Keep these principles in mind as you progress through the rest of the activities in this assignment.
In Assignment 3, we began exploring the age of the Earth. Through presentation and discussion of individual ideas, the class reached agreements as to the best way to complete each of the prompts.
You worked in small groups and as a class to complete the "If Scientists Think. Today's assignment will allow you to compare and contrast your ideas to some of the actual methods scientists used to develop an estimation of the age of the Earth.
If the geological record was 100% complete and there were no breaks in sedimentation, the stratigrapher's job would be an easy one.
However, breaks in sedimentation do occur and when this happens, geologists' refer to this missing strata as an unconformity.
When found in rocks as far away as Australia you could reasonably expect those rocks to be the same age as those in Cliviger Valley!
A third fact emerges from the study of stratigraphy - the UNCONFORMITY.The table below summarises key features: Gastrioceras listeri is a particularly good example of a ZONE fossil.As it is free swimming it could have travelled a considerable distance.Now that you have discovered the method that scientists originally used to date geological features, you may be questioning the accuracy of this dating method.After all, it is possible that rock layers can be disturbed, overturned, and altered in both natural and unnatural ways.This is shown below: The Angular Unconformity The strata A to E was deposited first, tilted, subjected to erosion (peneplained) and submerged.