A Web of Pathways
A Web of Pathways is a Grade 7 science concept from Amplify Science (California) Chapter 3: Movement of Rock Formations, explaining that the rock cycle is not a simple circular loop but a complex web of possible pathways. The path any individual rock takes depends entirely on how plate motion transports it, determining whether it weathers into sediment, subducts into magma, or undergoes metamorphism.
Key Concepts
The rock cycle is not a predictable, circular loop; it acts more like a complex web of possibilities. Rocks do not follow a set itinerary.
Plate motion is the driver that determines the path. An igneous rock might remain on the surface and erode into sediment, or it could be buried immediately and melt again. The path a rock takes depends entirely on how the plates move it.
Common Questions
Why is the rock cycle described as a web of pathways rather than a simple loop?
The rock cycle is not linear — rocks can take many different paths depending on where plate motion takes them. A rock might weather into sediment, or be buried and metamorphosed, or subducted and melted, based entirely on its tectonic journey.
What determines which path a rock takes in the cycle?
Plate motion is the primary driver. Where a plate carries a rock — to the surface to be weathered, deep underground to be metamorphosed, or into the mantle to be melted — determines which transformation it undergoes.
Can the same type of rock follow different paths?
Yes. Two identical igneous rocks could have different fates depending on whether their plate is subducted, uplifted, or remains at the surface. The rock itself does not determine the path — plate motion does.
What do Grade 7 students learn about rock cycle pathways in Amplify Science?
In Chapter 3 of Amplify Science California Grade 7, students learn that the rock cycle is a complex web driven by plate motion, with multiple possible transformations rather than one fixed circular sequence.