Improving Global Stratigraphic Resolution and Timescales for the Late Cretaceous: Carbon Isotope Chemostratigraphy and Integration With Biostratigraphy, Geochronology, and Orbital Tuning

Abstract

The accurate correlation and precise dating of strata in sedimentary basins are essential prerequisites to develop reliable facies and sequence stratigraphic models, assess the scale and continuity of potential source and reservoir intervals, document sea-level and climate change, test geophysical models, and reconstruct basin history. From exploration to field development, increasing benefits may be gained from the availability and application of a high-resolution stratigraphy. The Cretaceous represents a time interval of exceptional interest to the petroleum industry, with the deposition of source rocks that have generated the largest volume of oil and gas of any time interval in the geological record, and the formation of a high proportion of the World’s conventional and non-conventional reservoirs. Major advances in the correlation and dating of Cretaceous strata have been made over the last decade by the integration of carbon isotope chemostratigraphy and biostratigraphy¹, a step-change in the precision of radiometric dating², and the spectral analysis of physical and chemical time series to develop orbitally tuned successions³. The combination of carbon isotope chemostratigraphy, radiometric dating and cyclostratigraphy offers a unique approach for the correlation of marine and non-marine strata⁴.The state-of-the-art for Upper Cretaceous carbon isotope chemostratigraphy will be reviewed, and selected case studies will be presented to demonstrate how integration with complementary stratigraphic methods enable correlation and dating with a resolution of 40 kyr. Intercontinental, global-scale correlation is possible, with inclusion of both marine and non-marine successions⁵. This enables an Earth-system scale analysis of carbon cycle perturbations, oceanic anoxic events, volcanism, weathering, sea-level and climate change, including their impact on source and reservoir rock development.¹Jarvis, I. et al. 2006 Geol. Mag. 143, 561-608.²Sageman, B.B. et al. 2014 GSA Bull. 126, 956-973.³Thibault, N., Jarvis, I. et al. 2016 Paleoceanography 31, 847-865.⁴Arimoto, J. et al. 2018 Cret. Res. doi: 10.1016/j.cretres.2018.08.007.⁵Jarvis, I. et al. 2015 Deposit. Record 1, 53-90.

AAPG Datapages/Search and Discovery Article #90350 © 2019 AAPG Annual Convention and Exhibition, San Antonio, Texas, May 19-22, 2019