High-resolution stable isotope records from the Upper Cretaceous rocks of Italy and Spain: Glacial episodes in a greenhouse planet?

Abstract

Research Article| February 01, 2000 High-resolution stable isotope records from the Upper Cretaceous rocks of Italy and Spain: Glacial episodes in a greenhouse planet? Heather M. Stoll; Heather M. Stoll 1Department of Geosciences, Princeton University, Princeton, New Jersey 08544 Search for other works by this author on: GSW Google Scholar Daniel P. Schrag Daniel P. Schrag 2Department of Earth and Planetary Sciences, Harvard University, Cambridge, Massachusetts 02138 Search for other works by this author on: GSW Google Scholar GSA Bulletin (2000) 112 (2): 308–319. https://doi.org/10.1130/0016-7606(2000)112<308:HSIRFT>2.0.CO;2 Article history received: 15 May 1998 rev-recd: 04 Mar 1999 accepted: 11 May 1999 first online: 01 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share MailTo Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation Heather M. Stoll, Daniel P. Schrag; High-resolution stable isotope records from the Upper Cretaceous rocks of Italy and Spain: Glacial episodes in a greenhouse planet?. GSA Bulletin 2000;; 112 (2): 308–319. doi: https://doi.org/10.1130/0016-7606(2000)112<308:HSIRFT>2.0.CO;2 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract High-resolution δ13C and δ18O records from upper Albian to lower Santonian pelagic carbonates of the Contessa Quarry section in Italy exhibit large positive oxygen isotopic excursions of ∼1‰ in the lower Cenomanian and upper Turonian–Coniacian strata. Within the uncertainties of biostratigraphic correlation, these positive excursions appear to correspond to times of large sea-level regressions in global sequence stratigraphic sea-level curves. Several lines of evidence suggest that the major δ18O excursions in Contessa reflect episodes of global cooling and not differential diagenesis. Numerical models of oxygen isotope exchange during diagenesis show that a high contrast in the degree of alteration would be required to produce these signals as artifacts of diagenesis, and lithological data provide no evidence for such large contrasts in the degree of alteration. Furthermore, although precise correlation with a section in the south of Spain is hampered by stratigraphic complexities, the general sequence of major positive δ18O excursions is reproduced. It is unlikely that differential diagenesis would produce similar artifacts in multiple sites. One explanation for the link between episodes of global cooling and sea-level falls is that global cooling events led to polar ice-sheet accumulation, lowering sea level. Although ice-free conditions have been inferred from evidence for a much warmer climate in Late Cretaceous time, our results suggest that the relationship between continental high-latitude ice sheets and overall climatic warmth warrants further examination. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.