Students should be able to understand the principles and have that as a background so that age determinations by paleontologists and geologists don't seem like black magic. Geologists in the late 18th and early 19th century studied rock layers and the fossils in them to determine relative age.
William Smith was one of the most important scientists from this time who helped to develop knowledge of the succession of different fossils by studying their distribution through the sequence of sedimentary rocks in southern England.
is a way to use geometric relationships between rock bodies to determine the sequence of geologic events in an area.
Relative dating is different from absolute dating in which specific dates are assigned to geologic events (we will discuss absolute dating techniques later).
Geologists still use Steno's principles, with some refinements and additions.
They are summarized as the Principles of Relative Geologic Age Determination, sometimes referred to as the Principles of Relative Dating.
(light brown) Next, fossil-rich sedimentary rocks were precipitated.
These rocks are tilted due to deposition on the non-horizontal surfaces of primitive rocks.
How would today's sediments appear to a geologist millions of years in the future examining outcrops of sedimentary rock that originated in our time?This aspect of Werner's model was useful for explaining the origin of tilted sedimentary rocks.(dark brown) Flat lying sedimentary rocks were eventually precipitated.Absolute dating places events or rocks at a specific time.If a geologist claims to be younger than his or her co-worker, that is a relative age.If a geologist claims to be 45 years old, that is an absolute age.