Xenoliths, meteorites, and Mercury
The reputation of Goldschmidt is certainly well deserved, it is indeed huge, certainly the largest conference I’ve attended – four floors of the conference centre filled door to door with geochemists of all flavours!
Sticking to my interest in volatiles in magmatic systems, Monday started with a trip into the mantle in session 14b. Ann Peslier gave a great keynote talk reviewing the current status of water in the cratonic lithosphere (CL) through the study of water in nominally anhydrous olivine and pyoxene. Ann’s latest data converges on the idea that the lithoshpere is on the whole is relatively dry with kimberlitic magmas preferentially exploiting metasomatised (wet and weakened) CL leaving our xenolith population biased towards wetter mantle samples.
After lunch you’d have been hard pressed to find a more jam packed room than Club E and it’s not really surprising given the breadth of meteoritics on offer in the session (23c). From using variations on the Grand Tack model to produce a Mars that is indeed Mars-sized (keynote by Rubie, Izidoro) to reconciling the W-isotopic signatures of lunar samples with post giant impact equilibration (Kruijer), to creating bononitic magmas in the interior of Mercury capable of producing the vast flood basalts of the northern mercurian volcanic plains (Vander Kaaden), just to name a few.
It was fantastic too, to see the recent analytical advancements made in measuring Cr and Ru isotopes with such high precisions. Pierre Bonnand gave a hint that the new resolutions possible in Cr measurements of chondritic meteorites could yield some interesting information about mass dependent fractionations related to core formation. Fischer-Godde too presented stunning Ru data for a range of extra terrestrial samples concluding that meteorites in the current meteorite collection on Earth cannot be the source of the purported ‘late veneer’!
Here’s hoping tomorrow is just as diverse, lively, and compelling!