Rock Thinking Questions Set #2
Name: ____________________________
1.
Rocks are classified as igneous, sedimentary, or metamorphic based primarily on their
a. texture
b. crystal or grain size
c. method of formation
d. mineral composition
2.
Which three minerals are most commonly found in the igneous rock granite?
a. amphibole, calcite, and hematite
b. amphibole, biotite mica, and gypsum
c. plagioclase feldspar, pyroxene, and olivine
d. plagioclase feldspar, potassium feldspar, and quartz
3.
Which physical characteristic best describes the rock phyllite?
a. glassy texture with gas pockets
b. clastic texture with angular fragments
c. bioclastic texture with cemented shell fragments
d. foliated texture with microscopic mica crystals
The diagram below shows four magnified block-shaped sandstone samples labeled A, B, C, and D. Each sandstone sample
contains quartz grains of different shapes and sizes. The quartz grains are held together by hematite cement.
4.
To which class of rock does this sample belong?
a. Glassy Igneous
b. Foliated Metamorphic
c. Clastic Sedimentary
d. Vesicular Basalt
5.
In which sample did the quartz grains undergo the most abrasion during erosional transport?
a. A
b. B
c. C
d. D
6.
Sample B is most accurately called a “conglomerate”. What is the most accurate term for sample D?
a. Andesite
b. Breccia
c. Gabbro
d. Porphyry
The cross section below shows several rock formations.
7.
What is the name of the scientific theory that indicates that the Stockton sandstone is the oldest rock layer?
8.
State one piece of evidence shown in the diagram that supports the fact that the Palisade Sill is younger
than the Brunswick sandstone.
9.
Based on what you know about rocks, describe the type of magma from which the Basalt Flow crystallized.
10. Based on what you know about rocks, describe the size of the mineral crystals (the texture) of the basalt.
The diagram represents a felsic igneous rock. Letters A, B, and C represent three different minerals in the rock sample. The table
describes the physical properties of minerals A, B, and C found in the igneous rock sample.
11. Identify the texture of this igneous rock.
12. State two factors that significantly affect the formation of crystals in an igneous rock.