Good Morning! 1. Complete your warm-up: What happens at a convergent boundary? Be specific. 2. Have out your Venn Diagram. You may have it pasted in your notebook, I am coming around to check for completion. 3. Copy tonight’s HW: Matching half sheet 4. Read silently.
26
Embed
Good Morning! 1. Complete your warm-up: What happens at a convergent boundary? Be specific. 2. Have out your Venn Diagram. You may have it pasted in your.
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Good Morning!1. Complete your warm-up: What happens
at a convergent boundary? Be specific.2. Have out your Venn Diagram. You may
have it pasted in your notebook, I am coming around to check for completion.
A Trip Through Geologic TimeNOTE: Under “Kinds Of Fossils” you need to
ADD Trace Fossil.
FossilsFossils are
traces or remains of ancient life.Fossils show how life has changed over time.
Scientists who study fossils are paleontologists.
Fossils Fossils are usually found in sedimentary rocks.
Kinds of FossilsPetrified Wood: stone fossil of a tree.
Kinds of Fossils
Molds and Casts
Mold: is a hollow area in the shape of an organism.
Cast: is a copy of the shape of an organism.
Kinds of Fossils Carbon Films: an extremely thin coating of carbon on rock; shows the soft parts of the organism.
Trace Fossils: evidence of the activities of ancient life. Ex: footprints, animal trails, feces, or animal burrows.
Kinds of FossilsOriginal Remains actual body parts of an organism. May form in ice (best preserver), amber (sap), or tar.
Why Study Fossils?1. To learn what past
life forms were like.
2. To classify organisms in the order in which they lived.
3. All the fossils found on earth make up the fossil record.
Fossil Record Provides evidence about the history of life on Earth.
Shows how different groups of organisms have changed or evolved; while others became extinct.
Remember!The fossil record is incomplete; most organisms do not become fossils.
Other evidence show change in life and the environmentTree Rings- show weather patterns
Ice Cores- show how the atmosphere has changed over time
R
O
C
K
D
A
T
I
N
G
Ages of Rocks The relative age of a rock is its age compared to other rocks. Use words like: “older or younger”
The absolute age of a rock is the number of years since the rock was formed. Ex: 358-360 mya
Rock Joke!!What does a rock want to be when it grows up?
A Rock Star!!
The Position of Rock LayersIt can be difficult to
determine a rocks absolute age. So… scientists use the law of superposition.According to the law of superposition, in horizontal sedimentary rock layers the oldest layer is at the bottom. Each higher layer is younger than the layers below it.
Rock Joke!!How do rocks wash their clothes?
The Rock Cycle!!
Other Clues to Relative Age
Clues From Igneous Rock
Lava that cools at the surface is called an extrusion. Rock below an extrusion is always older.
Magma that cools beneath the surface is called an intrusion. An intrusion is always younger than the rock layers around and beneath it.
Other Clues to Relative AgeFaults (a break
in the rock) are always younger than the rock it cuts through!
Unconformities: An unconformity is a gap in the geological record. New rock forms on top of eroded rock
Using Fossils to Date Rocks!Scientists use
index fossils to match rock layers.
An index fossil must be widely distributed and represent a type of organism that existed only briefly.
They tell us relative age of the rocks
The TrilobiteOne example of an index
fossil is a trilobite.Trilobites were a group
of hard-shelled animals whose bodies had three distinct parts.
They evolved in shallow seas more than 500 million years ago.