Mathematics – Logic
Scientific paper
Jan 2012
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012gecoa..77..383t&link_type=abstract
Geochimica et Cosmochimica Acta, Volume 77, p. 383-395.
Mathematics
Logic
Scientific paper
We present petrologic and Secondary Ion Mass Spectrometry (SIMS) oxygen isotope analyses of Ca-carbonate within a group of paired Antarctic CM2 chondrites. The carbonates can be grouped into two isotopically and morphologically distinct populations. Type 1 grains (small matrix grains) possess average δ18O of 33.7 ± 2.3‰ (1σ) and average Δ17O of -0.81‰ ± 0.90‰ (1σ). Type 2 grains (calcite aggregates) possess distinct oxygen isotopic compositions, average δ18O of 19.4‰ ± 1.5‰ (1σ) and average Δ17O of -1.98 ± 0.9‰ (1σ). These differences are interpreted to indicate that the two populations of calcite formed under different conditions at different times. The carbonates have textural features that suggest an extraterrestrial origin. The data presented here fall within error of a previously measured array for carbonates from CM falls (Benedix et al., 2003). The presence of two generations of carbonate suggests carbonate formation in two discrete events on the parent body of these meteorites. The oxygen isotopic data presented here deviate from prior bulk carbonate measurements undertaken for these meteorites. Most likely, this deviation is because bulk carbonate analyses included vein carbonate which formed during terrestrial weathering.
Farquhar James
Guan Yifeng
Leshin Laurie Ann
Tyra M. A.
No associations
LandOfFree
An oxygen isotope dichotomy in CM2 chondritic carbonates—A SIMS approach does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with An oxygen isotope dichotomy in CM2 chondritic carbonates—A SIMS approach, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and An oxygen isotope dichotomy in CM2 chondritic carbonates—A SIMS approach will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-910013