To observe the folds using sand box.

To observe the folds using sand box.

EQUIPMENTS REQURED:Sand box saw dust and colours.

THEORY:

Folds:-Folds are wave like bends, occurs in crystal rocks, due to Compressive force resulting from endogenic forces. A complete fold is composed of arched portion or Anticline and a depressed trough or syncline.In a series of folds it is evident like waves. They consist of alternate crests and troughs. The crest of the fold is termed as anticline while the trough is called synclines. An anticline and syncline constitute a fold. The elasticity of rocks determine the intensity of bending. The size of the angle between the limbs reflects the intensity of compression of the fold.

TYPES OF FOLDS:

Monocline: This is fold in which only one limb is bent.

Plunging or pitching fold: This is the fold whose axis is at the some angle with the horizontal.

Isocline fold:This is the fold whose limbs dip at the same angle in the same direction. The two limbs in this case are parallel. The axial plane may be vertical, inclined or horizontal.

Recumbent fold:This is the fold whose limbs are bent back on themselves almost horizontally.

Symmetrical fold: A fold whose limbs have the same angle of dip relative to the axial surface.

Asymmetrical fold: A fold whose limbs are not at the same angle of dip relative to axial surface. Anasymmetrical foldis one in which the axial plane is inclined.

PROCEDURE:

• Firstly, we have to empty the previous contents of sand box.
• We have to prepare sawdust of different colors by dissolving colors into sawdust.
• Place the layers of equal width of colored sawdust in box one after another.
• Layers should be properly placed and thoroughly compacted.
• Different colored layers of sawdust are representing different layers of rock.
• The whole set up should be left for 24 hours before observing folds.
• Push it from the one end, two equal and opposite forces will be acting and hence folds can be observed.

OBSERVATIONS:

OBSERVATION

COMMENTS: