Results 21 to 30 of about 692 (139)
Geofluids, Volume 2021, Issue 1, 2021., 2021 Organic pores play an important role in shale reservoirs. Organic pores occur where shale gas was produced and accumulated. However, there is little scientific understanding of the distribution and connectivity of organic pores. Organic pore types and their structural characteristics were studied using a total organic carbon (TOC), thin section ...
Tao Jiang +6 more
wiley +1 more source
Geofluids, Volume 2021, Issue 1, 2021., 2021 The pore structure characterization and its controlling factors in overmature shales are keys to understand the shale gas accumulation mechanism. Organic matter in source rocks is a mixture of various macerals that have their own specific evolutionary pathways during thermal maturation. Pores within macerals also evolve following their own path.
Lin Wei +8 more
wiley +1 more source
Microfossils in the Ordovician erratic boulders from Southwestern Finland [PDF]
Bulletin of the Geological Society of Finland, 1995 Chitinozoans, ostracods and acritarchs found in four glacially transported limestone boulders from the south-western coast of Finland have been studied in order to test the usefulness of these microfossil groups in age determinations. Also rare specimens
J. Nõlvak, T. Meidla, A. Uutela
doaj +1 more source
Geochemistry and correlation of volcanic ash beds from the Rootsiküla Stage (Wenlock–Ludlow) in the eastern Baltic [PDF]
Estonian Journal of Earth Sciences, 2011 Nine altered volcanic ash samples from the shoal and lagoonal sediments of the Rootsiküla Stage (Wenlock–Ludlow boundary interval, Estonia) were analysed, compared and correlated with five samples of deep sea environments from Latvia.
Tarmo Kiipli +5 more
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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
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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
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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
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
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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
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A new chitinozoan species from the Middle Ordovician of Estonia [PDF]
Estonian Journal of Earth Sciences, 2012 A new species Baltochitina delicata is formally defined. This rare species has been identified in the Aseri Regional Stage (Darriwilian) in North Estonian sections. The genus Baltochitina was known so far only by a single species B. nolvaki, which occurs
Jaak Nõlvak
doaj +1 more source