Put rock layers in order
Grade 9 Science Worksheet
Circle the best answer.
Ari lists the events on card K. Which list runs from oldest to youngest?
- Units 1 to 3, erosion surface, dike D, Unit 4, fault F
- Fault F, Units 1 to 3, dike D, erosion surface, Unit 4
- Units 1 to 3, dike D, erosion surface, Unit 4, fault F
- Units 1 to 4, then dike D, then fault F
Bo lists the events on card G. Which list runs from oldest to youngest?
- Units 1 to 4, then granite B and the uneven surface
- Granite B, Units 1 and 2, uneven surface, Unit 3, Unit 4
- Units 1 and 2, uneven surface, granite B, Unit 3, Unit 4
- Units 1 and 2, granite B, uneven surface, Unit 3, Unit 4
On card G, Esme wants two facts that together show granite B is older than Unit 3. Which pair?
Use the picture in question 2.
- The granite cuts Units 1 and 2, and Unit 3 lies above both of them
- The granite holds chunks of Unit 1, and Unit 3 is a conglomerate rock
- The uneven surface cuts the granite, and Unit 3 holds granite pebbles
- Unit 4 lies above Unit 3, and the granite lies far below Unit 4
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.
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?
- Y is older, since S is listed lowest in the table
- 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
- X and Y formed together, since both hold R
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?
- Layer c at Site 1 was wrongly dated by its fossils
- Slice 4 has no rock at Site 2, so there is a gap
- Site 2's layers are overturned, so the fossil order is flipped
- Nothing is missing; the two sites hold exactly the same record
Card H shows tilted layers under flat layers. Which sequence of events made Milo's contact?
- D and E laid down first, then A to C slid in beneath them
- Flat A to E laid down, then just A to C were tilted
- Flat A to C laid down, tilted, eroded, then D and E laid down
- A to C tilted as they formed, then D and E laid on top of them
NPS (Grand Canyon)
The basal Grand Canyon Supergroup is about 1,250 Ma; the Layered Paleozoic Rocks above it are about 510 Ma. They touch along the Great Angular Unconformity.
NPS: at one contact, 510 Ma rocks lie directly on the 1,250 Ma Supergroup. At most, how much record is missing, by Noah's subtraction?
- About 1,760 million years, found as 1,250 plus 510
- At most about 740 million years, found as 1,250 minus 510
- No time, because the two rocks touch directly
- About 510 million years, the age of the upper rock
“Cross-section:” Pia sees flat sandstone resting on eroded granite. Which kind of contact is it, and what happened?
- The granite is younger, because the sandstone sits on it
- A conformable contact: the sandstone formed from the granite with no break
- A nonconformity: the granite formed, wore down, then sandstone covered it
- An angular unconformity: the granite is tilted below
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.
Ren reads the clues on card W. Which bed is the oldest?
- Bed 1, the lowest bed in the cliff, so it came first
- Bed 2, the middle bed that sits between the two clues
- 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
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
- At most 22 million years, between ash and dike
- About 402 million years, found as 212 plus 190 Ma
- Exactly 22 million years