Chapter 10 - Geologic Time

Catastrophism - great catastrophes had shaped the landscape

 

James Hutton & his dog Missy

 

UNIFORMITARIANISM ? the physical, chemical and biological laws that operate today are the same ones that operated in the past.

Your book neglects to mention William Smith first geologic map.

 
 

Relative Dating -sequence of formation, does NOT tell you how old or how long (has nothing to do with Tenn.)


 

Law of Superposition -  in undeformed strata the oldest rocks are at the bottom.
 

Principle of Original Horizontality -  layers of sediments are generally deposited in horizontal layers. So it they are still horizontal they are not disturbed
 

 
 

Principle of Cross-cutting Relationships- what do you think this is (Fig. 10.5 pg. 276)
 

Inclusions -  pieces of one rock that are included within another


 

Unconformity - a surface that represents a break in the rock record caused by erosion or nondeposition. Multiple types p.276-277.

 

Correlation

 

Fossils -  RFC p. 278-283.

Dating with Radioactivity


 

Isotopes
 

Half-Life - time required for 1/2 of the nuclei in a sample to decay. Not all rocks can be dated radiometrically.
 

Dating with Carbon 14 - ~75,000 yrs.
 

 
 

Dating with Jlo - ~ 1 yr.
 

 
 
The Geologic Time Scale ( Figure 10.17 p. 289)