What are strata?

Which layer is the oldest?

Which layer is the youngest?

Relative age determines exactly how old a rock layer is.

Preserved remains or traces of animals, plants, and other organisms from the distant past

History of life as documented by all fossils, preserved in sedimentary rock strata

Indicate to geologists the boundaries in geological time

Which of the following is NOT a characteristic of index fossils?

_________________ is/are used to determine the age of the rock strata.

If two different rock strata in different areas on Earth contain the same index fossils, then the strata are probably the same age.

Most accurate form of dating rocks and fossils

Uses the decay of radioactive elements to find the exact age of a rock or fossil

Relies on the property of half life

The predictable time an element takes to decay

Geologists tend to mix and match relative age and absolute age dates to piece together a geologic history

•All of Earth’s geological history represented on a chronological time chart

•Based on rock strata and the fossil record

Which choice lists the geologic time chunks in order from largest to smallest?

The earliest eon of the earth's history. Makes up 88% of Earth's geologic time.

•Broken into 3 parts Hadean, Archean, and Proterozoic

•Marks the beginning of Earth approximately 4.6 b.y.

•Oldest rock fragment on Earth contains a mineral, zircon, that is 4.4 m.y.(found in Australia)

•Marks the formation of the super continent, Pangaea

•Life developed rapidly

•Marine plants and invertebrates

•Fish and ferns

•Amphibians

•Mass extinction at the end

•Increased complex life forms including:

•Dinosaurs

•Small mammals

•Birds

•Conifers and flowering plants

•Rocks in the Petrified Forest in AZ were deposited during this time.

∙mass extinction at the end

•Currently in this Era

•Development of:

•Large mammals

•Human beings

•Periods of ice ages played a role in the formation of the geological features visible on Earth today.

Which Epoch do we live in?

During the Earth’s 4.6 billion years, it has suffered ___ major mass extinctions

A(n) ____________________ is the end of a group of organisms, usually a species

•Most recent extinction is called the Cretaceous-Tertiary extinction event.

•Happened 65.5 m.y. ago

•Climate and geologic changes are thought to have weakened the organisms.

•A meteor strike was probably the final blow.

•Found in sedimentary rock layers

•Can be as small as bacteria or as giant as a dinosaur

The study of fossils:

Which of the following are conditions needed for fossil formation?

Most fossilized structures are ______________________________.

Fossils are found in _______________________ rock.

Fossils and the rock layer in which they are found are __________________________.

This picture shows the _____________________________________.

•Tells us when organisms lived and how they changed over millions of years (evolved)

•Can also give us a clue as to the environment at that time

•Recorded on the Geologic Time Scale

•Two types – Replacement and Permineralization

•Both result in organic material converting into stone or a similar substance

•Happens when water dissolves the original solid material and replaces them with mineral matter such as calcite, silica, pyrite and hematite

•Happens slowly

•Bones, shells, and wood are often fossilized in this manner.

This type of fossil forms when:

•Groundwater carries dissolved minerals into the pores and cavities of bone, wood, or shells.

•The original material is preserved rather than replaced.

⋅Bones, teeth, and shells can be preserved this way

This type of fossil forms when an organism dies and there is no filling of the cavity with minerals.

This type of fossil forms when an organism dies and the cavity fills with minerals, maybe sand or clay.

•The process by which all substances of plants and animals decay, except carbon.

•This leaves a carbon film on the sedimentary rock.

•This process particularly occurs in plants and fish.

The amber seen here is a type of fossil called ________________________.

Whole body preservation can happen by which kind of fossil(s)?

This type of fossil:

•Provides indirect evidence of life in the past rather than the body of the animal itself.

•Examples:

•Footprints

•Tracks

•Burrows

•Feces

•Borings

•Rock like structures built by blue-green algae.

•First forms of life on Earth - oldest known fossils (3.5 b.y.)

•Still found in some remote areas of the world today

By studying fossils, scientists theorize that changes in organisms happened over time.

Jesus loves you and made you fearfully and wonderfully.

In which time period are we currently living?

Name the 4 characteristics of index fossils.

Which rock layer is the newest?

Which fossil is older than the fish fossil?

Approximately how old is the Earth?

Saying you are older than your sister is an example of:

If the same index fossils are found in different rock strata miles apart, what is probably true about the rock layers?

What are the 4 requirements for a fossil to be an index fossil?

In the rock drawing shown, what is the order of rock layers from oldest to youngest?

What do geologists look for in order to correlate rocks in different locations?

Paleontologists have discovered a shark tooth that is 1.2 million years old. Which method of dating did they use?

In order for scientists to use absolute age dating, __________________________ must be present in the rock or fossil.

Which increases the likelihood that a dead organism will be fossilized?

Which fossil type helps geologists infer that rock layers in different geographic locations are similar in age?

The units of the geologic time scale from longest to shortest are _______________________.

What are the many division in the geologic time scale based on?

Fossil of ferns and other tropical plants reveal that Earth was very __________ 100 million years ago.

Fossils of organism like __________________ reveal that Earth was ______________ at during a certain time on the geologic time scale.

The law of inclusion helps geologists understand that Rock B is ___________ than the sediment that it contains.