Put rock layers in order

Grade 9 Science Worksheet

Circle the best answer.

1. 1.

   Ari lists the events on card K. Which list runs from oldest to youngest?

   • Fault F, Units 1 to 3, dike D, erosion surface, Unit 4
   • Units 1 to 4, then dike D, then fault F
   • Units 1 to 3, dike D, erosion surface, Unit 4, fault F
   • Units 1 to 3, erosion surface, dike D, Unit 4, fault F
2. 2.

   On card G, Esme wants two facts that together show granite B is older than Unit 3. Which pair?

   • The granite holds chunks of Unit 1, and Unit 3 is a conglomerate rock
   • Unit 4 lies above Unit 3, and the granite lies far below Unit 4
   • The granite cuts Units 1 and 2, and Unit 3 lies above both of them
   • The uneven surface cuts the granite, and Unit 3 holds granite pebbles

3. Read this first

   Table, Fossil ranges (made up), with columns Fossil, Time slices lived (1 oldest, 6 youngest), Where found

   P, 1 to 4, worldwide; Q, 2 to 3, one basin only; R, 3 to 5, worldwide; S, 5, worldwide. Note: A time slice is one equal span of time.

4. 3.

   Jun finds layer X at Site 1 with Q and R, and layer Y at Site 2 with R and S. Which statement fits the ranges?

   • X formed in slice 3 and Y in slice 5, so X is older
   • Both formed in slices 3 to 5, so their order is unknown
   • Y is older, since S is listed lowest in the table
   • X and Y formed together, since both hold R
5. 4.

   Kira reads Site 1, bottom to top: layer a holds P; b holds P and Q; c holds P and R; d holds R and S. Which layer formed in slice 5?

   • Layer d, because R and S overlap only at slice 5
   • Layer b, because it sits in the middle of the column
   • Layer c, because R reaches slice 5
   • Layer a, because P is the oldest fossil
6. 5.

   At Site 1, layer c (P, R) lies between b (P, Q) and d (R, S). At Site 2, d lies directly on b. What does Luz infer?

   • Slice 4 has no rock at Site 2, so there is a gap
   • Nothing is missing; the two sites hold exactly the same record
   • Layer c at Site 1 was wrongly dated by its fossils
   • Site 2's layers are overturned, so the fossil order is flipped
7. 6.

   Card H shows tilted layers under flat layers. Which sequence of events made Milo's contact?

   • Flat A to C laid down, tilted, eroded, then D and E laid down
   • Flat A to E laid down, then just A to C were tilted
   • A to C tilted as they formed, then D and E laid on top of them
   • D and E laid down first, then A to C slid in beneath them
8. 7.

   “Cross-section:” Pia sees flat sandstone resting on eroded granite. Which kind of contact is it, and what happened?

   • A conformable contact: the sandstone formed from the granite with no break
   • An angular unconformity: the granite is tilted below
   • A nonconformity: the granite formed, wore down, then sandstone covered it
   • The granite is younger, because the sandstone sits on it

9. Use this

   made up. Mud cracks open at the surface a bed had when it dried. Sand settles coarse first, then fine, as a current slows.

10. 8.

    Ren reads the clues on card W. Which bed is the oldest?

    • Bed 2, the middle bed that sits between the two clues
    • Bed 1, the lowest bed in the cliff, so it came first
    • Bed 3: mud cracks and grain size show the beds are upside down
    • Nothing can be said; stacking order cannot be used on tilted beds
11. 9.

    Granite B on card G holds chunks of Unit 1. Tala says that proves Unit 1 is older than B. Is Tala right?

    • No: B cuts Unit 1, and a cutter is the older one
    • Yes: chunks inside a rock must have existed before that rock
    • No: B surrounds the chunks, so B must be the older rock
    • No: a radiometric date is needed to show which one is older
12. 10.

    On card N, Zee notes Unit 3 lies above the 212 Ma ash and is cut by the 190 Ma dike. At most, how long did Unit 3 take?

    • 190 million years, the age of the dike
    • About 402 million years, found as 212 plus 190 Ma
    • Exactly 22 million years
    • At most 22 million years, between ash and dike