Geology Exam 1

slate, phyllite, schist, gneiss, migmatite

Give examples of Foliated Metamorphic rocks.

hornfels, marble, quartzite

Give examples of non-foliated metamorphic rocks.

Youngest in the middle, older as you go outward.

How is the magnetic reversal pattern organized from the ridge outward in terms of age?

44

How many sites have been identified on US 64 through the Ocoee River Gorge that are in danger of failure?

crystal habit

This is the process by which a mineral grows.

Petroleum Geology

What was Marie Tharpe's concentration (major) for that Masters degree?

Hanging wall

the block of rock that lies above

S waves second only solids

A type of seismic wave that moves the ground up and down or side to side. # of arrival? Can it go through solids and liquids?

thrust fault

30 degree angle reverse fault

normal fault

A type of fault where the hanging wall slides downward; caused by tension in the crust

P waves first Both solids and liquids

A type of seismic wave that compresses and expands the ground. # of arrival? Can it go through solids and liquids?

Slide 32

Answer the question.

Slide 33

Answer the questions.

Forms mountains

Continental-Continental Collision dynamics.

Forms subduction zone

Continental-Oceanic collision dynamics.

Crust has lower density Mantle has higher density Buoyancy effect

Explain densities related to isostasy.

Cleavage

How a mineral breaks along specific planes of weakness.

Fracture

How a mineral breaks when it does not have any significant planes of weakness. For quartz it is conchoidal—like glass.

He was plotting the epicenters of earthquakes. He found that earthquakes were found where the mid-ocean ridges were located. This supports continental drift theory.

Howard Foster was creating a map at the same time as Marie Tharp. What was the significance of what he was tracing when compared to Marie's Map?

Felsic

Igneous classification that includes lighter minerals—both in density and color.

Mafic

Igneous classification that includes minerals that are more dense and darker in color.

Towards the road

In what direction were the rocks that caused the landslide dipping?

• Pressure • High temperature (without melting) • Chemically active fluids

Name 3 factors that cause metamorphism in rocks.

• Puzzle Pieces • Fossil Evidence -fresh water & terrestrial reptiles, & plants • Glacial evidence in tropical regions • Similar lithologies across long distances separated by oceans • Magnetic polar wandering

Name evidence for the theory of continental drift.

There is no driving mechanism/no explanation.

Name the main problem with continental drift.

convergent, divergent, transform

Name three plate boundaries

Forms an island arc

Oceanic-Oceanic Collision dynamics.

Slump height decreases as percent of basalt aggregate increases

Slump height to percent of basalt aggregate relationship.

Love waves third only solids

Surface waves that shear the ground in a lateral direction. # of arrival? Can they go through liquids and solids?

Rayleigh waves fourth liquid, solids and gases

Surface waves that travel in a backward-rotating, elliptical motion, causing both vertical and horizontal ground movement. # of arrival? Can they go through liquids and solids?

Isostasy

The balancing of the downward force of the crust and the upward force of the mantle. (something to do with glaciers)

Uniformitarianism

The theory that says that the present is the key to the past.

index minerals

These are minerals found in metamorphic rocks that indicate the temperatures and pressures to which the rock has been exposed.

Detrital or Clastic Sedimentary Rocks

This category of sedimentary rock is classified by the size of the clasts within the rock.

Asbestos

This fibrous mineral group is either chrysotile or amphibole in structure and was previously used for fire protection. It has been linked to lung cancer and the lung disease mesothelioma.

Anticline

This geologic structure is caused by compressive stress at depth, is shaped like an upside-down U and when eroded, has the oldest material in the center.

Syncline

This geologic structure is formed by compressive stress at depth and is shaped like a U. When eroded, the youngest material outcrops at the center.

Cation Exchange Capacity and Clay minerals

This important characteristic of clay minerals provides a mechanism for vegetation to access essential nutrients in soil.

Unconformity

This is a boundary between two different rock beds or layers that indicates a period of missing time—either erosion or period of non-deposition.

Foliation

This is a metamorphic fabric that occurs in direct response to overlying pressure. It is best scene in gneiss when the mafic and felsic components are separated into separate "layers"

Mineral Classification

This is based upon the dominant anion of a mineral.

Protolith

This is the rock prior to metamorphic process alters it to a metamorphic rock, or the type of metamorphic rock before it was metamorphosed further.

Mohs hardness scale

This is the scale used to determine relative hardness of an unknown mineral.

Mylonite

This metamorphic rock is formed locally when shear forces change the character of the rock. Along a fault zone this is referred to slickensides.

Migmatite

This rock is a combination of an igneous and metamorphic rock. After the rock has become foliated it becomes exposed to additional heat and pressure, such that the felsic components melt and subsequently recrystallize.

Pyritic rocks

This type of rock, when oxidized creates problems that include heave, concrete degradation, steel corrosion, environmental damage, acid mine drainage, and accelerated weathering of rock with concomitant effects on strength and stability.

Limestone!

This type of sedimentary rock is biochemical in nature and made from either small bits of shells or direct precipitation of calcium carbonate in the form of calcite or aragonite.

A wider catchment area These include rock bolts, welded wire mesh draping, rock catchment fencing and shotcrete

What are some of the solutions recommended in this summary?

1) Layer of iridium on earth (common asteroid material) 2) Giant impact crater in gulf of mexico

What are two pieces of evidence that indicate an asteroid was responsible for the mass extinction event at the end of the Mesozoic - (The one that wiped out the dinosaurs)

The older stuff will be at the bottom and the newer stuff will be closer to the surface.

What did Nicolas Steno say about the age of strata?

Very little, if any ditch

What did the authors of the Executive Summary indicate was the primary reason for the high hazard in the specific region of US 64? (Note: this reason is entirely inadequate given the size of the slope failure.)

Climate shift caused for a warmer and drier climate.

What event occurred approximately 34 million years ago that led to the expansion of grasslands and the evolution of horses and antelopes?

Hadean Eon

What is the name of the oldest Eon that is characterized by constant volcanic activity, meteoric bombardment, and air so hot it could melt metal?

angular unconformity

What type of unconformity is shown below?

Nonconformity

What type of unconformity is shown below? (igneous rock)

Disconformity

What type of unconformity is shown below? (no igneous rock)

1) Possible meteorite impact off the coast of south America. 2) Massive volcanic eruptions evidence in Siberia.

What were two possible causes of the "Great Dying" at the end of the Paleozoic Era?

She found that the ocean floor was not a flat plain but instead displayed mountains, ridges and canyons.

When Marie Tharp created a map of the ocean floor, what did she discover?

Principle of Cross-cutting

When an igneous intrusion or fault cuts across another rock. The intrusion or fault is younger than the rock through which it intrudes or cuts.

Anywhere, usually around the plate boundaries.

Where do Earthquakes occur?

Jacques Cousteau

Who was the famous oceanographer that set to disprove Marie Tharp's theory of mid-ocean rifting only to discover her theories were correct?

It was believed to be of strategic relevance for future battles with submarines during the Cold War.

Why was the US navy interested in mapping the seafloor?

1) Only composed of one mineral—such as limestone (marble) and sandstone (quartzite) 2) Contact metamorphism does not create foliation as it is a result of heat and not overlying pressure

Why would a metamorphic rock be non-foliated?

strike-slip fault

a type of fault where rocks on either side move past each other sideways with little up or down motion

reverse fault

a type of fault where the hanging wall slides upward; caused by compression in the crust (at 60 degrees)

Footwall

block below the fault

Subducting lithosphere

mechanism to start and maintain plate tectonics.

Wadati-Benioff zone

the band of earthquakes in a downgoing plate

elastic rebound theory

theory that rocks that are strained past a certain point will fracture and spring back to their original shape