Decoding Geologic Clues
Decoding Geologic Clues is a Grade 7 science concept from Amplify Science (California) Chapter 2: Understanding Plate Boundaries, explaining how geologists identify plate boundary types by reading geologic indicators. New rock formation and spreading indicates a divergent boundary; subduction zones, trenches, and collisions indicate convergent boundaries — allowing scientists to map invisible plate interactions.
Key Concepts
Scientists act as detectives to identify plate boundaries. They cannot always see the plates moving, so they look for geologic indicators . The direction of movement defines the boundary type.
If the evidence shows new rock forming and plates separating, it is a divergent boundary . If the evidence shows subduction, trenches, or plates colliding, it is a convergent boundary .
Common Questions
How do scientists identify the type of plate boundary in a region?
Scientists look for geologic indicators. New rock formation and plates spreading apart indicate a divergent boundary. Trenches, subduction evidence, and colliding rock formations indicate a convergent boundary.
What geologic features indicate a divergent boundary?
Divergent boundaries are indicated by rift valleys, mid-ocean ridges, new rock formation at the edges of plates, and shallow earthquakes in a linear zone. These features show plates are moving apart and new material is rising to fill the gap.
What geologic features indicate a convergent boundary?
Convergent boundaries are characterized by deep ocean trenches, volcanic arcs, mountain ranges from colliding plates, and deep earthquakes from subducting slabs. These features show plates are pressing together and rock is being destroyed.
What do Grade 7 students learn about geologic clues in Amplify Science?
In Chapter 2 of Amplify Science California Grade 7, students learn to read geologic evidence like detectives, using specific indicators to determine whether a boundary is divergent or convergent even without directly observing the plate motion.