1. Paleontology and Fossils www.charmouth.ukfossils.co.uk/.../Fossil-2.jpg images.usatoday.com/.../2006/11/07/fossil472.jpg

2. Uni-form-i-ta-rian-ism  In 1798, ____________, published the Theory of the Earth.  He said that the Earth’s geologic processes, that shaped the Earth, have been working together to continue reshaping the Earth.  This principle is called______________.

4. Ca-ta-stro-phism  _____________is the belief that all geologic change occurs suddenly.  These scientists believed that catastrophes (earthquakes, floods, hurricanes, etc.) caused the Earth to change.

5. Which Theory is Correct?  Scientists now believe that _______ processes shape the Earth!  It is believed that some catastrophes do change the Earth. For example, an Asteroid hit the Earth and caused extinction of Dinosaurs.

6. How Do Scientists Know about the Earth?  Studying layers of the Earth explains our history. (stratification!)  Scientists use 2 types of Dating:  ______________ is determining whether an object is older or younger than another by using____________.  ______________ is determining the _____age of an object by using a number of years.

7. Dating – A Measure of Time  Which statement describes Relative or Absolute age? 1.She is 12 years old. ______________ 2.She is my younger sister. _____________ 3.The 75 foot oak tree is older than the 12 foot oak tree. _________________. 4.The man is older than the teenager. _______________

8.  Write a short paragraph explaining why geologists use both absolute and relative dating to interpret the past.(pg. 137 1 st 2 paragraphs, pg. 142 1 st paragraph)  __________________________________ __________________________________ __________________________________ __________________________________ __________________________________ __________________________________ __________________________________ __________________________________ __________________________________

9. Relative Dating  Superposition is a principle that states younger rocks lie above older rocks.  “Law of Superposition”

10. Law of Superposition By applying this law scientists know that layer A is older than Layer C. Layer C is younger that Layer B. Which layer is the youngest? ______

11. Challenges  _______________ cause older layers to be pushed above younger layers and makes it hard to distinguish between older and younger.  They have used ___________ from all around the world to create a geologic column.

12. Geologic Column  The ______________is a ________ of ____________ that contains all the known fossils and rock formations on Earth arranged from _______to youngest.  View geologic column: The column The columnThe column

14. 4 Disturbances  Natural forces are disturbances that cause changes in rock layers. (pg. 139)  All ____________are _______than the rock around them.  Faults  ___________  Folding  ________

15. Disturbances continued  Geologists use ________that __________ existing rock to help determine the rock’s ____________.  ______are breaks in the Earth’s crust where breaks______.  When molten rock squeezes into existing rock and cools it is called an_________.

16. Disturbances continued  _______occurs when rock layers bend and buckle from Earth’s internal forces.  _______occurs when internal forces slant rock layers without folding them.  _____________ are always _______than the rock layers that they affect.

17. Formation of Unconformities  When layers of rock are missing in sequence we call this____________.  ________and _____________have a lot to do with wearing away rock and causing unconformity.  Where does this rock go?

19. Types of Unconformities (pg. 141)  Unconformities link: Unconformities Unconformities  _____________– part of a parallel rock layer is missing. ___________.  _____________– sedimentary rock layers __________of eroded igneous or metamorphic rock.  ____________________– appears between horizontal layers that are ______ or_______.

20. Absolute Dating  To determine the __________ of rocks and fossil scientists use a process called _______________.  To do this they need to analyze radioactive isotopes.  ________are atoms of the same element that have the ___________ of _______ but different numbers of neutrons.

21. Isotopes  Most isotopes are stable.  Unstable ones are called___________.  Radioactive isotopes tend to __________ into stable isotopes over a period of time called ________________.  This _________happens at a ______pace and scientists use the relative amounts of stable and unstable isotopes to determine the object’s age.

22. How Does Radioactive Decay Work?  Link: Radiometric Dating Radiometric DatingRadiometric Dating  Determining the ratio of parent material to daughter material.  Link: Half-life Half-life  For every half-life, the parent material decreases by one-half.

24. Types of Radiometric Dating  ____________(has the longest half-life)  Potassium-40  __________(Used to determine the most accurate and precise age of the Earth)

25. Fossils ___________are preserved remains or traces of ____________. LLLLiving things die and are ______ by sediments. SSSSediments slowly harden into ___________ rock. AAAA ______________ is a scientist who studies fossils.

26. Types of Fossils  _________________– fossils found in tar, amber, or frozen. Even hair/teeth are preserved! Saber Tooth Cat!  _______________–______________all or part of an organism.  _____________ occurs to wood when water, rich in dissolved minerals, seeped into plant cells and then evaporated leaving hardened minerals behind.  ______ and ______ – Most_______. Copy of the shape of the organism.

27. Fossils Found in Rock www.pbs.org/.../images/quiz-fossil-l.jpg Molds and casts

28. Fossils Found in Rock  ____________– thin film of carbon is left from a living organism. This can occur as an organism decays and gases are released, only carbon is left behind. Carbon film www.geosociety.org/.../03FossilWasp.jpg

29. Fossils Found in Rock  A ______is a hollow area in sediment in the shape of an organism or part of an organism.  A ____ is a copy of the shape of an organism. When an animal’s footprint ____ with ________ and _____ to rock.

30. Trace Fossils  _____________ are fossils that provide evidence of the activities of ancient organisms:  Footprints  Nests  Burrows – a shelter made by an animal that dug into the ground.

31. Change over time  Together, all of the information that paleontologists have gathered about past life is called the _____________.  The _____________ provides evidence about the _______________ on Earth.  The fossil record also shows that _________ groups of __________ have _______ over time.

32. Change over time  _____rocks contain fossils of _______ organisms while _______rocks contain fossils of ____________organisms.  __________is the gradual change in living things over long periods of time.

33. Geological Time Scale  How old is the Earth? Approximately ___ billion years old.  The time _____was developed by ______ rock ______ and ____________ worldwide.  Placed layers by ________ages, then used ________dating to refine the scale.

35. Geological Time Scale  Basic units of geologic time scale are:  Eons  _____  Periods  _____

36. Geological Time Scale  _____– the _______division of time.  Eras –______largest division.  _______– eras are divided into these  _______– periods are divided into these

37. Eons  Hadean eon – found __________and _____from the moon.  _______ eon – found ________know _____on Earth  Proterozioc eon –________________with well-developed cells appeared.

38. Eras  __________Era – first land-dwellers, plants and amphibians.  ________Era – Age of the_________  Cenozoic era – Age of________