نتایج جستجو برای: middle cretaceous

تعداد نتایج: 163403  

Journal: :Bulletin of The Geological Society of Denmark 2022

A new trace fossil, Koptichnus rasmussenae, was recently reported from the Cretaceous of Denmark. This burrow is thickly lined with cuboids that tracemaker cut siliceous sponges. newly discovered specimen lower Selandian Kerteminde Marl, found in a loose boulder Gundstrup gravel pit (Fyn, Denmark), extends stratigraphical range this ichnotaxon previously known Coniacian to middle Paleocene and ...

Journal: :نشریه دانشکده فنی 0
کاظم سید امامی

between the lower and upper cretaceous there were some diastrophic movements, belonging to the austrain phase. these movements, which can be traced in many parts of north and central iran, caused extensive precenomanian erosion. even in southwest iran a wide spread discontinuity is reported at the base of the kazhdumi formation, which is possibly related to these movements. in the kopet - dagh ...

2011
Hussam Zaher Diego Pol Alberto B. Carvalho Paulo M. Nascimento Claudio Riccomini Peter Larson Rubén Juarez-Valieri Ricardo Pires-Domingues Nelson Jorge da Silva Diógenes de Almeida Campos

Advanced titanosaurian sauropods, such as nemegtosaurids and saltasaurids, were diverse and one of the most important groups of herbivores in the terrestrial biotas of the Late Cretaceous. However, little is known about their rise and diversification prior to the Late Cretaceous. Furthermore, the evolution of their highly-modified skull anatomy has been largely hindered by the scarcity of well-...

2002
LYNN M. WALTER

-Isotopic measurements (Sr, O, D) on formation waters from the Alberta Basin have been made, covering a stratigraphic range from Devonian to Upper Cretaceous. These measurements, combined with chemical compositional trends, give evidence for two distinct water regimes. One hydrological regime is composed of waters hosted in Devonian-Lower Cretaceous reservoirs, the other waters from Upper Creta...

2013
Mark A. Loewen Randall B. Irmis Joseph J. W. Sertich Philip J. Currie Scott D. Sampson

The Late Cretaceous (∼95-66 million years ago) western North American landmass of Laramidia displayed heightened non-marine vertebrate diversity and intracontinental regionalism relative to other latest Cretaceous Laurasian ecosystems. Processes generating these patterns during this interval remain poorly understood despite their presumed role in the diversification of many clades. Tyrannosauri...

Journal: :Basin Research 2021

The Late Cretaceous to Cenozoic is known for its multiple inversion events, which affected Central Europe's intracontinental sedimentary basins. Based on a 2D seismic profile network imaging the basin fill without gaps from base Zechstein seafloor, we investigate nature and impact of these events salt structures in Baltic sector North German Basin. These insights improve understanding structure...

2003
Paul Kapp Michael A. Murphy An Yin Mark Harrison Lin Ding Jinghu Guo

[1] In the Shiquanhe area of far-western Tibet, midCretaceous strata lie unconformable on ophiolitic melange and Jurassic flysch associated with the Bangong-Nujiang suture zone. On the basis of our mapping and geochronologic studies, we suggest that these Cretaceous strata were shortened by >57% over a north south distance of 50 km during Late Cretaceousearly Tertiary time. The Late Cretaceous ...

Journal: :iranian journal of earth science 0
fatemeh hadavi professor, department of geology, ferdowsi university of mashhad, mashhad, iran marziyeh notghi moghaddam assistant professor, department of geology, payame noor university, tehran, iran lida khodadadi department of geology, payame noor university, tehran, iran

calcareous nannofossil assemblages recovered from a long, continuous section have been described from the sarayan region in lut block in east iran. the marine upper cretaceous sediments of this section yield medium diverse and well-preserved calcareous nannofossil assemblages. a structural analysis of upper cretaceous calcareous nannofloras has revealed 30 nannofossil species. a revised zonatio...

Journal: :Nature communications 2012
Stephen L Brusatte Richard J Butler Albert Prieto-Márquez Mark A Norell

The extinction of non-avian dinosaurs 65 million years ago is a perpetual topic of fascination, and lasting debate has focused on whether dinosaur biodiversity was in decline before end-Cretaceous volcanism and bolide impact. Here we calculate the morphological disparity (anatomical variability) exhibited by seven major dinosaur subgroups during the latest Cretaceous, at both global and regiona...

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