ИСТИНА

The comparison of marine and terrestrial carbon isotope stratigraphy is essential to understanding perturbations in the global carbon cycle. Marine and terrestrial carbon isotope records have been compared in a number of published studies (e.g., Ando ef a/., 2003; Robinson & Hesselbo, 2004). However, such work has almost always compared marine and terrestrial records from geographically different successions and this presents a major problem in terms of accurately correlating the observed isotopic trends. Geological successions containing an abundance of both terrestrial organic matter and marine carbonate are scarce, and consequently, isotope data from coeval marine and terrestrial records are rarely published. The data presented here however, comprise Ryazanian-Hauterivian carbon isotope ratios analyzed from fossil wood and belemnites from the shallow marine Boyarka River succession in Siberia. Additional belemnite carbon isotope ratios from the Izhma River succession in Russia are also presented. The wood-derived and belemnite-derived isotope ratios are considered to primarily reflect changes in the terrestrial and marine carbon-isotope reservoirs respectively.