A pathway is a chain of rocks joined by processes. Write the starting rock, name the process that changes it, name the next rock, and repeat.
This lesson belongs to rocks and rock-cycle reasoning. It assumes you can already classify a rock from supplied formation evidence.
How do you read a rock-cycle diagram?
Treat each arrow as a sentence: rock, process, rock. If an arrow has no process written on it, supply one yourself.
The processes fall into three groups: breaking down and moving rock, squeezing and heating rock, and melting and cooling rock.
Worked example: two routes from one starting rock
Start with an intrusive igneous rock, such as granite.
Pathway 1, through sediment.
- Uplift exposes the granite, and weathering breaks it into fragments.
- Erosion and transport carry the fragments to a river mouth.
- Deposition lays them down, and layers build up.
- Compaction and cementation turn the layers into sedimentary rock, for example sandstone.
Pathway 2, direct to metamorphic.
- Earth movements bury the granite deep underground.
- Heat and pressure change the minerals and align them in bands without melting the rock.
- The result is metamorphic rock, for example gneiss.
Both routes begin in the same place and finish differently. That shows the cycle is a set of options.
From pathway to written answer
Use this frame: “The [rock] is changed by [process] into [rock], because [condition].” Pathway 2 becomes: “Granite is changed by heat and pressure into gneiss, because deep burial squeezes and warms the minerals until they align.”
Each sentence stays short and each carries one process.
The mistake that costs marks
A common slip is to draw the pathway as rock names only: “granite, sandstone, gneiss”. That shows the rocks but not why they change, so it loses the process marks.
The other slip is to skip a step. Going from granite to sandstone with no weathering, transport or deposition makes the answer incomplete.
Check yourself
Start with sandstone. Describe one pathway to igneous rock in three steps, naming the process at each step.
Answer
- Burial deep underground raises the temperature until the sandstone melts, forming magma.
- The magma rises through cracks in the crust.
- The magma cools and solidifies, and crystals form as intrusive igneous rock.
What to study next
Read avoiding the assumption that every rock follows one fixed sequence to see why no single route is correct, then link pathways to properties in explaining a rock property in relation to its formation.
If you want a teacher to listen to you narrate a pathway, see online one-to-one Geography tuition.