Le probleme de la limite Cretace-Tertiaire en Corse-du-Sud

2000 ◽  
Vol 171 (4) ◽  
pp. 451-459 ◽  
Author(s):  
Bernard Peybernes ◽  
Pierre Cugny ◽  
Marie-Josee Fondecave-Wallez

Abstract In the autochthonous unit of Punta-di-Calcina (southern Corsica, France), Upper Cretaceous deposits are reworked (clasts of orbitoid-bearing limestones, Globotruncanidae) within marine lowstand breccias of Danian age, that are overlying Jurassic limestones or granitic basement. These Danian breccias can be dated by means of subautochthonous planktonic foraminifera (Globigerinidae and Hedbergellidae), belonging to the Plb and Plc subzones. The K/T boundary coincides with an ante-Danian submarine erosional surface (major unconformity) underlining the gap of the whole Cretaceous. It is probably impossible to find the iridium-level of the K/T boundary along this surface. This stratigraphic framework suggests the occurrence of main (compressional ?) tectonic movements just before the beginning of the Palaeocene, inducing deep erosions on a Corsican-Sardinian block partially covered at this time by Maastrichtian marine carbonate platforms, now disappeared.

2019 ◽  
Vol 55 (1) ◽  
pp. 241
Author(s):  
Nikolaos Dimopoulos ◽  
Eleftherios Georgoulas ◽  
Savvas Peridis ◽  
George Iliopoulos ◽  
Nikolina Bourli ◽  
...  

Sedimentological studies of the Cretaceous limestones in the central Ionian basin (Amfilochia, Arta as well as Kerasonas areas) indicate that these deposits are composed of calciturbidites interbedded with breccia-microbreccia deposits. In the Amfilochia new cross-section, with a NNW-SSE direction, the lower Cretaceous Vigla limestones and Vigla shales were outcropped for the first time. This section is directed parallel to the paleo Ionian basin axis and the fact of the lateral discontinuity of Vigla limestones and Vigla shales indicate that during the sedimentation of these two Formations there was a restriction along the paleo basin axis, probably due to synsedimentary transfer fault activity. Forty-two (42) samples from Vigla shales were analyzed for their content in CaCO3 and TOC, showed that these sediments present poor to fair hydrocarbon potential. In the Arta new cross-section, with a NE-SW direction, the Upper Cretaceous Senonian deposits showed strong deformation that took place during the compressional regime that affected the Ionian basin after sedimentation. This deformation appears stronger in the western part being close to a major thrust, and thus it is possible that this deformation could be responsible for the high secondary porosity of Upper Cretaceous deposits. Microfacies analysis of these deposits showed in general that deep-sea depositional environments prevailed, nevertheless in a few cases indications for the presence of environments with a shallow character imply the existence of isolated carbonate platforms close to the studied sections. In the studied sections with an E-W direction, no lateral changes were observed in the depositional conditions within the same Formation introducing standard depositional conditions across the paleo basin.


Author(s):  
L. F. Kopaevich ◽  
P. A. Proshina ◽  
I. P. Ryabov ◽  
M. N. Ovechkina ◽  
N. O. Grechikhina

The article presents the results of the determinations of foraminifera and nannoplankton from the section of Upper Cretaceous deposits Alan-Kyr (Central part of Crimea Mountains). Interpretation of these data to gether with the palinological ans paleomagnethic materials obtained earlier in this section allows to justify the age of deposits. In the lower part of the section planktonic foraminifera assemblages are correlated with the Satonian part of the Dicarinella asymetrica Zone. The benthic foraminiferal assemblages also show on the Santonian interval and allow it to be divided in more detail. On the nannoplankton data it was possible to identify fossils of the transition Zone CC17, corresponding to Upper Santonian–Lower Campanian. Within these deposits is the base of a probable magnetic chron analogue C 33r, which is proposed to be used as a primary feature to define the lower boundary of the Campanian.


Stratigraphy ◽  
2018 ◽  
Vol 15 (1) ◽  
pp. 47-66
Author(s):  
Elham Davtalab ◽  
Mohammad Vahidinia ◽  
Ebrahim Ghasemi-Nejad ◽  
Alireza Ashouri

2019 ◽  
Vol 59 (6) ◽  
pp. 1074-1085
Author(s):  
E. A. Sokolova

The article analyzes own data on the species composition of shells of planktonic foraminifera from the Upper Cretaceous sediments of the Indian Oceans, as well as from the sections of the offshore seas of Australia. The species of planktonic foraminifera are grouped and arranged in a climatic series. An analysis of the change in the systematic composition of foraminifers made it possible to distinguish periods of extreme and intermediate climatic states in the Late Cretaceous.


2011 ◽  
Vol 85 (2) ◽  
pp. 234-249 ◽  
Author(s):  
Dirk Fuchs ◽  
Neal Larson

Morphologic analyses of a large collection of coleoid cephalopods from the Lebanese Upper Cretaceous yielded a much higher diversity than previously assumed and revealed numerous extraordinarily well-preserved, soft-part characters. An analysis of the Prototeuthidina, a gladius-bearing group with a slender torpedo-shaped body, revealed two species:Dorateuthis syriacaandBoreopeltis smithin. sp. Previously unknown soft-part characters, such as the digestive tract, the gills, and the cephalic cartilage considerably improved our knowledge ofD. syriaca.Since none of the investigated specimens show more than eight arms, similarities with modern squids are regarded as superficial.Boreopeltis smithin. sp. is erected on the basis of its comparatively wideParaplesioteuthis-like gladius. The latter species represents the first unambiguous record of this genus in Upper Cretaceous deposits. Phylogenetic analyses indicate that the prototeuthidid clade consists of two lineages. The plesioteuthidid lineage originates from early JurassicParaplesioteuthisand leads toPlesioteuthisandDorateuthis.The other lineage is morphologically more conservative and leads toBoreopeltis.


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