LATE ALBIAN-CENOMANIAN PLANKTONIC FORAMINIFERAL BIOSTRATIGRAPHY, TAXONOMY AND PALEOCEANOGRAPHIC INFERENCES ...

• Main Author: GILARDONI, SILVIA ELENA
• Format: Text
• Language: English
• Published: Universit� degli Studi di Milano 2017
• Subjects: Leckie; Planktonic foraminifera
• Online Access: https://dx.doi.org/10.13130/gilardoni-silvia-elena_phd2017-02-24; http://air.unimi.it/handle/2434/479427

The mid-Cretaceous period (about 120 Ma to 80 Ma) was characterized by unusually warm climate, low thermal gradient between latitudes and by a series of Oceanic Anoxic Events (OAEs) promoting deposition of black shales (e.g. Br�h�ret, 1988; Gale et al., 1996; Coccioni, 2001; Bornemann et al., 2005; Gambacorta et al., 2014, among others). During the late Albian-Cenomanian (~105-93 Ma), a major radiation of planktonic foraminifera did occur for the first time in their evolutionary history and was marked by the appearance of novel morphologies (biserial taxa and single-keeled trochospiral taxa with supplementary apertures) and by the development of new and more complex wall textures (macroperforate, muricate and costellate) on planispiral and trochospiral taxa that lasted until the end of the Cretaceous (Gonz�lez-Donoso et al., 2008; Lipson-Benitah, 2008; Georgescu and Huber, 2006, 2009; Huber and Leckie, 2011). However, the often imprecise usage of the key taxonomic criteria for species identification ...