Mike Tuke’s

Dip and Strike (See also outcrop patterns) Dip and strike model D To demonstrate strike, dip angle and dip direction make the model in the photo from the following: a piece of hardboard 30cm by 30cm, clear plastic sheet 2mm thick 17cm by 30cm, piece of wood 14cm radius and with 40^o angle.  Measuring dip angles on photos A I F 2 min per photo  Students use protractors to measure the dip angle shown on photos of strata taken at right angles to the strike. Measuring dip and strike on block models  P F 3 min each Students measure dip angle and dip direction and strike of strata patterns painted on wooden blocks. Details of how best to make these are given in the Making the equipment. F. Apparent dip D To demonstrate apparent dip use a wooden block with strata painted on with the strike not parallel to any side. Or use a transparent box at least 10cm by 10cm by 10cm partly filled with sand.  Beware the slope changes if the box is jogged.  Idea from Peter Loader Apparent dip II  A P 3 min for each block Students are given a variety of blocks with apparent dips. They work out the true dip direction from the strike and dip angle and then measure the apparent dip. They should discover that the true dip angle is always greater than the apparent dip and that apparent dip decreases as the angle of the rock face to the strike decreases.

Earth Science Activities and Demonstrations