trace (minor) elements

Question 1

what is a trace (minor) element

Answer 1

<0.1wt% of rocks composition
Reported at ppm or ppb

commonly reported as oxide

Question 2

trace element examples

Answer 2

TiO2
MnO
P2O5
CO2

Question 3

why analyze trace elements

Answer 3

sensitive to processes of magma genesis and differentiation

Question 4

partition coeffiecient

Answer 4

behaviour of trace elements in igneous processes

whether they prefer to enter a crystallizing mineral or remain in melt

concentration of a particular element in a solid/concentration of a particular element in a melt

Question 5

incompatible trace elements

Answer 5

trace elements concentrated in melt during crystallisation or partial melting

Kd < 1

Question 6

compatible trace elements

Answer 6

trace elements concentrated in solid during crystallisation or partial melting

Kd > 1

Question 7

incompatible trace elements examples

Answer 7

large ion lithophile elements (LILE)

high field strength elements (hfse)

rare earth elements (ree)

Question 8

compatible trace elements examples

Answer 8

Ni
V
Cr
Co
Sc

Question 9

large ion lithophile elements (LILE) behaviour

Answer 9

fluid-mobile, like to get transported in aqueous fluids

subducting oceanic lithosphere dewaters in subduction zone, carrying LILE. goes up mantle wedge

Question 10

high field strength elements (hfse) behaviour

Answer 10

not fluid mobile, staying in rocks but when melted, staying in melt

Question 11

rayleigh fractionation

Answer 11

using trace elements to model perfect fractional crystallization

Question 12

what are REE atoms

Answer 12

lanthanides

form cations with 3+ charge

ionic radius decreases from la to lu

Question 13

light and heavy REE compatibility

Answer 13

light REE more incompatible