Grand canyon relative dating exercise
I have only marked the most significant unconformities.They occur above and below the Zoroaster Granite, at the base of the Temple Butte Limestone, and at the base of the Surprise Canyon Formation. The upper part of the group is non-marine and tracks of quadrupeds are found on bed tops.Once the rocks are deposited flat, forces can act upon them to tilt or fold them.Law of superposition: This is one of the most basic techniques of relative dating geologists use.
Using geologic dating principles and fossils preserved in the layers, the ages of each layer have been established.The letters to the left of each layer in the diagram show abbreviations for the geologic time periods when the rocks formed.Not used for dating rocks, except carbonates from Earth's surface such as recent coral reefs.These tracks are believed to have been made by amphibians or primitive reptiles.Sediments appear in many places to be thin beds spread over wide areas in short periods of time. At its base, the limestone is interbedded with green shale and sandstone.
It is generally chocolate brown, but is lighter colored in some areas. Ripple marks, showing strong currents in one direction can also be found.