The first Pacific record of the Late Aptian warming event

Abstract

Carbonate platforms consisting of hermatypic coral, rudists and larger foraminifers formed along the margin of the NE Japanese islands during the mid-Late Aptian. The geographical northern limit of the carbonate platforms extended to c . 36°N at that time, which is the highest latitude for coral and/or rudist formation in the North Pacific region. This geographical extension of the carbonate platform in the NW Pacific indicates extreme climatic warmth in the mid-latitudes and strong poleward heat transport systems. Contemporaneous warming has been detected in European and Australian regions, as represented by the migration of Tethyan fauna toward the boreal realm and the positive excursion of δ 13 C and negative excursion of δ 18 O in deep-sea carbonates. Our new constraint on the northern limit of ‘reef’ growth reinforces the view that an interval of greenhouse-like warmth punctuated the Late Aptian climate.

Shallow water carbonate platforms (Late Aptian–Early Albian, Southern Apennines) in the context of supraregional to global changes: re-appraisal of palaeoecological events as reflectors of carbonate factory response

“…This allows a better comparison of the isotope record of the studied sections with reference curves (cf. Bralower et al, 1999;Clarke and Jenkyns, 1999;Fassel and Bralower, 1999;Jenkyns and Wilson, 1999) and the main climatic and volcanic events of the Aptian (Haq et al, 1987;Weissert and Lini, 1991;Takashima et al, 2007;Mutterlose et al, 2009).…”

“…Note that the planktonic foraminiferal zones refer to different zonal schemes. Aptian substages on the Piobbico and Cismon isotope curve are from Takashima et al (2007). The lower/upper Aptian boundary on the Tobenna-Faito and Serra Sbregavitelli isotope δ 13 C curves is inferred from the Piobbico and Cismon curve.…”

“…The "Orbitolina Level" of the middle Gargasian, in all likelihood, formed at the same time as part of the "Niveau Fallot" formed in a hemipelagic setting connected to the Tethyan Ocean, and probably to the Thalmann black shale event in California and a dark horizon on the Mazagan Plateau (DSDP Site 545; cf. , as well as an organic-rich horizon in the Aptian of Iran , that is in a period when sea level was falling (Haq et al, 1987;Herrle and Mutterlose, 2003;Takashima et al, 2007). A fall of sea level is accompanied by erosion, seaward transport and oxidation of organic carbon-rich sediments and other organic matter, and therefore by a drop in carbon isotope values (Jenkyns et al, 1994) as is the case for the reference curves in the G. ferreolensis to G. algerianus zone Bralower et al, 1999;Jenkyns and Wilson, 1999;Fig.…”

“…8) invites to link the "Orbitolina Level" with processes that affected the global carbon cycle during the lower Cretaceous (cf. Weissert and Lini, 1991;Takashima et al, 2007;Heldt et al, 2010). The "Orbitolina Level" of the middle Gargasian, in all likelihood, formed at the same time as part of the "Niveau Fallot" formed in a hemipelagic setting connected to the Tethyan Ocean, and probably to the Thalmann black shale event in California and a dark horizon on the Mazagan Plateau (DSDP Site 545; cf.…”

“…The Aptian-Albian was a time punctuated by biotic and environmental changes (e.g. Takashima et al, 2007;Hay, 2008;Huck et al, 2010;Donnadieu et al, 2011) that resulted in the drowning of many Tethyan carbonate platforms (Föllmi et al, 1994;Graziano, 1999Graziano, , 2000Heldt et al, 2010;Masse and Fenerci-Masse, 2011;Skelton and Gili, 2012). Increased geodynamic activity and massive injection of carbon dioxide in the ocean-atmosphere system accelerated the water cycle and increased weathering rates, thus threatening carbonateprecipitating organisms (e.g.…”