic
rocks.
Nonconformity
Nonconformity
Nonconformity
Grand Canyon
Nonconformity
Egypt
Unconformities
SOME Relative
Dating Practice
Write the correct order of events by
numbering their occurances.
Include any and all cross-cut
relationships.
Relative Dating Example
Relative Dating
Relative Dating
Relative Dating
Correlation
is using rock and
fossil evidence
to match up
dating at different
locations.
Correlation
Index Fossils
are used for
dating the rock
layers in which
they are found.
(p. 4 Notes)
Index Fossils
are species that
were abundant all
over the earth, but
existed for shorter
periods of time.
Index Fossil
trilobite
Index Fossil
ammonite
Index Fossil
reptaculite
Index Fossil
Correlation using index fossils
Index Fossil
Correlation using index fossils
Index Fossil
Correlation
Journal #5
Draw a geologic cross-section with the following:
1.) At least 5 sedimentary rock layers
2.) At least 3 cross-cuts
Write a geologic history that explains the
order of occurrence of each event.
Paleontology Notes
RETURN YOUR REMOTE
 Finding Clues to Rock Layers
HW: (Pal Pack)
 p.18 “The Grandest Canyon of All”
 p.19 “Relative Order of Geologic
Events”
 p. 20 “Geologic Puzzles”
Absolute Age
is the age in years
of a rock or other
object (as
determined by
radiometric
dating.
Radiometric Dating
entails finding the
amount of certain
radioactive
elements left in a
rock or object.
Radioactive Decay
is the release of
particles and
energy from the
nuclei of unstable
atoms.
Radioactive Elements
are elements
whose nuclei are
unable to hold
together, and
eject particles
and energy.
The Parent Element
is the element
whose nucleus
radioactively
decays into
another element.
The Daughter Element
is the new
element that is
produced after
the decay of the
parent element.
Half-Life
is the time it
takes for half of
the atoms in a
sample to
decay.
Half-Life
is always the
same. It does
not depend on
the amount of
atoms.
Half-Life
is unaffected by
almost all other
outside factors.
Decay occurs at
a steady rate.
Sample Half-lives
ISOTOPE
HALF-LIFE
PARENT
DAUGHTER
URANIUM 238
LEAD 206
4.5 BILLION YEARS
POTASSIUM 40
ARGON 40
1.3 BILLION YEARS
THORIUM 232
LEAD 208
14.0 BILLION YEARS
CARBON 14
NITROGEN 14
5,730 YEARS
Sample Half-lives
Iodine-129
16,000,000 years
Carbon-14
5730 years
Strontium-90
28 years
Sodium-24
15 hours
Technetium-99
6 hours
Fluorine-18
110 minutes
Oxygen-15
124 seconds
Radiometric Dating
As time passes,
the amount of a
parent isotope in
a rock decreases
as it decays.
It has decayed into the
daughter element.
Radiometric Dating
basically involves
measuring how
much of the
daughter element
has formed.
Age Determination
can then be made
by using the known
half-life to
determine how
much time has
passed.
Age Determination
typically, the
dating can be
estimated only up
to a MAX of 10
half-lives.
Common Types of
Radiometric Dating
Potassium-argon dating
Uranium-lead dating
Rubidium-strontium dating
Radiocarbon dating
Potassium- Argon Dating
Potassium-40 decays to Argon-40.
Potassium-40 has a half-life of
1,300,000,000 years.
(used on igneous & metamorphic rock)
Uranium-Lead Dating
Uranium-235 decays to Lead-207
Half-life: 700,000,000 years
Uranium-238 decays to Lead-204
Half-life: 4,500,000,000 years
(used on igneous & metamorphic rock)
Rubidium-Strontium Dating
Rubidium-87 decays to
Strontium-87
Rubidium has a half-life of
50,000,000,000 years.
(used on igneous & metamorphic rock)
Radiocarbon Dating
Carbon-14 decays to Nitrogen-14.
Carbon dating is used to measure
how long an organism has been
dead.