7.5: Activity 7D - Determining Textures and Compositions from Samples
- Page ID
- 14810
For this section, you will need igneous rock samples selected by your instructor. Locate these samples before you begin.
-
Select the first sample designated by your instructor. Is this sample composed mainly of crystals, holes, glass, or clasts?
-
Crystals
-
Holes
-
Glass
-
Clasts
-
What is the textural term for this sample?
-
Crystalline, aphanitic
-
Crystalline, phaneritic
-
Vesicular
-
Glassy
-
Pyroclastic or fragmental
-
What is the likely cooling history of this sample?
-
This sample cooled as magma, slowly, in the intrusive cooling realm.
-
This sample cooled as lava, quickly, in the intrusive cooling realm.
-
This sample cooled as magma, slowly, in the extrusive cooling realm.
-
This sample cooled as lava, quickly, in the extrusive cooling realm.
-
What is the overall color of this rock?
-
Green
-
Dark - dark gray, green, black
-
Gray
-
Light - pink, white, beige
-
What is the likely composition of this rock?
-
Felsic
-
Intermediate
-
Mafic
-
Ultramafic
-
Identify this igneous rock by name:
-
Select the next sample designated by your instructor. Is this sample composed mainly of crystals, holes, glass, or clasts?
-
Crystals
-
Holes
-
Glass
-
Clasts
-
What is the textural term for this sample?
-
Crystalline, aphanitic
-
Crystalline, phaneritic
-
Vesicular
-
Glassy
-
Pyroclastic or fragmental
-
What is the likely cooling history of this sample?
-
This sample cooled as magma, slowly, in the intrusive cooling realm.
-
This sample cooled as lava, quickly, in the intrusive cooling realm.
-
This sample cooled as magma, slowly, in the extrusive cooling realm.
-
This sample cooled as lava, quickly, in the extrusive cooling realm.
-
What is the overall color of this rock?
-
Green
-
Dark - dark gray, green, black
-
Gray
-
Light - pink, white, beige
-
What is the likely composition of this rock?
-
Felsic
-
Intermediate
-
Mafic
-
Ultramafic
-
Identify this igneous rock by name: