Rock cycle and geological transformation
Rock materials can change through multiple geological pathways.
Key knowledge
The rock cycle connects igneous, sedimentary and metamorphic materials through processes such as melting and crystallization, weathering and sediment formation, and alteration by heat, pressure or fluids. It has multiple pathways rather than a required starting point or sequence.
Conditions and scope
- Metamorphism changes pre-existing rock without bulk melting; crystallization after melting belongs to an igneous pathway.
- A cycle diagram does not specify the rate or detailed history of a particular rock.
Sources · 3
References
Sources retain their recorded scope. A source link alone does not establish verification of every statement.
Evidence and review
USGS's documented rock types, transformation pathways and metamorphism distinction; no sample identification or dating.
2026-10-10 · English process scope checked against the USGS rock-cycle sections and metamorphic-rock FAQ.
Foundational review
2026-10-10 · Fresh primary-source inspection of the complete compact record, including every statement, equation, quantity and material condition, followed by independent AI editorial review. This check does not certify all linked lessons or every passage of every cited publication.
Sources from other places
Agreement within this scope
Formation and transformation of the three main rock classes.
Rock cycling offers multiple pathways rather than one required sequence.
British Geological Survey
- Rocks and minerals United KingdomEnglish
What is a rock?; The rock cycle; sedimentary, igneous and metamorphic descriptions
- Rocks and minerals
Entry details
Permanent link to this entry ↗- Record identity
- earth-rock-cycle
- Revision
- core.1
- Structured reference record
- Essential core · first collection