8.E.2.1 Review

8.E.2.1 Review

8.E.2.1

Infer the age of Earth and relative age of rocks and fossils from index fossils and ordering of rock layers (relative dating and radioactive dating)

Fossils

• Fossils are preserved remains or traces of living things.

• Fossils normally form in sedimentary rock.

• Hard parts are the only parts of an organism that leaves a fossil.

Fossil Formation

• Other fossils may be found in tar, amber, or ice.

• Large beds of sedimentary rocks indicate a former marine or aquatic/semi aquatic environment

• Sedimentary rocks form when sediments (sand, silt, mud) are hardened into stone as the environment changed in response to changes in climate or geography.

• The presence of fossils in sedimentary rocks indicate that the past environment supported life.

Index Fossils

• Must be widespread and represent an organism that was short lived

• One example is a trilobite

Multiple Choice

Which fossil makes the best index fossil?

• Fossil 1
• Fossil 2
• Fossil 3
• None follow all of the rules

Multiple Choice

 These are dinosaur footprints. What is this a example of?

• All of the below!!!!!
• index fossil
• permineralized  remains
• trace fossil

Multiple Choice

Paleontologist come across an old reptile fossil. What could help scientist approximate the age of this fossil

• Scraping carbon and running a DNA analysis

• Using trace fossils to compare it too

• Using Index fossils found in similar locations

• Radiometric dating

Multiple Choice

A type of rock created when deposits of minerals and animal remains have collected over time.

• Metamorphic rock

• Sedimentary Rock

• Igneous Rock

• Limestone

Multiple Choice

If you found an index fossil in a layer of rock in Montana and a similar fossil in a layer of rock in Texas, you would know that:

• the fossils and rock layers are the same age

• the fossils from Montana are older

• the fossils from England are older

• none of the above

Multiple Choice

Which of the following can be learned by using the fossil record?

• When organisms changed or evolved

• when organisms appeared on Earth

• when organisms became extinct

• All the above

Relative Dating

• The geologic age of a fossil organism, rock, geologic feature, or event, defined relative to other organisms, rocks, features, or events rather than in terms of years

Law of Superposition

• The bottom layer of rock forms first, which

  meads that it is the older

• Each layer above that is younger than the one below and the top layer is the youngest of all

• This ordering is a type of relative dating

  because you can’t be sure when each layer

  was formed, so you know the layer’s age in

  relation to the other layers

Multiple Choice

Relative dating gives me:

• Exact age

• Tells me if something is younger or older than something else

• Is only used to determine the age of fossils from 1 million years ago

Multiple Choice

The Law of Superposition states:

• Oldest is on the top layer, youngest is on the bottom

• Oldest in the middle layers, youngest is on the bottom

• Oldest is on the bottom layer, youngest is on the top

• All of the rock layers are the same age

Multiple Choice

Is the bone fossil older or younger than the intrusion?

• older

• younger

Multiple Choice

Is the intrusion (letter F) older or younger than the surrounding layers?

• older

• younger

Multiple Choice

Which letter represents an intrusion?

• A

• B

• E

• D

Multiple Select

Index fossils help us determine the age of something. They are used because: (THERE ARE TWO ANSWERS)

• They lived for a short period of time

• They are widely distributed

• They lived for a long period of time

• They lived in only one area

Multiple Choice

Scientists find dinosaur fossils in the bottom rock layers of a cliff and mammal fossils in the middle rock layer of the cliff. Which could best be concluded from this evidence?

• Dinosaurs ate plantes

• Dinosaurs were eaten by the mammals

• Dinosaurs lived on Earth before the mammals

• Dinosaurs and mammals lived at the same time

Multiple Choice

True or False: intrusions are located above the ground

• True

• False

Absolute Dating

• With absolute age dating, scientists determine the absolute age of a rock in millions of years before present rather than just the age of the rock relative to the rock units around it. 

• Absolute age is generally determined using a technique called radiometric dating, which uses radioactive isotopes of elements in the rock to estimate the age of the rock.

Multiple Choice

Geologists use radioactive dating to determine THE ABSOLUTE AGE OF ROCKS.

• True
• False

Multiple Choice

All plants and ANIMALS contain carbon.

• True
• False

Multiple Choice

Which of the following is defined as the breakdown of a radioactive element releasing particles and energy

• Radiometric Dating

• Half LIfe

• Law of Superpostion

• Radioactive Decay

Multiple Choice

The length of time required for half of the radioactive atoms in a sample to decay is its...

• era
• age
• half-life
• eon

Multiple Choice

What element is usually used to date fossils?

• uranium-235
• carbon-14
• mercury-203
• thorium-234

Multiple Choice

Which term is defined as the age of a rock given as the number of years since the rock formed?

• Relative Age

• Geology

• Absolute Age

• Law of Superposition