Rare Earth Elements and Igneous Processes

The lecture covers rare earth elements, their properties, and their significance in technology and geochemistry. It explains the systematic behavior of these elements, including their ionic radii and partition coefficients. The lecture also discusses the normalization of rare earth element data using CI chondrite and primitive upper mantle references to identify patterns. Finally, it introduces large igneous provinces, their formation through mantle plumes, and their role in continental rifting and volcanism.

What is a unique property of most Rare Earth Elements?

• They have a two plus charge.

• They are commonly found in nature.

• They are not used in technology.

• They typically have a three plus charge.

Why is it important to normalize REE data to CI chondrite?

• To increase the concentration of REEs.

• To remove initial variability from the solar nebula.

• To make the data more complex.

• To decrease the concentration of REEs.

What happens to the REE pattern as the degree of melting increases?

• The pattern becomes steeper.

• The pattern becomes flatter.

• The pattern remains unchanged.

• The pattern becomes more zigzagged.

Which mineral is europium compatible with?

• Plagioclase

• Olivine

• Quartz

• Pyroxene

What is the significance of a negative europium anomaly in a rock?

• It shows an increase in heavy REEs.

• It suggests the removal of plagioclase.

• It indicates a high degree of melting.

• It indicates the presence of olivine.

What is the effect of fractional crystallization on REE patterns?

• It decreases REE concentrations.

• It increases REE concentrations without changing the slope.

• It makes the pattern more zigzagged.

• It changes the slope of the pattern.

What typically causes the formation of large igneous provinces?

• Volcanic eruptions

• Meteorite impacts

• Mantle plume heads

• Tectonic plate collisions

What is the typical magnesium content in continental flood basalts?

• Variable magnesium content

• No magnesium content

• High magnesium content

• Low magnesium content

How do large igneous provinces relate to continental rifting?

• They can initiate rifting.

• They occur after rifting.

• They are unrelated to rifting.

• They prevent rifting.

What is a characteristic feature of oceanic plateaus?

• They are primarily composed of quartz.

• They have very thick oceanic crust.

• They are formed by tectonic collisions.

• They have thin oceanic crust.