Sea-water temperatures of the early Cretaceous derived from stable isotopes of belemnites and TEX86 of organic-rich sediments
Final Report Abstract
The major findings can be summarized as follows: 1) The Valanginian - Aptian of the Boreal Realm is characterized by significant temperature variations which have been documented by using the palaeo-thermometry of the stable oxygen isotope ratios. The Valanginian and Hauterivian were generally cool, warmest phases have been demonstrated for the early Barremian. The "Aulacoteuthis warm pulse" records the highest T°C throughout the entire Valanginian – Aptian in the Boreal Realm. 2) Both TEX 86 and delta 18 O Bel proxy data indicate very warm water temperatures for the Barremian with, however, a constant off-set of 4°C between both data sets. These findings have been interpreted to indicate a subsurface dwelling of belemnites in water depth of perhaps 100m, explaining the relative “cold” delta 18 O Bel values. 3) Positive delta 13 C excursions, well known from the Tethys, have been documented for the Boreal Realm both for the mid Valanginian and the early Aptian. 4) The Mg incorporation in belemnite rostra suggests a biological control for "Acroteuthis" spp. and "Hibolithes jaculoides", perhaps reflecting different food sources. 5) Modern cephalopds originated 35 my before the Cretaceous/Paleogene extinction in the North Pacific due to faunal isolation.
Publications
- 2009. Temperature controlled deposition of early Cretaceous (Barremian - early Aptian) black shales in an epicontinental sea.
Palaeogeography, Palaeoclimatology, Palaeoecology, 273, 330-345.
Palaeogeography, Palaeoclimatology, Palaeoecology, Vol. 273. 2009, Issues 3–4, pp. 330–345.
Mutterlose, J., Pauly, S., Steuber, T.
(See online at https://dx.doi.org/10.1016/j.palaeo.2008.04.026) - 2010. TEX86 and stable δ18O paleothermometry of early Cretaceous sediments: Implications for belemnite ecology and paleotemperature proxy application. Earth and Planetary Science Letters, Vol. 298. 2010, Issues 3–4, pp. 286–298.
Mutterlose, J., Malkoc, M., Schouten, S., Sinninghe Damsté, J.S., Forster, A.
(See online at https://dx.doi.org/10.1016/j.epsl.2010.07.043) - 2010. The early Barremian warm pulse and the late Barremian
cooling: a high-resolution geochemical record of the Boreal Realm.
Palaios, vol. 25. 2010, p. 13–22.
Malkoč, M., Mutterlose, J.
(See online at https://dx.doi.org/10.2110/palo.2010.p09-029r) - 2010. Timing of the Early Aptian δ13C excursion in the
Boreal Realm. Newsletters on Stratigraphy, Vol. 43. 2010, Number 3, pp. 251-273.
Malkoč, M., Mutterlose, J., Pauly, S.
(See online at https://dx.doi.org/10.1127/0078-0421/2010/0043-0251) - in press. Belemnite extinction and the origin of modern cephalopods 35 m.y. prior to the Cretaceous−Paleogene event. Geology, Vol. 39. 2011, no. 5, pp. 483-486.
Iba, Y., Mutterlose, J., Tanabe, K., Sano, S., Misaki, A., Terabe, K.,
(See online at https://dx.doi.org/10.1130/G31724.1)
