Results 41 to 50 of about 342 (179)

Silurian bentonites in Lithuania: correlations based on sanidine phenocryst composition and graptolite biozonation – interpretation of volcanic source regions [PDF]

Estonian Journal of Earth Sciences, 2014
Integrated correlation of bentonites (altered volcanic ashes) and graptolite biozonation is presented. Detailed study of two Lithuanian drill core sections extended previous knowledge of the occurrence and composition of bentonites to the south ...
Tarmo Kiipli, Sigitas Radzevičius, Toivo Kallaste   +2 more
doaj   +1 more source

Inferring Cenozoic Cover Thickness and Bedrock Sedimentary Material in 3D From Geophysical Data Using Machine Learning Algorithms: A Case Study in the Lockington Region, Victoria, Australia

Earth and Space Science, Volume 13, Issue 3, March 2026.
Abstract This study presents a supervised machine learning approach to constructing a 3D geological model for the Lockington area in Victoria, Australia, by integrating borehole observations, geophysical surveys (magnetic, gravity, and radiometric), and elevation data.
Limin Xu, Eleanor C. R. Green, Mark A. McLean   +2 more
wiley   +1 more source

Tectonics, geology and origins of Te Riu‐a‐Māui / Zealandia

New Zealand Journal of Geology and Geophysics, Volume 68, Issue 4, Page 531-567, December 2025.
ABSTRACT Te Riu‐a‐Māui / Zealandia is a 95% submerged, five million square km southern hemisphere continent that includes the islands of New Zealand and New Caledonia. For the last 45 million years (Ma) Zealandia has been cut by the Pacific‐Australian plate boundary which today changes character from a west‐dipping subduction zone in the north to ...
Nick Mortimer
wiley   +1 more source

The Early to Middle Ordovician graptolite faunal succession of the Trail Creek region, central Idaho, U.S.A

Geologica Acta, 2005
The Middle Ordovician graptolite biostratigraphy of the Trail Creek region of Idaho is reviewed and revised. The oldest known fauna belongs to the Didymograptellus bifidus Biozone. The Isograptus victoriae lunatus, I.
J. Maletz, D. Goldman, M. Cone
doaj   +1 more source

Mercury Deposition in South China Across the Ordovician‐Silurian Transition: Implications for Climate Change

Geochemistry, Geophysics, Geosystems, Volume 26, Issue 7, July 2025.
Abstract Most of the global climate changes are closely associated with volcanic activity. However, the link between global cooling during the Ordovician‐Silurian (O‐S) transition and volcanism remains unclear due to limited constraints on large volcanic events before, during, and after the peak of the Hirnantian glaciation (PHG). Here, we present high‐
Weiliang Kong, Zhen Qiu, Jiaqiang Zhang, Wen Liu, Qin Zhang   +4 more
wiley   +1 more source

Re-Understanding the Sedimentary Environment of the Wufeng–Longmaxi Shales in the Sichuan Basin

Applied Sciences
The current understanding of organic matter enrichment in marine shales remains highly controversial. Most scholars argue that deeper water environments and warmer climates facilitate the enrichment of organic matter.
Xiaoping Mao, Xiurong Chen, Fan Yang, Shuxian Li, Zhen Li, Yuexing Yang   +5 more
doaj   +1 more source

Ordovician graptolites from the basal part of the Palaeozoic transgressive sequence in the Karadere area, Zonguldak Terrane, NW Turkey [PDF]

Estonian Journal of Earth Sciences, 2014
The Karadere area to the east of Safranbolu in NW Anatolia is one of the very few localities in Turkey where the contact between the Cadomian basement and the Lower Palaeozoic transgressive succession is well exposed.
M. Cemal Göncüoglu, Valeri Sachanski, Juan Carlos Gutiérrez-Marco, Cengiz Okuyucu   +3 more
doaj   +1 more source

High‐Resolution Tracking of Baltica's Northward Drift in the Ordovician

Geophysical Research Letters, Volume 52, Issue 7, 16 April 2025.
Abstract We investigated the paleogeography of Baltica via a paleomagnetic study of 471‐454 Ma limestones from the Siljan (Sweden) impact structure. Stepwise thermal demagnetization isolated a well‐defined magnetization component that unblocks up to the Curie temperature of magnetite and passes fold and reversal tests, indicative of a primary ...
Nastaran Ahanin, Stuart A. Gilder
wiley   +1 more source

Characteristics of shale gas reservoirs in Wufeng Formation and Longmaxi Formation in Well WX2, northeast Chongqing

Petroleum Research, 2017
To further understand shale reservoir characteristics of Wufeng Formation and Longmaxi Formation in the Wuxi area, northeast Chongqing, based on drilling data of Well WX2, and taking the graptolite biostratigraphy as the standard marker of stratigraphic ...
Jin Wu, Feng Liang, Wen Lin, Hongyan Wang, Wenhua Bai, Chao Ma, Shasha Sun, Qun Zhao, Xiaojiang Song, Rongze Yu   +9 more
doaj   +1 more source

Lateral heterogeneity of basin‐plain turbidites of the Cloridorme Formation, Quebec, Canada: Implications for horizontal well prediction

The Depositional Record, Volume 11, Issue 1, Page 22-43, February 2025.
Exceptional outcrop exposures of the Cloridorme Formation, Quebec, Canada, offer a rare opportunity to quantify the lateral continuity of event beds and elements of a basin‐plain depositional environment. Eighty‐two per cent of the mapped event beds are present across a 530 m outcrop transect parallel to depositional dip. However, even in this overall ‘
Zane Jobe, Chance Seckinger, Thomas Martin, Kaci Kus, Luke Pettinga   +4 more
wiley   +1 more source