9 Why are some of the layers tilted Why are some of the layers tilted? What happened to the top of the folded rocks? The missing rock layers is called an __________.
10 What events might have caused the rock layers to become tilted? Why is the top flat?What caused the angular unconformity?What type of rocks formed above?
11 Index FossilsSome species of organisms only lived for a short period of time before they became extinct. If you use radiometric dating to get an age for the fossil, then you know that the rock the fossil is found in is also that age.Trilobite: Index fossil for the Paleozoic EraAge: mya
12 GraptoliteIndex Fossil of the Ordovician PeriodAge: mya
13 Fossil B lived 10 million years ago – 2 million years ago. Fossil A lived 20 million years ago- 8 million years ago.What do you know about the age of the rock containing both fossils?
14 What is “B”?Place the layers in order from oldest to youngest