(DY-AS-TRUH-FIZ’M)

Diastrophism

DIASTROPHISM

Refers to the series of processes by which the major features of the earth’s crust were formed and changed due to relative changes in the position and in the formation of rock, which maybe sudden, causing earthquakes.

3 classification of earth’s movement

1. Uplift- is either local or wide spread of the crust.

2. Subsidence- occurs when the earth’s crust sinks.

3. Thrust- is a horizontal motion of the crust.

3 classification of earth’s movement

1. Uplift- is either local or wide spread of the crust.

Upward Movemen

t

UPLIFT

Island in Pacific

Scandinavian in Sweden

3 classification of earth’s movement

2. Subsidence- occurs when the earth’s crust sinks.

Downward

Movement

Subsidence

Island in Pacific Drowned

Valley

3 classification of earth’s movement

3. Thrust- is a horizontal motion of the crust.

THRUST

1906 Movement of rock in

San Francisco

Effects of DIASTROPHISM

Stress

CompressiveTensional

shear

Strain

Elastic

PlasticFracture

Folding

domeBasinAnticlin

eSynclineMonocline

Faulting

Dip-slip

Strike-slip

Oblique-slip

Effects of diastrophism

1. Stress and strain

2. Folding3. Faulting

Effects of diastrophism

1. Stress and Strain

THE DIFFERENCE BETWEEN STRESS AND STRAIN

Stress- is a force that tends to compress, pull apart, or distort a rock.

Strain- is the adjustment to stress which could result into a change in volume or shape or could even lead to breaking.

3 types of STRESS

Compressive stress- result from the movement of two plates pressing on a stationary plate.

Tensional stress- effect of one plate moving away from a fixed plate.

Shear stress- results from the sliding motion of two plates which pass one another or by one plate sliding a fixed plate.

3 types of STRESS

Compressive stress- result from the movement of two plates pressing on a stationary plate.

3 types of STRESS

Tensional stress- effect of one plate moving away from a fixed plate.

3 types of STRESS

Shear stress- results from the sliding motion of two plates which pass one another or by one plate sliding a fixed plate.

3 types of Strain

Elastic strain- flexibility of rock units are displayed by going back to their original shape after they are freed from stress.

Plastic strain- rock units are deformed either by molding or bending after the stress was released.

Fracture strain- rock units break or crack.

Effects of Diastrophism

2. Folding- curving of layered bedrocks where there is an application of stress.

FOLDS- are warps in layered bedrocks.

There are 5 types of folds:1. Dome2. Basin3. Anticline4. Syncline5.Monocline

TYPES OF FOLDS

Dome- vertical upward stress with big ascending bulge

Basin- downward bulging fold Anticline- arch shaped fold Syncline- trough shaped fold Monocline- horizontal beds are

modified by step warps

TYPES OF FOLDS

TYPES OF FOLDS

Dome- vertical upward stress with big ascending bulge

TYPES OF FOLDS

Basin- downward bulging fold

TYPES OF FOLDS

Anticline- arch shaped fold

TYPES OF FOLDS

Syncline- trough shaped fold

TYPES OF FOLDS

Monocline- horizontal beds are modified by step warps

EFFECTS of DIASTROPHISM

3. Faulting- results when there is a fracture in the continuity of a rock formation.

FAULT MOVEMENT- direction of slippage

There are 3 types of fault movement:1. Dip Slip fold2. Strike slip fold3. Oblique slip fold

TYPES OF FAULT MOVEMENT

Dip-slip fold- movement is parallel to the fault surface. Normal Fault Reverse Fault

Strike-slip fold- indicates the horizontal motion parallel to the strike of the fault surface.

Oblique-slip- has both strike slip and dip slip components

TYPES OF FAULT MOVEMENT

Dip-slip fold- movement is parallel to the fault surface. Normal Fault Reverse Fault

TYPES OF FAULT MOVEMENT

Strike-slip fold- indicates the horizontal motion parallel to the strike of the fault surface.

TYPES OF FAULT MOVEMENT

Oblique-slip- has both strike slip and dip slip components

DIASTROPHISM causes…….