The amount of a single sample should not be less than 200g, but larger samples are desirable - up to 1kg. (You´ll never know in advance the content of quartz or feldspars) In order to avoid an underestimation of the age, the sample should not be exposed to light. This means the sample must be collected under circumstances that minimise or eliminate the influence of light and must be stored in opaque bags. The best time to collect the samples is at night, without moonlight. s A common daylight solution is to use a metallic cylinder (stainless steel), which is driven into the sediment and to seal both ends with opaque caps. The sediment at the ends of the cylinder, which were exposed to daylight can be removed in the laboratory. Furthermore it is very important to make sure, that the sediment in the cylinder is compact, not slack. Otherwise the light-exposed ends will mix up with the unexposed centre. In case of the cylinder is not completely filled up, some kind of stopper is needed to avoid the sediment from moving around. If the sediments are too hard to drive a cylinder in, a block of sediment can be removed as long as it keeps its integrity. Later on in the laboratory the upper layer of the block (the one who was exposed to daylight) can be removed.
Using steel cylinders during daylight, please follow steps 1 to 10: