- 2059 Chaitra (old course) · 4 marks
Petrification versus metamorphism
Short answer
Petrification is the replacement of organic matter by minerals to form a fossil, preserving original structure. Metamorphism is the solid-state alteration of pre-existing rocks by heat, pressure, and fluids, forming new rocks like marble.
Differentiate between petrification and metamorphism.
| Point | Petrification | Metamorphism |
|---|---|---|
| Meaning | Conversion of organic remains (wood, shells, bones) into stone by replacement with minerals | Change of an existing rock into a new rock by heat, pressure and fluids in the solid state |
| Material changed | Organic matter such as plants and animals | Igneous, sedimentary or older metamorphic rock |
| Process | Mineral-rich water replaces the organic tissue, molecule by molecule (silica, calcite, pyrite) | Recrystallisation, new minerals, and new textures without melting |
| Agents | Mineral-bearing ground water | Heat, pressure, chemically active fluids |
| Result | Fossil (petrified wood, shell) retaining the original form | New rock (marble, slate, schist) with a new texture and structure |
| Example | Petrified wood | Limestone to marble |
✓ Answer checked by Claude Opus 5.5 (high effort)
Related questions
- Weathering versus erosion · Engineering Geology I, chapter 6 · asked 5×
- Primary versus secondary geological structures · Engineering Geology I, chapter 5 · asked 4×
- Convergent versus divergent plate boundary · Engineering Geology I, chapter 2 · asked 3×
- Intrusive versus extrusive igneous rocks · Engineering Geology I, chapter 4 · asked 3×
- Engineering geology versus geology; disciplines · Engineering Geology I, chapter 1 · asked 2×
- Body waves versus surface waves · Engineering Geology I, chapter 2 · asked 2×
- Image space versus object space methods · Computer Graphics, chapter 7 · asked 9×
- Call by value versus call by reference · Computer Programming, chapter 6 · asked 8×
- Random scan versus raster scan display · Computer Graphics, chapter 1 · asked 7×
- Rock mass versus intact rock · Engineering Geology II, chapter 6 · asked 7×