Results 41 to 50 of about 1,559 (216)
New insights into the chemical composition of chitinozoans [PDF]
Organic Geochemistry, 2007 The chemical structure of isolated chitinozoan specimens extracted from Early Silurian marine rocks has been investigated by micro-FTIR, laser micro-Raman spectroscopy and laser micropyrolysis-gas chromatography/mass spectrometry (LmPy- GC/MS). The samples were subjected to relatively low thermal stress as attested by several indices.
Jacob, Jérémy +6 more
openaire +2 more sources
A summary and revision of the East Baltic Silurian chitinozoan biozonation [PDF]
Estonian Journal of Earth Sciences, 2012 The biostratigraphical data on the East Baltic Silurian chitinozoans are summarized. Based on the study of nine East Baltic drill cores, 28 regional chitinozoan zonal units, including 26 biozones and 2 interzones, are briefly characterized. In comparison
Viiu Nestor
doaj +1 more source
Palynomorphs from abra límite, zenta range, Eastern Cordillera, Northwestern Argentina [PDF]
, 2010 This study presents the first Devonian palynological record in the Zenta Range in Eastern Cordillera, Argentina. Two associations were recognized on the basis of differences in palynomorphs and palynofacies.
Di Pasquo Lartigue, Maria +1 more
core +1 more source
Darriwilian (Middle Ordovician) conodont biostratigraphy in NW Estonia [PDF]
Estonian Journal of Earth Sciences, 2012 Darriwilian conodonts have been studied in numerous sections of Baltoscandia, but few data are available from the classical outcrop area in northern Estonia. In this paper we report the succession of Darriwilian conodonts and chitinozoans from the bed-by-
Olle Hints, Viive Viira, Jaak Nõlvak
doaj +1 more source
Paleoceanography and Paleoclimatology, Volume 35, Issue 12, December 2020., 2020 Abstract Variations in depositional rates affect the temporal depositional resolutions of proxies used for paleoenvironmental reconstructions; for example, condensation can make reconstructed environmental changes appear very abrupt. This is commonly addressed by transforming proxy data using age models, but this approach is limited to situations where
E. Jarochowska +5 more
wiley +1 more source
Chronostratigrahy of Acritarchs and Chitinozoans from upper Ordovician Strata from the Robat-e Gharabil Area, NE Alborz Mountains, Northern Khorassan Province: Stratigraphic and Paleogeographic Implications [PDF]
Journal of Sciences, Islamic Republic of Iran, 2018 The Palaeozoic rock units mainly, Ghelli, Niur, Padeha, Khoshyeilagh and Mobark formations are well-exposed in the north of Robat-e Gharabil village. 116 out of 157 surface samples were analyzed to determine aged relationships of Ghelli Formation.
M. Ghavidel-Syooki, S. Borji
doaj +1 more source
Possible metazoan egg fossils from the Darriwilian (Middle Ordovician) of Baltoscandia [PDF]
Estonian Journal of Earth Sciences, 2021 The Baltoscandian lower Palaeozoic succession is well known for the abundance, diversity and excellent preservation of various groups of microfossils, such as acritarchs, chitinozoans, scolecodonts and conodonts.
Olle Hints, Jaak Nõlvak, Yan Liang
doaj +1 more source
Ordovician geology and stratigraphy of China: A synthesis [PDF]
Estonian Journal of Earth Sciences, 2023 China presently comprises several tectonic blocks and regions assembled over geological time and having independent histories. During the Ordovician, these blocks included South China, North China, Tarim, Qaidam, Junggar, Qiangtang-Qamdo, Lhasa and ...
Yuandong Zhang +9 more
doaj +1 more source
A Cenozoic-style scenario for the end-Ordovician glaciation [PDF]
, 2014 The end-Ordovician was an enigmatic interval in the Phanerozoic, known for massive glaciation potentially at elevated CO2 levels, biogeochemical cycle disruptions recorded as large isotope anomalies and a devastating extinction event.
Achab, A +10 more
core +8 more sources
Chitinozoan Contribution to the Ordovician and Lower Silurian Paleobiogeography [PDF]
The Journal of Geology, 1992 Relationships between various Lower Silurian chitinozoan assemblages are established using statistical methods such as calculation of the number of species in common and similarity coefficient. Conclusions clearly indicate that Eastern Canadian chitinozoan fauna are distinct from those of the north Gondwana margin.
Achab, Aïcha +2 more
openaire +2 more sources