Warm Up (complete on p 18 or 19) Match the type of evidence with what scientists could learn about it. Type of Evidence: 1)Tree rings 2) trace fossils 3) mold fossils 4) petrified wood What can be learned: A) ancient trees B) shape of organisms footprints D) recent weather patterns Homework : Vocab Set 3, Day 1

When you are done, copy next vocab Vocab Set 2 Quiz When you are done, copy next vocab Uniformitarianism Geologic Time Scale Evolution Charles Darwin Overproduction Adaptation Variation Natural Selection Isolation Speciation Independent Variable Dependent Variable Control Qualitative Quantitative

5.01 Interpret ways in which rocks, fossils, and ice cores record Earth's geologic history and the evolution of life including: Geologic Time Scale. Index Fossils. Law of Superposition. Unconformity. Evidence for climate change. Extinction of species. Catastrophic events.

EQ: How can we determine the age of various rock layers EQ: How can we determine the age of various rock layers? Obj: TLW be able to describe the different methods for determining the age of rock layers.

Table of Contents Date Session # Activity Page 9/27-28 12 Tree Ring diagram 26 Ice Core diagram 27 9/29-30 13 Rock Layer Diagrams 28 Index Fossils & Superposition Notes 29

Dating Rock Layers Notes p29 Relative Age: rock’s age when compared to the ages of other rocks. Layers of rock that are younger will be deposited on top of layers of rocks that are older. Index Fossil: a fossil that is widely distributed and represents a type of organism that existed only briefly

Create your own relative age example and write it into your notes Create your own relative age example and write it into your notes. Be prepared to share

Law of Superposition: in horizontal sedimentary rock layers, the oldest is on the bottom and each higher layer is younger than the layer underneath it Stack three layers of clay (lightly), draw it into the superposition area of your notes, label youngest and oldest layer

Overturning: Horizontal rock layers tilt or fold due to movement of tectonic plates. Using the layers created previously, gently fold your layers in half (like a taco). Draw it into the overturning section of your notes. Label the youngest and oldest layers.

oldest middle youngest

Carefully unfold your rock layers. Gently remove the top layer. Unconformity: a gap in the geologic record showing where some rock layers have been lost because of weathering and erosion. Mechanical weathering: wind, water examples Chemical weathering: acid rain examples Biological – tree roots Carefully unfold your rock layers. Gently remove the top layer. “Erode” (remove) part of the middle layer Replace the top layer Draw this into the unconformity section of your notes. Label the part of your diagram that is the unconformity.

Chemical weathering (acid rain most common)

Mechanical Weathering (wind, water, gravity, ice wedging)

Mechanical Weathering (wind, water, gravity, ice wedging)

Biological Weathering

Unconformity

Fault: a break in earth’s crust Fault: a break in earth’s crust. When examining rock layers, the fault will have occurred after the layers it cuts across and before the continuous horizontal layers above it.

Fault: a break in earth’s crust Fault: a break in earth’s crust. When examining rock layers, the fault will have occurred after the layers it cuts across and before the continuous horizontal layers above it. Happened: Sixth Fifth Fourth Third Second First

Intrusion: lava can cut/melt through rock layers Intrusion: lava can cut/melt through rock layers. It cools and hardens into igneous rock on the surface. It is younger than the sedimentary layers it cuts through and may be older than the sedimentary layers above it. Carefully layer the three clay colors again Insert your pencil through the bottom two layers, make sure you can see it Draw the clay model into the intrusion/extrusion section of your notes Label the youngest and oldest layer, label the intrusion.

Intrustion

Absolute Age: the number of years since rock has formed Absolute Age: the number of years since rock has formed. Radioactive Dating: Gives the absolute age of rock by using the unique half-life of an element. Half-Life: the length of time it takes for half the atoms in a sample to change from one form to another form. Radioactive elements with long half-lives are better for determining the absolute age of rocks.

You cannot use radioactive dating on sedimentary rocks because THEY ARE MADE FROM BITS AND PIECES OF OTHER ROCKS. You can use radioactive dating from igneous rocks/intrusions