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1
Content available remote Revision of the Upper Cretaceous ammonite fauna of the Bakony Mountains (Hungary)
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EN
A revision of the ammonites from the Bakony Mountains (Hungary) based on collections of the Geological Institute of Hungary (MAFI) in Budapest, revealed the following sequence of faunas. The youngest Campanian ammonites from the South Bakony are three specimens of Pachydiscus (P.) praecolligatus COLLIGNON, 1955 from the Sumeg area; this is a typical Campanian species. Two specimens of former "Lower Maastrichtian Pachydiscus neubergicus (HAUER)" from Haraszt quarry have been re-determined as Early Campanian Eupachydiscus levyi (GROSSOUVRE, 1894). The fragmentary specimen of Mortoniceras sp. has been determined as Texanites (Texanites) sp. from the Upper Santonian. Two ammonite zones can be recognised for these sequences: Texanites sp. (Santonian) and Eupachydiscus levyi (Lower Campanian)
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Content available remote Santonian ammonite stratigraphy of the Munster Basin, NW Germany
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EN
The upper Coniacian and Santonian ammonite stratigraphy of the Munster Basin, Westphalia, NW Germany, is described in the context of regional litho-, inoceramid- and sequence stratigraphy. The Sphenoceramus pachti & S. cardissoides Zone, previously regarded as basal Santonian, is placed in the uppermost Coniacian. The Lower Santonian corresponds to the Cladoceramus undulatoplicatus Zone, the lower Middle Santonian to the Cordiceramus cordiformis Zone. The Sphenoceramus pinniformis Zone spans the upper Middle Santonian to the lower Upper Santonian. The succeeding Sphenoceramus patootensiformis Zone corresponds approximately to the Marsupites testudinarius crinoid zone of the upper Upper Santonian. Occurrences of the belemnite Gonioteuthis are discussed. The ammonite occurrences are documented in the context of inoceramid and where possible, belemnite and crinoid stratigraphy. A Texanites (Texanites) pseudotexanus Zone extends from the uppermost M. subquadratus Zone to the Upper Coniacian/Lower Santonian boundary. The Kitchinites emscheris Zone comprises the Lower and Middle Santonian. The Upper Santonian corresponds to the Boehmoceras arculus Zone. The ammonite faunas are predominately endemic from the Upper Coniacian to the Middle Santonian. Only the Upper Santonianyields supraregional and even global ammonite taxa such as Boechmoceras arculus and B. krekeleri, which co-occur with the widespread crinoids Uintacrinus socialis and Marsupites testudinarius. Sequence boundaries, followed by transgressive pulses, are identified in the uppermost Coniacian, with a subordinate event in the Middle Santonian, the most significant event in the basal Upper Santonian and the last in the Lower Campanian. Ammonite occurrences are clearly related to the sequences recognized.
EN
Radiolarians are widely distributed in two siliceous intervals that coincide with the Tithonian–Berriasian and Santonian–Campanian boundaries in the Mesozoic of the Russian Arctic and Pacific Rim. The first level is rich in organic matter and typical of Jurassic–Cretaceous boundary strata from the Russian North European Margin (Barents−Pechora, Volga−Urals, and Siberian hydrocarbon provinces, as well as western Kamchatka). Abundant and diverse representatives of the family Parvicingulidae provide a basis for establishing the new genus Spinicingula (uppermost Middle Volgian–Lower Berriasian); another new genus, Quasicrolanium (Upper Volgian–Upper Berriasian) is also described. A Santonian– Campanian siliceous interval with radiolarians is documented from the margins of northern Asia (eastern Polar Ural, Kara Basin, Kamchatka). The Boreal genus Prunobrachium makes its first appearance at the Santonian–Campanian boundary and reaches an acme in Campanian strata. Radiolarian data can be used for basin biostratigraphy and correlation, as well as palaeogeographical interpretation of these hydrocarbon−rich facies. The Arctic and northern Pacific rims are well correlated on the basis of parvicingulids, while in Sakhalin these are absent and calibrations are based on Unitary Associations zones of the Tethys. In addition to the two new genera noted above, five new species (Parvicingula alata, Parvicingula papulata, Spinicingula ceratina, Lithostrobus borealis, and Spongurus arcticus) are erected, while 60 radiolarian species typical of the Russian Arctic and Pacific rims are illustrated.
EN
The taxonomy of the Middle-Late Coniacian and Santonian inoceramids of the US Western Interior, including some specimens from the Canadian Western Interior, is revised, based mainly on the extensive collections of the US Geological Survey. The classic Meek and Hayden material is discussed. Forty-four species are described of which 5 are new: Inoceramus americanus, Inoceramus sokolovi, Inoceramus robertsoni, Inoceramus glacierensis, and Sphenoceramus gilli. The Middle Coniacian to Santonian inoceramids of the Western Interior represent a uniform Euramerican fauna. This allows the application of a uniform biostratigraphical zonation throughout the whole biogeographical region. Starting in the Late Coniacian, inoceramid faunas are characterised by relatively strong north.south biogeographic differentiation. The inoceramid zonation applied is discussed, diagnosed, and compared to previously used schemes, and to the ammonite zonation commonly used in the US Western Interior.
EN
Decapod crustaceans are the most diverse group of fossil invertebrates from the Upper Cretaceous Sahel Alma Lagerstätte (Lebanon, Middle East). They are mainly represented by abundant crest−bearing shrimps which were first described as Penaeus libanensis. We review this species applying the new systematic nomenclature and we propose a more complete description based on 54 unpublished specimens. This review leads to the erection of Palaeobenthesicymus gen. nov. and to the new combination Palaeobenthesicymus libanensis that is the oldest record of the family Benthesicymidae. A neotype is herein designated. Detailed comparisons with extant analogues suggest that the crest bearing shrimps inhabited relatively deep water settings most probably exceeding 150 m, at the transition between the lower circalittoral and the upper bathyal zones, under dysphotic or aphotic conditions.
EN
In the Santonian chalk glacial deposits exposed at Kornica (eastern Poland) an assemblage of echinoderms comprising asteroids, echinoids, ophiuroids, and crinoids (comatulids, roveacrinids, and Bourgueticrinus, Isocrinus, Isselicrinus, Marsupites) is documented. The Santonian age of sediments at Kornica has been determined with foraminifers. Numerous occurrences of the crinoid Marsupites testudinarius, indicate their late Santonian age.
EN
Palynological investigation of the Vrabchov dol locality (Western Bulgaria) which recently yielded fragmentary dinosaur bones attributed to the clade Titanosauria, reveals well-preserved sporomorph assemblages dominated by angiosperm pollen from the Normapolles group, spores and rare gymnosperms. The age assessment of the studied sequence is based on the diagnostic Normapolles species, such as Oculopollis orbicularis Góczán, 1964, Oculopollis zaklinskaiae Góczán, 1964, Krutzschipollis spatiosus Góczán in Góczán et al., 1967 and Krutzschipollis crassus (Góczán, 1964) Góczán in Góczán et al., 1967. The concurrent presence of these pollen species suggests a late Santonian–early Campanian age for the succession. The sporomorph association is encountered in a palynofacies dominated by continental elements, including translucent phytoclasts (tissues, wood remains and plant cuticles). The sedimentary succession shows no evidence of marine elements and a very low proportion of AOM that attests to deposition within a lagoonal to foreshore marine environment, with high continental input and short transportation. The vegetation in the studied area was primarily composed of a range of Normapolles-producing angiosperms and secondarily of pteridophyte spore-producing plants. Gymnosperms were rare. Such a vegetation pattern reflects a warm, seasonally dry climate during the late Santonian–earliest Campanian in the studied area. The dinosaurs inhabited a wet lowland area, probably rich in herbaceous plants.
EN
The WalMart section on Ten Mile Creek, Lancaster, Dallas County, Texas, exposes a 23 metre section of Austin Chalk that can be integrated into a more than 60 m composite sequence for the Dallas area on the basis of bed-by-bed correlation. The section was proposed as a possible candidat e Global Boundary Stratotype at the 1995 Brussels meeting on Cretaceous Stage boundaries, with the first occurrence of the inoceramid bivalve Cladoceramus undulatoplicatus (ROEMER, 1852) as the potential boundary marker. An integrated study of the inoceramid bivalves, ammonites, planktonic foraminifera, and calcareous nannofossils places the first occurrence of Cl. undulatoplicatus in a matrix of ten ancillary biostratigraphic markers. The candidate Global boundary Stratotype Section and Point (GSSP) is located within a composite stable carbon isotope curve for the Austin Chalk as a whole. This shows it to lie 3.5 m below the Michel Dean stable carbon isotope event, originally recognised in the English Chalk. The first occurrence of Cl. undulatoplicatus lies in the same position in relation to stable carbon isotope events in both Texas and England that can in principle be recognised globally in marine sediments. The WalMart section satisfies many of the criteria required of a GSSP for the base of the Santonian Stage, although ownership and access require clarification.
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