Paleo Test Paleo Test Review GuideReview Guide

Hutton’s principal of Hutton’s principal of uniformitarianism states….uniformitarianism states….

-current geologic processes are the -current geologic processes are the same processes that were at work same processes that were at work in the past.in the past.

Relative age indicates…Relative age indicates…

-one layer of rock is older or younger -one layer of rock is older or younger than another layer. It does not tell than another layer. It does not tell an exact numerical age.an exact numerical age.

The law of superposition states…The law of superposition states…

-an undeformed sedimentary rock -an undeformed sedimentary rock layer is older than the layers above layer is older than the layers above it and younger than the layers it and younger than the layers below it.below it.

The principle of original The principle of original horizontality states…horizontality states…

-sedimentary rocks left undisturbed -sedimentary rocks left undisturbed will remain in horizontal layers.will remain in horizontal layers.

A break in the geologic record is A break in the geologic record is an….an….

-unconformity.-unconformity.

Three types of unconformity…Three types of unconformity…

-nonconformity, angular -nonconformity, angular unconformity, and a unconformity, and a disconformity. disconformity.

Absolute age is…Absolute age is…

-the numerical age of something.-the numerical age of something.

The law of crosscutting The law of crosscutting relationships states…relationships states…

-a fault or igneous intrusion is -a fault or igneous intrusion is always younger than the rock always younger than the rock layers it cuts through.layers it cuts through.

Four ways to determine absolute Four ways to determine absolute age are…age are…

-rates of erosion, rates of -rates of erosion, rates of deposition, varve count, and deposition, varve count, and radiometric dating.radiometric dating.

Radiometric dating is…Radiometric dating is…

-using radioactive decay to -using radioactive decay to measure absolute age.measure absolute age.

What are isotopes?What are isotopes?

-atoms of the same element that -atoms of the same element that have different numbers of have different numbers of neutrons.neutrons.

What is half-life?What is half-life?

-amount of time it takes half the -amount of time it takes half the mass of a given amount to decay mass of a given amount to decay into its daughter isotopes.into its daughter isotopes.

Carbon-14 is an isotope. What is Carbon-14 is an isotope. What is it’s effective dating range?it’s effective dating range?

-less than 70,000 years.-less than 70,000 years.

The remains of animals or plants The remains of animals or plants that lived in a previous geologic that lived in a previous geologic time are called….time are called….

-fossils-fossils

The study of fossils…The study of fossils…

-paleontology. -paleontology.

Almost all fossils are found in Almost all fossils are found in what type of rock?what type of rock?

-sedimentary rock-sedimentary rock

What are the five main ways What are the five main ways fossils can be formed?fossils can be formed?

-mummification, amber, tar seeps, -mummification, amber, tar seeps, freezing, and petrification. freezing, and petrification.

The four main types of fossils The four main types of fossils are…are…

-imprints, molds & casts, coprolites, -imprints, molds & casts, coprolites, gastroliths, and trace fossils.gastroliths, and trace fossils.

Index fossils…Index fossils…

-occur only in rock layers of a -occur only in rock layers of a particular geologic age. Can be particular geologic age. Can be used to estimate absolute ages of used to estimate absolute ages of specific rock layers.specific rock layers.

What is a geologic column?What is a geologic column?

-represents a timeline of Earth’s -represents a timeline of Earth’s history. The oldest rocks are at the history. The oldest rocks are at the bottom and the youngest are bottom and the youngest are towards the top.towards the top.

What are the four main eras?What are the four main eras?

-precambrian, paleozoic, mesozoic, -precambrian, paleozoic, mesozoic, cenozoiccenozoic

The Devonian Period is best The Devonian Period is best known as…known as…

-The Age of the Fishes!-The Age of the Fishes!

What is the leading theory on how What is the leading theory on how the dino’s became extinct?the dino’s became extinct?

-meteorite impact hypothesis. -meteorite impact hypothesis.

What era is considered the Age of What era is considered the Age of the Mammals?the Mammals?

-Cenozoic Era-Cenozoic Era

What are the most common types What are the most common types of fossils you would expect to find of fossils you would expect to find dating back to Precambrian Time?dating back to Precambrian Time?

-stromatolites-stromatolites

What are the three periods of the What are the three periods of the Mesozoic Era?Mesozoic Era?

-Triassic, Jurassic, and the -Triassic, Jurassic, and the CretaceousCretaceous

The largest unit of geologic time The largest unit of geologic time is called…is called…

-an Eon.-an Eon.

The gradual development of new The gradual development of new organisms from preexisting organisms from preexisting organisms is called?organisms is called?

-evolution-evolution

Large areas of exposed Large areas of exposed Precambrian rocks found on every Precambrian rocks found on every continent are called…continent are called…

-shields-shields

Coal deposits found in Coal deposits found in Pennsylvania, Ohio, and West Pennsylvania, Ohio, and West Virginia can be linked to what Virginia can be linked to what period?period?

-Carboniferous Period-Carboniferous Period

When and what caused the When and what caused the Appalachian Mountains to form?Appalachian Mountains to form?

-End of the Permian period -End of the Permian period (Paleozoic Era), the collision of the (Paleozoic Era), the collision of the continents forming into Pangea.continents forming into Pangea.

The Mesozoic Era is also known as The Mesozoic Era is also known as the…the…

-Age of Reptiles-Age of Reptiles

The Cenozoic Era is also called The Cenozoic Era is also called the…the…

-Age of Mammals-Age of Mammals

What mountain ranges were What mountain ranges were created in the Cenozoic Era?created in the Cenozoic Era?

-Alps, Himilayas-Alps, Himilayas

Mountain ranges created in the Mountain ranges created in the Mesozoic Era include…Mesozoic Era include…

-Sierra Nevada’s and the Andes-Sierra Nevada’s and the Andes

A decrease in temperatures A decrease in temperatures during the Cenozoic Era resulted during the Cenozoic Era resulted in…in…

-new species of animals being -new species of animals being developed.developed.

Explain the concept of evolution Explain the concept of evolution as brought on by geologic as brought on by geologic change.change.

-figure this one out on your own!-figure this one out on your own!

What period and era mark the What period and era mark the end of the dino’s?end of the dino’s?

-end of the Cretaceous period, -end of the Cretaceous period, Mesozoic Era.Mesozoic Era.

What method of dating seems to What method of dating seems to be the most accurate?be the most accurate?

-radiometric dating.-radiometric dating.