New constraints upon isotope variation during the early Cretaceous (Barremian–Cenomanian) from the Pacific Ocean

Abstract

Carbon and oxygen isotope data from a succession of Cretaceous (Barremian-Cenomanian) age recovered from the Pacific Ocean (DSDP site 463) are presented. The carbon isotope curve reveals a large isotope excursion within the early Aptian where δ 13 C values reach ∼4.8 ‰ in the L. cabri-G. ferreolensis foraminifera zone. A decrease in δ 13 C values is observed at the base G. algerianus zone, before a return to more positive values at the top of the G. algerianus-T. bejaouaensis zone. The pronounced early Aptian positive event is preceded by a large negative isotope excursion, confined to the G. blowi zone. Synchronous with this excursion are increased total organic carbon values and increases in Mn and Fe concentrations. Integrated biostratigraphic and magnetostratigraphic data, together with the carbon isotope profile, suggest that the organic-rich units of site 463 are correlatable with Oceanic Anoxic Event 1a. The input of isotopically light volcanic CO 2 in concert with the intensification and upwelling of intermediate water enriched in 12 C could account for the observed trends. A potential trigger may have been the destabilization of the water column and the prodigious CO 2 emissions associated with hydrothermal activity and the emplacement of the Ontong Java Plateau. Coupled with faunal evidence, the subsequent positive carbon isotope excursion is interpreted to be resulting from high, but decreasing, productivity and possibly increasing ocean stratification resulting in strong carbon isotopic gradients and 13 C-enriched surface waters. The decrease in δ 13 C within the G. algerianus zone is coincident with more positive δ 18 O values. If these are interpreted in terms of temperature this interval may be characterized by a period of cooling and possibly a waning of C org cycling. A return to lower δ 13 C values during the middle Albian is considered to be related to the increased influence of upwelling, as opposed to a waning of C org cycling. Upwelling introduced isotopically light carbon to the surface, arresting the stratified oceanic conditions.

Environmental consequences of Ontong Java Plateau and Kerguelen Plateau volcanism

“…C (Price, 2003;Ando et al, 2008;, nannofossil biostratigraphy (Erba, 1994), magnetostratigraphy (Tarduno et al, 1989). ODP Site 866: Jenkyns, 1995).…”

“…In particular, OAE 1a is marked by a complex C isotopic anomaly that has been recognized in the Tethys, North Atlantic, and Pacifi c Oceans (Weissert, 1989;Weissert and Lini, 1991;Grötsch, 1993;Bralower et al, 1994Bralower et al, , 1999Jenkyns, 1995;Vahrenkamp, 1996Vahrenkamp, , 2010Ferreri et al, 1997;Menegatti et al, 1998;Erba et al, 1999;Jenkyns and Wilson, 1999;Luciani et al, 2001;Ando et al, 2002;Bellanca et al, 2002;Price, 2003;Immenhauser et al, 2005;Millán et al, 2009;Hu et al, 2012a;Huck et al, 2012;Bottini et al, 2014), and in terrestrial sequences (Gröcke et al, 1999;Hesselbo et al, 2000;Jahren et al, 2001;Heimhofer et al, 2003). An initial negative spike documented in marine and terrestrial records suggests a large input of isotopically light carbon into the ocean-atmosphere system, perhaps due to intensifi ed volcanogenic CO 2 emissions during the GOJE (Larson, 1991a;Weissert and Lini, 1991;Bralower et al, 1994;Erba, 1994;Weissert et al, 1998;Menegatti et al, 1998;Larson and Erba, 1999;Price, 2003), methane liberation from gas-hydrate dissociation (Gröcke et al, 1999;Hesselbo et al, 2000;Jahren et al, 2001;Beerling et al, 2002;…”

“…Short-and long-term temperature changes have been reconstructed for the latest Barremian through Aptian time interval using micropaleontological proxies (e.g., Kemper, 1987;Premoli Silva et al, 1989a, 1999Hochuli et al, 1999;Herrle and Mutterlose, 2003;Heimhofer et al, 2004;Rückheim et al, 2006a;Mutterlose et al, 2009;Keller et al, 2011;McAnena et al, 2013;Bottini et al, 2014Bottini et al, , 2015, stable oxygen isotopes (Weissert and Lini, 1991;Jenkyns, 1995;Menegatti et al, 1998;Luciani et al, 2001;Bellanca et al, 2002;Price, 2003;Ando et al, 2008;Millán et al, 2009;Kuhnt et al, 2011;Jenkyns et al, 2012;Hu et al, 2012a;Price et al, 2012;Maurer et al, 2012;Bottini et al, 2014), and biomarkers (Schouten et al, 2003;Mutterlose et al, 2010;Keller et al, 2011;McAnena et al, 2013;Bottini et al, 2014Bottini et al, , 2015. A global warming marked OAE 1a, while generally cooler temperatures persisted in the late Aptian, as indicated by the presence of glendonites and possible ice-rafted debris at high latitudes (Kemper, 1987;Frakes and Francis, 1988;De Lurio and Frakes, 1999;Price, 1999).…”

Deciphering Early Angiosperm Landscape Ecology Using a Clustering Method on Cretaceous Plant Assemblages

“…According to Erbacher et al (1998), the black shales of level "Jacob" of OAE 1b may have formed because of the inputs of detritic organic matter (DOAE) related to an increase in the precipitation. In contrast, the level "Paquier" of OAE 1b is considered as a phase of warming (8°C according to Price et al, 2003) and wetting (Heerle et al, 2003).…”

Paleoenvironments and Geochemical Signals from the Late Barremian to the Middle Aptian in a Tethyan Marginal Basin, Northeast Spain: Implications for Carbon Sequestration in Restricted Basins

“…Nonetheless, regardless of the sedimentary responses to the global perturbation, all the sites carry the same characteristic geochemical pattern that allows meaningful chemostratigraphic correlations and assess paleodepositional conditions for that time Price, 2003;Kujau et al, 2012;Godet et., 2014). Indeed, the carbon isotope stratigraphy ( 13 Carb and …”