EESA06H3 Lecture 8: EESA06-LEC8.docx
Document Summary
Geological time: geological time is divided into periods in our lifetimes. Slide 3. 1: these are rocks find in arizona, the grand canyon. In the geological book we find more chapters that are missing as there more gaps than records because huge amount of geologic time go past without any rock record. It"s more like episodic recording of past environment than continuous record: the gaps that we find are called unconformities which has no primary record of ancient environment. These rocks at the top contains fossils while there is none at the bottom. Here we established the relative ages of rocks but what we are really interested in is absolute age. Slide 3. 2: the layers we see are called strata and we can see they are flat and horizontal between two layers (between top and bottom) are unconformities. We call this angular unconformity because the top layers sit on top of the bottom rocks which don"t have layers.
