Related by context. Frequent words. (Click for all words.) 75 isotope ratios 70 isotopic composition 67 oxygen isotopes 62 isotopic 60 marine sediments 59 foraminifera 59 microfossils 58 otolith 58 otoliths 57 abundances 57 elemental composition 57 noble gases 57 lake sediments 56 diatom 56 aragonite 56 radiocarbon 56 morphologically 55 zircons 55 morphologies 55 biogeochemical 55 biogenic 55 chemical composition 54 igneous rocks 54 aerosol particles 54 terrestrial ecosystems 53 Fig. 1A 53 spectral signatures 53 faunal 53 infrared spectroscopy 53 lavas 53 photochemistry 53 solar nebula 52 geochemists 52 osmium 52 mesoscale 52 electron density 52 naturally occuring 52 radiocarbon dated 52 magmas 52 spatial scales 52 montane 52 tropospheric 51 methylation patterns 51 sorption 51 metamorphism 51 atmospheric CO2 concentrations 51 braincase 51 sediment cores 51 anisotropy 51 basalts 51 Cenozoic 51 atmospheric methane 51 morphology 51 diffraction pattern 51 goethite 51 radioactive decay 51 nitrogen fixation 50 ALH# 50 atmospheric pollutants 50 microstructural 50 forcings 50 hydrothermal activity 50 basaltic 50 olivine 50 S. cerevisiae 50 uranium thorium 50 morphological 50 metallicity 50 Quaternary 50 stable isotope 50 Computer simulations 49 calcareous 49 physicochemical 49 plankton blooms 49 relict 49 protoplanetary disks 49 spherules 49 iron oxides 49 Supplementary Fig 49 prokaryotes 49 tropopause 49 arsenate 49 apatite 49 nuclei 49 Geochemistry 49 sulfide minerals 49 mid latitudes 49 Willerslev 49 inorganic compounds 49 abiotic 49 amphipods 49 solar irradiance 49 igneous 49 Soil samples 49 angiosperms 49 Conductivity 49 sediments 49 oxidise 48 striations 48 noctilucent clouds 48 hydrologic cycle