Paleomagnetism

HideShow resource information
Preview of Paleomagnetism

First 243 words of the document:

Palaeomagnetism
Magnetic inclination
When a rock is cools the magnetic minerals align parallel to
the magnetic field: when they reach the Curie point
The Curie point
The Curie point is the temperature at which certain materials
lose their permanent magnetic properties, to be replaced by
induced magnetism.
Orientation gives the position of the pole at time of cooling which can indicate latitude
Can be preserved in sediments at the time of deposition
Polar wandering curves
Determines the position of the magnetic pole at the time of cooling
Can be used in rocks of different ages
Plotting positions of the poles of different ages on a map and joining
up the points (see picture) to produce an apparent Polar wandering
curve across a continent
"Apparent" because the continent moves not the pole
Lots of continents have polar wandering curves and there cannot have been several
poles at the same time more likely that the continents were once joined and have since
been separated
Shows changes in the poles relative to continents over time
Also shows continent _ collision _
and separation
Evaluation
Useful techniques if backed up by other studies (such as sediments and fossils)
Assumes magnetic field has always been dipolar and close to geographic north
Inaccuracies caused by problems with radiometric dating of rocks

Other pages in this set

Page 2

Preview of page 2

Here's a taster:

Assumes rocks have not been overturned or magnetically disturbed since
formation…read more

Comments

No comments have yet been made

Similar Geology resources:

See all Geology resources »See all resources »