Related by context. Frequent words. (Click for all words.) 68 isotope ratios 66 isotopic composition 64 oxygen isotopes 64 elemental composition 64 isotopic 61 abundances 60 marine sediments 59 noble gases 59 zircons 57 lavas 57 lake sediments 57 radiocarbon 57 stable isotope 57 apatite 56 radiocarbon dated 56 osmium 56 aragonite 55 foraminifera 55 spectral signature 55 electron density 55 spectroscopic 55 Radiocarbon dating 55 solar nebula 55 carbon isotope 54 igneous rocks 54 atmospheric methane 54 lithosphere 54 aerosol particles 54 anisotropy 54 microfossils 54 olivine 54 nanosized 54 infrared spectroscopy 54 Fig. 1A 54 Archaean 53 paleoclimate 53 calcite 53 monazite 53 otoliths 53 lunar soil 53 iron oxides 53 stromatolites 53 colorimetric 53 Mass spectrometry 53 noctilucent clouds 53 basaltic 52 tropospheric 52 volcanism 52 oceanic crust 52 stalagmite 52 magmatic 52 morphologies 52 basalts 52 heavily cratered 52 geoid 52 photoluminescence 52 eU#O# 52 microlensing 52 spinel 52 mineralogy 52 spectral signatures 52 otolith 52 radiocarbon dating 52 igneous rock 51 regolith 51 mineralogical 51 sorption 51 kimberlitic 51 undersea volcanoes 51 clasts 51 lithology 51 continental crust 51 Computer simulations 51 baryons 51 X ray fluorescence 51 spherules 51 placental mammals 51 sediments 51 radioactive decay 51 diatom 51 diffraction pattern 51 zeolites 51 biogeochemical 51 magmas 51 crustal 51 solar irradiance 51 perovskite 51 gravity anomalies 51 silicates 51 redshifts 51 ultraviolet wavelengths 51 mudstone 51 SWNTs 51 reflectance 51 phylogenetic analysis 51 Conductivity 51 haematite 51 radial velocity 51 sediment cores 51 moonlets 51 chemical composition