Lab 8 Dating Lab

Two Types of Dating

-Relative Dating: Stating age of one unit relative to another. ex- unit A is older than unit B, but younger than unit 3.

-Absolute Dating: Quantitatively determining the age of a unit. ex- unit A is 176.543 Million Years old.

Tools to determine relative age:

- Superposition: Oldest unit on the bottom

- Horizontality: Units were originally horizontal

-Cross Cutting: If one unit cuts through another unit, the unit bieng cut is older than the unit that is cutting

*Read and know the other rules on Page 152*

Fossils can be used to determine both absolute and relative dates. See Figs 8.2-8.3

Become familiar with the timescale on page 159, don’t memorize this, just understand what it says.

Principles of Absolute age determination:

-Parent is the starting isotope ie 267 Pb

-Daughter is the isotope after decay ie 266 Pb

-Half Life: time it takes an isotope to decay to one half its original amount

*Look at and understand how to use graphs on page 161*

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