OES 112N Exam 1 Review

Minerals and Rocks

100

This is naturally occurring, inorganic, crystalline, and has specific chemical composition.

What is a mineral?

200

98.5% of the earth's crust is composed of this many minerals.

What is eight?

300

This is a primary difference between ferromagnesian and non-ferromagnesian silicates.

What is density?

400

These are layered deposits of rock fragments, precipitated minerals, or compacted plant and animal remains.

What are sedimentary rocks?

500

This and shear can lead to foliation in metamorphic rocks.

What is pressure?

Plate Tectonics

100

The discovery of a plant fossil on 4 continents with varied climate was early evidence for this theory.

What is continental drift?

200

Scientists use this attractive principal to establish that the continents were formerly united as a single land mass.

What is earth's magnetic field?

300

There are three main categories of these.

What are plate boundaries?

400

These rock sequences are important for recognizing ancient convergent boundaries.

What are ophiolite?

500

This and "ridge push" are the competing theories for the driving force behind plate motion

What is slab pull?

Sed. Rocks

100

This grain is roughly the size of a green pea. 

What is a pebble?

200

Symmetrical ripples form from this type of water movement.

What are waves?

300

These can be important tools for determining depositional environments, helping to decipher both the age and original location of a deposit.

What are fossils?

400

Deposits left by these rivers have little to no mud preserved.

What are braided rivers?

500

Salt playas are extensive deposits of this type of chemical sedimentary rock.

What are evaporites?

Geologic Time

100

Using these principals, we can establish the order in which a set of rocks was deposited, but not necessarily when it happened.

What is relative dating?

200

This era came after the Cambrian but before the Silurian.

What is the Ordovician?

300

In an undisturbed sedimentary sequence, the oldest rocks are here.

What is the bottom?

400

A radioactive element pair is useful for dating rocks that are younger than five of these.

What is a half life?

500

This radioactive element has a half life of 5,730, and is useful for dating organic matter. 

What is Carbon-14?

Rocks, Fossils, and Time

100

This concept can be summarized by the saying "the present is the key to the past"

what is the Principle of Uniformitarianism?

200

this is a gap in the geologic record caused by erosion or non-deposition

What is a hiatus?

300

This is an erosional surface on tilted or folded rocks, with younger sedimentary rocks deposited on top.

What is an angular unconformity?

400

During a marine transgression, water level does this.

What is rises relative to the land?

500

Marine regressions tend to lead to this type of sedimentary sequence.

What is coarsening up?