SME
Historical Geology · Problem type
Name the unconformity
Use this for “Flat sandstone lies on eroded granite. What kind of unconformity is it?”
Sort
What lies under the gap: which unconformity is it?
Tap a card, then tap its group.
Assumptions
•
An unconformity is a buried erosion surface or a gap in deposition: time missing from the record.
•
The rocks under the surface name it: tilted beds, parallel beds, or igneous or metamorphic rock.
•
A disconformity is the hardest to see; a channel, a soil or missing fossils give it away.
Topic check
See what you know: 5 questions on this topic
New questions each time. Pass to mark it complete.