Results 31 to 40 of about 455 (173)

Neverovsky Palaeoreef and Associated Deep-Marine Facies: High-Value Late Devonian Geoheritage from the Rudny Altai

open access: yesHeritage
The Rudny Altai is a western segment of the Altai orogenic belt. Its geological richness makes its geoheritage exploration an urgent matter. Investigations in the Loktevsky District (Altai Region, Russian Federation) have led to the finding of three ...
Jaroslav M. Gutak, Dmitry A. Ruban
doaj   +1 more source

Resolving Micrometre‐Scale Zircon Growth in Silicic Systems by 7 μm LA‐MC‐ICP‐MS U‐Pb Dating: Linking Petrology and Geochronology in Silicic Volcanic and Granitic Rocks from Victoria, Australia

open access: yesGeostandards and Geoanalytical Research, Volume 50, Issue 3, Page 625-647, September 2026.
Key Points 7 μm spot‐diameter LA‐MC‐ICP‐MS analyses yield accurate zircon U‐Pb ages. 1013 Ω amplifier resistors improve low‐signal Pb measurements. Saturn correction protocols minimise down‐hole fractionation effects. We present a systematic evaluation of high spatial‐resolution zircon U‐Pb dating using a Thermo Scientific Neoma multi‐collector ICP‐MS ...
Cristiano Lana, John D. Clemens
wiley   +1 more source

CONODONT BIOSTRATIGRAPHY OF UPPER DEVONIAN TEPHRA BEARING DEPOSITS IN THE İSTANBUL-ZONGULDAK TERRANE, NW TURKEY: INSIGHTS ON THE KELLWASSER EVENTS

open access: yesRivista Italiana di Paleontologia e Stratigrafia
New evidence for a biostratigraphic assessment of the limestone succession comprising K‐bentonite levels exposed in the Yılanlı Formation of the Istanbul-Zonguldak Terrane are provided from conodonts at the Gavurpınarı quarry in Bartın area (NW Turkey).
AYŞE ATAKUL-ÖZDEMIR   +4 more
doaj   +1 more source

The Ames impact structure, Oklahoma: New radioisotopic constraints and implications for North American impact chronology

open access: yesMeteoritics &Planetary Science, Volume 61, Issue 8, Page 2103-2139, August 2026.
Abstract The Ames impact structure (Oklahoma) is thought to have formed during the Ordovician Meteor Event, based on conodont biostratigraphy of its crater fill. Here, U–Pb zircon dates from its impact‐melt portion, conducted using secondary ion mass spectrometry and laser ablation–inductively coupled plasma–mass spectrometry (n = 37 spots), yield a ...
Elizabeth J. Catlos   +9 more
wiley   +1 more source

Frasnian carbonate mounds from Belgium:sedimentology and palaeoceanography

open access: yesGeological Society, London, Special Publications, 2007
Abstract The facies architecture, sedimentary dynamics and palaeogeographic evolution were reconstructed for a number of middle-late Frasnian carbonate mounds from the south side of the Dinant Synclinorium (Belgium). Nine facies were recognized in the buildups, each characterized by a specific range of textures and assemblage of organisms ...
openaire   +2 more sources

New Zealand Geological Timescale 2025

open access: yesNew Zealand Journal of Geology and Geophysics, Volume 69, Issue 1, March 2026.
New Zealand Geological Timescale 2025 (NZGT 2025) is the first comprehensive update and revision of the New Zealand Geological Timescale in a decade. The criteria used to establish age ranges of New Zealand Stages within the NZGT have been reviewed, calibrated, and revised where required against the 2023/04 International Chronostratigraphic Chart and ...
Christopher D. Clowes   +13 more
wiley   +1 more source

Lithological and biostratigraphic characteristics of the Upper Silurian and Lower Devonian deposits of the southwestern part of the field named after Roman Trebs

open access: yesGeoresursy, 2018
A conodont sequence from the Przhidolian stage of the Upper Silurian and almost the entire Lokhkovian stage of the Lower Devonian has been established in the sections of the Upper Silurian-Lower Devonian on the southwestern part of the field named after ...
Т.М. Mavrinskaya   +2 more
doaj   +1 more source

Sediment‐stressed reefs over the past 420 Myr

open access: yesThe Depositional Record, Volume 12, Issue 1, February 2026.
In order to fully elucidate the relationship between siliciclastic sedimentation and reef development, there needs to be a significant step change in how we record ancient and recent reefs. Only through the collection of constrained quantitative data, we can progress beyond the largely conjectural associations postulated for many ancient reefal systems.
Tanja Unger   +4 more
wiley   +1 more source

FRASNIAN AND VISEAN-NAMURIAN CONODONT FAUNAS AT PRAPROTNO, SLOVENIA

open access: yesRivista Italiana di Paleontologia e Stratigrafia, 2017
Conodont faunas from the limestone pebbles of the Upper Paleozoic Conglomerate at Praprotno, Slovenia demonstrate the presence of two faunas. The older fauna, marked by Palmatolepis surecta and Polygnathus decorosus is indicative of the Frasnian stage ...
TEA KOLAR-JURKOVSEK, BOGDAN JURKOVSEK
doaj   +1 more source

Iron–Phosphorus–Carbon Coupled Cycling in Lacustrine System of Ordos Basin During the Middle Triassic

open access: yesGeochemistry, Geophysics, Geosystems, Volume 27, Issue 2, February 2026.
Abstract Widespread organic‐rich shales are associated with perturbations in productivity or preservation conditions; however, the major controlling factors, especially the phosphorus (P) and iron (Fe) interactions and their impacts on organic carbon burial in the paleolake ecosystem remain poorly understood.
Bo Wang   +7 more
wiley   +1 more source

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