Principles of Stratigraphy

Which TWO (2) of the following primarily caused the major extinction event at the end of Permian period (252 Mya)?

• Major asteroid impact

• Very high global temperatures

• Close distance to the Sun

• Toxic ocean waters

Which TWO (2) of the following primarily explains why geologic time scale is important in stratigraphy?

• It is used for dating rocks.

• It is used to classify rock types.

• It is used to identify the formation processes of rocks.

• It is used to relate rocks to Earth's geologic history.

In which Eon period did the Earth start to form?

• Hadean

• Proterozoic

• Phanerozoic

• Archean

What type of rock contact does feature A represent?

• Fault contact

• Disconformity

• Angular unconformity

• Intrusive contact

Which type of depositional contact is formed when there is no major erosion event involved?

• Conformable deposition contact

• Angular unconformity

• Disconformity

• Unconformity

How is disconformity different from angular unconformity?

• Disconformity is at an angle to the underlying rock layers.

• Disconformity does not involve erosion at all.

• The rocks below the disconformity are tilted or folded.

• Disconformity is usually parallel to the rocks above and below it.

Which of the following BEST describes about rock contact B?

• This rock contact is the plane where two rock bodies slide.

• This rock contact is formed due to major erosion process.

• This rock contact is formed due to an igneous intrusion.

• This rock contact does not involve any movements of rocks.

What do you think the dotted lines represent? State the type of rock contact.

• Intrusive contact

• Fault contact

• Unconformity

• Conformable contact

"A geologist found two sets of sedimentary rock layers separated by an irregular surface. He also observed that the rock layers underlying this surface are extremely folded."

Based on the case scenario, what is the most likely rock contact that the geologist can conclude from his/her observations?

• Angular unconformity

• Disconformity

• Conformable contact

• Intrusive contact