Results 91 to 100 of about 21,253 (209)

Domed‐rim microbial polygons and their preservation potential

open access: yesThe Depositional Record, Volume 12, Issue 1, February 2026.
Microbially induced sedimentary structures (MISS) derive through interactions between minerals and microorganisms. We define a domed‐rim MISS, morphologically distinct from abiotic mud cracks and demonstrate its potential for long‐term preservation. These structures represent promising biosignatures in ancient environments on Earth and potentially Mars.
Franziska R. Blattmann   +11 more
wiley   +1 more source

Reconstructing Environmental and Microbial Ecosystem Changes Across the Permian–Triassic Mass Extinction at Lusitaniadalen, Svalbard

open access: yesPaleoceanography and Paleoclimatology, Volume 41, Issue 2, February 2026.
Abstract The Permian–Triassic environmental crisis triggered fundamental changes in marine ecosystems, culminating in the most severe biodiversity crisis of the Phanerozoic. Yet, the environmental and geochemical conditions governing the crisis and ecosystem recovery remain debated.
S. Z. Buchwald   +17 more
wiley   +1 more source

The study of the umbilical system in planktonic foraminifera in relation with depth of the Ziarat-kola section at the Maastrichtian, Central Alborz, IRAN [PDF]

open access: yes, 2009
The main aim of this research is study of the planktonic foraminifera morphogroups distinction genus to perform by changing the umbilicus area in Ziarat-kola section to find novel results.
Behnaz Balmaki   +2 more
core   +1 more source

Relationship and Source of Whitings Used as a Painting Ground in Icons From Polish Museum Collections Based on Their Calcareous Nannofossil Content

open access: yesArchaeometry, Volume 68, Issue 1, Page 132-143, February 2026.
ABSTRACT In icon painting, chalk whiting is key to creating a gesso ground, providing a smooth, absorbent surface for paint. Calcareous nannofossils, tiny marine skeletons found in chalk, are an ideal tool for analyzing the origin of an icon's chalk ground, often the only reliable information about where the icon came from.
Mariusz Kędzierski, Mirosław P. Kruk
wiley   +1 more source

Biotic and abiotic processes in Ediacaran spheroid formation

open access: yesFrontiers in Earth Science
Organic-rich shales from the uppermost Doushantuo Fm. (South China) record one of the most negative carbonate carbon isotopic excursions in Earth’s history, known as the Shuram excursion, and contain meter to micro-size spheroids.
Fuencisla Cañadas   +6 more
doaj   +1 more source

New vertebrate microfossils expand the diversity of the chondrichthyan and actinopterygian fauna of the Maastrichtian–Danian Hornerstown Formation in New Jersey [PDF]

open access: yesActa Palaeontologica Polonica
The abundance of shark and actinopterygian fossils in the Cretaceous and Paleogene strata of the Atlantic Coastal Plain is well documented; but much remains unknown about the survivorship patterns of these major components of shallow marine faunas in the
ZACHARY M. BOLES   +4 more
doaj   +1 more source

Palaeobathymetry of the Abderaz Formation using foraminifera, Iran [PDF]

open access: yes, 2009
Abderaz Formation at its type section with an age of Turonian-early Campanian and a thickness of 300 m contains light grey shale and marl. The study of the planktonic foraminifera in isolated form led to differentiate three morphotype groups.
Ebrahim Ghasemi-Nejad   +1 more
core   +1 more source

Estudio de microfósiles de residuos adheridos en pipas cerámicas del sitio Villa JMC-1 Labranza, Región de la Araucanía Microfossil study of ceramic smoking pipe residues, Villa JMC-1 Labranza site, Region of the Araucania, Chile

open access: yesMagallania, 2012
Se aplica el estudio de microfósiles en dos pipas del sitio Villa JMC-1, definido como un contexto funerario del Complejo Pitrén, con el fin de reconocer qué plantas fueron utilizadas en la acción de fumar.
LUCIANA D QUIROZ   +4 more
doaj  

Expedition 306 summary

open access: yes, 2006
The overall aim of the North Atlantic paleoceanography study of Integrated Ocean Drilling Program Expedition 306 is to place late Neogene–Quaternary climate proxies in the North Atlantic into a chronology based on a combination of geomagnetic ...
Aboud, Essam   +26 more
core   +1 more source

Fundamental Molecules of Life are Pigments which Arose and Evolved to Dissipate the Solar Spectrum

open access: yes, 2014
The driving force behind the origin and evolution of life has been the thermodynamic imperative of increasing the entropy production of the biosphere through increasing the global solar photon dissipation rate.
Michaelian, Karo, Simeonov, Aleksandar
core   +2 more sources

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