Rocks Flashcards
formed when molten rock (magma) from within Earth cools and solidifies
Igneous rocks
rocks solidify beneath Earth’s surface
intrusive igneous
example of extrusive igneous rocks
Rhyolite, basalt, obsidian, andesite
rocks solidify at the surface
extrusive igneous
formed when sediment (bits of rock plus material such as shells and sand) gets packed together. They can take millions of years to form. Most rocks that you see on the ground are *
Sedimentary rocks
example of sedimentary rocks
Limestone, sandstone, shale
are sedimentary or igneous rocks that have been transformed by heat, pressure or both. Metamorphic rocks are usually formed deep within Earth, during a process such as mountain building
Metamorphic rocks
example of Metamorphic rocks
Schist, marble, slate
- form from the cooling and crystallization of hot molten lava and magma. Igneous rocks undergo weathering and erosion to form *
Igneous rocks, sediments
Sediments are deposited and lithified by compaction and cementation to form * . Sedimentary rock become buried by additional sedimentary deposition, and when they are deep within the Earth, they are subjected to heat and pressure which causes them to become * With further burial and heating, they begin to melt. Partially molten metamorphic rocks are known as *
sedimentary rocks
metamorphic rocks
migmatite
As melting proceeds with increasing temperatures and depths of burial, eventually the rock becomes molten and becomes *, which cools and crystallizes to form * , or which is erupted onto the Earth’s surface as *, and cools and crystallizes to form volcanic *.
magma, plutonic igneous rock,
lava, igneous rock
Breaking down of rocks brought about by either physial or chemical means giving rise to sediments or ther rock fragments
WEATHERING
o rock breaks off into leaves or sheets along joints which parallel the ground surface;
o caused by expansion of rock due to uplift and erosion; removal of pressure of deep burial;
• Exfoliation or unloading
o repeated daily heating and cooling of rock;
o heat causes expansion; cooling causes contraction.
o different minerals expand and contract at different rates causing stresses along mineral boundaries.
• Thermal expansion -
water expands when it freezes
• Frost wedging
Rock reacts with water, gases and solutions (may be acidic); will add or remove elements from minerals
B. Chemical weathering
contain calcite and are soluble in acidic water
o Limestone and marble
o Karst topography forms on * terrain and is characterized by: caves/caverns, sinkholes, disappearing streams, springs
limestone
the process by which rock fragments and sediments are carried along by such agents as wind and running water
EROSION
the process by which rock fragments and sediments ae carried by agents of erosion are dropprd or deposited in other places.
DEPOSITION
the process by which rock fragments and other materials that accumulated, usually at the bottom of a thick column of water, get cemented together and harden into rock
COMPACTING
a change in constitution of a rock brought about by pressure, heat and chemical action resulting in a more compact and highly crystalline condition of the rock.
METAMORPHISM
are solid, inorganic (not living) substances that are found in and on earth
building blocks of rocks
Minerals
are minerals or pearls that have been cut and polished
Gems
are the most valuable gems
They include diamonds, rubies and emeralds
Precious stones
examples of minerals
Limestone, clay and quartz
