Folding and faulting

Name the fold type covered

Symmetrical/simple fold

Name the fold type covered

Asymmetrical

Name the fold type coevered

Overtured

Name the fold type covered

Recumbent

Name the fold type covered

Over-thrust

Name the feature covered

Syncline

Name the term covered

Anticline

Name the term covered

Limb

Name this process of faulting

Tension

Name this process of faulting

Compression

Name this process of faulting

Shear

Name the feature covered

Footwall

Name the feature covered

Fault plane

Name the feature covered

Fault line

Name the feature covered

Scarp

Name the feature covered

Heave

Name the feature covered

Throw

Name the feature covered

Hanging wall

Name this fault type

Normal fault

Name this fault type

Reverse fault

Name this fault type

Transform

Name this feature

Dome

Fold

A curve that forms in sedimentary rocks buried in the Earth’s crust.

Ductile

Flexible. Used to refer to heated flexible rock that has the ability to change shape without breaking

Strata

Layers of rock

Buckle

How rocks change shape and bend without breaking.

Anticline

The layers of the rock that have been folded upwards

Syncline

The layers of the rock that have been folded downwards

Limbs

The slopes of a fold that connect the anticline and syncline

Symmetrical folds

Also known as even folds, form when an equal amount of pressure is applied on both sides

Asymmetrical folds

When pressure applied from one side is slightly greater than the other. As a result, one limb is steeper and shorter than the other.

Overturned folds

When pressure from one side is far greater than the other. This causes one limb to fold over on top of the other.

Recumbent fold

When the pressure from one side is so great that the limbs are horizontal to each other and moving in the same direction

Over-thrust fold

When the pressure from one side is so great that the strata of rock on one side fractures, causing one limb to be pushed up and over the other

Caledonian Orogeny

Occurred roughly 400mil years ago. Eurasian and north American plates. E.g. Croagh Patrick

Amorican Orogeny

Occurred roughly 250mil years ago, Eurasian and African plates. E.g. Macgillycuddy Reeks, Co. Kerry

Alpine orogeny

Began 60mil years ago, ongoing. African and Eurasian plates. E.g. Alps and Apennine Mts

Fault

A fracture or crack in the Earths crust

Tension

When rocks are pulled apart from both sides.

Compression

When rock is pushed together from both sides

Shearing

When layers of rock are moved sideways in opposite directions.

Scarp

The cliff formed by the vertical displacement of rock

Throw

The distance the crust has moved upwards/downwards

Heave

The horizontal movement of the rock

Fault plane

The surface which the faulted rock slides along

Hanging wall

The section of rock that slides

Footwall

The section of rock that does not move

Normal faults

Created by tension which stretches the crust at a divergent boundary. Can form a ridge valley, a section of the crust that sinks downwards between two parallel faults. E.g. East African Ridge Valley

Reverse fault/thrust fault

Formed when the crust is compressed together at a convergent boundary. Can form a horst, a block mountain that forms when a section of the crust is thrust upwards between two parallel faults, e.g. Killarney-Mallow thrust

Transform faults/tear faults

When two sections of crust move sideways at transform/passive plate boundaries, e.g. San Andreas Fault