Geology 300: Physical Geology

Geology 301: Physical Geology Lab

Geology 305: Earth Science

Geology 306: Earth Science lab

Instructor: Arthur Reed, P.G.

 

 

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Igneous Rock Samples for Geol 301 Lab Activity 5.7

All samples are approximately 1 3 in size

 

 

 

SAMPLE 530

This is similar to the intrusive igneous rock of our Sierra Nevada batholith. (note the lack of the peach-colored mineral potassium feldspar)

 

 

SAMPLE 530b (also 530c)

 

 

SAMPLE 530c

 

 

SAMPLE 531

 

 

SAMPLE 535

 

 

SAMPLE 535b (also 535)

 

 

SAMPLE 536

 

 

SAMPLE 537

 

 

SAMPLE 546

 

 

SAMPLE 547

Very low specific gravity (less than 1)

 

 

SAMPLE 549

 

 

SAMPLE 550

Generally dark igneous rocks are higher in iron and magnesium, lower in silica, and higher in density.

This sample is an exception to that rule. Note the conchoidal fracture.

 

SAMPLE 563

 

 

SAMPLE 585

 

 

 

SAMPLE 586

 

 

SAMPLE 620

 

 

 

 

 

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