Integrated stratigraphy at the Bartonian–Priabonian transition: Correlation between shallow benthic and calcareous plankton zones (Varignano section, northern Italy)

2019 ◽  
Vol 132 (3-4) ◽  
pp. 495-520
Author(s):  
Valeria Luciani ◽  
Eliana Fornaciari ◽  
Cesare A. Papazzoni ◽  
Edoardo Dallanave ◽  
Luca Giusberti ◽  
...  
Keyword(s):  
Late Eocene ◽  
Northern Italy ◽  
Critical Interval ◽  
Larger Foraminifera ◽  
Ne Italy ◽  
First Occurrence ◽  
Calcareous Plankton ◽  
Stratotype Section ◽  
Primary Base ◽  
Zonal Boundary

Abstract The Varignano section (Trento province, northern Italy) provides an exceptional opportunity for a direct correlation between shallow benthic (SB) zones and standard calcareous plankton zones at the Bartonian–Priabonian transition (middle–late Eocene). This transition has attracted great attention by biostratigraphers in the last decades in searching for a boundary stratotype section. The Alano di Piave section (NE Italy) is the leading candidate for the base Priabonian Global Stratotype Section and Point (GSSP). However, at Alano, larger foraminifera-bearing resedimented levels occur exclusively well below the critical interval. Conversely, the Varignano section, located ∼80 km west of the Alano section, preserves several coarse bioclastic levels rich in larger foraminifera throughout the section. These levels are intercalated with basinal marlstones, crystal tuff layers, and an organic-rich interval. The Varignano section spans planktic foraminiferal Zones E10 and E11 to lower E14, calcareous nannofossil Zones MNP16Bc to MNP18 and Chrons 18n to 17n.2n. The main calcareous plankton events recently proposed as primary base-Priabonian correlation tools, i.e., the last occurrence of the genus Morozovelloides and the Base common (= acme beginning) of Cribrocentrum erbae occur, respectively, within C17n.3n and C17n.2n. We correlate prominent crystal tuff layers exposed at Varignano with those outcropping at Alano, including the Tiziano bed, whose base has also been proposed as the GSSP level. The Varignano section spans the upper SB17 and the lower SB18 Zones, with the zonal boundary marked by the first occurrence of the genus Pellatispira. This event occurs in the lower part of Zones E13 and MNP17A within C18n, well below all the potential criteria to identify the GSSP that also includes Chron C17n.1n base. We point out that the usage of shallow-water biostratigraphers in placing the base of the Priabonian at the base of Zone SB19 is inconsistent with the proposed plankton events.

On the age of the Early/Middle Eocene boundary and other related events: cyclostratigraphic refinements from the Pyrenean Otsakar section and the Lutetian GSSP

2010 ◽  
Vol 148 (3) ◽  
pp. 442-460 ◽  
Author(s):  
A. PAYROS ◽  
J. DINARÈS-TURELL ◽  
G. BERNAOLA ◽  
X. ORUE-ETXEBARRIA ◽  
E. APELLANIZ ◽  
...  
Keyword(s):  
Middle Eocene ◽  
Basque Country ◽  
Time Lapse ◽  
Early Eocene ◽  
Calcareous Nannofossil ◽  
Current Time ◽  
Correlation Criterion ◽  
First Occurrence ◽  
Stratotype Section ◽  
Zonal Boundary

AbstractAn integrated bio-, magneto- and cyclostratigraphic study of the Ypresian/Lutetian (Early/Middle Eocene) transition along the Otsakar section resulted in the identification of the C22n/C21r chron boundary and of the calcareous nannofossil CP12a/b zonal boundary; the latter is the main correlation criterion of the Lutetian Global Stratotype Section and Point (GSSP) recently defined at Gorrondatxe (Basque Country). By counting precession-related mudstone–marl couplets of 21 ka, the time lapse between both events was calculated to be 819 ka. This suggests that the age of the CP12a/b boundary, and hence that of the Early/Middle Eocene boundary, is 47.76 Ma, 250 ka younger than previously thought. This age agrees with, and is supported by, estimates from Gorrondatxe based on the time lapse between the Lutetian GSSP and the C21r/C21n boundary. The duration of Chron C21r is estimated at 1.326 Ma. Given that the base of the Eocene is dated at 55.8 Ma, the duration of the Early Eocene is 8 Ma, 0.8 Ma longer than in current time scales. The Otsakar results further show that the bases of planktonic foraminiferal zones E8 and P10 are younger than the CP12a/b boundary. The first occurrence ofTurborotalia frontosa, being approximately 550 ka older that the CP12a/b boundary, is the planktonic foraminiferal event that lies closest to the Early/Middle Eocene boundary. The larger foraminiferal SBZ12/13 boundary is located close to the CP12a/b boundary and correlates with Chron C21r, not with the C22n/C21r boundary.

The Sub-Boreal/Boreal ammonite succession at the Oxfordian/Kimmeridgian boundary at Flodigarry, Staffin Bay (Isle of Skye), Scotland

2005 ◽  
Vol 96 (4) ◽  
pp. 387-405 ◽  
Author(s):  
Bronisław A. Matyja ◽  
Andrzej Wierzbowski ◽  
John K. Wright
Keyword(s):  
Close Correlation ◽  
Current Standard ◽  
First Occurrence ◽  
Stratotype Section ◽  
Isle Of Skye ◽  
Zonal Boundary

ABSTRACTThis paper describes extensive new collections of ammonites made bed-by-bed across the Oxfordian/Kimmeridgian boundary sequence in the Flodigarry sections at Staffin Bay on the Isle of Skye. The ammonites belong to the Sub-Boreal family Aulacostephanidae and the Boreal family Cardioceratidae, enabling recognition of both the current standard Sub-Boreal and Boreal ammonite zonations. In consequence, it is possible to make a close correlation of these two zonal schemes through the interval studied in Skye. The research has provided new palaeontological data at levels of precision that justify the proposal of the section at Staffin as the site of a potential Global Boundary Stratotype Section and Point (GSSP) for the Oxfordian/Kimmeridgian boundary.The traditional Oxfordian/Kimmeridgian boundary placed at the Pseudocordata/Baylei zonal boundary of the Sub-Boreal zonal scheme corresponds precisely to the Rosenkrantzi/Bauhini zonal boundary of the Boreal zonal scheme. This level is characterised by the appearance of the first Pictonia (Pictonia flodigarriensis sp. nov.) together with first Prorasenia, replacing an older assemblage of Ringsteadia–Microbiplices (Sub-Boreal). It is also characterised by the first occurrence of small-sized Amoeboceras (Plasmatites) spp., as well as large Amoeboceras schulginae Mesezhnikov (Boreal). An alternative level that may be considered as a potential GSSP is the boundary between the Bauhini Zone and the Kitchini Zone of the Boreal zonal scheme, characterised by first occurrence of Amoeboceras (Amoebites) of the A. bayi group. This level corresponds to the Planula/Galar subzonal boundary of the Sub-Mediterranean zonal scheme, and lies close to the currently accepted Oxfordian/Kimmeridgian boundary in the Sub-Mediterranean Province.

scholarly journals Age and Depositional Environment of Walat Formation Based on Palynological Analysis in Sukabumi Regency, West Java, Indonesia

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Rizki Satria Rachman ◽  
Winantris ◽  
Budi Muljana
Keyword(s):  
Data Analysis ◽  
Chemical Treatment ◽  
Depositional Environment ◽  
Treatment Method ◽  
Late Eocene ◽  
West Java ◽  
Palynological Analysis ◽  
First Occurrence ◽  
Pollen And Spores

AbstractWalat Formation is equivalent to Bayah Formation. This formation is the beginning of Bogor basin deposition. In this case, age and environment of this formation have been analyzed by previous researchers, but the results of age and environment interpretations have different ranges, especially from its palynological aspect which until now Walat Formation is rarely analyzed using this aspect. This research was conducted to identify the age and depositional environment of Walat Formation in Sukabumi region by using pollen and spores to confirm different interpretations of previous studies. Measure section was carried out in sampling and chemical treatment method was carried out to see palynomorph content in the rock. Furthermore, data analysis was carried out with range of interval zones and pollen grouping based on their environment.The results show that Walat Formation has Late Eocene age based on the interval zone between first occurrence of Verrucatosporites usmensis and Meyeripollis naharkotensis, and the last occurence of Proxapertites operculatus, Proxapertites cursus, and Cicatricosisporites eocenicus. Walat Formation has fluvial depositional environment characterized by the dominance of Proxapertites operculatus and Proxapertites cursus. The results of this study confirm that the Walat Formation has an Eocene age and a fluvial depositional environment from a palinological aspect.

Correlation of calcareous nannofossil zones to the local first occurrence of Pachydiscus neubergicus (von Hauer, 1858) (Ammonoidea) in European Upper Cretaceous sections

2003 ◽  
Vol 82 (3) ◽  
pp. 283-288 ◽  
Author(s):  
M. Wagreich ◽  
T. Küchler ◽  
H. Summesberger
Keyword(s):  
Upper Cretaceous ◽  
Type Locality ◽  
Calcareous Nannofossil ◽  
Northern Spain ◽  
Northern Margin ◽  
First Occurrence ◽  
Stratotype Section ◽  
Sw France

AbstractThe first occurrence (FO) of the ammonite Pachydiscus neubergicus (von Hauer, 1858) has been correlated to calcareous nannofossil zonations in several European sections along the northern margin of the Tethyan palaeobiogeographic realm. Both the proposed stratotype section of Tercis (SW France) and complete, ammonite-bearing sections in northern Spain document the FO of P. neubergicus within standard nannofossil zone CC23a (UC16), below the LO of Broinsonia parca constricta. Other sections such as the type locality Neuberg (Austria), Nagoriani (the Ukraine) and Bjala (Bulgaria) indicate considerable diachroneity of local FOs and show P. neubergicus to range up to nannofossil zone CC25b/c (UC20; Late Maastrichtian).

Late Eocene brachiopods from the Euganean Hills (NE Italy)

2005 ◽  
Vol 98 (1) ◽  
pp. 103-111 ◽  
Author(s):  
Maria Aleksandra Bitner ◽  
Iginio Dieni
Keyword(s):  
Late Eocene ◽  
Ne Italy

An Eocene wrasse (Perciformes; Labridae) from Seymour Island

1992 ◽  
Vol 4 (2) ◽  
pp. 235-237 ◽  
Author(s):  
Douglas J. Long
Keyword(s):  
Climatic Change ◽  
Trophic Structure ◽  
Late Eocene ◽  
Pharyngeal Tooth ◽  
Tooth Plate ◽  
Antarctic Waters ◽  
La Meseta Formation ◽  
First Occurrence ◽  
Wide Scale ◽  
Seymour Island

A nearly complete lower pharyngeal tooth-plate from a large (over 60 cm long) fossil wrasse (Perciformes: Labridae) was recently recovered from the middle to late Eocene La Meseta Formation on Seymour Island, Antarctic Peninsula. This find increases the number of teleosts from the Eocene of Antarctica to five taxa, and further illustrates the diversity of the ichthyofauna in the Eocene Weddellian Sea prior to wide-scale climatic change in the Southern Ocean. The fossil wrasse represents the first occurrence of this family in Antarctica, and is one of the oldest fossils of this family from the Southern Hemisphere. Wrasses are not found in Antarctic waters today, and probably became extinct during the Oligocene due to a combination of climatic change, loss of shallow-water habitat, and changes in the trophic structure of the Wedell Sea.

scholarly journals The relationship between tectonism and desertification inferred from the provenance and lithofacies changes of the Cenozoic terrestrial sequence of the southwestern Tarim basin

2020 ◽  
Author(s):  
Aki Sakuma ◽  
Ryuji Tada ◽  
Tomohiro Yoshida ◽  
Hitoshi Hasegawa ◽  
Naomi Sugiura ◽  
...  
Keyword(s):  
Tarim Basin ◽  
Global Climate ◽  
Crystallinity Index ◽  
Late Eocene ◽  
Taklimakan Desert ◽  
Tectonic Events ◽  
First Occurrence ◽  
History Of ◽  
Age Model ◽  
Fluvial Sandstone

Abstract The Tarim basin is one of the most arid areas in the world and its major part is occupied by the Taklimakan desert. Although unraveling the history of aridification of Taklimakan desert is important to understand the global climate change during the Cenozoic, the timing and the mechanism of its formation are still controversial. One of the hypotheses is that the uplift of the Pamir locating to the west of the Tarim basin blocked the intrusion of the moist air and induced the aridification in the Tarim basin. In this study, we explored the linkage between the uplift of the Pamir and the desertification in the Tarim basin during the period from the late Eocene to the middle Miocene. Provenance changes of the fluvial deposits along the Aertashi section, which is located in the southwestern edge of the Tarim basin and offers the longest record with the reliable age model, was examined using Electron Spin Resonance (ESR) signal intensity and crystallinity index (CI) of quartz in the sand fraction of fluvial sandstone and the thin section observation to identify the timings of tectonic events in the Pamir from which clastic materials were supplied by rivers. Our results suggest that major provenance changes in the drainage of the river delivering the clasts to the Aertashi section occurred at ca. 26 Ma, 20 Ma, and 15 Ma. These timings are mostly consistent with the timings observed in the previous provenance studies in the Aertashi section and probably reflect tectonic events in the Pamir. On the other hand, the Tarim basin was under the relatively arid condition after ca. 34 Ma based on the first occurrence of sand dune deposit. Hence, our result does not support the hypothesis that the onset of the aridification in the Tarim basin was caused by the uplift of the Pamir and consequent shut down of the moisture supply from the Paratethys Sea although the afterward intensification of tectonic events in the Pamir might be related to the phased uplift.

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