Geochemistry Flashcards
What are CI chondrites and why are they such an important reference in isotope geochemistry?
CI Chondrites are primitive meteorites with a composition similar to that of the bulk solar system and the material from which the Earth formed
Discuss and explain why the Nd isotope composition of the BSE is observed to be essentially identical to CI chondrites and why, contrastingly, the Sr isotope compositions of the BSE and CI chondrites differ significantly. Refer to the parent/daughter ratios of the respective isotope systems
The BSE has a chondritic Sm/Nd ratio because these two elements are both refractory and lithophile.
The BSE has a non-chondritic Sr isotope composition due to a non=chondritic Rb/Sr ratio. That is beceause Rb is volatile and depleted in the BSE whilst Sr is enriched because it’s a refractory and lithophile element
