Complex sentence: Carbon has two stable isotopes, 12 C and 13 C, and one radioactive isotope, 14 C. Carbon isotope ratios are measured against Vienna Pee Dee Belemnite (VPDB), and have been used as an indicator of paleoclimate as well as to track ocean circulation.
Split into simpler sentences: Carbon has two stable isotopes, 12 C and 13 C, and one radioactive isotope, 14 C. Carbon isotope ratios are measured against Vienna Pee Dee Belemnite (VPDB). They have been used as an indicator of paleoclimate, as well as to track ocean circulation.