Results 51 to 60 of about 809 (126)

Confirmation of the impact origin of the Late Ordovician Tvären impact structure (southeast Sweden) and emplacement of impactites in a marine setting

Meteoritics &Planetary Science, Volume 61, Issue 7, Page 1188-1212, July 2026.
Abstract The Tvären structure in southeastern Sweden has been listed as a confirmed marine‐target impact structure for decades. However, to date, no measurements and/or indexed data of planar deformation features in quartz grains from the structure have been published or any other unequivocal evidence of impact.
Katarzyna J. Gajewska, Sanna Alwmark, Mikael Calner, Sylvain Richoz, Jens Ormö, Erik Sturkell, Carl Alwmark   +6 more
wiley   +1 more source

Significado estratigráfico y tectónico de los complejos de bloques resedimentados cambro-ordovicios de la Precordillera Occidental, Argentina

Estudios Geologicos, 1992
En el flanco oriental de la Sierra de Yerba Loca, sobre el corte del río Jáchal, aflora una secuencia de edad paleozoica temprana correspondiente a los afloramientos más septentrionales de la Formación Los Sombreros.
J. L. Benedetto, N. E. Vaccari
doaj   +1 more source

Revisiting the Hummeln structure, Sweden—A shallow marine Cambrian impact structure

Meteoritics &Planetary Science, Volume 61, Issue 7, Page 1213-1242, July 2026.
Abstract Hummeln is a simple impact structure located in south‐eastern Sweden. It is approximately 1.2 km in diameter and almost completely covered by a lake. Here, we present the first detailed investigation of impactites and mapping of the 164.25 m deep drill core Hummeln‐1 with a focus on impact metamorphism and the impact process.
S. Alwmark, J. Granbom, P. Ahlberg, M. Calner, S. Richoz, K. J. Gajewska, W. R. Hyde, K. Ljung, C. Alwmark   +8 more
wiley   +1 more source

Putative Analogs of Pyrite Suns Forming in Proglacial Alaska Mudflats

Journal of Geophysical Research: Biogeosciences, Volume 131, Issue 5, May 2026.
Abstract Disc‐shaped pyrite suns of the Pennsylvanian age Anna Shale are thought to have formed where pressure restricted pyrite crystal growth to a flattened disc shape during diagenesis at the Anna Shale and the underlying Herrin coal boundary.
Heather L. Fair, Trinity L. Hamilton, Jeff R. Havig   +2 more
wiley   +1 more source

The trilobite Maurotarion megacephalum sp. nov. (Aulacopleuridae) in the Lower Devonian of Argentina: phylogenetic and paleobiogeographic remarks

Revista Mexicana de Ciencias Geológicas, 2013
Maurotarion megacephalum sp. nov., del Pragiano (Devónico Inferior) de la Formación Talacasto, cuenca de Precordillera, centro-oeste de Argentina, es descrito e interpretado como la primera especie malvinocáfrica del género, no perteneciente al subgénero
Juan José Rustán, N. Emilio Vaccari
doaj  

Affinity in Concentric Circles (ACC): A Geometric Representation of Dendrogram and Interpretation

Journal of Biogeography, Volume 53, Issue 5, May 2026.
ABSTRACT Aim We introduce “Affinity in Concentric Circles” (ACC), a method that converts dendrograms to a geometric form using similarity scores to compare dendrograms and identify affinity change patterns. Location China for trilobites and global for nisusiid brachiopods.
Yeongju Oh, Jikhan Jung, Tae‐Yoon Park, Dong‐Chan Lee   +3 more
wiley   +1 more source

Modelling Palaeodistributions in Marine Environments: A Review

Journal of Biogeography, Volume 53, Issue 5, May 2026.
ABSTRACT Aim This scoping review (ScR) synthesises the current literature on the application of Species Distribution Models (SDM) to past marine environments. We assess how these models have been used to reconstruct past environmental suitability, track biogeographical shifts and investigate long‐term ecological dynamics, while identifying key ...
Sarah Mathilde Salomé Beauvais, Emna Ben Lamine, Konstantina Agiadi, Maria Bas, Grégory Beaugrand, Tatiana Theodoropoulou, Virginie Raybaud   +6 more
wiley   +1 more source

Bioestratigrafía a partir de trilobites de las Formaciones de Balang y “Tsinghsutung” (Serie Cámbrica 2, Piso 4) en el área de Balang, Jianhe, Guizhou, China meridional

Estudios Geologicos, 2019
Se está trabajando en las formaciones de Balang y “Tsinghsutung” para encontrar un candidato adecuado para la base de la Serie 2 del Cámbrico, Piso 4.
Y. Zhao, S. Peng, J. Yuan, J. Esteve, X. Yang, M. Wu, Z. Chen   +6 more
doaj   +1 more source

The Permian–Triassic transition in Türkiye: New insights and 3D outcrop models for accessible, reproducible and sustainable fieldwork

The Depositional Record, Volume 12, Issue 2, April 2026.
We studied the Permian–Triassic successions of south‐western Türkiye at five locations, synthesised sedimentological and palaeontological data, putting it into a consistent stratigraphic framework and incorporating 3D digital outcrop models. Abstract The Permian–Triassic transition is characterised by major environmental changes and the largest known ...
Baran Karapunar, Xia Wang, Stella Z. Buchwald, Anja B. Frank, Mónica Alejandra Gómez Correa, Müjde Gürsoy, Zhipeng Liu, Xuanni Xu, Lingzan Meng, Damla Demir, Erdal Koşun, Aymon Baud, William J. Foster   +12 more
wiley   +1 more source

The making of pure quartzose sand in continental interiors: Paraná River (Brazil and Argentina)

Sedimentology, Volume 73, Issue 3, Page 802-837, April 2026.
ABSTRACT As part of a comprehensive project on sedimentary processes in South America, this study focuses on sediment generation in the intracratonic Paraná Basin and monitors the evolution of sand composition along the Paraná River from central Brazil to the Río de la Plata estuary in Argentina.
Eduardo Garzanti, Marta Barbarano, Mara Limonta, Guido Pastore, Pieter Vermeesch, Giovanni Vezzoli   +5 more
wiley   +1 more source