Describing age
The number of ways to describe the age of rocks?
2
Using the positioning of rocks, we are finding what type of age?
Relative
Fossils are found in this type of rock.
Sedimentary
In order to make a complete geological record, samples must come from ____ areas.
Different
Radioactive elements occur naturally in some _____ rocks.
Igneous
Absolute age
The number of years that have passed since the rock formed.
The name of horizontal layers of sedimentary rock.
Strata
Faults are always _____ then the rock they cut through.
Younger
When rock layers erode, a ___ rock surface may be exposed.
Older
Elements change from radioactive to _____ during radioactive decay.
Stable
Relative age
Age compared to the age of other rocks around it.
This law describes old rocks are position at the bottom and younger rocks are position towards the top.
The law of superposition
A certain fossil that can help geologists match and date rock layers.
Index fossils
_____ is a gap in the geological record.
Unconformity
The atoms of one element break down to form atoms of another element.
Geologist can find evidence of what from describing the age of rocks?
Past events
An igneous intrusion is always ___ then the rock it cuts through.
Geologist ____ that layers with matching index fossils are the same age.
Infer
This describes how younger rock may be at the bottom.
Folding
Scientists use this to find the absolute age of rocks.
Half life
My sister is 30, and my brother is 7. I am describing my age using ____ age.
Relative
An igneous extrusion is made up of ____ while an igneous intrusion is made up of _____
Lava
Magma
Using this, you can determine the relative age of a fault.
____ destroyed most of Earth geological record over billons of years.
Erosion
Potassium-40 decays into ____
Carbon-14 decays into____
Argon-40
Nitrogen-14