Connect multiple tectonic evidence lines

Supplied materials

• All measurements and observations below are supplied classroom examples. They are not data from actual learners or a claim about a particular real site.
• Paper or a browser document for a labeled drawing, table or explanation.
• Worked problem inputs: Matching coastal rocks and land fossils occur on separated continents. Explain why these clues should be combined.
• Assessment case 1: Matched fossil types occur on separated coasts, and fit/rock patterns also align. What is supported? Which inference or prediction is best supported?
• Assessment case 2: Which scientific label fits the specifically described step or feature? Supplied case: Matching rock bands across coastlines.
• Assessment case 3: Which scientific label fits the specifically described step or feature? Supplied case: Shaking events cluster along boundary.
• Assessment case 4: Which scientific label fits the specifically described step or feature? Supplied case: Young ocean crust near spreading ridge.
• Assessment case 5: Which scientific label fits the specifically described step or feature? Supplied case: Matching ancient organism remains.
• Assessment case 6: Seafloor ages increase from 2 to 8 to 20 million years away from a ridge. What mechanism fits? Which inference or prediction is best supported?

Learn the idea

Scientists combine fossil patterns, rock matches, earthquake distributions and seafloor patterns. One clue alone can have limits. Our descriptions identify what each evidence line measures.

Fossil pattern means matching ancient organism evidence. Rock match means similar geological units across locations. Earthquake pattern means clustered fault-motion locations. Seafloor age means ages arranged around spreading areas.

For the supplied mechanism problem, Matching coastal rocks and land fossils occur on separated continents. Explain why these clues should be combined. The different records jointly support a former connection or shared geological history. Each has identification and preservation limits; combining independent evidence is stronger than inferring a complete history from one resemblance.

1. Read the supplied problem and mark the structures, processes or quantities named: Matching coastal rocks and land fossils occur on separated continents. Explain why these clues should be combined.
2. Draw the relevant boundary, pathway or comparison and label it using the scientific ideas above.
3. Write a causal explanation or calculation, showing how each observation supports the result.
4. Compare your reasoning with the worked solution; name a condition that would change or limit the inference.

Check your reasoning

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Take it further

New evidence case: rock matches support a former connection, but one fossil identification is uncertain. Expected: preserve the rock evidence while qualifying the fossil evidence; one uncertain identification does not erase every independent observation.

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