Hardness Mohs Hardness Scale 1. Talc 2. Gypsum 2.5finger nail 3.5penny 3. Calcite 4. Fluorite 5. Apatite 5.0 nail glass and knife blade

6. Orthoclase (feldspar) 7. Quartz 8. Topaz 9. Corundun 10. Diamond

Striations odor magnetic Double Refraction

Mineral Resources Ore -- mineral that can be mined for a profit Gangue­­--worthless minerals in an ore body

examples of ores Ag silver Au gold Copper sulfides (covellite) Feoxides (hematite) PbS lead sulfide (galena) The U.S.A imports about 80% of the most used 16 metals!

Fig. 3.1

IGNEOUS ROCKS Magma- mostly silicate 500 – 1200 o C mobile natural

Fig. 3.2

Extrusive - crystallized from lava (aphanitic texture) Intrusive – crystallized from magma (phaneritic texture

Volcano- conical hill formed around an opening in the earth’s surface where hot rock (pyrocastic debris), gases and magma erupt.

Crater vs Caldera Opening in volcano. If 10,000 ft or greater in diameter, it is a caldera. Less than10,000 ft diameter makes it a crater.

Fig. 4.3

Fig. 4.3a-d

Fig. 4.14

Gases: steam carbon dioxide (CO 2 ) sulfur oxide methane ammonia nitrogen hydrogen resulting in acids

Fumeroles- volcanoes where “only” gases are expelled. Two explanations: 1.initial stage of volcanic formation 2. special class of volcanoe (only gases are expelled)

Pyroclastic Material – Formed by the explosive action of the gases, e.g., pumice.

Pyroclastics dust-ash cinders lapilli blocks bombs Pumice vesicles – “fossil” gas (bubbles in lava)

Box 4.5.1

Fig. 4.12

Fig. 4.6

Classification of Volcanoes shield Hawaii cinder cone Paricutin, Mexico strata cone or composite lava Vesuvius, Italy

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Box 4.6.1

Types of Lava Flows 1. Pahoehoe – smooth, ropeytexture, i.e., “fluid” 2. Aa – rough texture, viscous, not as hot, not as much gas content

Fig. 4.16

Fig. 4.17

Fig. 4.19b

Fig. 4.22

Fig. 3.24

GENERAL GEOLOGY 1113; SEC 04 Instructor: Roc Doc Last updated SYALLBUS OLD TESTS KEYS OLD TEST CALCULATE GRADE S GRADES POSTED KEYS FOR SPRING 2006 Geology Songs STUDY TIPS DR. BOSS' STUDY GUIDE DR. BOSS' VIRTUAL ROCK BAG DR. BOSS' TESTS These materials are not endorsed, approved, sponsored, or by or on behalf of the University of Arkansas, Fayetteville.

Fig. 4.22

Extrusive - crystallized from lava (aphanitic texture) Intrusive – crystallized from magma (phaneritic texture

TYPES OF MAGMA 1. granite rhyolite “coarse” “fine” phaneritic aphanitic silica (SiO 2 ) rich feldspar and quartz

2. basalt gabbro “fine” “coarse” aphanitic phaneritic iron – magnesium (Fe – Mg) rich ferromagnesian minerals, plagioclase (Ca, Na feldspar)

Granite 30 miles Basalt 5 miles Basaltic = mafic Granitic = felsic = silic

Fig. 4.30

Fig. 4.29

Fig. 4.28

Fig. 4.27