Home Contents About this website Links Help How to use this website

Mike Tuke’s

A = activity, D = demonstration, E = experiment, Pa = paper exercise,TE = thought experiment. Should be done as I = individual, P = pair, G = group. min = minutes. F = further information.
printable version of this page
further information
Crinoids Crinoidal limestone  E P F 30 min Provide a large rock slab or photo showing many crinoid stems. The slab or photo should have a north-south line drawn on.  Students measure the length, diameter and orientation of the crinoids. Students can then work out whether those crinoids in which the length is more than twice the diameter are better orientated than those whose length is less than twice the diameter by plotting rose diagrams of each group. They can also plot a size frequency diagram of the diameters. Orientation of crinoid stems  A P 20 min  Cylinders made of Fimo are used to represent crinoid stems.  They are then placed in a trough to see how they become oriented by waves.  Fimo is like plasticine but can heated to make it hard. It is available in art shops.
Earth Science Activities and Demonstrations