Rock Layers & Relative Dating · seed 1 · A4, ink-friendly. The answer key prints on its own page for grown-ups.

Rock Layers & Relative Dating

Science · Dinosaurs & Paleontology · ages 9-11
Name ______________________   Date ____________

  1. New rock layers form on top of older ones.

    Circle one:   True   False

  2. In a stack of rock layers, which layer formed first?

    • The top layer
    • The bottom layer
    • The middle layer

  3. What is it called when you figure out how old something is by comparing its position in the rock layers?

    • Relative dating
    • Fossil forming
    • The rock cycle

  4. Count the layers in the picture. How many rock layers are there in total?

    Layer 1Layer 2Layer 3Layer 4Layer 5

    Answer: ______________

  5. A fossil sits in the bottom layer of this cliff. Compared to a fossil in the top layer, is it older or younger?

    Top layerMiddle layerBottom layer
    • Older
    • Younger
    • The same age

  6. A fern fossil sits near the top of the cliff, and a trilobite fossil sits near the bottom. Which fossil is older?

    Fern fossilMiddle layerTrilobite
    • The fern fossil
    • The trilobite fossil
    • They are the same age

  7. A scientist finds three fossils: a shell in the bottom layer, a leaf in the middle layer, and a bird bone in the top layer. Which lists them from oldest to youngest?

    Bird boneLeafShell
    • Bird bone, leaf, shell
    • Leaf, shell, bird bone
    • Shell, leaf, bird bone

  8. Jamal looks at a cliff and says the fossil in the very top layer must be the oldest one there. What mistake is he making?

    • He has it backwards; the top layer is the youngest, not the oldest
    • He is right, top layers are always the oldest
    • It doesn't matter which layer a fossil is found in
LightMySky · lightmysky.comW1-mt_EGIlsfHxb6-s1

Answer key

For grown-ups. Fold this page away before handing over the rest.

Rock Layers & Relative Dating W1-mt_EGIlsfHxb6-s1

  1. True · Each new layer of sediment settles on top of the layers that are already there.
  2. The bottom layer · Rock layers pile up over time, so the very first layer ends up at the bottom.
  3. Relative dating · Relative dating compares position in the layers. It does not tell you an exact number of years.
  4. 5 · Counting each layer from top to bottom, there are 5 layers in the stack.
  5. Older · The bottom layer formed first, so a fossil found there is older than one found near the top.
  6. The trilobite fossil · The trilobite sits in a lower layer, which formed earlier, so it is the older fossil.
  7. Shell, leaf, bird bone · The shell is deepest, so it formed first. Reading from the bottom layer up gives the order from oldest to youngest.
  8. He has it backwards; the top layer is the youngest, not the oldest · Layers build up over time, so the top formed most recently. The oldest layer is at the bottom, not the top.
Worksheet · LightMySky