Wyniki wyszukiwania - BazTech

Ograniczanie wyników

2 Acta Geologica Polonica

Powiadomienia systemowe

Sesja wygasła!
Sesja wygasła!
Sesja wygasła!

Znaleziono wyników: 2

Liczba wyników na stronie

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych: US Western Interior

Sortuj według:

Ogranicz wyniki do:

Palaeontology and biostratigraphy of the Middle-Upper Coniacian and Santonian inoceramids of the US Western Interior

Walaszczyk I., Cobban W.

Acta Geologica Polonica

2006

Vol. 56, no. 3

241-348

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.

Campanian (Late Cretaceous) Ammonites from the upper part of the Anacacho Limestone in South-Central Texas

Kennedy W., Cobban W.

Acta Geologica Polonica

2001

Vol. 51, nr 1

15-30

The ammonite assemblage from the upper part of the Anacacho Limestone in Medina Country in south-central Texas consists of Pachydiscus (Pachydiscus) travisi (ADKINS, 1929), Pachydiscus (P.) sp., Pachydiscus (P.) streckeri (ADKINS, 1928), Hoplitoplacenticeras (H.) marroti (COQUAND, 1859), Eubostrychoceras reevesi (YOUNG, 1963), Bostrychoceras polyplocum (ROEMER, 1841), Lewyites clinensis (ADKINS, 1929), Baculites taylorensis ADKINS, 1929, and Trachyscaphites spiniger porchi (ADKINS, 1929). Several of these species are also found in the Pecan Gap Chalk in central and northeastern Texas and in the basal part of the Demopolis Formation in Mississippi and Alabama. The fauna is probably contemporaneous with the Baculites asperiformis zone in the U.S. Western Interior, which lies in the lower part of the middle Campanian in the sense of the Western Interior threefold division of the Campanian. In terms of the European twofold division of the Campanian the fauna lies in the lower part of the upper Campanian