Match the column-A with column-B.

Column-A (Rock)		Column-B (Structure type)
i.	Sedimentary rocks	a.	Stratification and lamination
ii.	Igneous rocks	b.	crystalline structure
iii.	Metamorphic rocks	c.	Foliation

The correct answer is i - a, ii - b, iii - c.

Key Points

• Igneous Rocks
  • Igneous rocks are crystalline solids that form directly from the cooling of magma.
  • This is an exothermic process (it loses heat) and involves a phase change from the liquid to the solid state.
  • Igneous rocks are given names based upon two things: composition (what they are made of) and texture (how big the crystals are)
  • Intrusive igneous rocks crystallize below Earth's surface, and the slow cooling that occurs there allows large crystals to form.
  • Examples: diorite, gabbro, granite, pegmatite, and peridotite.
  • Extrusive igneous rocks erupt onto the surface, where they cool quickly to form small crystals.
  • Some cool so quickly that they form an amorphous glass.
  • Examples: andesite, basalt, dacite, obsidian, pumice, rhyolite, scoria, and tuff.
• Sedimentary Rock
  • Sedimentary rocks are formed by the accumulation, Stratification, and lamination of sediments.
  • They are formed by
  • Weathering (breccia, conglomerate, sandstone, siltstone, and shale)
  • Can form when dissolved material precipitates from solution (Rock salt, iron ore, chert, flint, some dolomites, and some limestones)
  • Accumulation of plant or animal debris (coal, some dolomites, and some limestones)
• Metamorphic Rocks
  • Metamorphic rocks have been modified by heat, pressure, and chemical processes, usually while buried deep below Earth's surface.
  • Foliated rocks are a type of metamorphic rock that has a characteristic banded (or striped) pattern.
  • Exposure to these extreme conditions has altered the mineralogy, texture, and chemical composition of the rocks.
  • Examples: gneiss, phyllite, schist, and slate, Marble, etc.

Additional Information