Results 111 to 120 of about 16,764 (247)

The geology and geochronology of Al Wahbah maar crater, Harrat Kishb, Saudi Arabia [PDF]

open access: yes, 2014
Al Wahbah is a large (∼2.2 km diameter, ∼250 m deep) maar crater in the Harrat Kishb volcanic field in western Saudi Arabia. It cuts Proterozoic basement rocks and two Quaternary basanite lava flows, and is rimmed with an eroded tuff ring of debris from ...
Abdel Wahab, Antar   +4 more
core   +1 more source

Carbonate sedimentology: An evolved discipline

open access: yesThe Depositional Record, Volume 12, Issue 1, February 2026.
Abstract Although admired and examined since antiquity, carbonate sediment and rock research really began with Charles Darwin who, during a discovery phase, studied, documented and interpreted their nature in the mid‐19th century. The modern discipline, however, really began after World War II and evolved in two distinct phases.
Noel P. James, Peir K. Pufahl
wiley   +1 more source

Decimetre-scale multicellular eukaryotes from the 1.56-billion-year-old Gaoyuzhuang Formation in North China

open access: yesNature Communications, 2016
Macroscopic organisms are rare in the fossil record until the Ediacaran Period, beginning 635 million years ago. Here, Zhu et al. report the discovery of 1.56-billion-year-old carbonaceous compression fossils that provide evidence of the evolution of ...
Shixing Zhu   +8 more
doaj   +1 more source

Continental Thermal Structure and Carbonate Storage of Subducted Sedimentary Origin Control on Different Increases in Atmospheric CO2 in Late Ediacaran and Jurassic

open access: yesGeophysical Research Letters, 2023
Carbon release during continental rifting is thought to regulate atmospheric CO2 levels. Supercontinent dispersal‐induced extensional tectonics is similar during the Late Ediacaran and Jurassic, while they exhibit different increases in atmospheric CO2 ...
Xinxin Wang   +5 more
doaj   +1 more source

a new Pc-C boundary section [PDF]

open access: yes, 2016
The widespread, terminal Ediacaran Dengying Formation (~ 551–~ 542 Ma) of South China hosts one of the most prominent negative carbonate carbon isotope excursions in Earth's history and thus bears on the correlation of the Precambrian–Cambrian boundary ...
Gamper, A.   +4 more
core   +1 more source

Ediacaran and Cambrian stratigraphy in Estonia: an updated review [PDF]

open access: yesEstonian Journal of Earth Sciences, 2017
Previous late Precambrian and Cambrian correlation charts of Estonia, summarizing the regional stratigraphic nomenclature of the 20th century, date back to 1997.
Tõnu Meidla
doaj   +1 more source

The last common bilaterian ancestor [PDF]

open access: yes, 2002
Many regulatory genes appear to be utilized in at least superficially similar ways in the development of particular body parts in Drosophila and in chordates.
Davidson, Eric H., Erwin, Douglas H.
core  

Controls on the evolution of Ediacaran metazoan ecosystems: A redox perspective [PDF]

open access: yes, 2017
A growing number of detailed geochemical studies of Ediacaran (635–541 Ma) marine successions have provided snapshots into the redox environments that played host to the earliest known metazoans.
Aceñolaza   +254 more
core   +3 more sources

Vesicular microfossils on middle Cambrian shells: insights into early substrate colonization in North Greenland (Laurentia)

open access: yesPalaeontology, Volume 69, Issue 1, January/February 2026.
Abstract Biomineralization around the Ediacaran–Cambrian boundary enabled new ecological strategies, including encrustation, boring and cavity‐dwelling, across various lineages. Here we describe problematic vesicular fossils that are attached to, or embedded within, the calcium phosphatic shells of the tommotiid genus Tesella from the middle Cambrian ...
Sebastian Willman, John S. Peel
wiley   +1 more source

The laurentian record of neoproterozoic glaciation, tectonism, and eukaryotic evolution in Death Vally, California [PDF]

open access: yes, 2013
Neoproterozoic strata in Death Valley, California contain eukaryotic microfossils and glacial deposits that have been used to assess the severity of putative Snowball Earth events and the biological response to extreme environmental change.
A. E. Fallick   +62 more
core   +1 more source

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