Results 81 to 90 of about 6,689 (261)

Trans-Atlantic application of the Baltic Middle and Upper Ordovician carbon isotope zonation [PDF]

open access: yesEstonian Journal of Earth Sciences, 2015
Application of the recently introduced Baltic d13C isotope zonation to a composite North American Darriwilian through Hirnantian succession shows that in most intervals there is good trans-Atlantic agreement not only between the isotope zones but also ...
Stig M. Bergström   +4 more
doaj   +1 more source

Response and Recovery of the Comanche Carbonate Platform Surrounding Multiple Cretaceous Oceanic Anoxic Events, Northern Gulf of Mexico [PDF]

open access: yes, 2015
The ubiquity of carbonate platforms throughout the Cretaceous Period is recognized as a product of high eustatic sea-level and a distinct climatic optimum induced by rapid sea-floor spreading and elevated levels of atmospheric carbon-dioxide.
Da-Gama, Rui O.B.P.   +5 more
core   +1 more source

Chronostratigraphy and geochronology: a proposed realignment [PDF]

open access: yes, 2013
We propose a realignment of the terms geochronology and chronostratigraphy that brings them broadly into line with current use, while simultaneously resolving the debate over whether the Geological Time Scale should have a “single” or “dual” hierarchy of
Cita, Maria Bianca   +6 more
core   +1 more source

Chemostratigraphy of Jurassic-cretaceous Italian carbonate platforms

open access: yes, 2002
Samples of shallow-water carbonates were collected from Jurassic and Cretaceous Italian carbonate platforms and subjected to petrographic, diagenetic and chemostratigraphic analyses (87Sr/86Sr, δ13Ccarb, δ13Corg, δ18O). In general, the new chemostratigraphic data generated reflect trends established by previous work, some of which has been carried out ...
Woodfine, R, Woodfine, Richard Gareth
openaire   +1 more source

Linking palaeo‐wildfire to depositional environmental and ecological dynamics of an Early–Middle Pennsylvanian fluvial‐tidal transition zone—Palynology and pyrolysis evidence

open access: yesThe Depositional Record, Volume 12, Issue 1, February 2026.
The Pennsylvanian landscape in the Forest City basin was characterised by low‐lying lycopod tree and fern swamp forests with persistently high groundwater tables and adjacent fluvial channel, floodplain and upland environments. The occurrence of abundant charcoal within a specific thin interval in the Cherokee Group indicates substantial wildfire ...
Dustin Northrup   +3 more
wiley   +1 more source

The age of the Tojeira Formation (Late Jurassic, Early Kimmeridgian), of Montejunto, west-central Portugal [PDF]

open access: yes, 2017
Precise biostratigraphic dating of the Tojeira Formation (Late Jurassic, Early Kimmeridgian) of the Montejunto section of west-central Portugal, which has yielded important planktonic foraminiferal assemblages, is hindered by poor preservation in the ...
Gale, Andy S.   +3 more
core   +1 more source

Fluvial deposits of the Ahr river (western Germany) reveal recurring high‐magnitude flood events over the last 1,500 years

open access: yesEarth Surface Processes and Landforms, Volume 51, Issue 1, January 2026.
Floods are one of the most critical environmental threats in Central Europe. We show the importance of geomorphological records from Ahr flood deposits for reconstructing past high‐magnitude flood events. Our chemolithostratigraphical analysis shows that centennial to millennial scale high‐energy flooding is not the exception but the rule in the Ahr ...
Christoph Zielhofer   +9 more
wiley   +1 more source

Carbon isotope fluctuations in Precambrian carbonate sequences of several localities in Brazil

open access: yesAnais da Academia Brasileira de Ciências, 2000
Carbon isotope fluctuations in Precambrian sedimentary carbonates between 2.8 Ga and 0.60 Ga in Brazil are examined in this study. The carbonate facies of the BIF of the 2.8 Ga-old Carajás Formation, state of Pará in northern Brazil, has rather ...
SIAL ALCIDES N.   +6 more
doaj  

Seawater 87Sr/86Sr Stratigraphy of the Middle Ordovician in Central Virginia [PDF]

open access: yes, 2017
Throughout most of the past century, the correlation of strata in a region has mainly been defined through biostratigraphy, the dating of rock through fossil succession.
Newby, Sean
core  

Anomalous negative excursion of carbon isotope in organic carbon after the last Paleoproterozoic glaciation in North America [PDF]

open access: yes, 2010
Early Paleoproterozoic time (2.5–2.0 Ga) spanned a critical phase in Earth's history, characterized by repeated glaciations and an increase in atmospheric oxygen (the Great Oxidation Event (GOE)).
Bekker   +41 more
core   +1 more source

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