Geological Structures and Features

This lecture introduces the concept of faults, which are wave-like structures formed by bent rocks under compressional stress. It explains the role of hinge lines and axial planes in folding and describes various types of folds, including anticlines, antiforms, synclines, synforms, monoclines, domes, and basins. Each type of fold is characterized by its shape and the relative position of the oldest and youngest strata. The lecture concludes with a recap of these geological structures.

What is a fault in geological terms?

• A sedimentary layer

• A volcanic eruption

• A wave-like structure of bent rocks

• A type of rock

Where are faults most commonly found?

• Convergent plate boundaries

• Transform plate boundaries

• In the middle of tectonic plates

• Divergent plate boundaries

What is a hinge line?

• A line where rocks break

• A volcanic feature

• A type of fault

• An imaginary axis where layers bend

What is the role of an axial plane in folding?

• It connects all hinge lines and divides a fold into two symmetrical limbs

• It is a volcanic feature

• It causes rocks to break

• It is a type of fault

How is an anticline characterized?

• Convex in the direction of the youngest bed

• Concave upward

• Convex in the direction of the oldest bed

• Step-like structure

What is the difference between an anticline and an antiform?

• Anticline is convex upward, antiform is concave

• Anticline is convex toward the youngest bed, antiform is convex upward without age knowledge

• Anticline is a step-like fold, antiform is a dome

• Anticline is a basin, antiform is a dome

What defines a syncline?

• Convex in the direction of the youngest bed

• Convex in the direction of the oldest bed

• Concave upward

• Step-like structure

What is a cineform?

• A fold that is convex in the direction of the oldest bed

• A dome-like structure

• A fold that is concave upward without age knowledge

• A step-like fold

What is a monocline?

• A concave upward fold

• A basin-like structure

• A large step-like fold

• A dome-like structure

How is a basin characterized?

• A convex upward fold

• A step-like fold

• A downward structure with the youngest strata in the middle

• An upward structure with the oldest strata in the middle