Related by context. Frequent words. (Click for all words.) 73 isotope ratios 73 oxygen isotopes 69 isotopic composition 66 isotopic 64 elemental composition 63 noble gases 62 abundances 62 marine sediments 60 aragonite 60 osmium 60 lavas 59 microfossils 59 stable isotope 59 chemical composition 58 foraminifera 58 biogeochemical 58 zeolites 58 radiocarbon 58 aerosol particles 57 lake sediments 57 igneous rocks 57 sediments 57 atmospheric methane 56 solar nebula 56 magmas 56 carbon isotope 56 diatom 56 biogenic 56 zircons 56 otolith 56 sorption 56 radiocarbon dated 55 spectral signatures 55 perovskite 55 coprolites 55 electron density 55 morphologies 55 iron oxides 55 apatite 55 sediment cores 55 faunal 55 spherules 55 ALH# 55 morphology 54 atmospheric CO 54 diatoms 54 Fig. 1A 54 terrestrial ecosystems 54 basalts 54 igneous 54 nitrogen atoms 54 spinel 54 mineralogy 54 infrared spectroscopy 54 stromatolites 54 hydroxyl radicals 54 radioactive decay 53 nanosized 53 clathrates 53 prokaryotes 53 MgO 53 basaltic 53 otoliths 53 igneous rock 53 spectral signature 53 melanosomes 53 nitrogen fixation 53 particle sizes 53 olivine 53 silicates 52 tetrahedral 52 placental mammals 52 calcite 52 salt crystals 52 histone modifications 52 Radiocarbon dating 52 Cenozoic 52 paleoclimate 52 arsenate 52 colorimetric 52 anionic 52 tropospheric 52 snail shells 52 sulphates 52 Neandertal 52 stalagmite 52 anomalously 52 anisotropy 52 spectroscopic 51 mitochondrial genome 51 porphyrin 51 deglaciation 51 Pliocene 51 Meridiani 51 desorption 51 lunar soil 51 ^ sub 51 planetesimals 51 polar vortex 51 morphologically 51 X ray fluorescence