oa Mid-Cretaceous Sequences of the Arabian Plate and their Global Expression

Six maximum flooding surfaces (K90 – K140) of Albian – Early Turonian age were recognised across the Arabian Plate by Sharland et al. (2001). These MFS together with intervening sequence boundaries/correlative conformities and maximum regression surfaces can be reasonably well age calibrated by biostratigraphy (especially ammonites, planktonic foraminifera and nannofossils) and isotope data. This allows us to correlate these surfaces outside of the Arabian Plate and to test their eustatic origin by demonstrating their occurrence on a global scale. We have found evidence for the K90 – K140 sequences in locations ranging from Europe, Arctic North America, through the western interior of the US to offshore Brazil, the west coast of Africa, India and Australia. At all these location the expression of these surfaces is biostratigraphically calibrated and hence we can be confident in a eustatic driver for the K90 – K140 sequences. It is interesting to speculate on the causes of eustacy in the mid-Cretaceous. It seems likely that a growing body of direct and proxy evidence points to a coincidence of climatic fluctuation and eustacy, suggesting that melting and creation of ephemeral polar ice may be a causal mechanism, even in what is commonly regarded as a "greenhouse" time.