THE UNIVERSITY OF WESTERN ONTARIO

LONDON CANADA

Mid-Term Test - February 7th 1997

Time: 50 mins Intramural

1) What is a partition coefficient and how is it related to the concept of element compatibility?

2) What minerals are compatible with the following elements:

Sr Yb Rb Sc Ni

3) What is the difference between Raleigh Fractionation and Equilibrium Fractionation.

4) What equation would you use to determine the concentration of a trace element at any stage of single mineral fractionation from a melt?

5) Given an example of how you would: |

use a ratio plot to discriminate mineral |

fractionation: |

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6) What do the following acronyms mean:

MORB WP LKT CA synCOLG PK

7) What fractionation trends are exemplified on the following variation diagrams (draw the diagrams):

AFM TiO2 v FeO/MgO Ni v Y Nb v Y

8) Draw the plate tectonic fields commonly represented in a Ti/100-Zr-3*Y triangular plot?

9) What are the two normalization factors used in spidergram plots?

10) How are the elements ordered along the abscissa of spidergram diagrams?

11) What is the formula for d ¹⁸O ?

12) What is the general rule concerning light - heavy isotope fractionation in biogenic processes?

13) How do C/S ratios vary in oceanic sediments during the Paleozoic, and how would you explain the variation?

14) What is a Nicholayson graph (draw an example of the graph)?

15) During melting of the mantle are the following parent-daughter radioactive isotope pairs fractionated:

Rb Sr Re Os Sm Nd