Results 1 to 10 of about 5,414 (202)
Automated graptolite identification at high taxonomic resolution using residual networks [PDF]
iScience, 2023 Summary: Graptolites, fossils significant for evolutionary studies and shale gas exploration, are traditionally identified visually by taxonomists due to their intricate morphologies and preservation challenges.
Zhi-Bin Niu, Si-Yuan Jia, Hong-He Xu
doaj +3 more sources
Energies, 2022 Graptolite-rich shale is the main layer of shale gas resources in the southern marine sedimentary basin. Recently, shale gas resources were discovered in the Ordovician marine graptolite-rich strata in the Ordos Basin.
Fengjiao Li +8 more
doaj +3 more sources
International Journal of Coal Geology, 2018 Graptolite reflectance was thought to be one of the most useful thermal maturity indicators for graptolite-bearing sediments, however, the relationship between graptolite reflectance and vitrinite reflectance is not well-established.
Christian B. Skovsted +2 more
exaly +3 more sources
Petroleum Exploration and Development, 2016 Multiple tests were conducted on graptolite shale samples from Middle Ordovician Pingliang Formation in three typical areas in Ordos Basin to investigate the relationship between micro-nano pore structure, graptolite content, rock composition, TOC ...
Kun DENG +6 more
doaj +3 more sources
Influence of quartz types on mechanical parameters in the early silurian Longmaxi shale, Sichuan Basin [PDF]
Scientific ReportsQuartz is one of the most abundant minerals in shales, occurring predominantly in three forms: biogenic quartz (BQ), detrital quartz (DQ) and clay-transformed quartz (CTQ).
Qin Zhang +9 more
doaj +2 more sources
Characteristics of three organic matter pore types in the Wufeng-Longmaxi Shale of the Sichuan Basin, Southwest China [PDF]
Scientific Reports, 2018 A consensus has been reached through previous studies that organic matter (OM) pores are crucial to porosity in many shale gas reservoirs; however, their origins and types remain controversial.
Haikuan Nie, Zhijun Jin, Jinchuan Zhang
doaj +2 more sources
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 +2 more
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Biogeographic dynamics of graptolite species during the end-Ordovician mass extinction in South China [PDF]
Estonian Journal of Earth Sciences, 2023 Spatial and temporal analysis of geographical biodiversity dynamics and reconstruction of species distribution areas are essential for revealing the patterns of evolution of graptolites and their survival strategies during bio-events.
Qing Chen, Linna Zhang
doaj +1 more source
A new species of the problematic organism Webbyites from the Early Ordovician Fezouata Biota of Morocco [PDF]
Estonian Journal of Earth Sciences, 2023 The problematic colonial organism Webbyites has previously been considered to be a hydroid (phylum Cnidaria). In this paper, we describe a new species, Webbyites felix sp. nov., from the Early Ordovician Fezouata Konservat-Lagerstätte of Morocco.
Lucy A. Muir +1 more
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Andean Geology, 2023 New data and a biostratigraphic review on Silurian graptolites of the La Chilca Formation are presented. Silurian retiolitids and monoserial graptolites are described for the first time in the lower layers of the Salto Macho Member at the Poblete Norte ...
F. Lopez, C. Kaufmann
semanticscholar +1 more source