Furthermore, to achieve confidence in their estimates, geologists date 5 to ten zircon crystals from the identical rock. Occasionally, an outlying crystal will date to a much earlier time period than the others from the sample, and in these instances, geologists know that the rock sample has been contaminated by zircons from a special eruption. Furthermore, different radio-isotopic techniques can be used as independent traces of proof to validate the outcomes from the uranium-lead technique. Using such methods, scientists can very accurately date historic volcanic occasions and might extrapolate from these dates to study concerning the ages of different rock strata. To date previous occasions, processes, formations, and fossil organisms, geologists make use of quite so much of strategies. These embrace some that set up a relative chronology by which occurrences can be positioned in the correct sequence relative to at least one one other or to some identified succession of events.
This is also true of anomalies noted in carbon-14 dates, since carbon-14 relationship cannot be used to reliably date anything older than about 50,000 years (because the carbon-14 half life is only 5730 years). These methods provide legitimate age data in most situations, though there’s a small percentage of situations during which even these typically reliable strategies yield incorrect results. Such failures 
may be as a result of laboratory errors (mistakes happen), unrecognized geologic elements (nature typically fools us), or misapplication of the strategies (no one is perfect). You can decide what quantity of layers you wish to add, the thickness of each layer, add cross cuts… get creative! You could use anything small (that won’t soften or dissolve inside the dough) corresponding to rice or small rocks.