http://www.psrd.hawaii.edu/July12/water-inside-Mars.html

Water Inside MarsWater Inside Mars

Enriched Shergottites:High La/YbLow Sm/Nd (hence negative Nd)High Rb/Sr (hence high initial 87Sr/86Sr)Oxidized (higher oxygen fugacity)

Depleted Shergottites:Low La/YbHigh Sm/Nd (hence positive Nd)Low Rb/Sr (hence low initial 87Sr/86Sr)Reduced (lower oxygen fugacity)

Do water contents in mantle sources of the enriched and depleted shergottites differ like other geochemical parameters do? Measuring OH contents in apatite in Shergotty (enriched) and QUE 94201 (depleted) can answer that question.

Apatite in Shergotty

http://www.psrd.hawaii.edu/July12/water-inside-Mars.html

Water Inside MarsWater Inside MarsApatite:Ca5(PO4)3(F,Cl,OH)

H2O Measurements:Shergotty: 0.46 to 0.86 wt%QUE 94201: 0.22 to 0.64 wt%

H2O in magma when apatite crystallizes:Shergotty: 1.5 to 2.8 wt% QUE 94201: 0.7 to 2.1 wt%

H2O in pre-eruptive magma (assumes apatite crystallizes when 10% of melt remains):Shergotty: 0.15 to 0.29 wt% QUE 94201: 0.07 to 0.21 wt%

(McCubbin et al., 2012)