نتایج جستجو برای: paleocene

تعداد نتایج: 1189  

Journal: :Proceedings of the National Academy of Sciences of the United States of America 2008
Ellen D Currano Peter Wilf Scott L Wing Conrad C Labandeira Elizabeth C Lovelock Dana L Royer

The Paleocene-Eocene Thermal Maximum (PETM, 55.8 Ma), an abrupt global warming event linked to a transient increase in pCO2, was comparable in rate and magnitude to modern anthropogenic climate change. Here we use plant fossils from the Bighorn Basin of Wyoming to document the combined effects of temperature and pCO2 on insect herbivory. We examined 5,062 fossil leaves from five sites positione...

2017
Mathew Domeier Grace E Shephard Johannes Jakob Carmen Gaina Pavel V Doubrovine Trond H Torsvik

The notorious ~60° bend separating the Hawaiian and Emperor chains marked a prominent change in the motion of the Pacific plate at ~47 Ma (million years ago), but the origin of that change remains an outstanding controversy that bears on the nature of major plate reorganizations. Lesser known but equally significant is a conundrum posed by the pre-bend (~80 to 47 Ma) motion of the Pacific plate...

Journal: :European journal of environment and earth sciences 2022

The Maastrichtian–Eocene sediments (mainly shales and limestones) penetrated by the Itori borehole Ilaro boreholes in Dahomey Basin were investigated for foraminiferal biostratigraphy palaeoecological interpretation. These Araromi, Ewekoro, Oshosun formations at varying depths. Selected shale subjected to analysis many planktonic benthic species of foraminifera (agglutinated calcareous) recover...

2007
David W. FARRIS Scott R. PATERSON

Paleocene plutons on Kodiak Island, in Alaska, contain host-rock xenoliths that have undergone varying degrees of fragmentation, metamorphism and assimilation in the surrounding granitoid rocks, and therefore provide an excellent natural laboratory to study the processes of xenolith fragmentation and magma contamination. Kodiak Island has two belts of Paleocene plutons: the Kodiak batholith tha...

2014
Ellen Thomas

Deep-sea benthic foraminifera live in the largest habitat on Earth, constitute an important part of its benthic biomass, and form diverse assemblages with common cosmopolitan species. Modern deep-sea benthic foraminiferal assemblages are strongly infl uenced by events affecting their main food source, phytoplankton (a relationship known as bentho-pelagic coupling). Surprisingly, benthic foramin...

2015
Sofie Jehle André Bornemann Arne Deprez Robert P. Speijer Sigal Abramovich

The marine ecosystem has been severely disturbed by several transient paleoenvironmental events (<200 kyr duration) during the early Paleogene, of which the Paleocene-Eocene Thermal Maximum (PETM, ~56 Ma) was the most prominent. Over the last decade a number of similar events of Paleocene and Eocene age have been discovered. However, relatively little attention has been paid to pre-PETM events,...

Journal: :American journal of botany 2008
Fabiany A Herrera Carlos A Jaramillo David L Dilcher Scott L Wing Carolina Gómez-N

Both the fossil record and molecular data support a long evolutionary history for the Araceae. Although the family is diverse in tropical America today, most araceous fossils, however, have been recorded from middle and high latitudes. Here, we report fossil leaves of Araceae from the middle-late Paleocene of northern Colombia, and review fossil araceous pollen grains from the same interval. Tw...

Journal: :Palynology 2021

The upper Paleocene to lower Eocene Margaret Formation exposed at Stenkul Fiord on southern Ellesmere Island, Nunavut, Canada, represents a nearly continuous terrestrial succession of microfossil-rich clastic sediments and coal. These strata were deposited time extensive tectonic activity associated with Eurekan deformation. precise chronology the deformation is poorly known. Prior studies prov...

Journal: :Journal of applied science and environmental management 2022

Twenty surface samples were taken from road cuttings along Okpekpe and Imiegba areas located in Benin Flank of Anambra Basin, Nigeria with an aim to establish the biozones, age paleodepositional environments Mamu Formation. Using palynological laboratory standard procedures, shale collected Formation study area prepared analyzed. The recovered marker pollens, spores dinoflagellate cysts are Mil...

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