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1424. Fitoplankton, model kompleksnostiIvano Vascotto, Patricija Mozetič, Janja Francé, 2024, professional article Keywords: fitoplankton, biološka raznovrstnost, združbe, periodičnost, okoljski dejavniki, Tržaški zaliv, morska biologija Published in DiRROS: 09.07.2024; Views: 322; Downloads: 196 Full text (992,08 KB) This document has many files! More... |
1425. PETRI-MED: Advancing satellite-based monitoring for microbial plankton biodiversity in the Mediterranean SeaTinkara Tinta, Janja Francé, Katja Klun, Martin Vodopivec, Neža Orel, Patricija Mozetič, Vesna Flander-Putrle, 2024, published scientific conference contribution abstract Keywords: biodiversity, remote sensing, oceanography Published in DiRROS: 09.07.2024; Views: 334; Downloads: 135 Full text (310,44 KB) This document has many files! More... |
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1427. Tectonics and gravitational phenomena, part two : the Trnovski gozd-Banjšice-Šentviška Gora degraded plainLadislav Placer, Tomislav Popit, Igor Rižnar, 2024, original scientific article Abstract: The article describes the recent conditions at the Paleogene thrust contact between the External Dinaric Thrust Belt composed of carbonate rocks and the External Dinaric Imbricate Belt composed of flysch rocks, geographically, between the Trnovski gozd (Trnovski gozd plateau) and the Vipava Valley at the northwestern end of the Dinarides. Fossil and recent gravity-related phenomena that indicate the uplift of the southwestern edge of the External Dinaric Thrust Belt and the larger complex in the hinterland are found there. However, these phenomena are not related to the reactivated Paleogene thrust tectonics, but to the Neogene-recent underthrusting as a consequence of the Microadria (Adriatic Microplate) movement towards the Dinarides. Only arguments for these processes are presented in this article. Keywords: External Dinarides NW, geomorphology, gravitational phenomena, karst plains, degraded karst plains, Idrija fault Published in DiRROS: 09.07.2024; Views: 283; Downloads: 145 Full text (19,23 MB) |
1428. Isotopic composition of carbon (▫$\delta$▫13C) and nitrogen (▫$\delta$▫15N) of petrologically different tertiary lignites and coalsTjaša Kanduč, Miloš Markič, 2024, original scientific article Abstract: This study investigates the carbon (δ13Corg) and nitrogen (δ15N) isotopic composition of tertiary lignites and coals from six sedimentary basins: Velenje, Mura-Zala, and Zasavje in Slovenia; Sokolov in Czech Republic, Barito in Indonesia; and Istria in Croatia. The aim is to investigate the correlation between the fine detrital (fD) component and δ13C and δ15N in Velenje lignite samples. Additionally, we aim to evaluate the biogeochemical processes of organic substances during their deposition in all analyzed samples, calculate their δ13CCO2 values and compare the analyzed values of δ13C and δ15N to those reported in the literature. Thirty-two samples were analyzed, predominantly from the Velenje ortho-lignite (Pliocene), with additional lignites and coals from the Pannonian to Paleocene epochs for comparison. Carbon isotopic composition (δ13Corg) ranged from -27.9 to -23.6 ‰, and nitrogen isotopic composition (δ15N) ranged from 1.8 to 7.4 ‰. The fine-detrital lithotypes of the Velenje ortho-lignite exhibited the most negative δ13Corg values due to anaerobic bacterial activity in an intramontane alkaline lake environment influenced by the carbonate hinterland. Moreover, gelification processes affected fine-detrital organic matter more than larger wooden pieces. Terbegovci, Hrastnik meta-lignites, and Barito sub-bituminous coal also displayed low δ13Corg values, indicating limited gelification, while variations in the δ15N values suggested differences in mineralization. The Velenje xylitic lithotypes have higher δ15N values, indicating a more intense mineralization under aerobic conditions. Raša ortho-bituminous coal, deposited in a brackish environment, displayed the highest δ13Corg values and a wide range of δ15N values due to fluctuating water tables in a paralic carbonate platform environment. The lowest δ15N value was observed in the Sokolov Basin lignite coal, indicating minimal mineralization and low bacterial activity. The isotopic composition of CO2 in air (δ13Cair), which was calculated using the δ13C values in lignites and coal, ranged from -8.4 to -3.4 ‰, with Velenje lignite displaying the minimum value and Raša coal showing the maximum value. The determined δ13C and δ15N values of the coal and lignite samples in this research fall within the typical range of world coals. Keywords: lignite, coal, petrography, C and N isotopic composition, gelification, mineralization Published in DiRROS: 09.07.2024; Views: 246; Downloads: 113 Full text (20,60 MB) |
1429. Middle Triassic deeper-marine volcano-sedimentary successions in western SloveniaDragomir Skaberne, Jože Čar, Maja Pristavec, Boštjan Rožič, Luka Gale, 2024, original scientific article Abstract: A Ladinian – Carnian volcano-sedimentary succession from western Slovenia, paleogeographically belonging to the western Slovenian Basin, is presented in 17 sections. Except for the lowermost part, which is dominated by volcanics and volcaniclastics, most of the succession is dominated by shale, sandstone, and micritic limestone. Various authors use the name Pseudozilja and/or Amphiclina formation for this part, which is dominated by clastics, but they disagree on the differences between the formations. The lower Pseudozilja formation, represented by the Malenski Vrh section, comprises diabase, tuf and shale. No substantial differences in lithological composition have been observed between the upper Pseudoziljaformation and the Amphiclina formation, which are predominantly composed of shale, sandstone, and limestone. The shale and sandstone are largely composed of quartz, feldspar, and lithic grains (especially volcanics), which vary in proportions. Limestone varieties comprise hemipelagic limestones and resedimented carbonates deposited by gravity-flows. Deposition of the Ladinian – Carnian volcano-sedimentary succession took place on or near the continental slope that was generally inclined to the S, with the direction of transport mainly from N to S. Keywords: stratigraphy, carbonate-siliciclastic deposits, Slovenian Basin, Middle Triassic, Ladinian, Carnian, Pseudozilja formation, Amphiclina formation Published in DiRROS: 09.07.2024; Views: 250; Downloads: 111 Full text (20,41 MB) |
1430. Palaeoecological significance of the trace fossil Circulichnis Vyalov, 1971 from the Carboniferous of the Donets Basin, UkraineVitaly Dernov, 2024, original scientific article Abstract: The ichnogenus Circulichnis Vyalov is a horizontal a ring- or ellipse-shaped burrow and/or locomotion trace of an unknown producer, most likely an annelid or a “worm”, preserved on the bedding plane. This ichnogenus is known over a wide age interval (Ediacaran–Oligocene). Circulichnis demonstrates a wide ecological range and has been found in continental (Mermia ichnofacies), shelf, and relatively deep-water (turbidites) deposits. It is commonly interpreted as a sediment feeding trace, but the peculiarities of its formation remain somewhat mysterious, as it is unclear how the tracemaker reached the sediment surface, as lateral branches of the ring-shaped traces are extremely rare and have only been observed by a few researchers. A rather large specimen of Circulichnis montanus Vyalov, 1971 with a preserved lateral branch was found in the Mospyne Formation (upper Bashkirian, Lower Pennsylvanian) of the Donets Basin. This discovery confirmed the assumption made by Alfred Uchman and Bruno Ratazzi regarding the peculiarities of formation of Circulichnis. According to these authors, a single ring-shaped Circulichnis indicates an attempt to forage at a specific level in the sediment, while the lateral branches of Circulichnis are part of a vertical shaft leading to another level within the sediment. The study of Circulichnis montanus from the Donets Basin has confirmed that at least variant C of the Circulichnis formation scheme proposed by Uchman and Ratazzi is correct, i.e. the lateral branch is a horizontal or subhorizontal part of a generally vertical shaft. However, it is important to note that the correctness of variants A and B of the Uchman and Ratazzi scheme cannot be excluded. To answer this question unequivocally, new finds of well-preserved Circulichnis are necessary. Keywords: trace fossils, Circulichnis, Pennsylvanian, Ukraine Published in DiRROS: 09.07.2024; Views: 234; Downloads: 144 Full text (5,35 MB) |