Section 2Relative Dating: Which Came

First?

•Write a news article from the perspective of a geologist

•Include all of the key terms from this week

•Your story must make sense

•Be creative and have fun!

Relative Dating• Determining the age

and order of particular events or objects.

http://encyclopedia.laborlawtalk.com/wiki/images/thumb/1/14/250px-Grand_Canyon_geologic_column.jpeg

Superposition• Younger rocks lie

above older rocks in undisturbed sequences.

http://earth.geol.ksu.edu/liu/g100/figures/15_superposition.jpg

The Geologic Column• An ideal sequence

of rock layers that contain all the known fossils and rock formations on earth, arranged from oldest to youngest.

http://en.wikipedia.org/wiki/User:Maveric149/images/Idaho

http://www.nps.gov/care/resources/admin%20history/images/fig3.jpg

Disturbed Rock Layers

http://scamp.wr.usgs.gov/scamp/photo/aug88p07JKN-26M.jpg

http://www.stmarys.ca/conted/webcourses/GEO/GEO99/pubigneous/intrusion.gif

http://www.utdallas.edu/dept/sci_ed/torch/bb00_geo-al_files/image018.jpg http://www.nps.gov/care/graphics/wtrpkt1.gif

The Missing Piece

• Unconformity-a surface missing part of geologic column.–Nondeposition–Erosion

• Disconformities

• Nonconformities

• Angular Unconformities