21. The " fingerprint " of oxygen-isotope ratios inside the Antarctic rock resembles other apparent Martian rocks. 22. Oxygen isotope ratios are measured relative the standard, V-SMOW ( Vienna Standard Mean Ocean Water ). 23. Along with the neodymium isotope ratios this suggests that Panizos magmas have a strong crustal component. 24. An analysis of carbon isotope ratios indicated that neither person was subsisting on corn, he said. 25. Oxygen isotope ratios are not perfect proxies, however. 26. In freshwater environments, examining Sr87 / Sr86 isotope ratios is often employed to provide greater spatial resolution. 27. This spectrometer is adjusted to measure particularly the isotope ratios for oxygen, carbon, nitrogen, and heavier gases. 28. This normally involves isotope ratio mass spectrometry. 29. Strontium isotope ratios of the leucogranite intrusives are distinct from that of the gneiss and associated leucosomes. 30. Recently advanced high resolution gas source isotope ratio mass spectrometers can measure hydrogen isotopes of organic molecules directly.
