Geol 110Earth Materials

Lecture: MWF 1:25- 2:15 p.m.

Lab: T 9:30 – 12:15 OR Th 1:30 – 4:30 p.m

Professor: Greg Druschel

Office: Delehanty 321

Office Hours : WF 2:15-3:15 pm

T.A.: Phoebe Judge

Class Goals• Recognize major rock-forming minerals and other

selected minerals in hand specimen and thin section

• Master use of several techniques for the identification of minerals, including the petrographic microscope and x-ray diffractometer

• Develop the ability to relate crystal chemistry, crystallographic alignment, and physical attributes of a mineral to guide identification and assess a mineral’s origin and history

Grading

• Laboratories 20%

• Lab exam 10%

• Mid-term exam 20%

• Final exam 20%

• Adopted mineral paper 10%

• Homeworks 10%

• Participation 10 %

Where do earth’s materials form?

Structure of the Earth

Plate Tectonics

Spreading centers

Changing landscape

Energy• We will revisit the concept of energy as a

waveform in many manifestations – light energy, particle energy, sound energy

• Waves in water are also an expression of energy, but the expression of that energy has different forms, a point surfers know well…

Earthquakes

• Energy stored (in faults) due to movement of plates is periodically released, generating an earthquake

• Energy transmitted as different types of waves through the earth – the amplitude of the largest wave is the strength

• Richter Scale – Logarithmic measure of wave

• Mercalli index – Based on observations of earthquake damage

Mercalli Intensity(at epicenter)

Magnitude Witness Observations

I 1 to 2 Felt by very few people; barely noticeable.

II 2 to 3 Felt by a few people, especially on upper floors.

III 3 to 4Noticeable indoors, especially on upperfloors, but may not be recognized as an earthquake.

IV 4 Felt by many indoors, few outdoors. May feel like heavy truck passing by.

V 4 to 5Felt by almost everyone, some people awakened. Small objects moved. Trees and poles may shake.

VI 5 to 6Felt by everyone. Difficult to stand. Some heavy furniture moved, some plaster falls. Chimneys may be slightly damaged.

VII 6Slight to moderate damage in well built, ordinary structures. Considerable damage to poorly built structures. Some walls may fall.

VIII 6 to 7Little damage in specially built structures. Considerable damage to ordinary buildings, severe damage to poorly built structures. Some walls collapse.

IX 7Considerable damage to specially built structures, buildings shifted off foundations. Ground cracked noticeably. Wholesale destruction. Landslides.

X 7 to 8Most masonry and frame structures and their foundations destroyed. Ground badly cracked. Landslides. Wholesale destruction.

XI 8Total damage. Few, if any, structures standing. Bridges destroyed. Wide cracks in ground. Waves seen on ground.

XII 8 or greater Total damage. Waves seen on ground. Objects thrown up into air.

Water

• 70% of the surface of the earth is covered with water

• The interaction of water with rocks is responsible for many reactions in the crust

• Water is the one universal requirement for life as we know it – the range of conditions we know life to be present is constrained by the H2O being a liquid

Energy• We will revisit the concept of energy as a

waveform in many manifestations – light energy, particle energy, sound energy

• Waves in water are also an expression of energy, but the expression of that energy has different forms, a point surfers know well…

Waves• Any wave motion through any medium (water, air,

rock) does NOT involve any transfer of mass, i.e., a tsunami does not carry water particles thousands of miles

• Why does a wave have a physical manifestation then?

• Particles are affected by energy, but they are displaced, returning to their original state – water waves can displace particles up, down, sideways, and circularly shallow waves generate circular displacement, causing breaking

Tsunamis• Tsunami wave is generated by a physical

displacement – earthquake WITH ground rupture, landslides, glacial ice calving, etc.

• Extremely high energy, but the wave in the open ocean is very small…

• Energy of the wave extends to the bottom of the ocean (wind-generated waves are much lower energy!)

Volcanic provinces

Mt. Pinatubo

Lava

Volcanic settings

Cinder cones

Explosive eruptions

Volcanic provinces

Hot spots

Hot spots

Basalt flows

Plutons

Intrusions

Metamorphic settings

Orogenic settings

Ore deposits

Oil

Weathering

• How is massive rock broken down and transported?

Sedimentary deposition• Weathering of any rock and transport of that

material to lower E environment followed by lithification yields sed. rx

Depositional settings

• Keyed to transport of physical/ chemical components of parent material

• Tells 2 stories – who were the parents and how far away did it go?

Chemical deposition

• Formation of minerals from aqueous solution requires some change in environment for the ions to precipitate

Fossils• Here parent material were organisms – usually

ones that were partially composed of a durable mineral material

• Requires a special depositional setting– Quick burial, fine/ chemical covering, replacement

reactions

• Also tell us approximate age of deposition

Biominerals• Microorganisms may

also have a significant impact on mineralogy!

A word about classification…

• Umbrella terms

• Mineral nomenclature α taxonomy of animals, plants, and microbes