Oxygen isotope compositions of conodonts – analytical challenges of in situ SIMS studies

Bulk Oxygen-isotope Compositions of Different Lithologies in Sutter’s Mill

SIMS analyses of the oldest known assemblage of microfossils document their taxon-correlated carbon isotope compositions.

Analyses by secondary ion mass spectroscopy (SIMS) of 11 specimens of five taxa of prokaryotic filamentous kerogenous cellular microfossils permineralized in a petrographic thin section of the ∼3,465 Ma Apex chert of northwestern Western Australia, prepared from the same rock sample from which this earliest known assemblage of cellular fossils was described more than two decades ago, show their...

Herbivore tooth oxygen isotope compositions: Effects of diet and physiology

-The applicability of rapid and precise laser probe analysis of tooth enamel for 6 ~O has been verified, and the method has been applied to different modern herbivores in East Africa. Sampling and pretreatment procedures involve initial bleaching and grinding of enamel to <75 /~m, and elimination of adsorbed water and organic compounds with BrFs. Typical analytical reproducibilities for 0 .5-2 ...

Oxygen- and Mg-isotope Compositions of Cais from Rumuruti

Introduction: We have recently characterized the mineralogy and petrography of ~ 100 CAIs from ~20 R chondrites [1]. Here we report O-isotope compositions of ten R CAIs and Mg-isotope composition of three hibonite-bearing CAIs: H030

SIMS measurements on oxygen-isotopic compositions of chondrules and matrix in the Yamato 691 EH3 chondrite

Introduction: Whole rocks, chondrules and matrix from the same chondrite group typically have the same or very similar oxygen-isotopic compositions [e.g., 1]. Among the three major clans of chondrites, enstatite chondrites (ECs) have the most uniform oxygen isotopic compositions (Fig. 1). In order to study oxygen-isotopic heterogeneity of ECs in microscale, we carried out SIMS measurements on c...