Calcareous nannoplankton response at the culmination of the Paleogene greenhouse world

2014 ◽  
Vol 31 ◽  
pp. 155-156
Author(s):  
Cherry Newsam ◽  
Paul R. Bown
Keyword(s):  
Calcareous Nannoplankton

scholarly journals Age determinations of Neogene sediments from the English Channel and Western Approaches

1986 ◽  
Vol 5 (1) ◽  
pp. 5-6
Author(s):  
D. Graham Jenkins ◽  
Erlend Martini
Keyword(s):  
Middle Miocene ◽  
Planktonic Foraminifera ◽  
English Channel ◽  
Calcareous Nannoplankton ◽  
Lower Miocene ◽  
Published Evidence ◽  
Neogene Sediments ◽  
Age Range ◽  
Age Determinations

Abstract. Original published evidence indicated an age range of early Lower Miocene to early Middle Miocene for Globigerina silt samples from the English Channel and the Western Approaches. Suggested younger ages for these samples are refuted on the basis of planktonic foraminifera and calcareous nannoplankton.

scholarly journals Paleoenvironmental and paleobiological origins of coccolithophorid genusWatznaueriaemergence during the late Aalenian–early Bajocian

Paleobiology ◽  
2015 ◽  
Vol 41 (3) ◽  
pp. 415-435 ◽  
Author(s):  
Baptiste Suchéras-Marx ◽  
Emanuela Mattioli ◽  
Fabienne Giraud ◽  
Gilles Escarguel
Keyword(s):  
Marine Invertebrate ◽  
Time Interval ◽  
Calcareous Nannofossils ◽  
Calcareous Nannoplankton ◽  
Absolute Abundance ◽  
The Pacific ◽  
Relative Abundances ◽  
The Absolute ◽  
Oceanic Plates ◽  
Central Atlantic

AbstractThe latest Aalenian–early Bajocian time interval (ca. 171-169 Ma) is marked by a global reorganization of oceanic plates with the Central Atlantic opening and the formation of the Pacific plate. This time interval is also marked by a global geochemical perturbation of δ13C with a negative excursion at the Aalenian/Bajocian boundary and a positive excursion during the early Bajocian. Evolutionary diversifications of marine invertebrate taxa, namely ammonites, radiolarians, and coccolithophorids, are recorded at that time. Concerning coccolithophorids, this interval witnesses the diversification and expansion of the most successful Mesozoic genus:Watznaueria. In this study, we explore the potential environmental, ecological, and biological forcing at the origin ofWatznaueriadiversification and its effect on the coccolith assemblages through quantification of the absolute and relative abundances of calcareous nannofossils in two Middle Jurassic key sections: Cabo Mondego (Portugal) and Chaudon-Norante (France). In both sections, we find an increase in nannofossil absolute abundance and flux at the beginning of the lower Bajocian, coeval with an increase in absolute and relative abundances ofWatznaueriaspp., followed by a plateau in the middle and upper part of the lower Bajocian. The increase ofWatznaueriaspp. is synchronous with a decrease in relative abundance of other major coccolith taxa, whereas the absolute abundance of these species did not decrease. During the climatically driven early Bajocian eutrophication event,Watznaueriaspp. integrated into the calcareous nannoplankton community in two successive evolutionary steps involving firstW. contractaandW. colaccicchii, and secondW. britannicaandW.aff.manivitiae. Step 1 was driven by an increase in niche carrying capacities linked to the early Bajocian eutrophication. Step 2 was driven by specific adaptation of the newly evolvedWatznaueriaspecies to bloom in nutrient-rich environments not exploited before. These evolutionary events have initiated the 100-Myr reign ofWatznaueriaover the calcareous nannoplankton community.

scholarly journals Stratigraphy and tectonics of a tectonic window in the Magura Nappe (Świątkowa Wielka, Polish Outer Carpathians)

2011 ◽  
Vol 62 (2) ◽  
pp. 139-154 ◽  
Author(s):  
Marta Oszczypko-Clowes ◽  
Nestor Oszczypko
Keyword(s):  
Calcareous Nannoplankton ◽  
Group Of Units ◽  
Marginal Part ◽  
Tectonic Window ◽  
Outer Carpathians ◽  
Tectonic Windows

Stratigraphy and tectonics of a tectonic window in the Magura Nappe (Świątkowa Wielka, Polish Outer Carpathians)The Świątkowa Wielka Tectonic Window belongs to the Grybów Nappe of the Fore-Magura Group of units. This tectonic window is located in the marginal part of the Magura Nappe and is composed of Oligocene — Sub-Grybów Beds as well as the Grybów Marl Formation. These beds have been correlated with the Oligocene deposits of other tectonic windows of the Grybów Nappe in Poland. Our research reveals that the Krosno beds' shally facies, which occur at the western termination of the Świątkowa Wielka Tectonic Window, belong to the Dukla succession. On the basis of calcareous nannoplankton analysis, the Grybów Marl Formation as well as the Krosno Beds belong to the NP23-NP24, and NP24 Zones, respectively. The structure of the Świątkowa Wielka Tectonic Window reveals a multistage evolution of the Magura Nappe overthrust onto their foreland.

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