Examine the sides of this block carefully. Have you seen the type of markings shown here before?

On the sides of this block the cross bedded structure, the formation of which was explained at site 2, is clearly seen and as the block shows two faces nearly at right angles a more complete picture of the depositional process can be obtained. Cross bedding is a very important geological feature (sedimentary structure) as it enables the direction of the water depositing the rock forming sediment to be deduced and also, by analogy with structures found in the sediments of modern rivers and shore lines, enables deductions about past environments to be made.

Notice how the direction of slope of the cross bedding reverses at times and sometimes cuts across lower layers. This indicates a varying direction of flow of the depositing current and at times erosion of existing sediments.