WorksheetsIgneous Rocks
Total questions: 15
Worksheet time: 12mins
An igneous rock is one that
has crystallised at the Earth's surface
has crystallised well below the Earth's surface
contains either abundant quartz or glass
all of the above
A silicate magma rich in iron and magnesium
silicic
mafic
hydrous
vesicular
A very coarse-grained igneous rock believed to form from fluid-rich magmas
pegmatite
porphyry
glassy
basalt
The volcanic (extrusive) equivalent of gabbro
rhyolite
basalt
andesite
obsidian
Plutonic igneous rocks cool FASTER / SLOWER than volcanic igneous rocks
FASTER
SLOWER
Pyroclastic rocks are composed of
lava
crystals only
fragments of magma and pre-existing rocks
rocks only
A runny magma (low viscosity) will tend to produce a
coarse-textured rock because minerals will assemble easily
coarse-texted rock because the atoms will move more freely
fine-textured rock because the atoms will move less freely
fine-textured rock because the minerals will assemble easily
Felsic magmas have HIGH / LOW amounts of silica
HIGH
LOW
Magmas that cool very slowly will tend to produce a COARSE / FINE grain rock because the grain size is LARGE / SMALL
COARSE, SMALL
FINE, SMALL
FINE, LARGE
COARSE, LARGE
Aphanitic rocks cool
have pyroclastic material and cool quickly deep below Earth's surface
slowly on top of the surface
slowly with a fine-grained texture
quickly on top of the surface
An igneous rock with a phaneritic texture is composed of
pyroclasts
visible crystals
obsidian
pyroclastic material
Rhyolite is to granite, as basalt is to
volcanic ash
peridotite
gabbro
diorite
Choose the most correct answer:
Lava will form a(n) _________ igneous rock because it cools on the Earth's surface
Phaneritic
Glassy
Pyroclastic
Aphanitic
Pumice floats on water because it
is rich in silica
is full of gas
is full of gas bubble holes
is composed of crystals
Dark igneous rocks contain high concentrations of
silica
sodium
iron
iron and magnesium
